This is a digital copy of a book that was preserved for generations on library shelves before it was carefully scanned by Google as part of a project
to make the world's books discoverable online.
It has survived long enough for the copyright to expire and the book to enter the public domain. A public domain book is one that was never subject
to copyright or whose legal copyright term has expired. Whether a book is in the public domain may vary country to country. Public domain books
are our gateways to the past, representing a wealth of history, culture and knowledge that's often difficult to discover.
Marks, notations and other marginalia present in the original volume will appear in this file - a reminder of this book's long journey from the
publisher to a library and finally to you.
Usage guidelines
Google is proud to partner with libraries to digitize public domain materials and make them widely accessible. Public domain books belong to the
public and we are merely their custodians. Nevertheless, this work is expensive, so in order to keep providing this resource, we have taken steps to
prevent abuse by commercial parties, including placing technical restrictions on automated querying.
We also ask that you:
+ Make non-commercial use of the files We designed Google Book Search for use by individuals, and we request that you use these files for
personal, non-commercial purposes.
+ Refrain from automated querying Do not send automated queries of any sort to Google's system: If you are conducting research on machine
translation, optical character recognition or other areas where access to a large amount of text is helpful, please contact us. We encourage the
use of public domain materials for these purposes and may be able to help.
+ Maintain attribution The Google "watermark" you see on each file is essential for informing people about this project and helping them find
additional materials through Google Book Search. Please do not remove it.
+ Keep it legal Whatever your use, remember that you are responsible for ensuring that what you are doing is legal. Do not assume that just
because we believe a book is in the public domain for users in the United States, that the work is also in the public domain for users in other
countries. Whether a book is still in copyright varies from country to country, and we can't offer guidance on whether any specific use of
any specific book is allowed. Please do not assume that a book's appearance in Google Book Search means it can be used in any manner
anywhere in the world. Copyright infringement liability can be quite severe.
About Google Book Search
Google's mission is to organize the world's information and to make it universally accessible and useful. Google Book Search helps readers
discover the world's books while helping authors and publishers reach new audiences. You can search through the full text of this book on the web
at |http : //books . google . com/
r3
[
PHY3IC«^. LA3.
THE STORAGE BATTERY
jrt^^^
I
I
i
8
O
THE
STORAGE BATTERY
31 5|ractical Ereatige
ON THE CONSTRUCTION, THEORY, AND USE
OF SECONDARY BATTERIES
BY
AUGUSTUS TREADWELL, JR., E.K
ASSOCIATE MEMBER A. I. E. X.
THE MACMILLAN COMPANY
LONDON : MACMILLAN & CO., Ltd.
1906
All rights rtsirvfa
\ Copyright, 1898,
.By the MACMILLAN COMPANY.
Set up and electrotyped May, 1898. Reprinted January,
Z900 ; July, 190Z ; January , October, 190a ; December, 1906.
ITotfDOIltl IfttM
J. 8. Cuihing ft Co.-BenHck k Smith
Norwood Mmi. U.S.A.
PREFACE
In pursuing his work with storage batteries, the
author found himself greatly hampered by the lack of
any compact data concerning the construction of the
many cells which have been, and are on the market,
and by the paucity of reliable discharge curves. Be-
lieving that a book containing such data and curves,
together with rules for the handling and maintenance
of cells, would be of great value, not only to the stu-
dent and manufacturer, but also to all interested in
storage batteries, the author began the compilation of
the latest and most accurate data concerning the sub-
ject. He believes that the list of American and foreign
patents, which is given as foot-notes for the various
types, will prove of inestimable value to the inventor.
It must not be supposed, however, that the list given is
at all complete, or that the full list of patents, covering
each cell described, is given. So many patents relating
to storage batteries have been granted, that a complete
list would require a volume of its own ; only the prin-
cipal patents, therefore, have been given for each cell.
The chapter on the chemistry of secondary batteries
will be found to give the latest and most generally
accepted theory concerning the chemical reactions
taking place in an accumulator. This chapter was
vi PREFACE
submitted to, and approved by, a prominent chemist. Dr.
Sewal Matheson, whose courtesy the author desires to
acknowledge. The table of data, which is to be found in
the Appendix, may be relied upon as giving the latest
and most accurate figures which could be obtained, of
all the batteries. In the Appendix will also be found
methods for the measurement of the E.M.F. and internal
resistance of a storage battery, also data from which
the theoretical and practical capacity of an accumulator
may be determined.
The majority of the cuts illustrating Chapter VII.,
were obtained through the courtesy of Mr. Charles
Blizard, of the Electric Storage Battery Co. The
author also desires to acknowledge favors extended
by the various storage battery companies who have so
kindly aided him in the preparation of this work, by
freely giving information of every sort, and by furnish-
ing electrotypes. Thanks are also due to Dr. Samuel
Sheldon and Mr. John J. Rooney for valuable aid.
AUG. TREADWELL, Jr.
New York, March, 1898.
INDEX
PAGB
Accumulators for annex stations 145
Accumulators for cold climates . ' 237
Accumulator installations :
Belfast 151
Berlin 180
Birkenhead . . 153
Boston 158
Brooklyn 164
Burnley 179
Chester 148
Chicago Board of Trade . . . . . . .180
Commercial Cable Building, New York . . . -177
Edinburgh . . . 149
Hartford 155
Isle of Man — Douglas-Laxey R.R 148
Isle ofMan— Mt. SnaefelR.R 148
Manchester 150
Merrill 154
New York — Bowling Green 161
New York — 12th Street 161
New York — 59th Street 160
Philadelphia — Philadelphia Edison 168
Philadelphia — Union Traction Co 173
Rome . .178
Zurich , 146
Zurichberg 180
Accumulators in place of resistances 146
Accumulators in telegraphy 184
Albuquerque 189
Atlanta 187
Baltimore 190
vii
viii INDEX
FAGI
Accumulators in telegraphy — Continued i
Paris • 189
Washington 188
Wilmington 190
Accumulator stations in Europe 140
Accumulators to act as reservoirs 143
Accumulators to carry the peak of the load . . .141
Accumulators to carry the entire load at minimum hours . .142
Advantages of accumulators during an emergency . . • 144
Advantages of overcharging 136
Alkaline-zincate genus 9, 102
Alternating currents with storage batteries. . . •192, 224
Baillache 103
Berthelot^s discovery of persulphuric acid . . . .134
Boiling 227
Buckling 222
Cadmium plate test 239
Capacity, data for the practical calculation of . . . . 253
Capacities of modern batteries, table of 254
Capacity, theoretical calculation of 252
Celluloid in accumulator construction 239
Central stations, with and without accumulators . . •194
Characteristic curves 118
Charging at constant voltage, advantages of . . . . 223
Charging, hints concerning 237
Charge, length of 226
Charging, best rate of 221, 222
Chemical changes during charge 131
Classification of batteries, ordinary 8
Classification of batteries, Reynier^s 8
Color of plates when charged 228
Commelin 103
Comparison of thick and thin plates 129
Condusions regarding storage battery traction . . .218
Connecting cells 235, 245
Cosgrove on measurement of E.M.F 249
Cost of construction and operation of electric roads . . .215
INDEX ix
PAGB
Cost of horse and storage battery traction compared . . 200
Cost of overhead and underground trolley systems . . . 203
Cost of storage battery installations 191
Danieus on persulphuric acid 134
Darrieus^ theory 134
Data of operation of railways :
Compressed air line in Paris 205
Steam in Belgium 206
Steam in Denmark 206
Steam in Saxony 206
Steam in Paris 206
Storage battery in Birmingham 208
Storage battery in Paris 205
Trolley in Havre 205
Trolley in Marseilles 206
Defects of lead-sulphuric-acid storage battery . . . • 115
Definition of primary battery i
Definition of storage battery i
De Virloy . 103
Description of batteries :
Acme 83
American . 33
Barber-Starkey 80
Barker 99
Basset 107
Beaumont and Biggs 43
Blot 92
Boese . . 46
Boettcher 25, 99, 105
Brush 59? 88
Buckland 64
Chloride 39
Correns 76
Crompton 43
Currie 37
Darrieus 108
D'Arsonval 28
DeKabath 26
X INDEX
PAGB
Description of batteries — Continued:
De Meritens 25
Desmazure 103
Desruelles 47
Drake and Gorham 29, 70
Dujardin 25
Duncan 25, 37
Eickemeier 68
Electro-Chemical . .22
Elwell-Parker 16
Engel 95
E.P.S 66
Epstein 17, 100
Erving 98
Faure 48, 49
Faure-King, E.P.S. traction cell 67
Fitzgerald 43, 45
Ford-Washburn 77
Garassino 25
Gaudini 29
Gelnhausen 95
Gibson 74
Grout, Jones, and Sennet 89
Gruenwald 96
GUlcher 84
Hagen 50
Haid 107
Haschke 86
Hatch • 52
Hauss 74
Hering 91
Hess 82
HoUingshead 108
Hough 94
Jacquet 51, 70
James 50, 89
Johnson and Holdregge 78
Julien 51
Kalischer 107
INDEX xi
PAGE
Description of batteries — Continued:
Khotinsky . . 64
Knowles 51
Kowalski 85
Krecke 94
Lane-Fox 35
Lehman 108
Lelande-Chaperon 102
Lloyd .65
Lugo 100
Maloney 108
Marx 105
Mason 97
McLaughlin 45
Metzger 48
Monnier 43
Montaud . . . 35
Monterd 93
Nevins 51
New York Accumulator 31
Oerlikon 90
Ohio Storage Battery -30
Paget 19, 88
Payen 38
Percival 44
Peyrusson 29
Plantd 14? 16
Platner 106
PoUak 44, 63, 89
Pumpelly 81
Pumpelly-Sorley 35
Reckenzaun 90
Remington 36
Reynier 28, 97, 99
Reynier Elastic 79
Ribbe 85
River and Rail 100
Rooney 34, 55> 66
Schaeffer-Heineman . 95
xii INDEX
PAGB
Description of batteries — Continued:
Schenek-Farbaky 69
Schoop . . . . . , . . . 18, 105
Shultz . . . , .36
SUvey 36, 94
Simmen 28
Sola-Headland 79
Soriey 94
Standard 30
Starkey 25
Sutton 97
Tamine 100
Tauleigne 107
Theryc-Oblasser 82
Thompson-Houston , .102
Tommassi 75
Tribe 43
Tudor 6i, 88
Union . . ' 58
Van Emon 55> 66
VanGestel 78
Verdier 46
Waddell-£ntz 104
Willard .20
Winkler 55
Woodward 37> 64
Worms 51
Difference of potential between lead-antimony and active
material 120
Different chemical combinations on positive plate . . .128
Difficulty in making chemical analysis 109
Discharge, duration of 228
Discharge, duration of, reasons for 228
Discharge, effects of too prolonged a . . . -225; 228
Distribution of current 245
Eating away of lead salts . 10, 37
Effect of too high a discharge rate . . • . •129, 230
Efficiency of a storage battery 119
INDEX xiii
PAGE
Efficiency of accumulators, average 203
Efficiency of accumulator installations 194
Elbs and Schonherr on persulphuric acid 138
Electric carriages 219
Electro-chemical methods of formation . . . . lo, 16
Electrolysis of a lead salt 10, 35
Electrolyte, alteration in the 114
Electrolyte, density of 238, 240
Electrolyte, purity of 235, 241
E.M.F., calculation of, Streintz 251
E.M.F., calculation of. Wade 250
E.M.F., measurement of, Cosgrove . . . . . . 249
E.M.F., measurement of, Negrenau 249
End plates 243
Examples of storage battery installations . . . .146
Faure 48, 66, 67
Formation of lead-peroxide on negative electrode . . 127, 130
Forming charge, duration of 227
Future improvements 245
General theory of storage battery no
Generation of heat due to 124
Grassi, measurement of internal resistance .... 248
Griscom and Fitzgerald on active material . . . -137
Grooves 10, 59
Hanover, mixed system at 213
Higher capacity of positives overnegatives . . . .129
History of the storage battery 4
Brush 6
Davy 5
Erman 5
Faraday 5
Faure 6
Gautherot . 5
Grove 5
Jablochkoflf 7
Jamins 7
xiv INDEX
PAGB
History of the storage battery — Continued:
Marianini 5
Maxwell 6
Metzger 6
Niaudet .6
Nicholson and Carlisle .5
Plants 6
Ritter 5
Rue, de la ,. . . 6
Schoenbdn 5
Sinstedin 6
Volta 4, 5
Wheatstone 59^9^
Improvements in Plants type 10, 16
Improvements in Faure type io> 50
Influence of acid on open circuit voltage 117
Installations, storage battery I 140
Installing batteries 237
King, E.P.S. patents 66, 67
Lead-copper genus 9? 97
Lead-sulphuric-acid genus . . ... . . • 8, 14
Lead-zinc genus 99 9^
Life of a storage battery, average 204
Losses in a storage battery .119
Loss on open circuit 120
Mance, measurement of internal resistance .... 248
Manhattan Elevated R. R 184
Manufacture of traction cells 217
Mechanical improvements 10, 25
Method of making copper-oxide electrode . . . .102
Miscellaneous cells 9, 105
Negrenau on measurement of E.M.F 249
Occlusion of hydrogen theory 132
Operman's copper-oxide electrode ...... 102
Organic matter in active material ^ 239
INDEX XV
PAGE
Parker, E.P.S. patents 66
Passage of current from one plate to another . . . .121
Per cent load factor 196
Per cent maximum demand factor 196
Perforations 11, 66
Perforations, kinds of 11,66,241
Peroxide plate called positive i
Persulphuric acid theory . . . . . . . 134, 138
Berthelot 134
Elbs and Schonherr 138
Robertson and Darrieus 134
Plants and Faure types compared 48
Plates, construction of 241, 243
Potential of a cell due to 118
Position of cells 234
Preparation of active material 94
Prevention of buckling n? 90
Primary and storage batteries compared 185
Private plants 192
Reason that storage cells are not near perfection . . .109
Recuperation 184, 206, 215
Reduction of weight io> 50
by alloys io> 50
by non-conducting grids 1O7 52
Relation between capacity and discharge rate .... 230
Relation between capacity and specific gravity . . . 238
Relation between E.M.F. and acid concentration . . .117
Resistance measurements, Grassi 248
Resistance measurements, Mance 248
Resistance measurements, Sheldon 247
Resistance of a cell, Streintz 114
Retaining case made of conducting material . . . n, 75
Retaining case made of non-conducting material . . 1 19 79
Retention of paste io> 59
Reynier^s classification 8
Reversed polarity 244
Robertson on chemical theory 127
Room, choice of battery 233
xvi ^ INDEX
PAGB
Salomons, on best rate of charge 222
Salomons, on process of charging 131
Sellon, E.P.S. patents 66
Separators 235
Setting up a battery 234
Sheldon, measurement of internal resistance .... 247
Solid active material 10, 44
Specific resistance of acid 114
Spraying 236
Storage battery, economy of 3
Storage battery traction —
Berlin 210
Birmingham 208
Brussels — Tervueren 207
Chicago — Englewood 212
Dubuque 214
Hagen — Vienna 208
Hague — Sheveningen 211
Hanover 213
Madison Avenue, New York City 212
Paris 206
Streintz, calculation of capacity 251
Streintz, theory 112
Sulphating . 241
Superiority of lead-lead over other types 11
Swan, James W., originator of perforated plates ... 66
Telegraphy, storage batteries in 3> 184
Temperature variations during charge and discharge . .123
Testing a battery 231, 239
Tests of Theryc-Oblasser battery for traction .... 207
Tests of traction systems 205
Theoretical energy of lead 1 1 1
Theory 109, 126
Theory of Darrieus 112
Theory of primary and storage batteries identical . . .110
Theory of Streintz 112
Traction, storage battery 4> 198
Traction, storage battery, in Europe and America . . •199
INDEX xvii
PAGB
Transportation of battery after being used .... 244
Trolley and accumulator systems compared . . . .214
Trolley roads, disadvantages of 199
Uses of accumulators 2, 141
Volckmar, E.P.S. patents 66
Variation in capacity with temperature 125
Wade, calculation of capacity 250
Weight of storage batteiy cars, increased ..... 201
ILLUSTRATIONS
Batteries :
American 33
Blot . 93
Brush 60
Chloride 40, 41, 42
Correns 76
Currie 38
DeKabath 26
Drake and Gorham 70
Eickemeier 69
Electro-Chemical 23
E.P.S 67
Epstein 18
Gibson 74
Hatch 53
Hauss 71
Hering 91
Jacquet 74
Khotinsky 65
Montaud 36
New York accumulator 31
Ohio storage battery 30
Percival 44
Pumpelly-Sorley , . 35
Reckenzaun 90
xviii INDEX
PAGE
Batteries — Continued:
Rooney 34, 56
Schoop 19
Tommassi 75
Tudor 61
Union 58
Willard 20, 22
Battery curves :
Bradbury-Stone 75
Chloride 43
De Kabath 27
Electro-Chemical 24
E.P.S 68
Ford-Washburn jj
Gadot 224, 225
GUlcher 84
Haschke 87
Hatch 54
Hauss 72, 73
PoUak 63
River and Rail loi
Rooney 57
Tudor 62
Willard 21
Curves :
Berlin load curve 181
Capacity and specific gravity at close of discharge . .130
Charging at constant current 224
Charging at constant voltage . . . . . .225
Chicago Board of Trade, load curve . . .182
Effect of accumulators on voltage curve, Merrill . 154, 155
Effect of accumulators on voltage curve, Union Traction
Co., Philadelphia Frontispiece, 174
Elevator-load curve 183
E.M.F. and per cent of acid 116
E.M.F. of charge and discharge compared . . '113
E.M.F. and specific gravity at close of discharge . -131
Hartford load curve 157
INDEX xix
PAGB
Curves — Continued:
Influence of acid on open-circuit voltage . . . • n?
Load curve for Union Traction Co .176
Per cent load factor for English stations . . . -197
Per cent maximum demand factor for English stations . 196
Philadelphia load curve 144
Relation between capacity and discharge rate . . .231
Relation between capacity and specific gravity . . 238
Specific resistance of acid 115
Temperature variation during charge and discharge . 124, 125
Theoretical load curve 143
Zurich load curve 147
Installation illustrations :
Accumulator plant, Bowling Green, New York
Accumulator plant, Brooklyn ....
Accumulator plant, Philadelphia Edison .
Accumulator plant, Union Traction Co., Philadelphia
Cell regulators, Philadelphia Edison
Switchboard connections — Atlanta
Switchboard connections — Bowling Green
Switchboard connections — Burnley
Switchboard connections — Chicago Board of Trade
Switchboard connections — Zurichberg .
Switchboard connections — 12th Street, New York
Switchboard, Philadelphia Edison .
165
167
170
175
172
188
163
179
182
180
162
171
Measurements — diagram of connections :
Internal resistance — Grassi 248
Internal resistance — Mance 248
Internal resistance — Sheldon 247
E.M.F. — Negrenau 249
E.M.F. — Cosgrove 249
ABBREVIATIONS
E. W Electrical World, New York.
N.Y.E.E Electrical Engineer, New York,
L. E. R Electrical Review, London.
L. E The Electrician, London.
El. Anz Elektrotechnischer Anzeiger.
Wied. Ann Wiedemann's Annalen.
Trans. A. I. E. E. . . . Transactions of the American Institute
of Electrical Engineers.
A. P American Patent.
B. P British Patent.
F. P French Patent.
G. P German Patent.
L Lighting.
T Traction.
G Glass.
R Rubber.
W Lead-lined wood tank.
Cd Cadmium.
Alka — Zn Alkaline — Zincate type.
Pb — Zn Lead — Zinc type.
Pb — Cu Lead — Copper type.
Chlor Chloride battery.
THE STORAGE BATTERY
INTRODUCTION
According to Houston, a storage battery, accumu-
lator, or secondary battery, as it is variously . called,
" consists of two inert plates of metal, or metallic oxide,
immersed in an electrolyte, which is incapable of acting
upon them until a current has been passed from one
plate to another. On the passage of a current through
the electrolyte, its decomposition is effected, and the
electro-positive or electro-negative radicals are deposited
on the plates, so that on the cessation of the charging
current, there remains a voltaic cell, capable of generat-
ing an electric current." A primary battery, on the
other hand, is active in itself, and will give off electric
manifestations without being acted upon by a current
of electricity from some external source. There has
been much controversy, of late, concerning the reason
for calling the peroxide, the positive, rather than the
negative plate, as is the custom with many English
electricians. In answer to this, the London Electrician
stated editorially that the " positive plate of a secondary
battery is properly so called because it is plum-colored
2 THE STORAGE BATTERY
and peroxidized, while the negative plate is of a neutral-
color and not-oxidized."
As an economic factor in the working of stations for
the production of electric light or power, the value of
the storage battery is becoming more and more recog-
nized. In a paper read before the American Institute
of Electrical Engineers, Mr. C. L. Edgar ^ stated that
the uses of accumulators for central station purposes,
might be classed under four principal heads, viz. :
I. To carry " the peak of the load " ; that excessive
portion of the load, namely, which in electric lighting
stations has to be carried, for two or three hours a day
only.
II. To carry the entire load at minimum hours.
III. To act as equalizer or reservoir.
IV. For the equipment of annex or substations.
The peak of the load in the majority of stations rep-
resents from one-third to one-half the total maximum
load of the station. While some engineers have advo-
cated the use of cheaper and comparatively inefficient,
though reliable apparatus for this purpose, the majority
of managers are equipping their stations with accumu-
lator plants.
Although accumulators are used in Europe for carry-
ing the entire load at minimum hours, the consensus of
opinion in America is that the nature of the load is
against this practice, the period of minimum load being
too short to warrant laying off a shift of men, or to show
the economy of banking or drawing the fires.
1 Trans. A. I. E. E., Vol. 12, p. 592.
INTRODUCTION 3
Miller claims that when accumulators are used for
equalizing the load, at least 15% per year is saved in
fuel. By the use of accumulators in the station of
the Boston Edison Illuminating Co., the load on the
engines is never less than three-fourths of the maximum.
In this case, the battery costing JS50,ooo was used
instead of a steam engine and dynamo, of the same
capacity, costing $65,000. One of the first railway
plants to use storage batteries for equalizing the load,
was the power station at Zurich, Switzerland. Results
there have shown that a saving of 2.2 pounds of coal
per horse-power-hour is effected, representing $2500
per year. Allowing for interest and repairs of accumu-
lators, which, with accompanying apparatus, cost about
1^7400, the cost is saved in about four years by the
saving in coal. Since, however, the adoption of the
battery system replaced more expensive machinery,
and therefore actually reduced the first cost, the saving
is a direct one, and in a comparison should be credited
with the interest charges on the reduction in first cost,
and the maintenance of the machinery displaced.
Another growing use of secondary batteries, is for
telegraph and telephone work, where it replaces the
primary cells formerly in use. Of course, where the
size of the installation warrants it, dynamos are used,
but in the smaller offices, it has been found that the
practically constant E.M.F. and internal resistance of
storage batteries, the absence of " creeping " salts, cor-
roding connections, etc., are strong arguments in favor
of the use of secondary batteries. The Baltimore offices
of the postal Telegraph Co., the Atlanta, Ga., and the
4 THE STORAGE BATTERY
Washington, D.C., offices of the Western Union, the
Central Railroad of New Jersey, Long Branch, Scranton,
Pittsburg, and Hartford are among the most prominent
recent storage battery installations. At Washington,
724 Chloride cells have replaced 7300 Gravity cells,
and at Atlanta, 700 Chlorides have replaced nearly
8000 Gravity batteries. Storage batteries are also
used by the Stock Quotation and Telegraph Co. for the
operation of their instruments.
For traction purposes, the storage battery is still in
the experimental stage, although used to a small extent
in Europe, and on a few experimental roads in this
country. Within the past few years, the storage battery
has been used for self-propelled vehicles, and for this
purpose has easily taken the lead among the prime
movers. The earliest example, perhaps, was the
"Electrobat" of Morris and Salom.
Hitherto, the capacity of the storage battery has been
strained and its powers overestimated, but since the
manufacturers have become more conservative in their
claims, its applications have begun to extend. This,
together with the great first cost, and the rapid deteriora-
tion of an accumulator, the latter being due, partly at
least, to the efforts to secure lightness and to reduce the
cost, will account for the fact of storage batteries having
been so little used.*
Although the practical history of the storage battery
is included in the history of the past thirty years, the
knowledge of the phenomena upon which its actions are
based, dates back to 1801. In 1800, the year made
memorable by Volta's discovery of the galvanic battery,
INTRODUCTION 5
Nicholson and Carlisle found that a current from Volta's
cell could decompose water. In 1801, Gautherot found
that if the platinum or silver electrodes were connected
together, after having a voltaic current passed through
them, that a secondary current of short duration would
flow. Erman found that the positive pole of such a cell,
was the pole which had been connected to the positive
pole of the battery. In 1803, Ritter observed with gold
wire the same phenomenon as Gautherot, and con-
structed the first secondary battery, by superposing
plates of gold, separated by cloth discs, moistened with
ammonia.
Volta, Davy, Marianini, and others added somewhat
to the knowledge on the subject, and in 1837, Schoenbein
found that peroxide of lead could be used in secondary
batteries. Sir William Grove next came forward with
the discovery that metal plates, with a layer of oxide on
them, acted better than the plain metallic plates, and
Wheatstone and Siemens found still later that peroxide
of lead was the best for such purposes.
In 1842, Grove constructed his famous gas battery,
in which the E.M.F. came from the oxygen and
hydrogen evolved in the electrolysis of water acidu-
lated with sulphuric acid. By means of fifty such cells,
he obtained an arc light. Michael Faraday, when
electrolyzing a solution of lead acetate, found that per-
oxide was produced at the positive, and metallic lead at
the negative pole, and in his "Experimental Researches,"
he comments on the high conductivity of lead peroxide,
and its power of readily giving up its oxygen. Although
he made no apparent use of this discovery, it may be
6 THE STORAGE BATTERY
considered as the next important step in the develop-
ment of the storage battery. According to Niblett,
Wheatstone, de la Rue, and Niaudet were well aware
that peroxide of lead was a powerful depolarizer, but
nobody appears to have made use of this fact until
i860, when M. Gaston Plants constructed his well-
known cell with coiled plates. M. Duerlir claims that
Sinsteden used the secondary action of lead in sulphuric
acid in 1854. Although it is well known that Sinsteden
did notice the peroxidation of a lead plate in sulphuric
acid, we have no further proof that he put it to any
practical use.
Plant^'s researches extended up to 1879, and practi-
cally determined the state of the art. As to the theory
at this time, it may be stated that Clerk Maxwell,
although the leading electrician of his time, speaks of
the storage battery as storing up a quantity of energy
in a manner somewhat analogous to the ordinary con-
denser; hence the use of the word accumulator for
storage battery. In 1879, R- L. Metzger did away with
the tedious forming process, by mechanically applying
the active material. This important discovery was not,
however, generally known, until 1881, when Camille
Faure obtained important patents concerning the method
of shortening the time of formation. Charles F. Brush,
working independently of either Faure or Metzger,
arrived at the same result, and the United States Courts
have decided, after long litigation, that to him belongs
the priority of invention in this country.
It has been claimed by many that Plants, himself, was
the true discoverer of the mechanical application of the
INTRODUCTION ;
oxides. R. Jamins, in his work entitled "Recherches
sur les Accumulateurs Electriques," says :
" Le grand inconvenient de la pile Plants reside . . .
dans la longue dur^e exig^e pour sa formation. M.
Plants avait bien suppos6 qu'en d^posant du minium
sur les Electrodes en plomb, il reduisait le temps de la
formation de ses couples; mais il ne parvint jamais a
donner un adherance suffisante au minium qui reculait
et finissait par disparaltre."
It should be noted, however, that Mr. Bedford Elwell,
the translator of PlantE's " Recherches sur T Electricity,"
makes no mention of any process for mechanically apply-
ing oxides to storage battery elements, nor were the
alleged troubles referred to in his translation.
Jablochkoff in an application for British patent 1745,
April 22, 1 88 1, states that M. Plants proposed to apply
the active material mechanically to the support plate.
CHAPTER I
CLASSIFICATION OP BATTERIES
There are at present three classes of storage cells of
commercial importance. The first, the Plants type, or
autogenous cells, has plates composed of spongy or
granular lead; the second, the Faure type, or hetero-
geneous cells, has lead plates, or, more commonly, plates
composed of some alloy of lead, perforated with holes,
or grooved, and filled with lead compounds ; while the
third, the alkaline type, comprise those cells using zinc
in combination with lead peroxide or copper. There is
also a fourth type, the gelatinous, or dry cells. These
cells, though useful for portable work, and especially
for traction and submarine purposes, have so many
drawbacks, that they have not, as yet, found very
much commercial application.
The preceding classification, although the most gen-
eral, is not as good as Reynier's, by which the cells are
divided according to their construction. This classifi-
cation, which follows, will be used, with some modifi-
cations, in this work.
I. The Lead-Sulphuric-acid genus, — This class in-
cludes all those cells belonging to the Plants and
Faure groups, thus including the great majority of the
batteries in use to-day.
8
CLASSIFICATION OF BATTERIES 9
II. The Lead-Copper genus, — These cells consist of
sheets of metal coated with lead oxide, serving as the
positive electrode, and copper plates for the negative,
immersed in a solution of copper sulphate. The bat-
teries belonging to this class are not employed in
commercial practice, being useful only for laboratory
experiments.
III. The Lead-Zinc genus, — This group is very
similar to the preceding, differing from it only by
having zinc for the negative electrode, and zinc sul-
phate for the electrolyte. The E.M.F. of these cells
is slightly higher than that of the ordinary cells, and
their capacity per unit of total weight is very high ; but
they are apt to lose their charge on open circuit, be-
sides possessing most of the disadvantages of the
Plants cells.
IV. The Alkaline-Zincate genus, — In these batteries,
copper is used as the positive, and iron plates, or, more
commonly, iron gauze, as the negative electrode, and
sodium, or potassium, zincate as the electrolyte. This
type of cells has been used to some extent for traction
purposes, with very fair results.
V. Miscellaneous, — All those cells which cannot be
classed under any of the four preceding heads.
The first class, the lead-sulphuric-acid genus, is, as
mentioned, divided into A, the Plants ; and B, the
Faure groups of accumulators. Each of these two
groups is again divided, according to the improve-
ments in each, as follows :
10 THE STORAGE BATTERY
A. The Plante. — The improvements are :
1. Chemical, or Electro-chemicaL — The plates com-
ing under this head are subjected to some sort of
pickling process, or some special forming bath is
used.
2. Mechanical, — These plates are made up of granu-
lated lead wire, some form of finely divided lead, such
as shot, molten lead mixed with some foreign substance
before casting, or some special form of casting is used.
3. Electrolytic,
(i) The finely divided lead is obtained by the elec-
trolysis of some salt of lead.
(2) Some salt of lead is formed into a plate by press-
ure, or otherwise, and then reduced to metallic lead.
4. Plates built up of solid active material, — While in
reality being an improvement on the Plants type, these
plates might be correctly classed as a third subdivision
of the lead-sulphuric-acid group.
B. The Faure. — The objects in view in the devel-
opment of this group are fourfold :
1. The reduction of weight,
(i) This is often accomplished by making the support
plate of some alloy of lead.
(2) By making the support plate of some non-con-
ducting substance, which is unaffected by acid.
2. The retention of the paste, or active material. —
This is accomplished in four ways.
(i) The plates are grooved, have recesses on the
surface, or are cast with small projections, so as to
allow a lodgment for the active material.
CLASSIFICATION OF BATTERIES n
(2) The support plate is perforated with holes, which
are of three, general types :
a. Those holes which have the same diameter
throughout.
b. Those holes in which the diameter is smaller at
the centre than at the surface.
c. Those holes in which the diameter is smaller at
the surface than at the centre.
(3) The active material is enclosed by a perforated,
conducting retaining case. Very often the plain or
corrugated sheets of lead have been folded into boxes,
either before or after applying the active material.
(4) The enclosing vessel is made of some non-con-
ducting material, or some inert material is packed
between the plates to prevent short-circuiting, and to
retain the active material. In France the plates are
covered with perforated sheets of celluloid.
3. Provision for better contact between the support
plate and the active material, — This result is often
accomplished by rubbing the support plate with car-
bon, before applying the active material. The addi-
tion of carbon to the paste is recommended.
4. The prevention of buckling,
E. J. Wade, in an article on the " Chemical Theory
of Accumulators," claims that it will be difficult, if
not impossible, for any metal to supersede lead for
storage battery purposes, for the reason that the
metals are dissolved by the electrolyte, while lead,
because of its coating of sulphate, is insoluble. He
says : ^
1 London Electrician, Vol. 33, p. 603.
12 THE STORAGE BATTERY
"Herein lies the superiority of lead-lead-peroxide
cells to all others. If properly treated, it may be
regenerated electrolytically, and so nearly to its origi-
nal chemical and physical condition, that it can be
charged and recharged in this way hundreds and even
thousands of times, before the total results of the slight
changes that do take place, depreciate it sufficiently
to incapacitate it for further use, while with all other
cells, the changes that occur with each charging are
relatively so large, that although all possible means
have been tried to reduce them to a minimum, they
rapidly deteriorate, and require constant attention and
repairs. The reason for the more complete reversi-
bility of a lead cell is entirely due to the chemical
behavior of certain of the compounds into which the
metal enters. Lead alone, of all the metals, forms a
sulphate that is practically insoluble and unacted upon
in water and dilute sulphuric acid, and it also combines
with oxygen to form a peroxide, having a good electri*
cal conductivity, and equally unaffected by the liquid.
When, therefore, a lead-lead-peroxide couple is dis-
charged in dilute sulphuric acid, the lead sulphate,
which is the ultimate product formed at the poles, does
not dissolve up iri the solution, but remains on the sur-
face of the plates ready for reduction and reoxidation
when the current is reversed. Any local action that
goes on when the cell is not at work, also results in
this insoluble sulphate, which tends to form a protective
coating on the metal, and thus reduces losses from this
cause to a minimum. The compounds formed, when
other metal than lead is used as the negative, not
CLASSIFICATION OF BATTERIES 13
necessarily in a sulphuric acid electrolyte, but in any
other practically possible solution, are all soluble, and
dissolve in the liquid as fast as they are formed, and
this simple fact has, up to the present, barred the way
to any substantial progress with these classes of
reversible cells/'
CHAPTER II
LEAD-SULPHURIC-ACID GENUS
I. — A. Plant6 Type
THE PLANTE CELL
In i860 M. Gaston Plant6 constructed the first practi-
cal secondary battery. He used two sheets of lead,
60 cms. long, 20 cms.* wide, and i mm. thick, coiled
about a wooden cylinder, insulated from each other by
pieces of felt, and immersed in dilute sulphuric acid, —
1.070 specific gravity. On sending a current through
the plates, the electrolyte was decomposed and hydrogen
and oxygen thrown off. The hydrogen was given off
at one pole, thus producing a very bright surface of
pure lead. The oxygen, which was given off at the
other, produced a plate of lead peroxide. After dis-
charge, which continued until the plates had assumed
their normal condition, the connections were changed,
and the cell was recharged in the opposite direction.
By several such reversals the capacity of the cell was
found to be much increased.
It has been assumed by many writers that the Plants
cell was one of inherently small capacity. That this is
not true will be seen from the following figures. Plant6
found that the completed cell gave 7.25 ampere-hours
LEAD-SULPHURIC-ACID GENUS
IS
per pound of lead, a result which has not been exceeded
in any cell of the same type upon the market to-day.
This result was obtained with a charging current of 8 to
lo amperes per square metre of total surface of his
plates, — counting the double surface of each plate.
For the discharge Plants states in a letter to Dr.
Leonard Paget, and from which the above results are
taken i^
" For the discharge, I believe we may without incon-
venience discharge with a notably stronger expenditure
than 10 amperes, if the end pieces, or flattened parts of
the plates, are sufficiently thick so as not to become
heated, and consequently get brittle under the influence
of the passage of the discharge current."
Geraldy has also found that such a cell has an energy
efficiency of y2(^o, with a capacity of 11,239 foot-pounds
per pound of lead.
The chief drawback to this cell is that a number of
reversals are necessary in order to obtain good storage
capacity, and that when the maximum capacity has been
reached the plates are about rotten. These reversals
are troublesome as well as expensive.
In the later cells belonging to the Plants type, these
reversals have been entirely done away with, and the
formation is accomplished in a few hours by means of
pickling or forming baths. All batteries of the Plants
type, although they may be classified under the second,
third, or fourth subdivisions, are now formed by means
of these baths.
1 Chips from a True Workshop, E. W., Vol. 26, p. 151.
l6 THE STORAGE BATTERY
Improvements in Type A
I. Chemical or Electro-chemical
PLANTE
In order to accelerate the formation of his plates,
Plants ^ pickled them in nitric acid, diluted with one-
half its volume of water, allowing the plates to remain
in this bath for 24 to 48 hours. The couples were then
washed thoroughly in a 10% sulphuric acid solution
and formed ; a certain quantity of the nitric acid was of
course retained. According to Lucas the plates may
be freed from the acid by washing them in ammonia,
and then decomposing the resulting salt by heating to
200"* C.
During formation heat is applied to the cell to open
the pores and allow the electrolyte to penetrate more
deeply into the lead ; the plates are given a period of
rest before each alternate charge. Plants found that
by giving the plates this rest the oxide formed on the
surface was bound more firmly to the plates, which
would when thus treated lose the oxide by the evolution
of gas on the true metal surface of the elements.
THE ELWELL-PARKER ACCUMULATOR
In this celP the positive plates are of the Plants type,
and the negatives of the Faure. The positive plates are
pickled in a bath of nitric and sulphuric acids for 30
hours. The negatives are of the ordinary grid type,
somewhat similar to the Drake and Gorham (vide
1 B. P., 3296; 1882. » B. P., 3197; 1887.
LEAD-SULPHURIC-ACID GENUS 17
page 70), the paste being applied under pressure and
the edges blurred over, as in that plate. Wooden sepa-
rators are used. These plates are used to a considerable
extent in England, but the writer is informed that unless
skilled attendants are in charge they give considerable
trouble.
This company also manufactures a pure Plants cell,
in which instead of coiled plates, cylindrical perforated
lead sheets, weighing two pounds per square foot, are
placed one within the other, with a clearance space of
one-half inch. Before formation the plates are pickled
for 24 hours in the regular bath. At least 30 reversals
are necessary before they reach their full capacity.
EPSTEIN
Messrs. Woodhouse and Rawson, who manufacture
this accumulator,^ form their plates as follows: lead
plates are placed in a 10% solution of nitric acid and
water, which is maintained at a temperature of 100° C.
for several days. When the coating is about one mil-
limetre thick, the plates are dried in the air. The last
traces of nitric acid are removed by placing the plates
as cathodes in dilute sulphuric acid containing some
copper sulphate, and passing a current until the plates
are completely reduced to spongy lead. The plates
are then formed in dilute sulphuric acid, containing
pyro-tartaric acid. The grayish yellow color of the
positive plates, which results from the acid treatment,
is changed by the formation to a deep dark brown.
1 A. P., 425,999 ; 1890. B. p., 6214 ; 1882: 4527 ; 1887 : 350 ; 1890.
C
i8
THE STORAGE BATTERY
After being used, the peroxide plates become soft.
In order to restore them to their former condition, it
■-irrniTi^-T r i ii
iilT^
wm
In ■ fTITI- -iTinil
m^
mmf^mrnmi^-mm
Figs, i and 2.
is best to reduce the peroxide with a negative, and
then to reform with a positive current. The shape of
the plates are shown in Figs, i and 2.
SCHOOP
The Schoop^ plates, manufactured by the Oerlikon
Co. of Switzerland, are placed in a solution containing
5 parts of sodium bisulphate, 0.75 parts potassium
chlorate, and 95 parts of water, at a temperature of
25® C, and a current is passed; the current density
used being about 0.33 amperes per square decimetre
for 72 hours. The action is stopped when it has pene-
trated the plates to a distance of 2 mm. The coating
is then reduced to spongy lead in dilute sulphuric acid
1 A. P., 434»093 ; 1890. B. p., 7513; 1890.
LEAD-SULPHURIC-ACID GENUS
19
(5%), with a current density of i ampere per square
decimetre. The plates are thoroughly washed and
are heated to nearly the melting-point of lead. Dr.
Schoop ^ has also tried the method of making an amal-
Fig. 3.
gam of lead and mercury, but does not think it to be
practicable. Fig. 3 shows the form of the Schoop posi-
tive plate, the negative being similar in form, but with-
out the centre rod.
PAGET
Edward and Leonard Paget ^ in 1894 perfected a bat-
tery wherein the chemical method of formation is used.
The lead plates are first boiled in dilute nitric acid to
remove the "skin," after which a head-piece and tail-
1 A. P., 434,301 ; 1890.
a A. P., 513,245 ; 1894. B. P., 17,223 ; i88S.
20
THE STORAGE BATTERY
piece of type metal is cast on. The electrodes are then
submitted to the action of a heated solution of nitrate
of magnesium, after which they are assembled and
formed in an electrolyte containing the double sulphate
of magnesium and ammonium. They are then reas-
sembled in a cell containing the proper electrolyte, and
put into commercial use.
WILLA.RD
The shape of this plate ^ is shown in Fig. 4. It
consists of a sheet of pure rolled lead, deeply cut on
both sides, leaving
leaves, or projecting
shelves, at an angle
to the surface of the
plate, — the thickness
and separation of the
leaves depending
upon the uses to
which the battery will
be put. . The plates
are then connected in
groups of one hun-
dred, and are placed
in large tanks. These
tanks contain a strong
oxidizing solution, —
the nature of which
is a secret, — which
attacks the grooves or surfaces of the leaves, and, by
lA. P., 576,177-576,178; 1896: 532,128; 1895.
Fig.
LEAD-SULPHURIC-ACID GENUS
21
a continuous process, there is a thick adherent deposit
of pure peroxide of lead produced which completely
fills the grooves.
The plates are left in this solution for four hours,
after which they are taken out, washed thoroughly,
and assembled into elements, to receive their charge
before shipping.
Each plate is protected by a corrugated hard rubber
case, so highly perforated that there is perfectly free
action for the electrolyte. That this is an economical
flL6
us
t.1
S.0
9 1.7
^^
Oh
trge
-i— i
"T
^^
X
-
"P'SC>
p2-
"
**%,^^^^
s.
\
\
\
.
\
\
\
\
'milart^'*
LO
1S84567S9 10 1111
HOURS
FiG. 5.
feature of the battery will be seen from the fact that
all scalings are collected at the bottom of this cell,
where they are held in contact with the central piece,
thus continuing in service as active material. Buckling
is impossible with this cell. A plate 7x8 inches has
an active surface of 14 square feet. At no point is the
active material more than ^ of an inch thick. These
two points alone insure a very low internal resistance to
the battery. The curve of discharge is shown in Fig. 5.
22 THE STORAGE BATTERY
This company also manufactures a new type of cell —
the concentric accumulator (shown in Fig. 6). The
principal novelty in its construction is that it requires
no containing cell, the negative element itself forming
the containing cell. The method of forming is the
same as with the other types.
THE ELECTRO-CHEMICAL STORAGE BATTERY CO.'s PLATE
This plate, shown in Figs. 7 and 8, was brought out
by Madden and Chamberlain.^ In the construction of
the plate, a sheet of pure rolled lead is passed through
a special machine producing deep grooves on either
side of the plate; this process, termed spinning, pro-
duces 21 grooves to the inch. If desired, the plate
may be cast instead of spun ; in either case no rim is
left on the plate. These plates are then placed in a
strong oxidizing solution, which attacks the surfaces of
the grooves, after which a current is passed, completely
filling the grooves with pure peroxide of lead. This
action, first chemical, then electrolytic, gives rise to the
name " Electro-Chemical."
The active material being produced in this way
possesses the highest conductivity, and precludes any
local action between it and the grid. There being no
frame exposed to the action of the electrolyte, local
action is stopped, and the danger of short-circuiting
reduced to a minimum. The manufacturers claim that
this plate, possessing such a large effective area, — a
plate measuring 6 x 7 x 0.5 inches, containing 700
1 A. P., 572,363 ; 1896.
LEAD-SULPHURIC-ACID GENUS
23
Fig. 6.
Fig. 8.
24
THE STORAGE BATTERY
square inches, — reduces the percentage of expansion
during both charge and discharge greatly, thus bring-
ing to a minimum the chances of buckling and distor-
i 9~io Ji jJB is M vi it ix ii in m ir ii nu i 'm
Hoars Dischargee
Fig. 9.
tion. Some very interesting curves for this battery are
shown in Figs. 9 and 10. Curve A was taken from an
S plate (cast), measuring 6.625 x 7.1875 x 0.5 inches,
and weighing 5.5 pounds; B and C from an L plate
(cast), 8 X 9 X 0.5 inches, weight 8.75 pounds; and D
11
a.0
-<
—
<^
5
^
^
\
'^
N
Ng.
L8
L7
>
D
C
J
I i
r J
i " 'i
1
'
r <
1
i
1 1
2 1
8 1
i U
Hours Discharge
Fig. 10.
from an N plate (spun), 6 x 7 x 0.4375 inches, weight
4.5 pounds. In each case the discharge was at a con-
stant current, 4 amperes for A, 7 amperes for B, 12
amperes for C, and 10 amperes for D.
LEAD-SULPHURIC-ACID GENUS 25
VARIOUS CHEMICAL METHODS OF FORMATION
Dujardin ^ uses as a forming bath a solution contain*
ing ID kilos of water, 2 kilos of sulphuric acid, and
I kilo, of alkaline nitrate, soda, potassium, or other
suitable alkali. Boettcher uses a bath of sulphuric
acid, acetic acid, and water. Garassino^ places spiral
perforated lead plates in a nitric acid bath for 12 hours,
then in caustic potash, and finally in pure water, after
which electrolytic spongy lead is formed in a hot caustic
potash solution, and the plates are pressed. By mis-
take Starkey^ placed some plates in dilute sulphuric
acid, which contained a small quantity of a solution of
chromic acid. He found that they set harder arid
quicker, and became more deeply peroxidized than in
ordinary acid ; they have since behaved in a most satis-
factory manner. By cooking his plates in' a solution of
litharge in caustic potash or soda, Duncan produced a
thick dense deposit of spongy lead.
It should be remembered that in order to have much
success with electro-chemical methods of formation, only
pure, soft, rolled lead should be used.
2. Mechanical
DE MERITENS' CELL
Many of the early investigators with storage batteries
worked along the lines of mechanical improvement in
order to obtain the maximum amount of active surface
1 F. P., 174,761; 1886. B. P., 16,408; 1886.
« B. P., 12,665; 1892. « E. W., Vol. 27, p. 466.
26
THE STORAGE BATTERY
for a given weight. Prominent among these stood M.
de Meritens,^ who constructed plates formed of thin
lead laminae 2 mm. thick. These lead laminae were
folded one upon the other somewhat in the form of a
book, and the whole was soldered to a stout framework
of lead. Having a large surface, a large amount of
oxygen was required ; the capacity, consequently, being
increased, with the attendant disadvantage, however, of
the local action being also increased. The film of per-
oxide was extremely thin.
Because of the rapid local action this accumulator
was a failure, especially where required to maintain its
charge for a lengthened period ; but where a
rapid rate of discharge was required, this type
gave excellent satisfaction.
DE KABATH
This cell ^ is made in the form of a number
of shallow perforated lead boxes, as shown in
Figs. II and 12. Each box contains between
180 and 190 lead
strips, alternately
straight and corru-
gated. Lead strips,
50 cms. long, I cm.
wide, and i mm.
thick, are so corru-
gated that their
Fig. II.
Fig. 12.
IB. P., 1173; 1882.
« A. P., 263, 124; 1882. B. P., 287 ; 1883. G. P., 21,689, 22,690; 1882.
LEAD-SULPHURIC-ACID GENUS
27
length is reduced to 36 cms., the straight strips being
of the same dimensions as the corrugated strips. The
complete element measures 38 cms. in length, 9 cms.
in width, and nearly i cm. in thickness, and weighs
2.2 pounds. The box may also* be made of cardboard,
caoutchouc, parchment, or other acid-proof material.
70,000
y
/
-1
U.
tn AH AAA
ULOMBS PER K<
I i i
y
/
>
y^
w,ww
^
2000
HOURS FORMATION
Fig. 13.
Fig. 13 shows the rate of increase of i kilo of lead
when made up into this form of element at any period
of time. This curve was obtained from a cell weighing
30 kilos, the weight of the elements being 21 kilos, and
that of the electrolyte 6 kilos.
28 THE STORAGE BATTERY
REYNIER
Reynier sought to increase the exposed surface by
making lead " plaits." His electrical connections being
bad, he took a steel frame which had been dipped into
an alloy of lead and antimony and placed the " plaits "
in that. He found that when the plates were charged
that they were less dense; they therefore buckled.
To obviate this, longitudinal slits were cut in the plates,
thus allowing for expansion.
d'arsonval
Hoping to obtain the largest surface for a given
weight, d^Arsonval substituted lead shot for the solid
lead plates. While this expedient would seem to give
good results, it must be remembered that in order to be
effective the shot must be in good electrical contact,
but since they would soon become oxidized, it would be
impossible to obtain good results.
SIMMEN
Simmen substituted lead wire for the shot, with the
result that his accumulator became much more efficient
than that of d'Arsonval. The lead wire was obtained
by pouring molten lead through a cullender into a pan
of cold water. This sudden cooling makes the sur-
face of the wire very rough, and the wire itself very
light and porous, so as to be easily acted upon chemi-
cally. Masses of this wire were taken and pressed to
the desired shape and placed in a perforated lead
chamber, thus forming one electrode. Owing to the
LEAD-SULPHURIC-ACIP GENUS 29
chemical action on these leaden chambers the com-
pressed wire was placed in a metal frame, which was
but slightly acted upon by oxidation. This improved
form has been termed the Simmen-Reynier cell.
DRAKE AND GORHAM
These elements, usually known as the D. P. plate,*
consist of a large number of narrow strips of lead, hav-
ing points or projections on their faces ; they are built
up one above the other. A large working area is thus
produced, and it is claimed that a- cell of this type can
be charged or discharged at a high rate without buckling
or disintegration,
GAUDINI
In this accumulator the plates are formed of a mix-
ture of lead and coke and retort carbon. By the U3e of
carbon the manufacturers claim to obtain greatly in-
creased porosity, . besides accelerating the formation.
The electrodes are separated from each other by porous
partitions. These partitions are made of any solid or
gelatinous acid-proof material, and may be either
straight or curved.
PEYRUSSON
This accumulator^ contains but two electrodes, placed
one within the other. The positive element is in the
form of a central rod, from which radiate thin sheets
of lead, half a millimetre thick, and placed within a
hollow cylinder, which forms the negative electrode.
This cylinder is composed of sheets of lead, bent so as
1 B. P., io,6o8; 1892: 12,650; 1894.
« B. P., 8226; 1886. A. P., 523,371; 1894.
30
THE STORAGE BATTERY
to expose both surfaces, and united by bands into the
form of a cylinder.
THE STANDARD BATTERY PLATE
This plate, which has been brought out by J. H.
Robertson,^ is made by mixing pumicestone with lead
while the latter is in a semi-molten condition. When
thoroughly mixed, the mass is compressed to the de-
sired shape and left to cool. This gives a very porous
plate, having a large active surface. Owing to the
nature of the pumicestone it is unnecessary to " eat it
away." The makers claim that the heat of the molten
lead renders the pumicestone more porous than it is
ordinarily.
OHIO STORAGE BATTERY
In this battery a plate made from chemically pure
rolled lead is passed through a machine which raises
circular grooves, i inch in
diameter, j^g inch deep, and
■^Q inch thick over the sur-
face, each circle being inde-
pendent, and separated from
each other by | of an inch,
as shown in Fig. 14. After
the grooves are formed, the
plate is put in a special
solution, and the grooves
are filled by electro-chemical
FIG. 14. ^c^^o^-
1 A. P., 546,739 ; 1895.
LEAD-SULPHURIC-ACID GENUS
31
For ordinary purposes the plates are separated by a
hard rubber comb, but in cases where the cells will re-
ceive extra hard usage each positive plate is covered by
a porous flexible envelope, thus absolutely preventing
short circuits. It is evident that as one groove expands
after usage it cannot crowd any others, except the ones
in its own circle. All buckling is thus prevented.
NEW YORK ACCUMULATOR AND ELECTRIC CO. S PLATE
This plate, which was brought out by Harris and
Holland,^ is shown in Figs. 15, 16, and 17. As will be
Fig. 15.
Fig. 16.
Fig. 17.
seen, it is an open-work, ribbed and grooved plate, with
the ribs of one side crossing those of the other, and
bodily, and therefore electrically joined to them. The
1 A. P., 574,417 ; 1896.
32 ^ THE STORAGE BATTERY
plate is made either by casting in a mould, or else by
pressing, rolling, or sawing it out of a piece of pure
rolled sheet lead. The grooves are made at an angle
of 20*^ to the horizontal. Where strength and dura-
bility are first considerations the plates are made
heavier, every tenth rib being- made thicker and the
adjoining grooves wider. For some uses, the positive
plates are protected by perforated sheets of insulating
material secured to the plate by rubber bands.
These plates are formed by immersing them in a bath
consisting of a mixture of dilute sulphuric acid (practi-
cally a non-solvent of lead) and nitric or acetic acids
(both solvents of lead), which produces a coating of
lead sulphate. They are then removed and subjected
to the action of an electric current in an electrolyte
consisting, preferably, of a moderately strong solution
of magnesium sulphate, or its equivalent (as aluminum
sulphate), and proportionately small quantities of sul-
phuric and acetic acids, and magnesium acetate, or
equivalents therefor. Thus two actions are constantly
taking place : the formation of lead sulphate by chemi-
cal action and the peroxidation of this sulphate by the
current, the magnesium sulphate and acetate being
used to facilitate the peroxidation of the difficultly
peroxidizable lead sulphate. When the formation has
penetrated to a sufficient depth, the plates are
thoroughly washed, and subjected to the action of the
current in an electrolyte of dilute sulphuric acid, and a
proportionately small quantity of an acid sulphate, as
that of sodium or potassium. This treatment com-
pletes the formation by converting any remaining por-
LEAD-SULPHURIC-ACID GENUS
33
tions of the lead sulphate to peroxide, but does not
increase the depth of formation. When fully formed,
such of the plates as are intended for negatives, are
reduced by connecting them to the negative terminal
of the charging current. The electrodes are then
ready to be assembled to form cells, where they are
charged in the usual way.
By this process well-formed plates are obtained from
the raw material in from 30 to 50 hours, depending on
the strength of current. It is not advisable, however,
to use too strong a current in forming.
THE AMERICAN BATTERY CO.
This plate is made from a solid sheet of pure rolled
lead, ^ of an inch thick, and grooved on both sides, as
shown in Figs. 18 to 20.
These grooves are j^g of an
f ^ . ^ 1 "^ -. inch wide and ^q of an inch
Fig. 18.
Fig. 19. Fig. 20.
thick. The active material, formed electrically in a
strongly oxidizing solution, completely fills the grooves.
34
THE STORAGE BATTERY
For long life, in constant and severe service, this con-
struction will be found to give excellent satisfaction.
In a former plate, brought out by Morrison,^ lead
ribbon was folded loosely upon itself, forming a square
plate ; the lead ribbon, ^ of an inch wide, was grooved on
both sides. The strips were solidly united at the ends
by a process which left the edges of the plate a solid
bar of metal, practically acid proof ; foot and terminal
pieces of the same metal were also cast on. The
grooves served, not only to key in the active material
when formed, but also as canals, permitting the electro-
lyte to act freely on every part. The lead strips were
so folded that they were about ^ of an inch apart ; this
allowed expansion to take place freely in a vertical
direction. Rubber combs were used as separators.
ROONEY
For his central station, or high discharge type, Mr.
Rooney builds his plates as in Fig. 21, which, as will be
r!*Tf 'f\ ^ ^"^V^^^H ^^^^» ^^ "^^^y similar to the
;|^^^^H De Kabath plate. Corru-
gated strips of lead ribbon,
alternated with straight
strips, are burned at one
end. A number of these
are then burned to a lead
conductor, and the whole is
electrically and mechani-
FiG. 21. cally connected to a lead
1 A. P., 512,514-522,479 ; 1894,
LEAD-SULPHURIC-ACID GENUS
35
frame. In this way all expansion and contraction are
provided for, and buckling is unknown. As a further
protection, the positive plates are surrounded by a per-
forated hard rubber retaining case. The plates are
formed in a few hours by a nitrate solution.
VARIOUS MECHANICAL METHODS
Lane-Fox 1 makes his plate by alternating lead lami-
nae with sand. Pumpelly-Sorley ^ constructed theirs
by clamping a sheet of pure rolled lead between two
Fig. 22.
plate forms, and then bringing it against a gang of
saws, thus producing the plate shown in Fig. 22. The
manufacturers claim to have produced the first integral
slotted rolled lead plate.
3. Electrolytic
(i) Electrolysis of a Lead Salt
montaud's elements
This investigator coated a lead sheet with electrolytic
lead, from a solution of lead in potassium and water.
lA. P., 285,807; 1883. a A. P., 521,897-467,522; 1894.
36
THE STORAGE BATTERY
Fig. 23.
The bath was heated to 100° C, so that the current
density might be high. With a current of 600 am-
peres, only 30 minutes was
required for making the
plates. After washing,
the plates were ready to
be formed. The shape of
the plates is shown in
Fig. 23, a rod of white
metal connecting the plates
of like polarity. For this
cell, the best charging rate is about 10 amperes per
square metre of active surface, and the discharging rate
about 20 amperes per square metre.
SILVEY
Silvey^ places lead plates in a solution containing a
mixture of acetic acid and potassium, and passes a cur-
rent through the cell. This decomposes the anodes,
depositing them in a metallic state on the cathodes.
The cathodes are then removed, and the deposit is com-
pacted by pressure ; after which the plates are placed
as positives in a storage cell and formed. '
VARIOUS METHODS
Shultz^ covers the lead with sulphur, and then heats
it to form lead sulphide, after which the plates are
placed in a bath and made spongy by electrolysis.
Remington^ immerses lead plates in a saturated solu'
lA. P., 512,757-523,689; 1894. '
8A. P., 342,855; 1886.
2 G. P., 21,454.
LEAD-SULPHURIC-ACID GENUS
37
tion of lead in caustic alkali, and then deposits a
coating thereon by electrolysis. Duncan^ produces a
coating by making the plates the anodes in a bath con-
taining a solution of oxide of lead in potassium.
• (2) Eating away of Lead Salts
WOODWARD
Woodward 2 pours molten lead on common salt, and
while still pasty, the salt and the lead are thoroughly in-
termixed, and the plastic material is compressed to the
requisite shape. The salt is then dissolved out and the
plates are formed. In another type of battery, designed
especially for traction purposes, the plates are placed
horizontally, and sheets of porous earthenware, or other
suitable porous insulating material, are placed between
them.
CURRIE
In the manufacture of this grid,^ a brass rod is placed
in an asbestos tube. Fused lead chloride is poured
into the mould, around the rod, and into the meshes of
the tube, thus filling up the interstices of the asbestos,
and forming a thin-walled tube. The brass rod is then
withdrawn, and an alloy of lead and antimony is poured
into its place, a connecting rod of the metal being cast
at the same time. The chloride is then reduced by
electrolysis, after which the plate is ready to be fitted
1 B. P., 15,433; 1888.
2A. P., 392,373-392,374-393,954-393,955; 1888:406,969; 1889.
» A. p., 447»27^45o»834-453»995-459,49i; 1891.
3S
THE STORAGE BATTER\
up and formed. Fig. 24 shows the arrangement of the
plate. The elements can be used with positives of simi-
lar shape, or with flat positives of the ordinary style.
[illlllilllllllillll
Fig.
24.
THE PAYEN ACCUMULATOR
There has been much controversy, of late, as to the
originator of chloride plates. It has been settled by
giving to Marchenay^ the honor of first mentioning
lead chloride for accumulator plates; to Maxwell- Lyte,^
the honor of constructing the first chloride of lead
plate; and to Andreoli,^ that of introducing the first
chloride of lead grid plate. It is to the Maxwell-Lyte
type that the Payen * battery belongs.
1 L. E. R., May 25, 1894. 2 a. P., 422,308; 1890. B. P., 3452; 1883.
«B. P., 8842-12,595; 1886: 18,807; 1892.
* A. P., 440,267-440,277-440,575; 1890.
LEAD-SULPHURIC-ACID GENUS
39
In the manufacture of these plates, an intimate mix-
ture of asbestos fibre and fused lead chloride is formed,
and the molten mass poured into a mould, crystallizing
as it cools. The result is a chloride of lead plate,
bound together with asbestos fibre. By making this
the cathode to an ordinary lead anode, the lead chloride
is transformed into spongy lead, after which the plates
are ready to be formed in the ordinary manner. A
mixture consisting of 90-95% lead chloride, and 10-5%
zinc or cadmium chloride is employed in the manu-
facture of the plates.
THE CHLORIDE STORAGE BATTERY
This battery, which is manufactured by the Electric
Storage Battery Co.^ of Philadelphia, has come into
prominent notice of late years, and stands among the
best of the batteries which are upon the market.
In the manufacture of this cell, commercial lead is
reduced to a fine powder, dissolved in nitric acid, and
then precipitated by hydrochloric acid. The lead
chloride thus obtained is washed and fused with zinc
chloride. The molten metal is poured into a mould,
and allowed to cool, forming pastelles, about -^q of an
inch thick. For the positive plates, the pastelles are
circular in form, | of an inch in diameter, with a
bevelled V-shaped periphery; for the negatives, they
are square, f of an inch on an edge. These pastelles
are placed in a mould, and a lead-antimony grid is cast
around them under pressure. By packing these grids
lA. P., 4iS»329-4i5»330-4i5»33i-4i5>333; 1889: 477»i82; 1892.
B. P., 1229; 1893: 10,836-12,953-12,954; 1895. G. P., 57,053; 189a
40
THE STORAGE BATTERY
between zinc plates in a tank containing a dilute solu-
tion of zinc chloride, and short-circuiting them, most of
the chlorine is extracted. The last traces of chlorine
Fig. 25.
can now be removed by thoroughly washing the plates
in running water; a pure spongy lead plate results.
The positive plates are then formed by packing them
tightly between perforated ebonite boards, in dilute sul-
LEAD-SULPHURIC-ACID GENUS
41
phuric acid, and passing a current through them in one
direction for two weeks.
Lately, however, the Electric Storage Battery Co.
has abandoned this method of making positive plates,
and constructs them of a lead-antimony grid -^ of an
inch thick, and having circular holes | of an inch in
Fig. 26.
diameter; the grid being cast under pressure to make
it dense. A corrugated, soft lead ribbon, also ^ of an
inch wide, is bent into the form of a spiral, and is
pushed into these holes; the active material being
formed from this ribbon by electro-chemical process.
The expansion of the active material, during use, tends
to wedge the spiral more tightly within the hole, thus
42
THE STORAGE BATTERY
improving the contact. This plate, known as the
" Manchester " plate, was brought out by Rhodin.^ It
lillllilllllll]|IUtBliliiuiiniiiiiiiiLiijiiiiiiiiiii^iiiji,LNiji;iiiiiiiii!iiLitiLikiLiuijiiij|jiii'.!''^^
Fig. 27.
is constructed essentially like the original Brush plate,
though the "active material, or material to become
1 A. P., 567,044-567,045; 1896.
LEAD-SULPHURIC-ACID GENUS
43
active/' is a spiral of ribbon lead, instead of the paste
or cement used by Brush.
In Figs. 25, 26, and 27 are shown the E-ii Portable
cell, the ordinary Portable cell, and the Central Station
2.1
8.0
V
— •
—
^
\
~
>^
-^
V
N
\
\
\
\
''Chhr
</«"
\
\
• 1
5 6 7
Hours Discharge
Fig. 28.
cell. Fig. 28 shows the charge and discharge curves of
this battery. They were taken from a 75 A. H. cell,
which was charged with a constant current, and dis-
charged through a constant resistance.
VARIOUS METHODS OF FORMATION
Monnier^ makes an alloy of lead with about 4%
of zinc ; the alloy is then cast into the desired shape,
and the zinc eaten away. Tribe ^ used various salts of
lead, mostly, however, the arsenides, phosphides, or
sulphides; the salt was then reduced to spongy lead
by electrolysis. Messrs. Beaumont and Biggs, ^ Fitz-
gerald,* and Crompton^ used alloys of lead containing
1 B. P., 1556 ; 1883. 2 B. p., 2073 ; 1884.
* B. p., 29 ; 1882. A. P., 524,710 ; 1894.
8B. P., 12,818; 1886.
» G. P., 22,816 ; 1882.
44
THE STORAGE BATTERY
tin, iron, or antimony from which the foreign material
was eaten away by electrolysis. Pollak,^ with some of
his plates, uses lead carbonate and caustic potash mixed
to a thick paste. They are then moulded to the re-
quired form and dried, after which a current is passed
to reduce them to spongy lead.
4. Plates of Solid Active Material
PERCIVAL*S SECONDARY PILE
In April, 1866, George G. Percival took out American
Patent 53,668, for a secondary electric pile; this was
the first United States patent
granted for storage batteries.
It is constructed of solid active
material, and is shown in Fig.
29. In this figure, ^ is a
wooden containing box, and C
is a porous partition. A^ A,
are layers of powdered gas car-
bon, powdered lead, or other
suitable conducting powder.
These two layers constitute the
two electrodes, and when in
use, are wet with dilute sul-
phuric acid. By placing these
pj^ layers in a horizontal posi-
tion, a layer of non-conducting
powder may be substituted for the partition.
inuifl
A-
11
«
III
-^
B^
U
IB. P., 813; 1893.
LEAD-SULPHURIC-ACID GENUS
45
FITZGERALD S LITHANODE
Professor D. G. Fitzgerald ^ makes his " compressed
active material " plate, by thoroughly mixing litharge and
ammonium sulphate, and then allowing the mass to dry
slowly under pressure, in the requisite shape. The
plate is converted into peroxide, by placing it in a bath
of magnesium hypochlorite, or other suitable chlorine
compound, for a preliminary coating ; this insures uni-
form peroxidation in the forming. The forming is
effected electrolytically in a bath of sulphate of mag-
nesium, for a lengthened period. The preliminary coat-
ing, may, however, if desired, be applied mechanically.
The contacts are of some unoxidizable metal, such as
gold or platinum. The plate is used as a positive to a
negative of ordinary lead. By the use of lithanode, a
positive plate is obtained which is unusually free from
local action, and the manufacturers claim that fully 90%
of the positive plate is lead peroxide.
In discharging a battery containing lithanode plates,
care must be taken not to run the E.M.F. down below
1.8 volts per cell. Professor Fitzgerald claims that when
used according to directions, the electrical capacity of
lithanode is almost exactly one ampere-hour per ounce ;
the best rate of discharge being -^ of an ampere per
square inch of lithanode plate.
MCLAUGHLIN
The electrode for this battery ^ consists of a conduct-
ing core having a ledge or seat at its lower extremity,
1 A. P., 524,710 ; 1894. B. p., 3731 ; 1890.
« A. P., 424,809; 427,785; 432,202; 1890: 475»33S; l89»-
46 THE STORAGE BATTERY
on which is placed a block of active material, so that
the entire surface of the active material, except the
lowest side, is exposed to the electrolyte. The makers
claim for this type of battery that there will be no twist-
ing, warping, or buckling, and that the battery will
stand a high rate of discharge.
BOESE
The Boese^ plates consist of a solid slab of active
material, enclosed in a lead frame, similar to the frame
of a slate. The slabs are formed of minium for the
positive, and minium and litharge for the negative, these
being formed into a paste with alcohol, containing cer-
tain hydrocarbons, such as anthracene, obtained from
a distillation of coal tar. After being moulded and
pressed into the frame, the plates are pierced with a
large number of small holes, for the escape of the gas ;
they are then baked, and placed in a dilute sulphuric
acid solution to harden, after which they are formed.
These plates are said to be extremely porous, and to
have a conductivity nearly equal to that of lead.
More than 20,000 of these cells are in use on the
German and Hungarian postal railway cars for lighting,
where they give excellent satisfaction.
VERDIER
Verdier^ mixes a lead oxide with a vegetable oil, or a
mixture of glycerine and water, to a thin paste. The
material is dried in air, and perforated. The plates are
1 G. p., 78,865 ; 1892. as. P., 8973; 1889.
LEAD-SULPHURIC-ACID GENUS
47
then transformed to spongy plates by treatment in a
solution of sodium sulphate, and a mixture of glycerine
and water ; after which they are formed in dilute sul-
phuric acid.
DESRUELLES
Desruelles ^ mixes 60 parts of lead peroxide, 40 parts
of graphite, 25 parts of pulverized porcelain, and 10
parts of white of egg, presses into shape, dries, and
heats until the albumen coagulates. A very porous and
extremely hard plate results.
1 G. P., 61,620 ; 1891. B. P., 4877; 1891.
CHAPTER III
LEAD-SULPHURIC-ACID GENUS
I.—B. Faure Type
The formation of accumulators by means of reversals
being an expensive as well as a troublesome process,
Metzger and Faure maintained that, if the active ma-
terial were mechanically applied, the previous tedious
formation would be saved, and that better results would
be obtained than with the old process. Experience has
proved the wisdom of these views, and to-day the use
of these two types is evenly divided, European practice
favoring the Faure type, and American practice the
Plants type. The advocates of the pasted type claim
that a larger percentage of the total weight of the plate
consists of active material, and that this, while not con-
ducive to high rates of discharge, permits the Faure
cell to take in a greater charge, and to obtain a greater
staying power than is possible with the Plants cell. On
the other hand, the Plants cell will do what the Faure,
with equal weight or surface, will not do, — produce rapid
discharges in currents of great volume.
metzger
In 1878, R. L. Metzger,^ of Alt-Breisach, Germany,
took a sheet of perforated lead, 1.5 mm. thick, formed
1 El. Anz., 1892 ; 651.
48
LEAD-SULPHURIC-ACID GENUS
49
it into the shape of a box, about 7 mm. deep, and filled
it with a paste composed of a lead oxide, dilute sulphuric
acid, and potassium silicate. After the paste was thor-
oughly dry, a perforated lead cover was soldered to the
box. Two such elements, placed in dilute sulphuric
acid, composed the battery. From 48 to 72 hours was
required for the formation.
.Somewhat previously to this Metzger had used the
two paste-filled boxes in the form of a hollow cylinder,
placed the one within the other. The lower part of
each was filled with some insulating material. This,
not proving satisfactory, was abandoned for the flat
electrode type.
FAURE
Although used in 1878 for the first time, the pasted
type was not universally known until 1880, when
Camille A. Faure,^ working independently of Metzger,
took out patents on that type. He took a lead oxide, in
the form of a paste, spread it upon a spiral Plants plate,
and allowed it to dry. It was insulated from the nega-
tive element by means of felt, or parchment paper, and
the whole was replaced in dilute sulphuric acid. Ac-
cording to some tests by Lord Kelvin, this type gave
about I2,cxx) foot-pounds per pound of cell complete.
In a cell composed of 16 plates, each 17 x 12.5 inches,
the amount of lead oxides present was 50 pounds, and
the total weight of the cell, 135 pounds. The capacity
lA. P., 252,002; 1882: 309,939; 1884. B. P., 129: 1676; 1881:
1769; 1882. G. P., 19,026; 1881.
s
50 THE STORAGE BATTERY
was 176 ampere-hours, at an 8-hour rate, and 299 am-
pere-hours at a 14-hour rate. The great disadvantage
with this cell is that " lead-trees " are soon formed.
Improvements in the Faure Type
z. Redaction of Weight
(i) Use of Alloys
HAGEN
In this battery, brought out by Gottfried Hagen,^ of
Germany, the lead frame consists of two halves, each
composed of ribs crossing each other at right angles.
Each rib is in the form of a triangular prism, with its
base outwards. The two halves are not cast solid along
the inner edge of the ribs, but are some distance apart,
and are held together by a series of short cross-bars, the
entire frame being cast in one piece. In this way a
very light and yet strong frame is secured, and one
which is capable of holding firmly a large amount of
active material. The plates are kept apart in the cell
by means of corrugated, perforated celluloid separators,
which offer considerable resistance to lateral pressure.
For stationary batteries the ratio of the weight of the
active material to the total weight of the plate is 50%,
while for transportable batteries it is 60%. The dis-
charge should never be continued under 1.88 volts.
JAMES
In this accumulator the positive plate consists of
an alloy of lead with 1% of cadmium, the negative
1 G. P., 52,880 ; 1889.
LEAD-SULPHURIC-ACID GENUS
51
containing 2% of antimony. Both plates are pierced
with circular holes, in which the active material is
placed.
For the positive plate the active material consists of
the following mixture: minium, 85%; litharge, 10%;
carded asbestos, 4% ; and powdered carbon, 1%. That
for the negative contains : litharge, 94% ; asbestos, 4% ;
sulphur, 1% ; and powdered carbon, 1%.
KNOWLES
The grid for this battery ^ is composed of an alloy of
82% of lead, 16% of tin, 1.9% of antimony, and 0.1%
of arsenic. Solid blocks of active material composed of
75% of red oxide of lead (minium), and 25% of yellow
oxide of lead (massicot), first thoroughly mixed, and
then treated with sulphuric acid, and hardened, are
placed between these perforated grids, which are held
together by rivets. The makers claim that by this
means a very light, as well as an unoxidizable, grid is
obtained.
VARIOUS METHODS
In the Jacquet^ battery the grid is composed of a
white metal alloy. Worms uses 96.5% of lead, 2.2% of
antimony, and 1.3% of mercury for his grid. Julien
employs 92% of lead, 4.5% of mercury, and 3.5% of
antimony. Nevins uses 30 parts of lead, and 100 parts
of tin. The usual alloy used is 96% of lead to 4% of
antimony.
1 A. P., 480,266-482,979-483,562-483,563 ; 1892: 538,919; 1895.
2 B.P.r 18,028; 1889.
52 THE STORAGE BATTERY
(2) Use of a Non-condticting Support
HATCH
In the old form of Hatch ^ battery the lead salts were
contained within the corrugations, or grooves, of a
highly porous zigzag plate of earthenware. When
these grooves were so filled as to present an even sur-
face, the requisite number of packed plates for a com-
plete cell were bound together between stout wooden
boards by means of flexible rubber bands, each plate
being separated from its neighbor by a sheet of two-
pound lead, which served as a conductor. Its internal
resistance varied from 0.0 1 to 0.042 ohm. Each
packed plate was capable of absorbing 50% of its
weight of water. 54% of the total weight of the plates
was active material.
In the latest type of plate ^ porous unglazed earthen^
ware is used, having square receptacles on its face side,
and grooves on its reverse side, as shown in Figs. 30 to
33. The face of each plate is packed with red lead,
filling the small squares, and rising \ of an inch above
the surface of the plate, so as to secure an agglomera-
tion with the electrode during the forming process.
The packed plates are then placed back to back, with
the grooves crossed, as shown in the figure. As in the
older type, two-pound sheet lead is used for the elec-
trodes, and is placed between the packed surfaces of
two adjacent plates. Fig. 33 shows a completed accu-
mulator, bound by means of stout rubber bands between
1 A. P., 44^4^3 J 1890. « A. P., l^A1^'%^An 5 '^7-
LEAD-SULPHURIC-ACID GENUS
53
iHif
l|MnB|
bbSiShI
llinH|iM^IH
llllll!
ri^yriBl
mBBBHSE
H PI PH |l' 1' [rjl!
jgllllll
Fig. 30.
Fig. 31.
Fig. 3a.
Fig. 33.
54
THE STORAGE BATTERY
rigid backs. By this means a circulation of the electro-
lyte is obtained, and an escape for the gases formed is
provided. The elasticity of the element allows for the
expansion and contraction of the active material, with-
out closing the pores of its own mass. The manufac-
turers claim that as no amount of curretit in either
direction can possibly injure the element, it is admirably
adapted for central station purposes, and that the abso-
lute confinement of the active material avoids deteriora-
tion by loss of that important part of the battery. The
internal resistance of the cell, at a lo-hour rate, is 0.006
ohm. Taking account of the weight of the central
conductor, it has been found that 65%, or, omitting this
factor, 77%, of the weight of the plates is active material.
The earthenware plates used will absorb 40% of their
weight of water. In Fig. 34 is shown the discharge
LEAD-SULPHURIC-ACID GENUS 55
curve of a icx) ampere-hour cell, discharged at a con-
stant current of 10 amperes.
WINKLER
An element of the Winkler ^ battery consists of a
series of troughs, of an acid-proof non-conducting mate-
rial, such as celluloid or vulcanite, in a frame of the
same material. The element is dipped in the active
material, which is in a semi-liquid condition ; any excess
of the active material being brushed off after drying.
A lead conducting wire is placed in the bottom of the
trough, and is embedded in the active material. The
electrolyte is a gelatinous mixture of sodium silicate,
sulphuric acid, and ammonium sulphate. The forming
charge lasts 26 hours. Where lightness is not a prime
desideratum, the element is made of lead, and the elec-
trolyte dilute sulphuric acid.
VAN EMON
In this electrode,^ a non-porous, non-conducting grid
is perforated, usually with square holes. Perforated
plates of lead are placed on one side of the electrode,
the other side being open to the electrolyte. Ribbed
separating frames are placed between the positive and
negative plates.
RODNEY
In this plate,^ a cut of which is shown in Figs. 35
and 36, the grid is built up of layers, or strips, of wool-
felt, which are placed in parallel rows at right angles
1 A. P., 471,590-471,591-471,592; 1892. ^A. P., 524,656; 1894.
•A. P., 549,023-549,077; 1895: 574*826; 1896.
56
THE STORAGE BATTERY
to each other, thus leaving square holes, or pockets, for
the reception of the active material. In order to make
metallic contact with the paste, perforated lead conduct-
ing strips are placed midway between the faces of the
plate.
In the construction of the plate, sheets of wool-felt,
painted on one side with a cement, which has been
softened by heat, are cut into narrow strips, about ^ of
an inch wide, and of the required length, these strips
illJUULt
!P^
Fig. 35.
Fig. 36.
being laid in parallel rows in a form. When the grid
has reached half its thickness, the lead strips are laid
in place, and when the form has been filled, heat is
applied to soften the cement. The plates are cooled
slowly under heavy pressure, which is maintained until
the cement has hardened, after which the grids are
lifted from the form.
The grids are then pasted as though metallic, and
when set, the lead strips are firmly embedded in the
LEAD-SULPHURIC-ACID GENUS
57
active material, leaving no metallic surface exposed to
the action of the electrolyte. Lead connectors are
burned to the centre conducting strips, and the whole
plate is surrounded by a perforated non-conducting
retaining case.
During expansion the paste presses more firmly
into the felt, thus absolutely preventing all buckling.
2.3
CD
I-
-J
o
>
1.9
1.8
4 5 6
HOURS DISCHARGE
Fig. 37.
This grid will absorb 230% of its own weight of
water.
Mr. Rooney has thus succeeded in obtaining a very
light yet strong plate, and one which has been found
to give excellent satisfaction under the most severe
conditions. Fig. 37 shows a curve taken from a 5-plate
cell, charged at a constant current of 7.8 amperes, and
discharged through a constant resistance, the average
current being 8.92 amperes.
58
THE STORAGE BATTERY
THE UNION STORAGE BATTERY
In this battery,^ which was put upon the market in
1898, the plates consist of horizontal porous earthen-
ware concave dishes, or saucers, filled with the active
material, the active material being placed in the plates
in the condition of a dry powder (see Fig. 38). The
conductor, of thin sheet lead, stamped into a shutter-
like form with lips and slots, is laid upon and pushed
down into the active material. Extension strips, lead-
FlG. 38.
Fig. 39.
ing from the conducting plates on alternate sides, reach
to the top of the cell ; these strips are brought together,
one-half on each side, and constitute the two terminals.
The dishes, thus filled and arranged, are stacked on
top of one another, and make up the complete element,
as shown in Fig. 39. A porcelain or earthenware
dish is laid on top, and the whole is bound together by
vulcanite rods.
1 A. P., 534,603 ; 1895.
LEAD-SULPHURIC-ACID GENUS
59
It will be seen that this arrangement effectually pre-
vents the plates from short-circuiting, and that any
tendency to buckle on the part of the conducting plates
is prevented by the porous dishes. No strain of any
amount can fall upon the dishes, as the conducting
plates are thin, and the associated active material is
in a more or less plastic condition.
Professor Langley,^ of the Case School of Applied
Science, tested this cell, and found that after less than
250 ampere-hours' formation, at a I2.s-ampere rate, the
cell gave 3.36 ampere-hours per pound of total weight,
at a S-hour rate ; the internal resistance, when charged,
being 0.007 ohm.
2. Devices for the Retention of Paste
(i) Grooves or Recesses
THE BRUSH GRID
To Charles F. Brush have been granted American
patents 2 covering the broad principle of mechanical
1 Professor Langley gives the following test of one of the cells :
Weight of element 11.5 pounds.
Weight of cell, complete, with electrolyte . 18.75 pounds.
Height of cell, over all ii.o inches.
Width of cell, over all 4.5 inches.
Length of cell 5.0 inches.
Discharge current 12.5 amperes.
Average E.M.F 1.86 volts.
Time 5.0 hours.
Capacity per pound total weight .... 6.2 ampere-hours.
2 A. P., 266,089-266,090-261,512; 1882: 337,298-337,299; i886h
B. P., 3579; 1884.
6c
THE STORAGE BATTERY
application to the support plate, no matter in what
form ; they also cover receptacles or perforations in the
support plate. After long litigation, he was also
awarded the priority of invention, in this country, oi
the pasted type of plate.
The form of his support plate is shown in Figs. 40,
41, and 42. The plates are cleaned chemically, and
immersed either in lead acetate or lead nitrate, and
Figs. 40, 41, and 42.
spongy lead is deposited electrolytically. They are
then washed and placed in dilute sulphuric acid until
the spongy lead has been converted into peroxide, after
which they are ready for use.
Another method of making the plates active is to fill
the grooves with lead sulphate, place them horizontally
in a solution of common salt and ammonia, with a zinc
plate hung above, and short-circuit them.
LEAD-SULPHURIC-ACID GENUS
6i
TUDOR STORAGE BATTERY
This accumulator, brought out by the Tudor Bros.,^
and manufactured by The Akkumulatoren-Fabrik Actien
Gesellschaft, Hagen, is much used on the Continent,
especially in Belgium, and to a small extent in this
country, the American patents for this battery being
controlled by the Electric Storage Battery Co.
Rolled lead plates are grooved, as in Figs.
43 and 44, The thickness of the plate be-
tween opposite grooves is 3 mm. for the posi-
FlG. 43.
Fig. 44.
tive, and 1.5 mm. for the negative plate. The width
of the grooves at the edge is 3 mm. for the positive,
and 2 mm. for the negative plate; the distance be-
tween the grooves at the edge being 1.5 mm. for
lA. P., 478,661; 1892. B. p., 11,543; 1887.
62
THE STORAGE BATTERY
both plates. The grooves are first coated with a thin
layer of lead peroxide by electrolysis, and then packed
with the usual oxides ; after which the plates are rolled,
to key in the active material. By this treatment the
formation of lead sulphate at the junction of the grid
and the active material is reduced to a minimum,
y
/
^
X
s
Char
se
-^
^
Ofschi
rSTB
L«
s.
L8
17
\
\
\
I
I
I
1
\
W^
HOURS
FiG. 45.
and the active material itself is less liable to scale
and disintegrate. The internal resistance varies from
0.0 1 5 to 0.02 ohms. Fig. 45 gives the curve for this
cell as obtained by Kohlrausch; the cell was charged
at a constant current of 5 amperes, and discharged with
a constant current of 6.5 amperes; the specific gravity
varying from 1.115 to 1. 147.
LEAD-SULPHURIC-ACID GENUS
63
POLLAK
In this accumulator ^ the lead plates are covered with
an electrolytic deposit of spongy lead, after which they
are worked in such a manner as to produce the appear-
ance of a short-bristle hair-brush. These hair-like pro-
trusions are about 2 mm. long, with a space of about
I mm. between the points. They are then coated with
electrolytic lead, washed, and covered with a mixture
2.2
2.1
(0
J 2.0
s
^"^^
\
^
l.v
1.R
\
3
HOURS
Fig. 46.
of lead sulphate and salt water. After being pasted,
they are packed between zinc plates in an acid bath,
and the sulphate is reduced to spongy lead. After the
sulphate is thoroughly reduced, the plates are rolled so
as to bend the hair-like rods, and key the active mate-
rial in place. The forming charge lasts about 45 hours.
IB. P., 7428; 1889. G. P., 67,290-73,548; 1892.
64 THE STORAGE BATTERY
Fig. 46 shows the curve of a 9-plate cell, total weight
24.75 pounds, which was discharged at a constant cur-
rent of 18 amperes.
WOODWARD
In the manufacture of these elements ^ a lead plate is
moulded with some substance, usually rock salt, which
is afterwards removed. This leaves a plate having a
highly porous surface. The active material is then
pressed into the cells and pores.
BUCKLAND
An element for this battery^ consists of a plain cast
lead plate, containing holes and slots, in the latter of
which are secured projecting pieces of some acid-proof,
non-conducting material, such as ebonite. These pro-
jecting pieces form, with the plate, horizontal troughs,
in which the active material is placed in the form of
a paste. By this means no part of the lead grid is
exposed to the action of the electrolyte, it being pro-
tected by the active material and by the supporting
troughs.
KHOTINSKY
Figs. 47, 48, 49, and 50 show the plate brought
out by Captain de Khotinsky,^ of Holland; Fig. 48
showing the cross-section of the inner plates, and Fig. 49
1 A. P., 392,373-392,374-393,954-393*955 ; 1888:406,969; 1889.
2 A. p., 550,480; 1895: 556,660; 1896.
« A. p., 345,511-347,231; 1886. B. P., 4490-4756; 1882: 3261-8416;
1885; 17,160; 1891.
LEAD-SULPHURIC-ACID GENUS
65
that of the end plates. These plates are cast under a
pressure of about 300 atmospheres. For a rapid dis-
charge, the ribs are made much
w
!JJ iiiii'^'Nii.!.!,i.ii':vi|iii!rii,^],yj
I
shorter than where a slow rate
is to be employed, and the pos- / {^iir^^vr: -
itive plates contain more ribs
than the negatives. For a slow
discharge, the 8-hour rate, the
positive and negative plates con-
tain an equal number of ribs ; but
in both cases the ribs on the posi-
tive are thicker than those on the
negative plates. The plates are
covered on both sides with parchment paper, asbestos,
or thin perforated celluloid sheets.
i; ' Ji
1- ....,^ji:u
r::?:;T ••;'""■::: ■ t-TTS
L -~;- -^
::l"":vl::::i^;;,:j::'.::l. — ^
L^^.n, . -J
■rr:: : ^. — t-j
Fig. 47.
Fig. 48.
Fig. 49.
Fig. so.
LLOYD
Robert McA. Lloyd ^ treats lead plates with a hot
nitric acid bath. This produces a " honeycomb '* struc-
ture in the surface of the plate, which is then filled with
active material.
1 A. P., 491,684; 1893. B. P., 8534; 1890.
66 THE STORAGE BATTERY
(2) Perforations
As stated before, the holes or perforations in lead
plates may be of three general types : ^, where the
diameter is the same throughout ; b^ where it is larger
at the surface than at the centre; and r, where it is
larger at the centre than at the surface. Of these three
general types, the second is undoubtedly the worst,
since the plugs of active material, having nothing to
hold them in place, tend to become loose and fall out,
especially during a heavy discharge; while the oppo-
site shape, or the last, is the best. Of these three gen-
eral types, the Van Emon ^ may be used to illustrate
the first, the Rooney,^ the second ; and the majority of
perforated plates the third ; although the Rooney may
as correctly be classed with the third type, because of
the methods employed to hold the active material in
place. According to a United States Court decision,
to James W. Swan^ belongs the honor of originating
the perforations which extend entirely through the
plate.
THE E.P.S. GRID
The patents* taken out by Messers. Sellon, Volck-
mar. King, Parker, Swan, and others, combined with
Faure's^ patents, cover what is known as the E.P.S.
battery, manufactured by the Foreign and Colonial
Electric Power Storage Co. of England. The grid in
1 Vide p. 55. a Vide p. 55.
» A. P., 312,599; 1885. B. P., 2272; 1881.
*A. P., 259,657; 1882: 321,759-324,597; 1885: 454,187; 1891.
8. P., 4781; 1887: 24,127; 1892. * FjV^p. 49.
LEAD-SyLPHURIC-ACID GENUS
67
its latest form is made of pure lead with perforations,
the shape of which is shown in Fig. 51. A thin per-
forated strip of metal runs across each aperture midway
between the edges.
Fig. si.
The paste, composed of minium and dilute sulphuric
acid for the positive ; and minium, litharge, and dilute
sulphuric acid, or a solution of magnesium sulphate for
the negative, is pressed into the grid and dried. The
plates are then hardened in dilute sulphuric acid, after
which they are ready for forming. A strong current
for 48 hours is required for the positive, and 24 hours
for the negative plates. To prevent short circuits, a
hard rubber ring is placed around the negatives, or glass
rods are placed between the plates. The internal resist-
ance of this battery at 9 amperes is 0.0045 ohm, and
at 10 amperes, 0.0038 ohm; 9 amperes being the
normal discharge rate of the cell tested. Fig. 52 gives
the results of a complete test of this battery.
In a cell put upon the market by this company in
1897, for autocar purposes, and designed by Camille
Faure and Frank King,^ the weight, as compared with
the E or EK type, has been reduced fully one-half. A
grid very similar in form to the ordinary E.P.S. grid is
used. This pasted grid is first wrapped in a cloth of
1 A. P., 501,728; 1893: 544»673-552,425; ^895: 568,447; 1896.
68
THE STORAGE BATTERY
silicated asbestos, and then placed in a close-fitting
envelope of perforated celluloid. The envelope is held
to the plate by means of celluloid pins, which are
2.4
2.3
2.2
■"""
"^
~"~
■"—
■""
■ChJ
xK-e
^_^^
2.1
.^
^-"
— 1
20
L.
1
1.9
Dis
char
ge"
— ■
— -
-^^
V
1.8
^
\
1.7
1.6
1.6
\
>
V
1 4
<n 1.3
JW l.tJ
-J 1.2
O
> 1.1
10
0.9
0.8
0.7
0.6
0.5
04
=^
%
^
i'i
^©
^^^
-^
,
2^
X
^
\
Chs
rjje
" —
—
\
r^
\
0.3
0J5
"-N
-—
t^ —
V
0.1
T
s
^
100
90
«>«
70 O
60£
40
^
1 2
4 5 6 7
8 • 9 10
HOURS
Fig. 52.
U 12 13 14 15 16 17 18
cemented on either side to celluloid diamond-shaped
washers, the pins taking different positions on the posi-
tive and negative plates.
EICKEMEIER
In this accumulator,^ a flat lead foundation is pierced
with polygonal holes. (See Figs. 53 and 54.) The active
material, packed around plugs, is inserted in these holes,
1 A. P., 413,339; 1889.
LEAD-SULPHURIC-ACID GENUS
69
and the plugs are afterwards removed. An insulating
plate, having its holes considerably smaller than those
in the leaden plates, is placed between the elements;
this prevents the active material from overlapping and
short-circuiting by contact with an adjacent plate. Each
vertical line of holes constitutes a chamber containing
FIG. 53.
the electrolyte ; the various chambers being connected
by channels in the base plate (see ff. Fig. 54), so that
the electrolyte has a constant circulation through the
battery. The chambers are filled by means of a funnel
which fits tightly in the feed aperture at the top. The
lead grid is thus protected from all action by the elec-
trolyte, except through the active material.
SCHENEK-FARBAKY
The positive plate for this type of celP consists of
a lead frame with a trellis formed of circular intersect-
1 A. P., 344,959-348,625; 1886: 359*248; 1887.
70
THE STORAGE BATTERY
ing bars ; thus giving polygonal holes which are filled
with active material. The smaller holes between two
of the intersecting arcs are left open in order to regu-
larly interrupt the continuity of the packing mass.
The active material for the positive plate contains
47-5% G^ch of minium and litharge, and 5% of coke,
treated with dilute sulphuric acid (10-15%); that for the
negative plate, 95% litharge, and 5% coarse powdered
pumicestone, with dilute sulphuric acid (10-15%). The
grids are filled with this paste and are partially dried.
The surplus paste is then scraped off, the plates are
entirely dried in air, are moistened with dilute sulphuric
acid, and again air-dried; are placed in sulphuric acid
for from 10 to 12 hours, and finally air-dried. The
elements are bound between paraffined wooden rods.
The internal resistance of this cell averages 0.00 1
ohm.
VARIOUS TYPES
In the Drake and Gorham^ grid a double dove-tail,
shown in Fig. 55, is obtained by passing the grid be-
iiiiiii
B
e
Mli
FIG. 55.
tween rollers. The Jacquet^ plates are shown in Figs.
56 and 57. In making these grids, Jacquet casts them
entire from a white metal alloy. To facilitate removal,
the plates are not burned together, but are bolted to
IB. P., 3986; 1888: 17,655; 1895.
2 B. p., 18,028; 1889.
LEAD-SULPHURIC-ACID GENUS
71
72
THE STORAGE BATTERY
0^
\
/
/
o
\
i
/
\
iH
1
a»
;
• i
Q
1
o
^
1
CO
iH
O
i
i
a
u
^ :
.^
^ '
1 :
H 1
■4 1
4
8110A
LEAD-SULPHURIC-ACID GENUS
7i
sunoH-auadiMv ni Aiiovdvo
74
THE STORAGE BATTERY
a cast white metal pole piece. The Gibson^ battery,
shown in Fig. 58, consists of a lead plate, whose per-
forations contain buttons with enlarged heads. The
active material is packed around these buttons. Figs.
59 and 60 show the D. J. Hauss plate. As will be seen,
Fig. 56.
Fig. 58.
Fig. 57.
it consists of an ordinary perforated pasted lead grid.
The active material is made by mixing sulphate of
calcium, or the sulphates of other light metals with the
litharge and alkaline solution, so as to form a plastic
mass. This is tempered in a slightly acid solution,
and then packed in the grids, and the pasted plates
formed in a saline solution. Fig. 61 shows the curve
for this plate, and Fig. 62, the relation between the
capacity and discharge rate.
1 A. P., 388,668; 1888: 397*796; 1889: 439*240; 1890.
LEAD-SULPHURIC-ACID GENUS
75
(3) Active Material surrounded by Conducting Material
TOMMASSI
The latest form of this celP consists of a perforated
conducting tube, filled with the active material, and
containing a conductor B, (See Fig. 63.)
An insulating plate A is placed at the bot-
tom of this tube, which is usually made
rectangular in form. The active material
for the positive electrode is composed of a
lead oxide, mixed with dilute sulphuric and
phosphoric acids to form a paste. Precipi-
tated or spongy lead is used for the nega-
tive. Short-circuiting between two adjacent
tubes is prevented by means of insulating
perforated retaining walls. In the older
forms the tubes were made of insulating
material, and the conductor was given the
Fig. 63.
S.0
x&
/
./
Ch
irge
. .
' "
■
_Dtscl
yge
""^*
V
N.
iO
a
12
19346 6 78
HOURS
Discharge Curve of Bradbury-Stone Battery. Class B 2, (3).
Fig. 64.
lA. P., 454,091; 1891.
'jQ THE STORAGE BATTERY
shape of a screw, or rod with branching arms. The
formation of the Tommassi elements is said to require
220 hours.
CORRENS
In this accumulator, ^ as will be seen from Fig. 65,
the two frames are composed of lattice work, and are
Fig. 65.
so placed that no two interstices fall opposite one an-
other. The two frames are connected by means of small
rods. The active material, minium for the positive, and
litharge for the negative, contain a lead silicate, neutral-
ized with ammonium chloride, and magnesia or white clay.
iG. P., 51,031; 1888: 52,853; 1889: 54,371; 1890: 63433; 1891.
LEAD-SULPHURIC-ACID GENUS
77
FORD-WASHBURN
In this accumulator, which is manufactured by the
Ohio Storage Battery Co.,^ of Cleveland, Ohio, the ele-
ments consist of a flat bar of lead for the positive pole,
placed within a perforated conducting cell of sheet
lead ; the cell being filled with lead dioxide. The con-
ducting cell is placed within a non-conducting porous
chamber, usually of earthenware. The space between
L9
5L7
0l9
h
-B
*
s^
*^
I>v
^^
s
V
N
s_
'■^
v
\
\
N
N
— N
V
\
\
\
\
\
\
\
\
\
\
\
\
\
\
\
\
C
\b
Va
D
I
1 t
\ i
H
B
0UC8[
%
)i8cha
rsre
I 1
D i
1 1
• J
i 1
Fig. 66.
the lead conducting cell and the porous non-conducting
cell is also filled with lead dioxide. Outside of the
earthenware cell is placed another perforated lead con-
ductor, having the space between it and the earthenware
cell filled with litharge. These two lead conductors
form a single element. The electrolyte consists of
dilute sulphuric acid, containing, by weight, 1.49% of
sodium sulphate.
» A. P., 451,541; 1891: 488,233; 1892.
78 THE STORAGE BATTERY
Professors Langley and Mayberry gave this battery a
thorough test They found that during a two months'
test, neither heavy charges or discharges, nor a pro-
longed course of vibration, imitating that of a street
car, produced any measurable deterioration of the bat-
tery; the internal resistance during the entire test
averaging 0.0048 ohm. Fig. 66 shows the curve
obtained by them from a S-element cell, the total weight
of the battery being 70 pounds, and that of the ele-
ments 42 pounds. The battery was discharged with a
constant current, the rates being 10 amperes for curve
A, 15 amperes for B, 20 amperes for C, and 30 amperes
for D.
VAN GESTEL
Van GesteP uses a lead tube, perforated, and filled
with active material. A lead-covered copper conduct-
ing wire passes through the centre of the tube, which
is bent upon itself, until it forms, practically, a square
plate.
JOHNSON AND HOLDREGGE
In this battery ,2 perforated lead plates, which are
ribbed only on one side, are covered on that side with
active material. Two plates are then taken, and so
bolted together that their ribbed sides are adjacent.
Conical steel pins are placed in the perforations of the
plates, before the introduction of the active material,
and are removed when the plates are thoroughly dry,
thus giving the electrolyte free access to the active
material.
1 A. P., 358.092; 1887. B- Pm 12,376 ; 1888. « B. P., 13,274; 1893.
LEAD-SULPHURIC-ACID GENUS 79
SOLA-HEADLAND
This plate ^ is composed of perforated rectangular
lead tubes, into which the active material is pressed.
The makers claim that since equal surfaces are exposed
on the four sides to the current, buckling is impossible,
even on short circuits. The ratio of the weight of the
active material to the total weight of the plate is less
than 50%. These batteries have been introduced in
London for the propulsion of autocars.
(4) Active Material surrounded by a Non-conducting
Material
REYNIER ELASTIC
Reynier,^ in his latest sulphuric acid cell, has endeav-
ored to so construct the elements as to permit them to
expand or contract during charge or discharge, without
damage to themselves. To accomplish this, the plates
are separated by porous sheets of silica, which, he
found, only slightly increased the internal resistance.
Each element contains one positive and two negative
plates, and four sheets of silica, the end sheets being
fluted to increase the available space for the electro-
lyte. The containing vessel is made of pure lead, sur-
rounded by an expansible corrugated case. The plates
themselves are made from a very fine lead wire net,
slightly compressed into the desired shape.
In the latest type, the cells are composed of a num-
ber of elements in series, placed between two rigid end
1 B. P., 15,120; 1892. « A. P., 438,827; 1890. F. P., 181,698; 1887.
8o THE STORAGE BATTERY
pieces, which are drawn together by means of strong
india rubber springs. Owing to the action of these
springs, expansion and contraction of the elements can
take place freely without causing disintegration.
BARBOUR-STARKEY
Mr. Barbour-Starkey ^ simply makes the cells of the
ordinary form solid by filling in the space between the
plates and the cell with a dry mixture of sawdust and
plaster of Paris, in the proportion of 25 : lo, and then
saturating the mixture with dilute sulphuric acid. A
non-resinous sawdust is found to be the best. Mr.
Barbour-Starkey claims that this method of treating
cells will effectually prevent all warping and buckling,
and will preserve the plugs of active material from
being detached. Recently a battery of E.P.S. traction
cells were treated in this way, and then put to regular
work. A loss of current capacity and general ineffi-
ciency was experienced, and the . battery had to be
ultimately abandoned.
OERLIKON
In this cell, brought out by Dr. Schoop,^ the amount
of active material on the grids is only about two-thirds
as great as in the ordinary type. In the manufacture
of the electrolyte, dilute sulphuric acid, specific gravity
1.250, is mixed with dilute sodium silicate, specific
gravity 1.180, in the proportion of 3:1. When freshly
made, this mixture is quite fluid, but it gradually solidi-
1 B. P., 15,754; 1887: 7619; 1889.
«A. P., 529,199; 1893. B. P., 7719; 1889.
LEAD-SULPHURIC-ACID GENUS 8 1
fies, and in about 24 hours it becomes a hard, jelly-like
mass, having a slightly bluish tinge. When bubbles of
gas are formed, as they sometimes are, they simply
push the gelatine aside and escape. When fully
charged, a small amount of acid is forced out, and
floats on top, the acid being again absorbed during
discharge.
This cell has received some very elaborate tests by
Dr. Kohlrausch, at the Hanover University, showing
very good storage capacity. Dr. Kohlrausch believes
that, by the use of this gelatinous electrolyte, the cells
may be in constant use for two years, giving their full
current capacity, and that they may be used for another
year with excellent results.
PUMPELLY
In this battery^ the grids are placed horizontally.
They are cast with stout legs on one side, so con-
structed as to bear the entire weight of the plate. The
legs also serve as conductors between plates of like
polarity. In building up a cell, the bottom plate is
laid upon a foundation of cellulose, or wood-pulp fibre.
The interstices of the grid are then filled with red-lead
or litharge, according to the polarity of the plate. The
requisite hardness of the active material is obtained by
hand pressure. Upon this plate is placed another
layer of cellulose or fibre, then another grid, packed,
and so on. The cell is then filled with the electrolyte
until the packing is thoroughly saturated, considerable
free liquid being left in the cell.
1 A. P., 416,299; 1889: 442,390-442,391; 1890.
6
82 THE STORAGE BATTERY
THERYC-OBLASSER
In the manufacture of this battery^ a perforated
envelope of celluloid, or similar material, is filled, while
in a plastic condition, with the oxides to be used, a core
of lead-antimony being placed in the centre. The open-
ing is then closed, and the whole is subjected to heavy
pressure. The core is thus protected from all electro-
lytic and chemical action.
THE HESS STORAGE BATTERY
This battery 2 differs from other existing types,
through the employment of a double electrode. In
the construction of the battery, lead plates contain-
ing square perforations are used. These perforations
and one side of the plate are covered with an extremely
porous non-conducting material, composed of quartz
sand, held together by asphalt. Two plates are placed
side by side, about J of an inch apart, with their exposed
lead surfaces facing each other, and so arranged that the
exposed lines, both vertical and horizontal, are half a
space removed from the corresponding lines on the
other plate.
The plates are provided with projecting ribs, and are
cemented around the edges, thus forming a pocket for
the introduction of the active material. The elements
are then assembled, the double electrode representing
one element. Hard rubber strips, with buttons at
1 A. P., 500,978-502,643; 1893. B. P., 5059-24,834; 1895.
a A. P., 525,017-525,018; 1894.
LEAD-SULPHURIC-ACID GENUS 83
intervals of 2 inches, are used as separators, leaving a
clearance space of | of an inch between the electrodes.
The assembled elements are now placed in the con-
taining cell, and the electrolyte is introduced, after
which they are ready for the introduction of the active
material. This is accomplished by means of an appli-
ance called a conveyer. The conveyer forces the active
material into tubes or conductors, which register with
the pocket of each electrode. The internal resistance
of this battery, as obtained by Houston and Kennelly,
varies from 0.0038 to 0.008 ohm.
The manufacturers claim for this battery, that it is
the only one in which there are no exposed metallic
surfaces ; that the conducting plates are protected from
consumption ; that there is no possibility of the active
material becoming disintegrated and falling out; that
the active material obtains a degree of porosity impos-
sible with other batteries; and that buckling or warping
is absolutely prevented. In a cell containing 15 plates,
each 9 inches square, the total surface for each elec-
trode is 7.875 square feet.
THE ACME BATTERY
In this battery, which was brought out by Kennedy
and Diss,^ each plate consists of a thin, slotted sheet of
rolled lead, which is covered on both sides with active
material. The active matter is held in place by per-
forated plates of insulating material, placed on each
side of the plate. Bolts at the corners hold all the
elements together.
1 A. P., 482,043-482,044 ; 1892.
84
THE STORAGE BATTERY
GULCHER
Giilcher ' uses a frame of parallel lead wires, around
which he weaves elastic glass wool, the method of
weaving resembling that of a wicker basket. The
active material is held in a finely divided state on the
lead wires by means of the glass wool. The plate is
saturated with a concentrated solution of lead acetate
and dilute sulphuric acid, and is placed between zinc
plates, covered with filter paper, and placed obliquely
AS
ts
o
&0
1.8
^^
-.
/
1
J
/
t
y
_^
__
...-
^
IIJ^
•^
/^
^
._
Oifl
cha
X«
— ^
^
HOURS
Fig. 67.
in salt water or very dilute muriatic acid for forming.
His patent reads : electrodes for electric accumulators,
comprising a fabric made of lead threads as warp^ and
glass or quartz threads as woof a frame of lead, and a
covering of spun glass.
These plates were tested for traction purposes by two
large German firms, and it was found after three months
of hard usage that the plates were uninjured and their
1 B. P., 6947 ; 1894. A. P., 562,396 ; 1896.
LEAD-SULPHURIC-ACID GENUS 85
capacity unchanged. Fig. 67 shows a curve taken
from a 40 A. H. cell charged with a constant current of
7.4 amperes and discharged through a constant resist-
ance. The average discharge current was 7.58 amperes.
KOWALSKI
The Kowalski, or I. E. S. plate, which is manufac-
tured by the International Electric Storage Co. (Ltd.), of
London, consists of a perforated envelope of celluloid,
in which is placed an electrode consisting of a number
of antimonous lead wires. The space between the elec-
trode and the envelope contains paper pulp and pulver-
ized oxides of lead. These are soaked in an electrolyte,
whose composition is kept a secret. The liquid is
absorbed by the powder, and after the electrode has
been immersed for 24 hours it is removed and dried,
and is then a compact mass. This battery is used on
50 cars on a French railway for lighting.
RIBBE
This grid^ consists of a sheet of rolled lead -^
of an inch thick, with elongated perforations. It
is coated on both sides with active material, which fill
the perforations and make a uniform layer. The grid
is then covered on both sides with ribs of celluloid of a
conical cross-section, about 4 mm. in breadth, so as to
divide the surface of the plate into long narrow rec-
tangles.. Each pair of adjacent ribs on opposite sides
of the grid are cemented by acetone solution at inter-
1 A. P., 553,596 ; 1896.
86 THE STORAGE BATTERY
vals through holes in the grid. In order to further
secure the active material in close contact with the grid,
finely perforated plates of celluloid are cemented to the
free surface of the ribs. Each plate then consists of a
continuous lead core, a layer of active material on each
side, and a close fitting cover of perforated celluloid,
which is strengthened at intervals by vertical ribs, the
ribs being cemented together through the grid.
HASCHKE
This plate is made from chemically pure sheet lead,
perforated with holes J of an inch in diameter and ^ of
an inch apart. The plates are first slightly disintegrated
by chemical action, and are then pasted with the active
material. The positive plates are about three times as
thick as the negative plates. Each positive plate is
enveloped by specially prepared insulating material.
The plates are then assembled and enveloped by stout
rubber bands, the plates being separated from each
other only by the thickness of the insulation (^ inch).
The positive plates rest on the bottom of the containing
cell, the negatives being held J inch above the bottom
by the compactness of the elements.
The insulating medium of this battery is specially
prepared cardboard, subjected to an electro-chemical
process. Certain chemicals, the composition of which
is a secret, are decomposed by electrolysis in a contain-
ing vat, and the gases therefrom rise and saturate the
insulation. A current of 35 amperes at 20 volts is used
to vaporize or treat 45 sheets of this board, each sheet
LEAD-SULPHURIC-ACID GENUS
87
being 26 inches by 16 inches in size. In Fig. 68 are
given some interesting curves, A being taken from a
250 A. H. cell, and B and C from a 100 A. H. cell.
The curve C was obtained during the burning of a
|-inch hole through a 2-inch sheet of steel.
In 1897 Mr. Haschke overhauled the old New York
Accumulator Co.'s cells in the family residence and
8.7
2.6
2.5
2.i
2.S
{2 2.2
-J
O 2.1
2.0
1.9
1.8
1.7
1.6
1.5
hi
c
^"^
^^
\,
u
\
s
w
\^
v
V
\
\,
\
\
\,
v\
>»^
\
\
\
\
^
\^
V.
\
^*>s
s>^_
^
^,
\^
A
^v.
B ^
C
1
8
3
* ^'
K~"
6
7
8
9 10
Curve A Time in Hours
Curve B Time in Minutes
Curve Time in Seconds
Fig. 68.
hotel of Mr. Potter Palmer, of Chicago. The small
amount of active material remaining in the cells was
removed; and after the plates had been subjected to
heavy pressure they were repasted, and the positives
were wrapped in the insulating material just described.
The plates are now in excellent condition, and are be-
lieved by many to be better than when new.
88 THE STORAGE BATTERY
3. Devices for Securing Better Contact
BRUSH
In his patents, Brush ^ specifies the use of pressure
sufficient to "weld the packing mass" to the sup-
port plate. In the manufacture of his battery, spongy
lead is deposited electrolytically before the applica-
tion of the active material. A current is afterwards
passed, thus forming a coherent mass of the active
material and the support plate.
TUDOR
In the Tudor 2 element, the plate is first oxidized,
either wholly or in part, before the application of the
active material. This method has the advantage that
the plate itself supplies active material to replace that
lost in the cell.
PAGET
In the method brought out by Dr. Leonard Paget,*
and used by the MacReon Storage Battery Co., fused
lead oxide is subjected to the action of a reducing agent,
such as carbon mixed with nitre. This reducing agent
is placed in the mould in such a manner that when the
fused substance is poured in, metallic lead is produced
by the reducing agent, thus giving a perfect union
between the active material and the support plate.
1 A. P., 262,523; 1882: 264,211; 1882. 3 A. p., 413,112; 1889.
» A. P., 397,607; 1889.
LEAD-SULPHURIC-ACID GENUS 89
VARIOUS METHODS
In addition to the three methods mentioned above
might be given those due to James,^ PoUak,* and Grout,
Jones, and Sennet.*
1 Vide ptge 50. « Vide page 63. » G. P., 21,376.
CHAPTER IV
I. The Prevention of Buckling
RECKENZAUN
These plates ^ are formed of tubes made from porous
compressed active material (see Fig. 69). The tubes are
placed in a mould, and
pure molten lead is poured
around them to form a
plate \ of an inch thick.
The space between the tube
is -^ of an inch, the diam-
eter of the tubes being ^
of an inch, and their length
1 1^ inches.
In another form of plate ^
an arc is passed between
the plates and an arc car-
bon, thus transforming the
surface of the plate into
peroxide to any desired
depth. By this method an
amount of chemical combi-
nation is produced in a few
minutes that it would take days to produce by the slow
process of electrolytic action. It has been found that
1 A. P., 385.200; i888- * A. P., 475.797; 1890.
90
Fig. 69.
THE PREVENTION OF BUCKLING
91
when the oxides are formed in this manner they do not
show any disposition to scale or fall off when placed in
an acid bath, or when subjected to electrolytic action.
The object in view in both of these methods is to pro-
duce a plate whose expansion will be in the direction of
the axis rather than at right angles to it.
HERING
This battery ^ contains but four elements, two positives
and two negatives, as in Fig. 70. The two outer plates
are composed of solid blocks
of lead peroxide, and the two
inner ones of spongy lead.
The peroxide plates are made
by mixing dry powdered lead
peroxide, minium, and lead
carbonate or sulphate, with a
solution of acetate of lead to
a stiff paste. The paste is
then pressed into a mould and
allowed to dry. Plates of con-
ducting material are placed
against the flat sides of these
porous blocks. Perforated
strips of non-conducting ma-
terial pass over both sides of
the electrodes, thus securing
good contact between the conducting material and the
porous blocks, and at the same time securing the ele-
ments against short circuits.
1 A. P., 429,272-429,273-429,274; 1890.
p-^ ;-■ r-:j
1 L' ■ ■ ■
" ■ +- ■ -
:•- 1.
j 1
1 I :.
i i ■ ■
1 '■ .■
■1
Fig. 70.
92
THE STORAGE BATTERY
Instead of using the usual sulphuric acid electrolyte,
Mr. Hering prefers sodium or potassium sulphate in the
acid. By this means the local action is greatly reduced.
This battery, although not on the market, is an excel-
lent one, the buckling or warping being almost entirely
stopped.
THE BLOT ACCUMULATOR
This plate, the invention of M. G. R. Blot,^ is of the
Plants type, and contains no pasted oxides whatever.
Each plate is made up of several longitudinal coils of
lead ribbon (see Figs. 71 to 75), the planes of which are
perpendicular to that of the plate. The windings of
these coils are alternately of embossed and corrugated
lead ribbon wound round a shuttle, and so fixed as to be
free to expand. The thickness of the ribbons and the
shuttle varies according to the capacity of the cell and
the rate of charge or discharge required. Only the
lower ends are soldered to the frame. The plates are
suspended in a somewhat complicated frame, in which
they rest on glass, and nowhere do they touch the bot-
tom of the cell.
The manufactures claim: (i) the maximum electri-
cal surface obtainable, the surface being one-third of a
square meter for each kilogramme of plate ; (2) rapid
charge and discharge, the cells being able to stand a
rate of 18 amperes per kilogramme of plate, and hav-
ing been charged at constant potential in one hour;
(3) absolute immunity from buckling, even on short
circuit ; (4) absolute and efficient conductivity between
1 A. P., 535,885; 1895.
THE PREVENTION OF BUCKLING
93
the frame and the active material; (5) durability and
low first cost.
MONTERD
In this battery, the plates consist of concentric cylin-
ders, one side of which is grooved, and contains the
active material.
94
THE STORAGE BATTERY
2. The Preparation of Active lliaterial
SORLEY
Sorley ^ prepares his active material by taking a lead
oxide, treating it with sulphuric acid to produce expan-
sion, and afterwards drying with heat.
This, it may be noted, is the usual method of prepa-
ration.
HOUGH
Hough 2 prepares his active material as follows: a
mixture of dry monoxide of lead and sulphate of mag-
nesia is first formed ; this is reduced to a paste by mix-
ing with ammonium sulphate and water. The plates
are coated with the paste, after which the magnesium
sulphate is eaten away.
SILVEY
In one of his batteries Silvey^ uses for the negative
plate a paste composed of a low oxide of lead, finely
divided metallic lead, and superficially oxidized parti-
cles of metallic lead, and water; for the positive, sul-
phuric acid and water, a high oxide of lead, finely
divided metallic lead, and superficially oxidized parti-
cles of metallic lead.
KRECKE
In a note in the Elektrotechnischer Anzeiger,^ it
was stated that Krecke has succeeded in producing
a very hard mass by mixing lead oxide with tannic
1 A. P., 419,728-423,091; 1890. 2A. p., 512,283; 1894: 535»54i> 1895-
» A. P., 538,628 ; 1895. * E. W., Vol. 28, p., 733.
PREPARATION OF ACTIVE MATERIAL
95
acid and albumen of glue, or by mixing lead oxide
with uric acid.
THE ENGEL SYSTEM
For the positive plate,^ litharge is mixed with sul-
phate of magnesia, washed grease, and hydrochloric
acid. For the negative plate, litharge is mixed with
calomel, or bisulphate of mercury and ammonia. These
materials are applied to the plate and hardened by im-
mersion in water for several days. The plates are then
formed in a solution of common salt, after which they
are used in the ordinary sulphuric-acid electrolyte.
SCHAEFER-HEINEMAN
These manufacturers ^ make a paste of glycerate of
lead, mixed with certain fatty acids; this is applied
to a plate of the grid form. The positive plates are
formed in an acid bath containing potassium perman-
ganate/ with a current density of 19 to 25 amperes
per square metre. The negative plates are formed
more slowly in an ordinary acid bath, without the
addition of the potassium permanganate.
GELNHAUSEN
In the Gelnhausen or "lead-dust" accumulator, the
active material consists of lead-dust and powdered
pumicestone, thoroughly mixed and moistened with
water. As this material shows a decided tendency to
set, the pasting must be done quickly.
1 B. P., 16,162; 1894. 2 G. P., 80,420-82,787-82,792; 1894.
96 THE STORAGE BATTERY
GRUENWALD
Gruenwald makes his active material by mixing pul-
verized lead with linseed oil and borate of magnesium,
formation changes the oil into a resinous substance,
which constitutes the binding material.
CHAPTER V
BATTERIES IN WHICH ONE OR BOTH ELECTRODES
ARE OF SOME OTHER METAL THAN LEAD
II. — Lead-Copper Genus
The advantages peculiar to accumulators of this type
are that they are easy and economical of construction,
and that they keep their charge fairly satisfactorily.
The voltage, however, is low, averaging about 1.25, and
the capacity per unit of weight small. These batteries
are not used in commercial practice, and are of little
interest save for laboratory purposes.
REYNIER
Reynier used an ordinary lead cell in which the
electrodes were placed horizontally, the electrolyte be-
ing composed of copper sulphate.
MASON
Edward J. Mason ^ used metallic plates containing
lead peroxide for the positive and iron plates coated
with copper for the negative electrode. The electro-
lyte was copper sulphate in a solution containing free
sulphuric acid.
SUTTON
In this battery a copper containing-vessel served as
the negative electrode ; the positive electrode was amalr
lA. P., 439,324; 189a
H 97
98 THE STORAGE BATTERY
gamated lead, and the electrolyte was copper sulphate.
As might have been foreseen, the copper vessel was
soon eaten away. The electrodes were separated by
wood.
ERVING
The cathode of this form of cell is of copper, con-
nected to a sheet of zinc, and placed outside of a porous
cup. The anodes are of lead with 2% of silver, placed
inside of the porous cup. A paste of lead peroxide and
aluminum is packed between the porous cup and the
lead. The electrolyte consists of ammonia and acid
bisulphate of mercury.
III. Lead-Zinc Genus
Wheatstone, in 1843, appears to have been the first
to have advocated the use of zinc instead of spongy
lead for the cathode. Since then many investigators
have taken up the problem, and have introduced sec-
ondary batteries of this kind. These have attained
considerable prominence of late years, and are in com-
mercial use to-day, although it is extremely doubtful if
they will ever supersede the lead-sulphuric-acid genus
in engineering work. By the use of zinc and lead
peroxide, it was found that the E.M.F. was increased,
but that new difficulties were introduced, principal
among which was the eating away of the zinc by the
electrolyte. Reynier has found, however, that if the
zinc be either chemically pure, or thoroughly amalga-
mated, local action is reduced to a minimum. The
construction of the lead-zinc cell is economical, and it
is the lightest, theoretically, of all types. The capacity
LEAD-ZINC GENUS
99
in watt-hours per pound of working substance, is, ac-
cording to calculation, 57% higher than in the case of
the lead-sulphuric-acid batteries.
BOETTCHER
In 1882 Emile Boettcher^ constructed a cell with
thin corrugated lead sheets for the positive and ordi-
nary zinc plates for the negative electrode. The lead
plates were covered with a paste of lead oxide moistened
with zinc sulphate, the electrolyte being zinc sulphate,
I : 3. The E.M.F. was 2.2 volts.
REYNIER
M. Emile Reynier, in 1883, constructed a battery with
four peroxide of lead plates of the Plants type for the
positive, and three smooth sheet-lead elements, covered
with chemically pure electrolyzed zinc, for the negative
electrode, in an electrolyte of zinc sulphate. The total
area of the positive active surface was 200 sq. dcm., and
that of the negative 1 50 sq. dcm. The total weight of
the cell was 17.16 kg., that of the elements being
9.6 kg. His cell gave 152 ampere-hours at a 6-hour
rate, the average internal resistance being .02 ohm.
The formation required 2CX) hours.
BARKER
In this accumulator amalgamated copper and zinc
plates riveted together are used for the negative elec-
trode, and leaves of lead foil, coated with graphite and
clamped together, for the positive. An acid solution of
1 G. P., 21,174; 1882: 23,916; 1883.
lOo THE STORAGE BATTERY
zinc sulphate forms the electrolyte. A minimum of
local action is claimed for this battery.
LUGO^
In the Lugo cell a negative plate of zinc, coated with
a lead oxide, and a positive plate of lead, also coated
with a lead oxide, are used in a solution of borate of
ammonium.
EPSTEIN
Ludwig Epstein^ sets the cathode in rotation during
charge and discharge. His cathode consists of zinc
amalgam, on a copper wire net, which is fastened to a
conducting shaft. The anode is lead peroxide.
TAMINE
Tamine* places lead and zinc electrodes, similar in
form to Plants plates, in a solution of looo parts of
concentrated zinc sulphate, 500 parts of sulphuric acid
(10%), 40 parts ammonium sulphate, and 50 parts of
mercuric sulphate. In constructing the anodes, 20
parts of electrolytic lead peroxide, 75 parts of lead
filings, and 5 parts of resin are cemented together
under a pressure of 300 atmospheres.
THE RIVER AND RAIL SECONDARY BATTERY
In this accumulator, which was brought out by Main *
and Meserole,^ the positive electrode consists of a num-
ber of thin lead plates, fastened by lead rivets to thicker
» A. P., 458424-458,425; 1891.
« A. P., 543,680; 1895. ' B. P., 12,824; 1884.
: * A. p., 359,934; 1886:401,289-401,290-401,291; 1889.
*A. p., 359,877-361,660; 1886: 381,941; 1887.
LEAD-ZINC GENUS
lOI
outside lead plates, all the plates containing a number
of fine holes. These plates are formed in the usual
Plants manner; that is, by electro-chemical action.
The negative plate consists of zinc amalgam, deposited
electrolytically on a tray-shaped copper plate. These
plates are made in a U form, the positive plate being
hung within, and separated from the negative by a hard
fi a 7 8
HOURS DISCHARGE
Fig. 76.
rubber ring. The electrolyte contains zinc sulphate and
mercuric sulphate. In an older form, the plates were
placed horizontally.
Fig. y6 shows a curve taken from one of these
batteries, which contained 14 plates, and was built
especially for traction purposes. The weight of the
cell was 45 pounds, and that of the plates 27
pounds.
I02 THE STORAGE BATTERY
IV. Alkaline-Zincate Genus
LALANDE AND CHAPERON
This cell, which is known both as the Edison-Lalande
and Lalande-Chaperon ^ accumulator, has copper oxide
as one electrode, and almost anything that can be plated
with zinc for the other; the electrolyte being either
caustic potash or caustic hydrate. Although it is claimed
that almost no local action takes place, it has been found
that the zinc is actually dissolved in the solution.
Opperman gives the following method for making a
very cheap copper oxide electrode. He immerses car-
bon plates in a saturated solution of copper nitrate for
a short time, and then dries them. This operation is
repeated until the plates are thoroughly saturated.
They are then carefully dried and heated, slowly at
first, until the copper nitrate is changed into copper
oxide. Care must be taken that the copper oxide is not
reduced to copper. These plates, he claims, are very
porous, and consequently very active. They may be
regenerated by washing with water, and air-drying for
several days. With these plates, the voltage, according
to Mr. Opperman, is 1.2 as against 0.8 for the ordinary
electrodes.
THOMSON-HOUSTON
The Thomson-Houston 2 accumulator consists of a
glass vessel which is divided into two sections by a po-
rous diaphragm placed horizontally. In each section is
placed a copper electrode parallel to the diaphragm,
1 B. P., 1464 ; 1882. 2 A. P., 220,507; 1879.
ALKALINE-ZINCATE GENUS
103
and the cell is filled with a saturated solution of zinc
sulphate. The capacity of this cell is claimed to be
independent of the extent of surface of the electrodes,
and only dependent upon the mass of the material to
be acted upon. The process of charging might be
described as the working of a gravity battery backwards.
Zinc is deposited and copper goes into solution as cop-
per sulphate under the action of the charging current.
The duration of the charging action is only limited by
the amount of zinc sulphate present, and by the thick-
ness of the copper element. When ready for use, after
charging, this cell constitutes a copper-zinc gravity
battery.
DESMAZURE
This type of cell was first experimented upon by
Lalande before he became identified with the Lalande-
Chaperon battery. He did not, however, obtain any
practical results. Desmazure^ then took up the prob-
lem, and with the aid of De Virloy, Commelin, and
Baillache succeeded in producing a secondary battery
which gave fair results, but which, for various reasons,
was not a commercial success. The problem of pro-
ducing a commerci^ copper-zinc storage battery was
finally taken up by Philip and Entz, who produced the
cell now known as the Waddell-Entz accumulator.
In the Desmazure battery, copper mud, compressed
into blocks, covered with brass gauze, and placed in a
parchment envelope, is used for the positive, and iron
gauze for the negative element. This copper mud is
^ A. P., 345,124 ; 1886 : 402,006 ; l£
104
THE STORAGE BATTERY
formed into blocks under a pressure of about looo
atmospheres ; a very porous block of copper, of about
two-thirds the specific gravity of sheet copper, being
the result. The containing chamber is thin tinned sheet
steel. The resistance of i sq. dcm. of electrode surface
is about 0.35 ohm. The solution usually employed is
composed as follows:
Water looo.o parts.
Zinc 144-67 parts.
Combined potash 200.82 parts.
Free potash 313.72 parts.
In the Waddell-Entz ^ battery the positive element
is composed of copper wire gauze, surrounding finely
divided copper, and enclosed in cotton bags. The nega-
tive plates are a network of fine iron wire, on which the
zinc is deposited. By heating the cells to a temperature
of 86° F., while charging, it was found that the copper
oxide was not dissolved.
While charging, zinc is abstracted from the solution,
and deposited upon the negative plates. At the same
time oxygen is developed, uniting with the positive
element, and forming a copper oxide. During the dis-
charge, the reverse action occurs. Zinc from the nega-
tive element reenters into solution, and oxygen is
abstracted from the copper oxide, till at length the
couple becomes quite inert. It is claimed that the
plates do not lose mechanical strength by the repeated
chargings and dischargings.
1 A. P., 42 1 ,9 1 6 ; 1 890 : 440,023-440,024 ; 1 890 : 46 1 ,823-46 1 ,858-
467,573; 1891: 425»26o; 1892.
ALKALINE-ZINCATE GENUS
BOETTCHER ^
105
On the bottom of an iron containing-vessel, but insu-
lated therefrom, is placed a zinc plate. About this is a
heavy layer of potassium solution in zinc oxide. A
block of porous copper oxide, serving as the anode, is
soldered to the iron vessel. The electrolyte is a 50%
solution of potassium hydroxide saturated with zinc.
As the zinc is taken from the above layer, the copper is
raised. The E.M.F. is i.i volts, and the internal resist-
ance 0.5 ohm.
scHOOP 2
The anode consists of 64 vertical copper rods, 8 mm.
in diameter. The two ends are provided with a cover-
ing of magnesia, the bottom covering serving to insulate
the electrode from the containing-vessel, and as a sup-
port for the surrounding diaphragm. A parchment
paper, or cotton-wool envelope, is fastened to the mag-
nesia rods by cotton-wool threads. The steel contain-
ing-vessel is divided into 64 square cells, by steel plates.
In these stand the copper rods, their tops being con-
nected to a copper plate. Zinc is deposited on the steel
sheets. The containing-vessel, together with the ziiic
deposit, serves as the cathode. .
V. Miscellaneous Types
THE MARX LIQUID BATTERY
In this battery ^ the energy is stored, not in the elec-
trodes, as is customary, but in the electrolyte itself,
1 G. P., 57,188; 1890. « B. P., 7711; 1893. • A. p., 440,175; 1890.
I06 THE STORAGE BATTERY
which is, therefore, termed electroline. The electrodes
are ordinarily of carbon, 2 negatives to i positive. The
electrolyte, or electroline, is made up as follows :
Perchloride of iron 450 grammes.
Water 900 grammes.
Hydrochloric acid 500 grammes.
The passage of a current between the plates causes
the liquid to assume a greenish tint. It then turns
yellow, and, finally, a yellowish brown. When the cell
is fully charged, which is indicated by the color of the
liquid, the electrodes are removed. In order to dis-
charge the cell, it has been found best to use electrodes
of varying conductivity, such as zinc or iron, in conjunc-
tion with carbon, iron being usually employed in prefer-
ence to the charging electrodes. When a highly porous
carbon block is placed in the electroline, between the
two metallic electrodes, and the outer circuit is com-
pleted, the liquid decomposes, passing through the same
series of colors, but in the reverse order, that it does
during the charge.
PLATNER ^
Zinc and carbon plates are placed horizontally in a
concentrated solution of pure ferricyanide of sodium.
When the cell is discharged, a pulverized coating of
ferrocyanide of zinc is formed on the zinc plates, and
the solution is reduced to ferrocyanide of sodium. The
reverse action takes place during charge.
1 G. P., 81,494-82,100; 1886.
MISCELLANEOUS TYPES
107
HAID^
Iron electrodes, covered with tin or lead, and having
apertures for the reception of the active material, are
used. The active material is formed of Prussian blue
and oxide of lead, a suitable covering being placed over
the electrodes in order to retain the active material.
BASSET
In this cell ^ each electrode is formed of carbon, cov-
ered with peroxide of iron and wrapped in blotting-
paper, and the electrolyte is a solution of protochloride
of iron. The containing-vessel is lined with a mixture
of wax, paraffin, and pulverized colcothar.
TAULEIGNE
Tauleigne uses carbon in a porous cup as the negative
electrode, lead chloride being packed firmly around the
carbon. Carbon also surrounds the porous cup, thus
serving as the positive element. The electrolyte con-
sists of a 60% solution of protochloride of iron.
KALISCHER
In 1885 Dr. Kalischer^ brought out a cell which was
intended to overcome the usual disadvantages of lead
accumulators. As an anode, he used iron, and as a
cathode amalgamated lead. The electrolyte was a con-
centrated solution of nitrate of lead. The iron resisted
the corroding action of the solution. The E.M.F. of
the cell was 2 volts.
1 A. P., 271,628; 1883: 294,464-296,164; 1884.
« A. P., 306,051; 1884. 8 A. P., 311,007-311,008; 1885.
I08 THE STORAGE BATTERY
MALONEY
The electrodes of a cell described in a patent issued
to J. F. Maloney,^ in 1883, are composed of black oxide
of manganese and carbon, the electrolyte containing
ammoniacal salts.
HOLLINGSHEAD ^
The positive plate of this cell is composed of dioxide
of manganese, and the negative plate of iron or steel.
The electrolyte is composed of water containing an iron
salt, which, on decomposition, deposits an insoluble com-
pound on the negative and a soluble compound on the
positive plate.
LEHMAN
Lehman ^ places commercial barium superoxide, in a
soft paste, on his plates, the electrolyte being a solution
of barium chloride, barium bromide, barium iodide, or
such an acid as will produce an insoluble, or nearly
insoluble, barium salt, (as nitric acid (.?), sulphuric acid,
or phosphoric acid).
DARRIEUS
According to some German patents granted to Dar-
rieus,* spongy antimony plates are used for the negative
and lead peroxide, or oxidized antimony, for the positive
electrodes, in a dilute, sulphuric-acid electrolyte. The
advantages claimed are : that sulphate is not formed on
the negative plates from local action, that the mechani-
cal strength is greater, and that the weight is less than
is the case with ordinary lead elements.
1 A. P., 271,880; 1883. « G. P., 70*708-72,199; 1893.
« A. P., 422,126; 1890. * G. P., 8i,o8a
CHAPTER VI
THEORY OF THE STORAGE BATTERY
Although much has been accomplished in the direc-
tion of the practical development of the storage battery,
during late years, and much valuable information has
been obtained, yet, at the present day, very little as
regards the precise chemical reactions which occur
have been definitely settled. E. J. Wade^ says: "It is
probably for this very reason that storage cells are
still so far from practical perfection, as compared with
dynamo electric machinery, and other apparatus in
whose development theory and practice have gone hand
in hand.'* It should be remembered, however, that the
chemical problems to be solved are exceedingly difficult.
Dr. Frankland^ called attention to this fact during the
discussion of Professor Ayrton*s paper on the " Chem-
istry of Secondary Batteries."
"The physical qualities of the cells are capable of
very accurate estimation and investigation. But when
you come to attempt to ascertain the chemical changes
that occur in the charging and discharging of a storage
cell, you encounter formidable difficulties. The outsider
has no idea of these diffibulties. Nothing seems more
simple than to determine the chemical changes that take
1 London Electrician, Vol. 33, p. 625.
2 London Electrician, Vol, 26, p. 177.
109
no. THE STORAGE BATTERY
place in either the positive or the negative plate of a
storage battery. It is not so in reality. The substances
used as active materials are in the first place mixtures,
and the materials obtained at the end of the reactions
are also mixtures, and these mixtures are insoluble in
any reagent which does not decompose them. They
cannot be volatilized ; they cannot be subjected to any
process of solution and crystallization in order to separate
and purify their elements.*'
The general theory of the storage battery is almost
identical with that of the primary battery. It is subject
to the same general laws, and is coupled up in the same
way as the ordinary voltaic cell, and when charged, it
becomes simply a primary battery. It, however, pos-
sesses this immense advantage, in that when used up,
its component materials can be brought back to nearly
their original condition by passing a current through
the cell.
The general theory of the storage battery may be
briefly stated as follows: During the discharge, both
electrodes are converted into lead sulphate, with the
extraction of sulphion from the electrolyte, thus reducing
the density of the solution. The action on the positive
plate is supposed to take place in two stages : first, the
reduction of the peroxide to monoxide, and then the
conversion of the monoxide into sulphate. On charging,
the action is reversed, the sulphate being converted into
peroxide on the positive and metallic lead on the
negative plate. Many investigators believe that it is
hydrated peroxide of lead (HgPbaOg), rather than lead
peroxide (PbOj), which is formed on the positive plate.
THEORY OF THE STORAGE BATTERY m
Many manufacturers now use lead sulphate as the active
material in pasting both their positive and negative
plates, instead of following the older method of apply-
ing minium to the positive and litharge to the negative
plates. The amount of electrical energy which can be
thus stored by the conversion of the lead sulphate into
peroxide, or hydrated peroxide of lead, as the case may
be, is proportional to the amount of active material
formed and capable of being acted upon.
"Theoretically, the amount of energy which one
pound of lead would generate, if wholly converted into
lead sulphate, could be produced by a quarter of a
pound of zinc or iron, or about half a pound of copper.
Practically, the very property of lead which at present
constitutes its superiority to other metals, that is, the
insolubility of its sulphate, at the same time limits its
efficiency, by reducing the energy obtainable per pound
of metal to a small fraction of the amount theoretically
possible. In the first place, the active material requires
a grid or support of inactive material, which, even in the
best form, will weigh nearly as much as itself, and in
the Plants type may be many times its own weight.
Secondly, under the best conditions, not more than one-
half of the active material is really acted upon, because
the sulphate formed on its surface effectually screens
the inner portions. The combined effect of these two
causes is that not more than 5% to 15% of the weight
of the electrodes is usefully employed." ^
The theoretical value of lead peroxide has been esti-
mated by Plants to be 4.48 grammes for one ampere-
* London Electrician, Vol. 33, p. 605,
112 THE STORAGE BATTERY
hour. A later investigator gives the value as 4.44
grammes per ampere-hour. The former value is prob-
ably the correct one, as the majority of investigators
have obtained that result This gives approximately
100 ampere-hours per pound of active material. As-
suming that the positive and negative plates are identi-
cal, the result would be 50 ampere-hours per pound of
peroxide and spongy lead. Plates of the highest capa-
city do not, however, yield more than 16 ampere-hours
per pound of peroxide and spongy lead. This difference
is due to the fact that all the active material cannot be
used, and that support plates of nearly equal weight
must be employed. Faure has calculated that with a
total thickness of 5 mm., the action penetrates to a
depth of J mm., thus making 80% of the weight dead
weight. With a greater porosity, of course, the per-
centage of dead weight would be much smaller.
Dr. Streintz ^ believes that the chemical energy in an
accumulator is due to the sulphating, neglecting the
secondary reactions, such as the absorption of hydrogen
at the negative plate, the generation of free gases,
and the formation of hydrated lead oxide. This theory
assumes as its foundation that metallic oxides cannot
exist in the presence of free acid. Dr. Darrieus^ has,
however, come to the conclusion that the oxides can so
exist. It has been found that when an acid acts on an
insoluble oxide, the product itself being insoluble, the
action is never complete. He believes that the sul-
phate which is to be found on the positive plate after
discharge is always variable in quantity, and is due
1 Wied. Ann., Vol. 53, p. 698. 2 L'Electricien,. May 18, 1895.
THEORY OF THE STORAGE BATTERY
"3
only to the local action of the acid on the oxide, and
that it is never included in the principal reactions of the
discharge.
If the chemical reactions occurring during the charge
and discharge of a cell were exactly the reverse of each
other, then the E.M.F. of charge and discharge would
be the same. Professor Ayrton^ has found that the
E.M.F. for about two-thirds of the charge is very nearly
0.14 volts higher than that during the corresponding
HA
2JZ
^
^
2.0
1.A
10
20
90 40
AMPERE-HOURS
Fig. 77.
60
70
periods of discharge, and that from this point onwards
the difference continually increases. Even after full
allowance has been made for the internal resistance of
a battery, the E.M.F. of charge is always higher than
that of discharge. Fig. ^^, which is taken from Pro-
fessor Ayrton's paper, illustrates this; curve a shows
the variation of E.M.F. during the charge, and curve b
that during the discharge. Curve b is expressed in rela-
tion to the ampere-hours contained in the cell, the point
at which the discharge is stopped being assumed to cor-
1 Jour. Inst. Elec. Eng., England, Vol. 19, p. 699.
114 '^"^ STORAGE BATTERY
respond to emptiness. It is, in reality, therefore, the
ordinary curve of discharge plotted backwards. These
curves were taken from an E.P.S. cell. The persul-
phuric acid which is the primary product at the positive
electrode during the charge is, according to Wade, the
cause of the high E.M.F. It is now generally believed
that there is no possibility of doing away with the waste
reaction in the formation of persulphuric acid.
It is interesting to note here that Dr. Streintz ^ has
found that the internal resistance of a battery is a func-
tion of the current. For small currents it is higher than
when on open circuit ; while for strong currents it falls,
and becomes less than when on open circuit. The
internal resistance of the accumulator when on open cir-
cuit increases with the number of discharges. Accord-
ing to Schoop, the internal resistance is the smallest
when the cell is about half discharged, after which it
increases, sometimes reaching as high as 15 times its
minimum value. In Fig. 78 are given curves showing
the specific resistance of the acid of a storage cell at
different strengths and temperatures. It will be seen
from these curves, that while an acid, the strength of
which corresponds to the specific gravity 1.250, has the
least resistance, it does not give the highest voltage.
The use of such acid possesses the disadvantage that
during the discharge the specific gravity diminishes, and
consequently the resistance of the cell increases and the
voltage falls.
The largest change that takes place in the electrolyte
is, naturally, an alteration in the degree of concentra-
1 Zeit. fur Elektrotechnik, Nov. i, 1893.
THEORY OF THE STORAGE BATTERY
IIS
tion. "The proper proportion between the active
hydrogen and that which appears electrolytically seems
to bear some relation to the capacity of the plate. It
does not, as Gladstone and Tribe suppose, vary inversely
with the current strength, but it is highly probable that,
for every plate, there exists a current density for which
this proportion becomes a maximum/' i
9
CO
z
o
I-
u
K
O ^
/
1
/ y
k^
^y
.y
^^
" —
LmA
n Electrician,
XXXV, m.
1.000 1.100 1.200 1.900 1.400 1.600
SPECIFIC GRAVITY OF ELECTROLYTE
Fig. 78.
1.000
1.700
According to Duncan and Weigand,^ the principal
defects of the modern lead-sulphuric-acid storage bat-
tery are :
I. Loss of energy.
II. Depreciation.
1 London Electrician, Sept. 4, 1891.^ ^ Trans. A. I. E. E., Vol. 6, p. 217.
Ii6
THE STORAGE BATTERY
III. Comparatively small storage capacity per unit
of weight.
IV. The low discharge rate necessitated by con-
siderations of efficiency and depreciation. The discharge
rate has, however, been so much increased in the later
8.0
2.7
91
~^
X^
?
g
\
\
8.1
"^
^
1J>
\
100 80 ao 40 ao
PER-CENT OF SULPHURIC ACID
Fig. 79.
forms of batteries, especially in those of the Plants type,
that the last objection has practically been done away
with.
The loss of energy manifests itself in two ways :
I. In the generation of heat
THEORY OF THE STORAGE BATTERY
117
2. In chemical reactions which are reversed during
discharge.
It is well known that the voltage of a cell varies
directly with the degree of concentration of the elec-
trolyte. Gladstone and Tribe have found that when
the acid is very weak, the chemical action is changed,
the result on the positive plate being the formation of a
2.8
>-,
■ —
laoo
*"2J8
z
q! 2.1
z
1.9
V
-
---
.-Jig.^^
■^^
XOIMJ
m meetrieian,
Axrr, m»
4 8 12 16 20
INTERVAL IN HOURS AFTER CHARGE
Fig. 80.
24
mixture of yellow and puce-colored lead oxides, while
on the other parts a white substance which is easily
detachable is deposited. Messrs. Gladstone and Hib-
bert have further proved conclusively that the E.M.F.
of a cell does depend, in some way, upon the strength
of the acid employed. Fig. 79 shows the result of their
observations. In Fig. 80 a set of curves is given,
showing the fall of the open-circuit voltage for 2 1 hours
after the completion of the charge, and the influence of
different strengths of acid.
Il8 THE STORAGE BATTERY
In a communication to the American Institute of
Electrical Engineers, in May, 1894, Mr. Griscom states
that the potential of a cell is partly due to the degree
of charge of the positive, partly to that of the nega-
tive plate, and partly to that of the electrolyte. If a
negative plate be taken from a fully charged cell, which
indicates, for example, 2.65 volts with the normal charg-
ing current, and be coupled with the positive from a
partly discharged cell, indicating 1.9 volts at the normal
rate of discharge, it will be found that the resulting
E.M.F. lies between the two. If the couple be removed
to other electrolytes, it will be found that the E.M.F.
will rise or fall according to the greater or less density
of the new solution as compared with the old. From
this it will be seen that the measurement of the poten-
tial difference at the terminals of a cell is not a sure
indication of the charge, unless both plates are equally
charged, and this is a condition which rarely obtains in
practice. It will be found, however, that the variations
of the specific gravity of the liquid are approximately
proportional to the useful capacity of the cell, if we
take account of the local action, the short-circuiting, the
changes in temperature, and the general sulphating of
the positive plates while idle.
The examinations of the characteristic curves of a
cell show very plainly the variations of the E.M.F. It
is found, for example, that, in a storage battery whose
plates are of nearly equal capacity, the changes in the
positive plate determine the characteristic curves of
potential on discharge, and the changes in the negative
those at the end of the charge.
THEORY OF THE STORAGE BATTERY
119
Although, according to the majority of laboratory
tests, an accumulator possesses an energy efficiency
of from 80% to 85%, yet, in commercial practice, an
efficiency of more than 70% is seldom realized. Besides
the regular transmission loss, about 15%, there is a loss
due to leakage, to local action, to the cells not being in
the best condition, and to several other causes which do
not occur in the laboratory tests.
Crosby and Bell divide the losses incurred into four
groups :
1. The direct losses due to heating.
2. The losses due to local action between the sup-
porting grid and the active material.
3. The losses due to local action in the active mate-
rial itself.
4. The losses due to the unreversed chemical action.
It is the last two sources of loss which are generally
the most formidable. Of the losses due to irreversible
chemical actions, a portion is ascribable to the produc-
tion of irreversible chemical compounds, and a portion
to the electrolytic action producing free hydrogen, oxy-
gen, ozone, and hydrogen peroxide. It has been found
that thick grids, with heavy plugs of active material of
corresponding thickness, are the most likely to suffer
from the various losses, except the first, because the
chemical action in a large and dense mass of material
is by no means uniform throughout, and consequently
differences of potential probably occur between differ-
eijt portions of the same plug.
The amount and character of the by-products formed
is very largely determined by the rate of .discharge and
I20 THE STORAGE BATTERY
the working temperature of the cell. During the dis-
charge of a cell, as has been stated, free oxygen, hy-
drogen, ozone, and hydrogen peroxide are formed in
the solution, and attack the plate, without materially
assisting in the discharge. Other and more compli-
cated substances are also produced, — basic sulphates
and the like.
Darrieus ^ has found that an antimony-lead grid and
lead peroxide will give 1.4 volts, and that the potential
difference between an antimony-lead grid and spongy
lead in dilute sulphuric acid is 0.52 volt.
It is a matter of common experience that if an accu-
mulator be discharged slightly, before being allowed to
rest for any considerable length of time, the local action
will be increased. In order to avoid local action, contact
between the conducting grid and the electrolyte must be
avoided. This is accomplished by having an unbroken
layer of peroxide on the surface. A slight discharge
breaks or destroys this layer; hence the increase in
local action. If the materials used in the plates be
pure, the electrolyte also pure and of the proper
strength, and if the conditions favorable to the forma-
tion of persulphuric acid be avoided, local action will
be found to be greatly reduced. According to a test by
Epstein,^ the average loss of charge of several accumu-
lators tested was only about 20% during a period of
three months ; and Sir David Salomons ^ has found that
of some discharged plates, which had been left idle for
four years, the only fault was a bad color. In all other
1 L'Electricien, Nov. 17, 1894. 2 London Elec. Rev., Feb. I, 1895.
* London Electrician, Dec. 15, 1893.
THEORY OF THE STORAGE BATTERY 121
respects they were as good as ever. " He feels assured
that, if the discharge has not been too rapid, no harm
would be done by allowing them to stand for years.
The plates are, however, certain to buckle if they are
not charged in the usual way. A sure method to
prevent this is to brush the positives with a stiff brush,
in order to remove the surface scale, after which they
may be charged, but slowly at first." Gaston Roux^
has also found that if an accumulator of the pasted
type be charged to saturation, and then left on open
circuit, that the local action will be very slight, and the
cell will lose, at a maximum, not more than 6% of its
capacity in three months.
Many investigators, including Messrs. Gladstone and
Tribe, were of the opinion that the local action between
the active material and the support plate in the positive
electrode led to the disintegration of the latter. If this
theory were correct, it would be advantageous to leave
the film of sulphate which covers the grid intact ; and
a battery should never be overcharged, as this would
tend to decrease the film in question. Later investi-
gators have, however, found that the film of peroxide
which is formed on charging from the lead sulphate is
the real protective coating. According to this view,
overcharging is, to a certain extent, beneficial, as it
tends to increase this coating, besides bringing all the
active material into the condition of lead peroxide.
One of the most interesting phenomena in the dis-
charge of a cell is the passing of current from one
plate to another. It has been found that, with plates
1 London Electrician, Vol. 25, p. 754.
122 THE STORAGE BATTERY
manufactured rigorously alike, kept in parallel, and
subjected to the same treatment, the current variations
often amount to more than 30%. It has also been
found that the E.M.F. of different plates of a cell,
connected in parallel and discharged through equal
resistances, will vary from 1.6 to 1.85 volts. This
gives rise to a rather peculiar phenomenon, that of
the exchange of charge. It had been previously held
that if one plate had less capacity than another, that
at a certain point it would cease to discharge ; but that
its E.M.F. would be the same as the rest, and conse-
quently there would be no flow of current. Mr. Griscom
has, however, found that, on breaking the circuit at the
end of the discharge, it was hours before the batteries
reached equilibrium, owing to the considerable flow of
current which passed. He explains this by saying that
"the deficient plate keeps on discharging at a lower
rate than the perfect plate, and finally reaches a much
lower point of discharge. On interrupting the current,
the plate which has not been discharged so completely
rapidly recovers a higher voltage than the other, and
therefore discharges into it. This effect will also take
place in different parts of the same plate, and may be
a cause for the formation of peroxide on the surface of
a negative plate after discharge." ^
Mr. Griscom also found that, when left at rest, the
positive plates in a section will discharge themselves.
Sir David Salomons, in a communication to the Ameri-
can Institute of Electrical Engineers, in May, 1894,
stated that "there are probably two causes for this:
1 Trans. A. T. E. E., Vol. ii, p. 302.
THEORY OF THE STORAGE BATTERY
123
first, the slight leakage which exists in every installa-
tion; and secondly, a leakage in the cell itself, apart
from any local action which may take place in conse-
quence of the material employed in building up a sec-
tion." Many users of the storage battery have found
that the addition of caustic soda, or of sulphate of soda,
greatly reduces the slow automatic discharge.
Indirect evidence as to the nature of the chemical
changes taking place in an accumulator may be derived
from an examination of the curves representing the
variations in the temperature of a cell during charge
and discharge. In both cases, if all the reactions were
absolutely electrolytic, no heat would be generated,
except that due to the internal resistance of the cell.
Any rise in the temperature, therefore, except that
which may be accounted for in this manner, must be
ascribed to wasteful, '* unelectrolytic, heat-producing
action," including local action. Curve a, Fig. 81,
shows the rise in temperature during the charge, and
curve b the fall during discharge. Upon calculating
the amount of heat liberated, to which the fall in tem-
perature corresponded, it was found to far exceed the
internal resistance of the cell, and in fact it was equiv-
alent to 17% of the total amount of energy put into
the cell while charging. Professor Ayrton has found
that the working temperature of a cell is always above
that of the air, even when its temperature is falling in
discharge. In Fig. 82, taken from the same article,
will be found curves representing the rise in temperature,
in degrees per ampere-hour. Curve a represents the rise
during charge, and curve b that during discharge.
124
THE STORAGE BATTERY
As before stated, Duncan and Weigand^ found that
the loss of energy exhibits itself in two ways, one of
which is a generation of heat. This rise in tempera-
ture they found to be due to :
1. The Joule effect.
2. The current set up by local action between the
active material and the support plate.
u
N
V
/
1.1
^
N
/
/
\
v
/
betweer
Cell
5
\
s.
/
s
^1
^^.
/
/
perature
and Idle
^
?
/
/
\
V
/
E-
*"« 0.8
.5 M
c
\
s/
>
A
V
|l0.T
/
\l
^
/
\
Q
0.6
r:^'
^f
\
^
,^
y
OJS
^
0L2345678
Time in Hours from Commencement of
Charge and Discharge
Fig. Si.
3. The current set up by local action in the plugs.
4. The heat losses corresponding to the electrolysis
of the solution.
It has been generally held that the temperature of
a cell varies with the internal resistance, and therefore
1 K»Vj5f page 116,
THEORY OF THE STORAGE BATTERY
125
that the chemical or cooling effect will at times predom-
inate, and at others the PR, or heating effects; and
that for every cell there exists a point where the two
factors wilt balance each other, and beyond which heat-
ing or cooling will ensue. The experiments of Ayrton,
Griscom, and Reckenzaun prove that this so-called law
very seldom holds. In one case, according to Recken-
zaun, the temperature of the cell was at least 4° below
OS
o
C O.
(0 1
2?/
</
10/
^
^
<
7
/ i
'f
/
c
r*^
y
^
10 20 30 M 50 60 70
Ampere - Hours
Fig. 82.
80 90 100 110 120
that of the normal, while the internal resistance was at
least double that of the average. Besides this, the
heating effects cannot vary as the square of the current
since the internal resistance diminishes as the current
increases, and what is still more remarkable, the E.M.F.
itself seems to rise.
The average variation in capacity in a cell whose tem-
perature ranges from 0° to 22^ C. is about one-half of
1% for each degree change in temperature.
126 THE STORAGE BATTERY
Since the tendency of the acid in the electrolyte is to
form sulphate of lead, from both the spongy lead on
the negative and the peroxide on the positive plate, the
generally accepted theory at present is that of the
direct formation of lead sulphate at both electrodes.
Each molecule of the peroxide is supposed to lose an
atom of oxygen, and each atom of spongy lead to gain
an atom of oxygen. Two atoms, or molecules, of
hydrogen sulphate are thus abstracted from the elec-
trolyte to react with the peroxide or spongy lead, and
their place is taken by two atoms of water. The reac-
tion for the positive plate, according to this theory, is,
therefore,
PbOg + H2SO4 = PbSO^ + H2O + O ;
and that for the negative plate is
Pb + O + H2SO4 = PbSO^ + H2O ;
or, including both reactions in one equation,
PbOg + 2 H2SO4 + Pb = PbSO^ + 2 H2O + PbSO^.
Thus the final result of the complete discharge of a
cell is to form lead sulphate and water by removing sul-
phuric acid from the electrolyte and depositing sulphate
of lead upon each plate.
The above is, fortunately, a self-limiting process, since
the sulphate is a poor conductor. All the peroxide is
therefore not acted upon, and at the end of the dis-
charge we have peroxide of lead crystals covered with
a coating of sulphate. It has been estimated that not
more than 50% of the peroxide is converted into sul-
phate.
THEORY OF THE STORAGE BATTERY 127
In Professor Ayrton's paper on the "Chemistry of
Secondary Cells," to which reference has already been
made, the following important conclusions were drawn
by his assistant. Professor Robertson:
1. The particles of the peroxide soon get coated in
the discharge with a layer of lead sulphate, which pro-
tects the peroxide from further action.
2. The analysis also shows that a proportion of active
material still remains at the end of the discharge.
3. The loose, powdery surface of the peroxide plate
seems to be thoroughly converted into lead sulphate.
4. When the peroxide on the surface of the plate
falls to about 31%, the cell very rapidly loses its
E.M.F., owing to the inactive layer of sulphate, which
impedes the action of the sulphuric acid on the active
material beneath ; and also to the formation of peroxide
on the negatives. The diffusivity of the acid is decreas-
ing, and it has to penetrate further and further into the
plate to find the active material. When the whole of
the paste approaches the composition of 31%, the cell
loses its E.M.F. entirely.
5. The action seems to take place most rapidly
where the current density is the greatest; the plate
becoming hard there from sulphate soonest during dis-
charge, and oxidizing there the quickest during charge.
Plant6, and Gladstone and Tribe, have noticed the
formation of lead peroxide on the negative electrode
during the discharge of a battery, and have pointed
out that when it commences to form more rapidly than
it is reduced, the two electrodes will rapidly approach
equilibrium. Since when the circuit is broken local
128 THE STORAGE BATTERY
action alone can take place, the peroxide on the nega
tive plates will be reduced, and on making the circuit
again the cell will once more give a current. In this
way Messrs. Gladstone and Tribe account for the re-
suscitating power of the storage battery, as well as for
the rise of E.M.F. on breaking the circuit.
If the positive plate of a lead secondary battery be
examined microscopically, there will be found soft,
porous crystals of a very dark color, which are proba-
bly electrolytic peroxide. There will also be found
some brilliant red crystals, probably Frank-land's red
sulphate ; also the yellow sulphate crystals, and finally
the well-known white sulphate. The negative plate
will show metallic lead, with one and sometimes two
sulphates. The production of the diverse chemical
products is probably attended by the production of
different potentials, and the final E.M.F. of the bat-
tery must therefore be a resultant with one or more
chemical reactions predominating at various parts of
the discharge.
In Mr. W. W. Griscom's paper on "Some Storage
Battery Phenomena," read before the American Insti-
tute of Electrical Engineers in May, 1894, several very
interesting curves of charge and discharge for both
positive and negative plates were shown. An^ exami-
nation of the curves for the negative plate of a Faure
cell showed at the end less capacity than that for the
positive plate. Within the working limits of charge
or discharge the negative plate did not vary over 2%
of potential difference. The positive plate showed a
fluctuation of about 6%. The total fluctuation of the
THEORY OF THE STORAGE BATTERY
129
cell after the first few minutes was 6% in discharge
down to 1.9 volts.
When a cell is supposed to be fully discharged, it is
often noticed that at least 30% of peroxide is still to be
found in the positive plate. From this it has been
inferred that the negative plate has 30% less capacity
than the positive. In one sense this is true ; but, more
strictly speaking, it is probable that the negatives have
the same capacity as the positives, but discharge 30%
sooner.
It is a well-known fact that a high rate of discharge
is injurious to a battery. Messrs. Duncan and Weigand
have found that when the rate of discharge is too rapid,
acid is taken from the solution inside the plug, thus
weakening the solution, which only gains acid by diffu-
sion from the outside. This diffusion increases greatly
as the capacity is lowered, the acid in the plug becom-
ing very weak, and a phenomenon which was noticed
by Gladstone and Tribe occurring. They found that
at a certain dilution the chemical action changes, and a
new compound is formed in place of the peroxide of
lead ; also that the plate becomes greatly corroded.
In Figs. 83 and 84 will be found curves showing the
capacities per pound of active material for different
specific gravities at the end of the discharge, and cor-
responding curves for the voltage. These were taken
from two Chloride cells, one having thin and the other
thick plates, the rate of discharge for each being 0.45
ampere per pound of plate. The rate per pound of
active material was approximately the same for both,
but the rate per unit of area was nearly 40% greater
K
I30
THE STORAGE BATTERY
for the thick plates. It will be found from an examina
tion of the curves, that the capacity practically varies
inversely as the thickness. Curve a was taken from
plates 0.24 inch thick, and curve b from plates 0.4
inch thick.
After a certain portion of the active material in a
plate has been converted into lead sulphate, further
sulphation is attended with a production of normal
O. Jjl2
11
1 1
O 3
^ CO
<
r
\
1
\
/
\
1
1
^
-\
\
}
/
\
s^
/
f
\
<H
s.
/
s
\
A
B>
'L
^B
UOO 1200 ISOO 1100 1500 IWO
Specific Gravity of Electrolyte
* at End of Discharge
Fig. 83.
white sulphate. At this stage in the discharge,, the
diffusion of the persulphuric acid which remains over
from the last charge, and its decomposition with the
formation of hydrogen peroxide, leads to the produc-
tion of peroxide of lead on the negative plate. The
formation of such a compound on discharge explains
the rapid fall of E.M.F. to be noticed at the close of
the discharging period.
When the discharge is very rapid, sulphation wiU
THEORY OF THE STORAGE BATTJIRY
131
take place rapidly, and the sulphuric acid which is dis-
tributed through the mass of the active material will be,
to a large extent, withdrawn before it can be replaced
by diffusion. It is evident that in such a case the
E.M.F. will fall, and that as soon as diffusion can take
place, a higher E.M.F. will follow. We are able to
explain thus the higher voltage of a cell after a period
of rest.
Before charging accumulators, the positive and nega-
tive plates which have been formed, either by the Plants
UOO 1200 1300 liOO ISOO 1600
Specific Gravity of Electrolyte
at End of Discharge
Fig. 84.
or Faure process, contain a sulphated salt of lead,
usually termed Tead sulphate (PbS04). During the
charge the lead sulphate is changed into peroxide of
lead (PbOg) on the positive plate, and spongy lead (Pb)
is formed on the negative plate. The liberated sul-
phion (SO4), combining with the Hg of the water, in-
creases the density of the electrolyte, and the liberated
oxygen combines to form PbOg. Sir David Salomons ^
has divided the process into three stages, and considers
it as follows : " The first stage indicates the. discharged
cell. The second indicates what might be termed the
.^
^
^A
^B
1
^/^
r"
^
>>
1 Elec. Light Installations, 7th edit., Vol. i, p. 100.
132 THE STORAGE BATTERY
rational change which takes place, though in all proba^
bility a number of equations would be necessary to
represent what really happens between the first and
last stages. In this stage molecules of water have been
taken from the electrolyte, and an equal number of
molecules of sulphuric acid added, thus increasing the
strength of the acid solution. In the third stage — •
the charged cell — the specific gravity of the electro-
lyte may decrease slightly."
Positive.
Electrolyte.
Negative.
1st stage
PbSo^
H2SO4 + H2O
PbSO^
2d stage
PbO
HgSO, + H2O
PbO
3d stege
PbOj
H2SO, + HjO
Pb
Besides this, an additional chemical action takes place
during the charging, gas being given off at the negative,
and when charging is nearly finished, at both electrodes.
Gladstone and Tribe,^ who have investigated the sub-
ject, say : "The principal, if not the only, function of the
hydrogen of the water is that of reducing the lead com-
pounds." Messrs. Streintz and Neuman, arguing from
this fact, claimed that the occlusion of the hydrogen
was the chief factor in the charge of an accumulator.
Strecker has proven, however, that the charge is based
chiefly on the reduction of the sulphate of lead, rather
than on the occlusion of hydrogen.
According to the occlusion theory, the oxygen and
hydrogen, dissociated during the charging, are occluded
at the electrodes, the hydrogen at the negative and the
oxygen at the positive pole ; and these gases on recom-
bining give the phenomena of discharge^ This theory
1 Chemistry of Secondary Batteries, p. 48.
THEORY OF THE STORAGE BATTERY
133
was strengthened by the fact that the activity of the
Grove gas battery was known to be due to the recom-
bination of the gases which covered the electrodes.
According to this theory, the presence of sulphuric acid
in the electrolyte is merely to give conductivity to the
water.
When dilute sulphuric acid is electrolyzed with plati-
num electrodes, the dissociation of hydrogen and oxy-
gen is accompanied by the absorption of energy ; which
energy, less that lost in overcoming the resistance, is
yielded upon the recombination of these gases. The
same E.M.F. which is needed to overcome the affinity
of the oxygen for the hydrogen will be developed when
these gases recombine. An E.M.F. of approximately
1.5 volts is needed for electrolyzing dilute sulphuric
acid. This result could be anticipated from the fact
that 34,180 e.g. calories are liberated when oxygen and
hydrogen combine to form water. According to the
method given by Lord Kelvin for calculating the " volta-
motive-force '* from chemical union, this energy corre-
sponds to 1.492 volts. Since the normal E.M.F. of a
lead-sulphuric-acid accumulator is very nearly 2 volts,
something more than the tension produced by the occlu-
sion of hydrogen and oxygen is necessary to explain
the E.M.F. of secondary cells. Of the hydrogen liber-
ated during charging, only .traces are found at the
negative electrode. Dr. Frankland has also proven
that neither oxygen nor hydrogen is occluded during
charging.
Although Plant6, Dr. Oliver Lodge, and other firm
believers in the occlusion theory had noticed the for-
134
THE STORAGE BATTERY
mation of lead sulphate throughout the active material,
and on the grid itself, they ascribed it to local action.
Dr. Lodge believed that, to obtain the best results, the
amount of acid in the electrolyte should be small. Many
investigators, even at the present day, hold that water
plays the most important part in the primary reactions
of electrolysis.
It is now generally assumed that the acid breaks up
under the action of the current into hydrogen (Hg) at
the negative and sulphion (SO4) at the positive elec-
trode. According to the modern views of electrolysis,
some portion of the hydrogen sulphate in the solution
already exists in a dissociated form as free molecules
of H3 and SO4. As soon as a difference of potential
is set up between them, these molecules are attracted
to either electrode, and their place is immediately taken
by others. If this assumption be correct, it is easily
seen that the water merely serves as a solvent, and as
a medium in which dissociation can take place, rather
than playing a direct part in the process. In 1878
Berthelot discovered persulphuric acid [1^2(804)2], and
showed that it was the primary product at the positive
electrode when dilute sulphuric acid was subjected to
electrolysis. Later Messrs. Robertson and Darrieus,
working independently of each other, obtained the
same result. Their experiments were conducted with
ordinary lead cells in actual use, and under normal con-
ditions. According to the theory advanced after these
discoveries, the freed sulphion, which cannot exist in
a free state, nor, in the case under consideration, enter
into combination with the substances on the positive
THEORY OF THE STORAGE BATTERY 135
electrode, combines with the sulphuric acid, rather than
with the water ; thus:'
H2SO, + S04=H2(S04)2.
It is this reaction which is the cause of the high
E.M.F. which is required to produce decomposition.
"For persulphuric acid is one of those comparatively
rare compounds, termed exothermic, whose formation
is accompanied by an absorption of energy, and which
liberate energy in decomposition. This acid is very
unstable, and almost immediately decomposes at the
electrode, reacting with the water, and passing back to
normal sulphuric acid, with the formation of hydrogen
peroxide, and then of water and liberated oxygen " ; thus :
H2(S04)2 + 2 H2O = 2 H2SO4 + H2O2,
H202 = H20 + 0.
At the end of the discharge the positive plate con-
sists of small particles of lead peroxide, covered with
lead sulphate, the free sulphion combining with the lead
sulphate, forming persulphate of lead [Pb( 804)2] :
PbS04 + S04 = Pb(S04)2.
This reacts with the water, forming lead peroxide, and
normal hydrogen sulphate :
Pb(S04)2 + 2 H2O = 2 H2SO4 + PbOg.
At the commencement of the charge, when there is
a large quantity of lead sulphate present, it is probable
that a very large percentage of the sulphion is absorbed
in this manner, and that only a small part reacts with
the hydrogen sulphate, forming hydrogen persulphate
136 THE STORAGE BATTERY
After a certain point in the charging has been passed,
the latter reaction will increase, because less and less
of the sulphate remains to be acted upon by the sul-
phion, most of the sulphate having been converted into
lead peroxide. When the plate has been thoroughly
peroxidized, and cannot be further attacked, it is prob-
able that the whole of the sulphion goes to form per-
sulphuric acid, with immediate redecomposition and the
liberation of oxygen. From this it would appear that
the difference between the curves of charge and dis-
charge, in Fig. 62, is in reality a measure of the amount
of persulphuric acid formed. Unfortunately, no data
are available that would enable it to be stated in abso-
lute figures.
On the negative plate, nascent hydrogen is liberated,
and exerts a powerful influence on the salts of lead that
are present, reducing them to the metallic state with the
liberation of hydrogen sulphate :
PbSO^ + H2 = Pb H- H2SO4.
When the reduction of lead sulphate is nearing com-
pletion, the surplus hydrogen commences to pass off in
a gaseous state, thus indicating the end of the charge.
From these facts it would appear that there is no
advantage to be gained by continuing the charging
after the hydrogen or oxygen has ceased to be ab-
sorbed freely, because the presence of some unoxidized
sulphate, although it increases the internal resistance,
rather impedes than promotes local action. On the
other hand, it is absolutely necessary that the minium
on the opposing plate should be thoroughly reduced,
THEORY OF THE STORAGE BATTERY 13;
because a mixture of peroxide and metallic lead is
very conducive to the production of lead sulphate,
thus increasing the resistance and diminishing the
E.M.F.
Griscom and Fitzgerald do not, however, believe that
lead peroxide is present on the positive plate, but rather
that the active material consists of hydrated peroxide of
lead. In support of this theory, Griscom^ says :
" The material on the charged positive plate is com-
monly called peroxide of lead, but it certainly differs
from it in its ability to generate E.M.F., and in its
appearance; and Fitzgerald has pointed out that its
composition corresponds to the hydrated peroxide of
lead (HgPbgOg). He further intimates that a higher
oxide, such as perplum'bic acid (HgPbgO^), may be
present. The fact observed by Gladstone and Tribe
that 34% more of oxygen was absorbed by the positive
plate than could be accounted for by the production of
peroxide of lead, becomes, by this means, explicable.
This large percentage of oxygen has probably been
used in converting the hydrated peroxide of lead into
perplumbic acid. Their suggestion that it has probably
been absorbed by local action between the grid and
peroxide is utterly untenable. There is no such action,
and if there were, the grid would not last through a
dozen charges. The conversion of HgPbgOg into
HgPbgOy would account for the abnormal rise of
E.M.F. at the end of the charge, and if it be assumed
that the HgPbgOy is unstable, yielding ozone gradually,
thus accounting for the odor of a freshly charged posi-
1 Trans. A. I. E. E., Vol. 11, p. 302.
138 THE STORAGE BATTERY
tive plate, it would account for the steady fall of E.M.F.
on interrupting the charging current."
As shown above, persulphuric acid diffuses through
the electrolyte, and undergoes decomposition, with the
production of heat, into hydrogen peroxide and normal
hydrogen sulphate ; the hydrogen peroxide being after-
wards decomposed into oxygen and water. That per-
sulphuric acid is formed during the charge, is indicated
both by analysis and by the temperature changes occur-
ring during that period. For the first two-thirds of the
period of charging, the temperature is constant, but
after that it steadily increases. This is exactly what
would be expected ; for, during the first two-thirds of
the charging period, the amount of persulphuric acid
in the electrolyte is nearly constant, but during the last
third of the charge, the amount continually increases,
until a point is finally reached where the persulphuric
acid is decomposed as fast as it is formed.
Although the persulphuric acid theory, which is
practically the same as that advanced by Darrieus, is
the generally accepted one at the present day, Messrs.
Elbs and Schonherr,^ who have investigated the subject,
oppose it. With a specific gravity of 1.300, and a cur-
rent density of 2800 amperes per square metre, they
found that the yield of persulphuric acid was only
24% of the theoretical yield, while with a current
density of 1 300 amperes per square metre, the amount
could only just be detected. They claim that since the
current densities in accumulators are much smaller than
this, the amount of persulphuric acid formed would
^ Zeitschrift fiir Elektrotechnik and Elektrochemie, ^895, pp. 41 7 and 468.
THEORY OF THE STORAGE BATTERY
139
be so small as to have no effect in the production of
the peroxide. According to their experiments, lead and
lead sulphate are not converted into peroxide by solu-
tions of sulphuric and persulphuric acids, no matter
what the concentration. They find that a clean lead
plate in such a solution is rapidly sulphated, without
the formation of peroxide, and that a peroxide plate, in
the same solution, is converted into sulphate with the
evolution of oxygen. They admit that persulphuric
acid is sometimes formed in accumulators, but they
claim that its formation is accidental, and that it is only
a secondary product.
Although these results are important, they seem to
have but little bearing upon the theory of Darrieus. It
must be remembered that the experiments of Darrieus
and Robertson^ were made with lead accumulators in
actual use, and under normal conditions, while those of
Elbs and Schonherr were with platinum electrodes.
That there are only traces of persulphuric acid in accu-
mulators is no proof that it is not a primary product,
since but little is actually known of the products formed
in lead accumulators. There is no method known by
which the potential difference of the electrodes in an
accumulator, as compared with an auxiliary electrode,
may be measured while the current is passing, unless we
except the cadmium plate test of Appleton. Further,
in order to disprove Darrieus' theory, it would be neces-
sary to show, by repeated experiments, that his results
were wrong. Since no proof has yet been given, it is
probable that Darrieus' theory will remain as the gen-
erally accepted one for some time to come.
1 Vide page 134.
CHAPTER VII
APPLICATIONS, — STORAGE BATTERY INSTAL-
LATIONS
Storage batteries are beyond question, to-day, a
commercial part of the central station lighting business,
and an important factor in the regulation at the power
station. As remarked by Mr. A. E. Childs at a meeting
of the American Institute of Electrical Engineers in
1895, "The great variations and fluctuations of the load
on power circuits, especially those power circuits sup-
plying trolley lines, are among the greatest difficulties
which engineers have to contend against, and any appli-
ances that will aid them to arrive at a satisfactory
running of their station is looked upon with favor by
them." Some engineers advocate the use of gas-
engines, and others the use of two classes of ma-
chinery, — one, the most expensive and of a type
giving the highest efficiency obtainable, and the other,
consisting of much cheaper and comparatively inefficient,
although perfectly reliable, machines. A constantly in-
creasing number of engineers, however, believe that in
the use of storage batteries lies the true solution of
this problem.
As an example of how important a part accumula-
tors are playing in central station development, it may
be stated that of 189 new lighting installations in
140
STORAGE BATTERY INSTALLATIONS
141
Switzerland, Sy contain storage batteries. On March i,
1897, of 265 central stations in actual operation in Ger-
many, 77% employ continuous currents, and 80% of
these use accumulators, whose total output is 31% of the
total power of the direct generators of these stations.
The total power represented by the continuous stations
is S9,i6okw., while that represented by the ordinary
alternating current and three-phase stations is 19,087 kw.
Of the 36 central stations belonging to the Association
of Representatives of German Electric Supply Under-
takings, representing Norway and Sweden, Denmark,
Germany, and Austria, 25 use accumulators, ranging in
power from 65 to 1746 kw. hr. The ratio of the gen-
erator output to the output of the accumulators is as
124: 119.
As shown in a previous chapter, the uses of storage
batteries may be classed under four great heads :
1. To carry the peak of the load at maximum hours.
2. To carry the entire load at minimum hours.
3. To act as an equalizer or reservoir.
4. For the equipment of annex stations.
These four principal heads include all or nearly all
the uses for which a storage battery may be employed.
I. To carry the peak of the load. — In all systems of
lighting, whether it be gas or electricity, there is a
large percentage of the connected load, which is used
for only a short period of the 24 hours. This period of
maximum demand, it has been found, varies from 1.5
to 4 hours per day. ^t is to take care of this load that
gas-engines and inexpensive machinery have been pro-
posed. The Boston Edison station have given both
142
THE STORAGE BATTERY
inexpensive machinery and storage batteries a thorough
test, and have found that the batteries give by far the
best results; so much so that in 1897 they placed an
order for a fourth plant. In the Boston station, 90%
of the total output is produced by means of multipolar
generators driven by vertical triple expansion engines ;
and yet the total capacity of this apparatus is not 50%
of the maximum load of the station during the winter.
If a steam plant be installed to take care of this 50% of
the maximum load, which is but 10% of the entire
output, measured in kilowatt-hours, it is evident that
the station will find itself running with an extremely
small load factor, and consequently with very low
efficiency.
2. To carry the entire load at minimum hours, — If
a station have a very small "motor load factor," as is
the case in many of the European stations, then it would
pay, perhaps, to shut down during this period, thus
saving one shift of men, and making a reduction in the
boiler room expenses, from drawing the fires. In the
majority of American stations, however, the period of
minimum load is so short, — in the Boston station being
only 6 hours, — that it is found to be more economical
to charge the battery during this period of light load,
than to draw the fires and to throw the work of the
station upon the batteries.
In a communication to the American Street Railway
Association, Mr. McCuUough gave a theoretical curve,
(shown in Fig. 85), which illustrates these two preced-
ing conditions. In this, the period of light load is
found to be S hours, from midnight to 5 a.m., while
STORAGE BATTERY INSTALLATIONS
143
during the remainder of the day, 5 a.m. to midnight,
the steam plant is operating at full capacity.
3. To act as an equalizer or reservoir. — It is this use
of the storage battery which will especially appeal to
engineers, whether they be connected with lighting
or power stations. In modern stations electricity is
delivered both to the "bus-bars'* in the central station,
400U
9000
Q.
i 2000
<
'
1
D
Battery
c
\
J
rH^
atlery
rscharge
h 1
V^dtt
-^y
Charge,
/
"
\
^BAtieryj
i
N.
r^
\
\ Battery
^JDischari
i
1000
12 1 S 3 4
Midnight
567 89 10 11 12 123456789 10 11 12
A.M. Noon P.M. Midnight
Fig. 85.
and to "bus-bars" in the annex stations, thus being
delivered at varying potentials. During the period of
light load, the drop will be scarcely noticeable, and the
pressure at the lamps practically constant. As the load
increases, extra dynamos are thrown in, until the maxi-
mum load is reached. Where a station is not equipped
with batteries, it is almost an hourly question as to what
it will be necessary to do next ; whether to start dyna-
mos or to stop them, or to change "boosters." This
144
THE STORAGE BATTERY
trouble is intensified by the uncertainty as to what the
load is going to be at any given time.
When, because of a sudden storm, a heavy load is
suddenly thrown on the machinery, it is impossible,
unless the station be equipped with batteries, to prop-
erly care for this load for a considerable time. This
point may be illustrated by means of Fig. 86, which
shows an actual load curve — from the Philadelphia
Tsm
Li 1 a a
«
9
la J
l
3
n
B 12
Midnight A.M.
lloon P.H
TIME
lOdnlghl
Fig. a
6.
Edison station — for a day in May, 1897, when, because
of a sudden storm, the load was thrown on very quickly,
the peak of the load being higher than usual. It should
also be noted that in case of a breakdown, the battery
is ready to carry the entire load for the short time
necessary to start up another unit. This is an advan-
tage which will not appeal so much to an outsider,
perhaps, as to a man intimately acquainted with station
management
STORAGE BATTERY INSTALLATIONS 145
Where accumulators are used as storage reservoirs,
it has been found that a floor space, approximately 10
yards square, will suffice for storing icxx) kw. hr. Such
a reservoir will cost less than those used for either air,
isteam, or water ; the depreciation will be less, and the
life will be longer. The pressure, moreover, will be
constant, thus enabling lamps of 2.5 watts per candle
to be used, which represents a saving of 20%. More-
over, steam storage is not a true reserve, only relieving
the boilers, while batteries are a true reserve, delivering
the electricity directly and under conditions of high
economy.
Many engineers claim that the great trouble with
storage batteries is their low efficiency. In the Boston
station, however, it has been found that the watts lost
by the inefficiency of the battery is made up more than
fourfold by the better efficiency of the steam plant.
In Hamburg, the loss in the accumulators is only 1.2%
of the average amount of electric energy generated
during the year. Manufacturers will guarantee the
efficiency of a battery, when operated in parallel with a
dynamo, to be greater than 75%. Moreover, foreign
experience has proven that the use of accumulators in-
volves a saving of at least 15% in fuel. According to
the New York Electrical Review for Oct. 16, 1895, a
battery plant, costing jg 150,000, when worked in con-
nection with the trolley system, will show a net increase
of j! 100,000 in earnings.
4. For the equipment of annex stations, — In cases
where a heavy load is required, at some distance from
the central station, it has been the practice, in the past
146 THE STORAGE BATTERY
either to install a separate station at that point, or to
run heavy feeders to the centre of distribution. The
consequence of the latter alternative being taken has
been heavy losses in the feeders, owing to the large cur-
rents transmitted, and heavy interest charges for the con-
ductors. Now, however, by the use of batteries, much
smaller conductors are required, on account of its not
being necessary to carry the current equal to the maxi-
mum load, thus reducing the interest charges. Moreover,
a high tension current would probably be employed, by
which the line losses would be still further lessened.
The battery in this case would act as a transformer,
being charged in series and discharged in parallel.
Manchester, New York, Boston, Brooklyn, and Phila-
delphia afford notable examples of accumulator sub-
stations, New York having two such stations.
Another method which has been developed by M.
Nodon is to use accumulators in place of resistances,
particularly with arc lamps. In such cases a consider-
able portion of the current is irrecoverably wasted in
heating the rheostat, while if a battery of accumulators
be substituted for this dead resistance, all the waste
current may afterward be utilized. The plan possesses
the further advantage of affording a much more con-
stant light.
Examples of Storage Battery Installations
ZURICH
The first example of accumulators being used in a
railway power station was at the power plant of the
Zurich-Hirslanden Railway, in Switzerland. The in-
STORAGE BATTERY INSTALLATIONS
147
stallation consists of 270 Tudor cells, connected in
parallel with the generator. When the line was first
installed, complicated automatic switches were used, to
regulate the number of cells in circuit, but in February,
189S, these switches were removed, and the battery was
connected directly in parallel with the line. The bat-
teries have been in use for 2 J years, with as yet no signs
MINUTES
Fig. 87.
of deterioration. The coal consumption is 3.9 pounds
per car-mile, which, when the smallness of the entire
plant — a steam engine of only 90 H.P. being used —
and the exceptionally heavy grades are considered, is
extremely small.
Fig. 87 shows a load curve taken from this plant.
The line ab represents the battery load curve ; cd the
generator load curve, and ef the voltage curve, It will
148 THE STORAGE BATTERY
be noticed that the E.M.F. varies only between 535 and
560 volts, and that ^^ averages 85 to 90 amperes.
DOUGLAS-LAXEY RAILWAY, ISLE OF MAN
On this road the battery station is at Groudle, nearly
midway between the two generating stations. A bat-
tery of 240 Chloride cells is employed, capable of
yielding, at 500 volts, 70 amperes for 9 hours, 140 am-
peres for 3 hours, or 300 amperes for 45 minutes. The
battery is placed in parallel with the line, charging or
discharging according to the demands of traffic. By
means of a "booster" in the station, it can be brought
up to full charge at any time. During the winter,
when only two cars daily are run, the accumulators
furnish the entire power, being charged once a week.
THE MOUNT SNiEFEL LINE, ISLE OF MAN
Here 246 Chloride cells are used, capable of furnish-
ing, at 550 volts, 176 amperes for 3 hours, 112 amperes
for 6 hours, or 72 amperes for 1 2 hours. The battery
is connected, and used in a manner similar, to that of
the Douglas-Laxey road, including the minimum winter
load.
CHESTER, ENGLAND
In this installation the three-wire system is employed,
and three direct-driven, shunt-wound, Parker generators
are used, giving 184 amperes at 440 volts. Two batter-
ies, each of 115 K-type E.P.S. cells, are employed, their
normal capacity being 300 ampere-hours at a S-hour
rate. They will also give 240 ampere-hours at a 3-hour
STORAGE BATTERY INSTALLATIONS 149
rate, and 60 ampere-hours at a o.S-hour rate. These
results are obtained with an electrolyte temperature of
55° F. Each cell contains 25 plates in glass jars. The
cells are supported by oil-insulators on dry-wood bear-
ers, and are placed "in parallel rows of two tiers each.
In each battery circuit, on the switchboard, is a regu-
lating switch interlocked with a "booster" reversing
switch. This reversing switch enables the "booster"
E.M.F. to be added to that at the "bus-bars" on
charge, or, on discharge, to that of the battery. All
the switchboard connections are of copper, but all bat-
tery connections are of brass, painted with an acid-proof
enamel, blue for the positive and red for the negative
connections.
EDINBURGH
Six direct-connected, bipolar, shunt-wound machines,
with drum armatures, deliver current to the two sides of
the three-wire system at 270 volts. Two similar gener-
ators, of smaller size, used as balancing machines, de-
liver current at 135 volts. The battery consists of 132
Crbmpton-Howell cells, 31 plate type, with a capacity
of 1000 ampere-hours at a 5-hour rate. Lead-lined
containing-cells are used, resting on glass oil-insulators
on wood bearers. The battery is divided into two half-
batteries, positive and negative, arranged in four rows of
two tiers each, on cast-iron stands, the 8 " hospital " cells
being on a separate stand. The 26 cells in each half
nearest the middle wire are used as regulating cells, and
are placed in parallel with each other as occasion de-
mands, the connections to the regulating switchboard
ISO
THE STORAGE BATTERY
being by solid copper rods. The battery room is a
well-lighted, well-ventilated room, with a fire-proof floor
which is covered with acid-resisting asphalt. Provision
is also made for a second battery, of similar size, in case
of necessity.
This method of connecting the central cells in paral-
lel, while necessitating a more complicated system of
connections than with the usual method of cutting out
cells on the outer end, renders the manipulation exceed-
ingly simple, and does away, to a great extent, with
the troublesome charging of the back cells. By this
arrangement of battery regulation, all of the cells in the
battery are always used, which is not the case with back
E.M.F. cells. In order that charging may go on at
light load, when there is only a small drop on the feed-
ers, the "hospital" cells are connected, four on each
side of the system.
Under normal circumstances, the battery is charged
during light load, the charging current varying with the
external load, so as to keep the engine load constant.
During heavy load, the batteries are kept, as far as
possible, idle, it being only in the case of a "peak," and
when the generators are shut down, that the batteries
are subjected to a high rate of discharge.
MANCHESTER
The electric-light works of Manchester, England,
have recently added to their plant a storage-battery sub-
station, situated about one mile from the generating
station, the five-wire system being used. A motor
STORAGE BATTERY INSTALLATIONS
ISI
generator, which carries the normal charging current
of 300 amperes, is used to raise the E.M.F. from 410 to
590 volfs. There are 224 cells divided into 4 series
of 56 cells each, each battery being again subdivided
into a main battery of 44 cells, and a regulating bat-
tery of 12 cells, with a total capacity of 1250 kw. hr. .
The normal rate of discharge is 300 amperes for
each battery, and the maximum, 600 amperes. The
battery carries the entire load after midnight, the
third shift of hands, from 10 p.m. to 6 a.m., being
almost dispensed with. On Sundays, the battery
carries the entire load up to 4 p.m., in addition to its
regular night load, thus relieving the second shift
of men.
The plates are supported in the cells by means of
glass hangers, and are separated from each other by
solid glass rods. The containing cells are supported
on iron and timber stands, the battery being insulated
throughout with duplex oil-insulators. Connections
are made to the switchboard by means of solid copper
rods carried around the walls on porcelain insulators
which are fixed to iron supports.
BELFAST
The plant in the engine room consists of four 120
LH.P., tandem, double-acting, horizontal gas-engines,
rope-connected to four 60 kw. Siemens' generators.
There are, likewise, two 60 LH.P., single-cylinder,
double-acting, horizontal gas-engines, rope-connected to
two 26.4 kw. Siemens' generators; also, two 150 LH.P.,
152.
THE STORAGE BATTERY
four-cylinder, single-acting, high-speed, vertical gas-
engines, direct-connected to two 72 kw. Siemens* gen-
erators. Ignition is made by means of hot tubes, which
are of ordinary wrought-iron, nickel-steel, and porcelain.
For starting, the generators are connected to the bat-
teries, and run as motors. The dynamos give 240
amperes at 240 volts, 220 amperes at 120 volts, and 300
amperes at 240 volts respectively.
All the generators are shunt-wound, bipolar machines,
with drum armatures. The two small machines have
double-wound armatures, the windings being connected
to separate commutators. By means of a plug switch-
board, these windings can be connected either in series
or parallel, so that the machines can be run at either
120 volts for balancing, or at 240 volts across the
system. The three-wire system is used.
The battery consists of 126 E.P.S. cells, of the 34-K,
or heavy-discharge type, divided into two sets of 63
cells each ; the normal capacity of the cells being 500
ampere-hours at a 5-hour rate. There are also 8 " hos-
pital'* cells, which can be used either to assist weak
cells, or can be put in series with the main battery.
The regulation in this station is accomplished by put-
ting the cells at the middle-wire end of the positive bat-
tery in parallel with cells at the middle-wire end of the
negative battery, the other end of the batteries being
connected through ammeters and switches to their re-
spective "bus-bars.'* In addition, the neutral wire is
shifted either toward the positive or negative end of
the batteries. The plates are contained in lead boxes,
which are supported, by means of glass oil-insulators.
STORAGE BATTERY INSTALLATIONS 153
on four rows of wooden stands. The connections from
the battery consist of bare copper rods, supported by
oil-insulators, suspended from the roof.
BIRKENHEAD
This station is arranged for the three-wire system,
but uses at present only two wires with a pressure of
230 volts. Three 80 H.P. engines are direct connected
to three 50 kw., shunt-wound, Crompton dynamos, with
an output of 200 amperes at 250 volts. The battery
consists of 136 E.P.S. cells, of the K-50 type, with a
capacity of 750 ampere-hours at a 5-hour rate, or 400
ampere-hours at a i-hour rate. Lead containing-boxes
are used in pitch-pine trays on glass insulators. The
battery is subdivided into the main battery of 126 cells,
and the "hospital" battery of 10 cells. Regulation is
accomplished by cutting in or out the end cells, of which
19 at each end, or 38 in all, are connected to the regu-
lating switches.
The cells are arranged in three long rows of two
tiers each, on pitch-pine bearers, supported by cast-iron
standards. These stands rest on thick stone slabs, the
slabs resting on a concrete foundation. Over this con-
crete foundation, and surrounding the slabs, is placed
a layer of roofing felt, then a layer of bitumen, and the
whole floor is then covered with slate. This acid-proof
floor is ridged to give drainage.
The end cells are connected from row to row by cop-
per rods, and regulating leads, also of copper, run over
the cells in wood cleats on ebonite insulators, and are
154
THE STORAGE BATTERY
supported by bearers resting on iron girders. Space is
provided for a similar battery, when the change to the
three-wire system is made.
MERRILL
In this station, which furnishes power for both light-
ing and railway circuits, the generators are all run from
the same shaft, the prime mover being water power.
It will be readily seen that under such circumstances
"BEFORE"
ftUU
8M
^
^
^-^-
-»
7
8S8
yT.
^
""1
/
A\
V
1
/)
8M
\
r"
/^
,„— -
J
W
i\^
f\/
' ,
?/
«OSM
u*
K
V]/
y
//
• aw
V
17
> i(g
112
,_^
-'>•
' — >
^v—
— ^
■^
-^
'"V-
r^/\
-irv-
^
\ «-
^^
M
v^
80
I \
I \
\ i
I {
A =
B-
J '
Ml
Rail
Ligh
r 1
NU1
way
ting
\
ES
Vol
Vo
9 1
tage
ltag<
1
i
1 1
% I
S i
i u
Fig. 88. •
the voltage would be far from steady. The advantages
derived from the introduction of storage cells are illus-
trated in Figs. 88 and 89, the curves being taken before
and after the installation of the batteries. Before the
batteries were installed, only one car could be run dur-
ing the heavy lighting hours, and then far from satis-
factorily. The battery was installed for the double
purpose of increasing the lighting capacity, and for
regulating the railway voltage; water-wheel governors
had previously been tried for this latter purpose, but
STORAGE BATTERY INSTALLATIONS
155
were found to be unsatisfactory. The battery is situated
in a sub-station, about | of a mile from the power
station, and about \ oi 3, mile from the centre of distri-
bution for the lighting service.
The battery contains 240 Chloride cells, of ii-F
type, with 500 ampere-hours capacity at a lo-hour rate.
It is divided into 4 series of 60 cells each, which can
6IS
"AFTER-
CO 480
>
184
J88
U8
118
w^^
t^
9^^^25^
ISa^ 567 89 10 UU
MINUTES
Fig. 89.
be connected 4 in series for the railway circuit, or 2
in parallel for the lighting circuit which is arranged
upon the three-wire system. A variable resistance is
put in circuit between the battery and railway, for cut-
ting down the voltage when the battery is fully charged.
Two large, double-throw, three-point switches connect
the battery to the railway, or to the three-wire lighting
system.
HARTFORD
The Hartford Electric Light Co. generate current at
500 volts, — three-phase system, — at the power station
on the Farmington River, 10.8 miles distant from the
city. This is raised by means of " step-up " transform-
156 THE STORAGE BATTERY
ers to 10,000 volts, and is transmitted over six ^o
wires, — two in multiple for each phase, — 1200 kws.
being transmitted in this way. At the Pearl St. station
the pressure is reduced to 2400 volts, and the current is
changed from three-phase to two-phase. Most of the
energy received at the Pearl St. station is used for three
purposes. It supplies the current to all the alternating
current lighting and power system. It supplies the
current to the rotary transformers at the State St.
station for charging the storage battery, and it
supplies the current to the three-wire, direct-current
system.
At the State St. station is placed a battery of 130
Chloride cells, 65 on each side of the system. Each
cell contains 30 positives and 31 negatives, the plates
being made in two parts, each 15.5x15.5 inches.
Manchester positives and Chloride negatives are used
in a lead-lined oak containing-cell. The normal ca-
pacity is 8500 ampere-hours at a S-hour rate, a 1.25-
hour rate being allowable if necessary. Twenty end
cells on each side are connected to the regulating
switches, the switches being mounted vertically, and
similar to those installed by the Electric Storage Bat-
tery Co.
The diagram (Fig. 90) shows the station operation
for Dec. 12, 1896. The line enclosing B and C spaces
show the current taken from either the rotary con-
verter or battery for line use. As shown, at midnight
the consumption had fallen to 350 amperes, and ran
along at this rate till 6 a.m., when it began to rise,
and at 8.30 had an output of 1550 amperes. During
STORAGE BATTERY INSTALLATIONS
IS7
this time the batteries had been charging from the
converters (see A space). At 8.30 the battery took
the peak of the load, and carried it for 1.5 hours. At
noon the demand dropped from about 1400 amperes
to 750 amperes for one hour, during which time
1*30912 8« • U
Midnight A.M. Nooi\ P.M» Midnight
N. r. Mlm, JBv.. XXin, 48.
Fig. 9a
the battery was charging. From i to 3 p.m. the
river current, as it is termed, was all required by
the lines, and the battery remained quiet. At 3.30 p.m.
the rotary transformers were shut down and the bat-
tery took the entire load till 11 p.m., when it was
shut down and charging began, the rotary transformers
also furnishing all line current.
158 THE STORAGE BATTERY
BOSTON
In 1897 the Boston Edison Co. already had three
battery plants in service, and were installing a fourth
one. The First, Second, and Third generating sta-
tions are situated at the points of an approximately
equilateral triangle ; the distance from the First to the
Third stations being 3800 feet, and from the Second to
the Third 4200 feet. The First and Second are each
connected to the Third by tie lines of 3,000,000 circular
mills capacity, on each side of the three-wire system.
The batteries are run in parallel with the generators.
The first battery plant was installed at the Third,
or main, generating station, 90% of the total output
being generated at this station. The battery consists
of 140 Tudor cells, the capacity being 4125 ampere-
hours at 1.25 hours, 5148 ampere-hours at 3 hours,
and 6940 ampere-hours at a lo-hour rate. In this
station are five sets of " bus-bars," to give the different
pressures as required ; therefore five sets of regulating
switches are employed on each side of the system.
The switches consist of 31 contacts to which 30 of the
cells are connected in each battery, and are entirely
automatic.
The second battery is installed at the First station,
and is the largest of the four batteries. It consists of
144 Tudor cells, the capacity being 8250 ampere-hours
at 1.25 hours, 10,296 ampere-hours at 3 hours, and
13,880 ampere-hours at a lo-hour rate. The contain-
ing-cells are lead-lined wooden boxes, each containing
37 frames. Each positive frame contains 16 plates.
STORAGE BATTERY INSTALLATIONS 159
7 inches square ; and each negative 4 plates, 14 inches
square; the plates being secured in their frames by
soldered lead strips. The elements stand on glass
plates set on edge, leaving a space of 6 inches below
the elements for the sledge. Each cell contains 640
litres of acid, and measures 3 feet 10 inches x 3 feet
4 inches x 3 feet; the cells are arranged in six rows
on three floors of the building, and stand on porcelain
insulators. The floor of the room is made of slate.
Connections from the cells to the switchboard are by
copper bars, 0.5 inch thick, and from 3 to 6 inches
broad. This station has three sets of " bus-bars," and
consequently three sets of regulating switches on each
side of the system. As in the other stations, the regu-
lation is entirely automatic, being accomplished by 0.25
H.P. electric motors.
The third battery is installed at the Fourth, or Scotia
St. station, and is distinguished by being situated in a
fashionable residence district, and is entirely a sub-
station, containing no generating machinery whatever.
It is 7000 feet from the First station, and nearly 1 1,000
feet from the Third or main station. The current is
sent from the Third to the First, and from there to
the Fourth station, at a high potential; the same
generators charging the First station batteries as well
as the Fourth. The battery consists of 140 Chloride
cells, resting on four "petticoat" insulators, of which
the capacity is 3000 ampere-hours at i hour, 4500 am-
pere-hours at 3 hours, and 6000 ampere-hours at a 7.5-
hour rate. The containing-cells are hard pine tanks,
18x22x38.75 inches, inside measurement, lined with
l6o THE STORAGE BATTERY
5-pound lead. Each cell contains 21 plates, Manchester
positives and Chloride negatives being used. Twenty-
four cells on each side of the system are connected to
the regulating switches by hard-drawn copper bars,
3x0.5- and 1.5x0.5 inches cross-section. These bars
are supported on porcelain insulators, resting on wooden
hangers, the hangers being supported from the floor by
iron pipes. The battery room floor is 12 inches con-
crete, with a regular cement finish.
The fourth battery is at the Second station, and will
have a capacity of 4000 ampere-hours at i hour, 6000
ampere-hours at 3 hours, and 8000 ampere-hours at a
lohour rate.
NEW YORK
The Edison Electric Illuminating Co. of New York
have at present three storage battery plants, — one at
the 59th St. station, another at the 12th St. Annex,
and a third at the new Bowling Green station. The
generating plants of the entire system, with the ex-
ception of that at the 26th St. station, have been shut
down several times over night, or over Sunday, in order
to test the practicability of running the system from
one generating plant, with the aid of the 12th St. bat-
teries, during the hours of minimum load. The results
show that this is quite practicable, and with the aid of
the Bowling Green station it is expected that consid-
erable economy will be developed in this way.
The 59th St. station contains the first successful
storage battery installation in American Electric Light
stations. The battery is of the English Crompton-
STORAGE BATTERY INSTALLATIONS 16 1
Howell type, with a capacity of 3000 ampere-hours at
3 hours, or 2000 ampere-hours at a i-hour rate.
In the 1 2th St. station, 150 cells, having a capacity
of 8000 ampere-hours at 10 hours, 6cxx) ampere-hours
at 3 hours, and 4000 ampere-hours at a i-hour rate,
have been installed. Each cell contains 39 elements,
the positive plates being of the Tudor and the nega-
tive of the Chloride type. The battery is arranged
in four rows of two tiers each, resting on wooden bear-
ers supported by iron standards. By a system of tie
feeders, this battery can be charged either from the
26th St. or the Duane St. stations. The 12th St.
station contains, besides the battery plant, a complete
steam equipment, which is run only during one watch
of maximum demand. The battery supplements this,
besides taking the entire load during the remainder of
the day. Fig. 91 shows the diagram of connections
for this station, and Fig. 92 that for the Bowling Green
Annex.
The Bowling Green Annex likewise contains 150
cells, 75 on each side of the three-wire system. In
this case, each cell contains 33 elements of the Man-
chester positive and Chloride negative type, in a lead-
lined, poplar, containing-tank, which measures 40.75
X 20.5 X 30.5 inches. The tanks rest on four "petti-
coat " insulators, which in turn rest on 6-inch vitrified
tile. The capacity of the battery is 2000 ampere-hours
at I hour, 3000 ampere-hours at 3 hours, and 4000
ampere-hours at a lo-hour rate. There are 20 regu-
lating cells at each end of the battery, each of which is
separately connected fo a block on the ordinary regu-
I62
THE STORAGE BATTERY
STORAGE BATTERY INSTALLATIONS
163
1 64 THE STORAGE BATTERY
lating switch. Two regulating switches are connected
in multiple on both sides, thus enabling the battery to
be discharged at two potentials, or to be charged and
discharged at the same time.
The battery room floor contains, first, a layer of con-
crete 1 8 inches thick, then a layer of pitch and felt,
then a series of vitrified hollow tiles, for conducting the
feeding cables, then more pitch and felt, then a 12-inch
layer of concrete, and finally a layer of vitrified white
tile. This elaborate flooring is necessary because the
battery is situated in the sub-basement of the Bowling
Green Building, the floor of which is below the water
line. The waterproofing on the side walls is retained
in place by a wainscoting of slate, securely fastened to
the brick walls at the top, and embedded in the concrete
at the floor level.
All connection between the cells, and between the
regulating cells and the switchboard, is by means of
copper bars 0.5 inch thick by 3 inches wide. The
area of all joints is 18 square inches, and each connec- .
tion is made by means of two |-inch bolts. These
copper strips are supported on porcelain insulators,
which rest on hangers, or horizontal iron beams.
Fig. 93 illustrates the battery room for this station.
BROOKLYN
The Brooklyn Edison Co. have, at the time of writ-
ing, one battery plant in complete operation, and are
installing a second and larger battery. The former is
located in what is known as their Second District
STORAGE BATTERY INSTALLATIONS 165
l66 THE STORAGE BATTERY
Station, located in Lexington Ave. The generating
machinery is only run during the period of maximum
load ; at other times, the station is used as a battery sub-
station, in connection with the First and Third District
stations, to which it is connected by tie lines. The
plant, illustrated in Fig. 94, consists of 160 Chloride
cells, ' containing Manchester positive and Chloride
negative elements. The capacity is 8000 ampere-hours
at 10 hours, 6000 ampere-hours at 3 hours, and 400*0
ampere-hours at a i-hour rate. Thirty end cells, on
each side of the three-wire system, are connected to
the cell-regulating switches, which are located in the
battery room, and the main distributing board is placed
on the main floor of the building, immediately under
the battery room. The regulating switches are oper-
ated, as usual, by electric motors, connected thereto by
worm gearing. Two 16-C.P. lamps are connected in
each motor-control circuit, one lamp being located on
the main distributing board and the other in the bat-
tery room. When the regulating brush is travelling
from one contact to another, these two lamps are in
series, and burn dimly ; but when the brush is entirely
on the contact, one Cell having been cut in or out,
one of the lamps is extinguished, and the other
burns brightly, thus giving an indication of when the
motor should be stopped. In addition to this, there
is an indicator telling the number of cells in circuit,
which works on the principle of the Wheatstone
bridge.
Charging is accomplished either by means of the
machines at the station, or by means of tie lines from
STORAGE BATTERY INSTALLATIONS
167
l68 THE STORAGE BATTERY
the other stations, a "booster" being used in either
case, as necessary.
The battery being installed is to be located at what
is known as the Citizens' station, and is to consist of
156 Chloride cells, with a capacity of 12,000 ampere-
hours at 10 hours, 9000 ampere-hours at 3 hours, and
6000 ampere-hours at a i-hour rate.
PHILADELPHIA
The Philadelphia Edison Co. have lately installed the
largest individual storage battery plant in the world.
At Hartford the cells are larger, but they are fewer
in number, and their total output is, therefore, less.
The Philadelphia plant consists of 160 Chloride cells,
containing 57 plates each, 31 x 15.5 inches. The capa-
city of the battery is 15,200 ampere-hours at 10 hours,
11,250 ampere-hours at 3 hours, and 7500 ampere-hours
at a I -hour rate. The plates are supported on glass
sheets, in ash containing-cells, which are lined with
4-pound lead. Thirty cells on each side of the three-
wire system are connected to the regulating switches .
by rolled copper bars, with a sectional area of 2 square
inches. These are supported on porcelain insulators,
which are mounted on channel irons hung from the ceil-
ing. All joints are bolted together by four |-inch bolts,
and are treated with Edison-Brown plastic alloy. All
other connections are made by means of lead " bus-bars,*'
reinforced with copper strip. All copper connections
are painted with an acid-proof enamel paint. The regu-
lating switches, which are operated by electric motors,
STORAGE BATTERY INSTALLATIONS 169
are placed on the outside of the battery room wall.
The main switchboard is located in the dynamo room,
on the second floor, immediately under the battery
room. Figs. 95, 96, and 97 illustrate, respectively, the
battery room, the switchboard, and the cell-regulators,
for this station.
On the battery room floor was first laid concrete, then
three thicknesses of paper coated with pitch to render
it waterproof, then chemical brick laid in cement for
one-half its depth, the other half being fiUeid with hot
pitch. The aisles are graded so that all liquid will
drain off in channels provided for that purpose. The
cells are supported on eight double "petticoat," porce-
lain insulators, set in vitrified tile, to raise them slightly
above the floor.
That portion of the main switchboard which is de-
voted to the battery connections is supplied with the
following instruments :
2 motor-control switches.
2 cell-regulating switch indicators.
2 ammeters ; for the cell-regulating switches.
I ammeter ; for the battery control.
1 voltmeter with five-point switch ; to indicate pressures
on the two "bus-bars.'*
2 cell-regulating switches (on the "charging-bus").
I low-reading voltmeter with 30-point switch (to indicate
the voltage of each regulating cell).
7 knife switches.
These instruments are all in duplicate, one set for
each side of the system. As a general rule, the battery
I70
THE STORAGE BATTERY
STORAGE BATTERY INSTALLATIONS
171
Fig. 96.
172
THE STORAGE BATTERY
Fig. 97.
STORAGE BATTERY INSTALLATIONS
173
carries the entire load from 12.30 a.m. to 6.30 a.m.,
about 8cx)0 ampere-hours being taken out; from 6.30
A.M. to 4.30 P.M. the battery is charged; at 4.30 the
peak commences, and lasts till about 6 p.m. ; from
then on till 12.30 a.m., the battery is charged, to be
ready for the night load. Fig. 86, which was taken
from this station, shows a load curve. This is not the
normal load curve, however, because of a sudden thun-
derstorm.
In 1890, when the Union Traction Co. of Philadel-
phia decided to extend their lines, it was found that
either a new power-house, or an accumulator annex,
would have to be built, as the needed addition to the
existing feeder system would require such an expendi-
ture for copper as to render it commercially impracti-
cable. The cost of copper alone would have been about
four times as great as the cost of a battery sufficient to
meet all requirements. The erection of a new power-
house was out of the question, because of the heavy
operating expenses. The capacity of the power-house
would have to be about 750 kw., and this, at an esti-
mated cost of $85 per H.P., would cost about $85,000.
The total cost of the annex, including the changes in
cables, was about $50,000. Before the extension was
made, the pressure at the end of the system was barely
sufficient to operate cars on schedule time, the pressure
varying as much as 50%. This condition is clearly
illustrated by the frontispiece, and by Fig. 98. After
the installation of the batteries the only variation in
pressure was between i and 5 a.m., when the battery
174
THE STORAGE BATTERY
was taken out of circuit. The installation consists of
248 G-13 Chloride cells, in lead-lined boxes, mounted on
two tiers of oil-insulators. All connections are made
by continuous weld, no mechanical contacts being em-
ployed. The maximum rate is 400 H.P. for one hour.
Fig. 98.
Figs. 99 and 100 illustrate, respectively, the battery
room, and a load curve for this station. The follow-
ing data regarding the operation of the installation
may be of interest ; they are taken from a communica-
tion to the Engineers* Club of Philadelphia, made by
Mr. Hewitt in December, 1896.
STORAGE BATTERY INSTALLATIONS 175
176
THE STORAGE BATTERY
:-:::";VT:-:^:::f:::;-TVrr-
JiH:
.^^ili^im^v^^
illiiuiij
Fig. 100.
STORAGE BATTERY INSTALLATIONS 177
The saving in favor of the battery for the year is
1^15,633.96.
Highest charge for 24 hours 456,000 watt-hours.
Lowest charge for 24 hours , 312,000 watt-rh ours-
Average charge for 24 hours 385,161 watt-hours.
Highest discharge for 24 hours 456,000 watt-hours.
Lowest discharge for 24 hours 216,000 watt-hours.
Average discharge for 24 hours 329,419 watt-hours.
Average efficiency for the month 85.5%
Maximum specific gravity at 6 p. M 1.201
Minimum specific gravity at 6 P.M 1.184
Average specific gravity at 6 p. M t.192
Maximum specific gravity at 12 P.M 1-194
Minimum specific gravity at 12 P.M i.i8z
Average specific gravity at 12 P.M 1.188
This last specific gravity is approximately that pre-
ceding the night charge, and is an indication of the
amount taken out during the day ; it should be borne in
mind that at 1.160 the battery is practically empty.
THE COMMERCIAL CABLE BUILDING, NEW YORK.
The battery plant in this building consists of 120-2500
ampere-hour Chloride cells, whose internal dimensions
are 20.5 x 26.5 x 20.75 inches. The containing-cells
are made of ash. They are lined with lead and painted
with asphaltum, and are mounted on glass insulators,
resting on hardwood blocks on 4-inch I beams. The
cells are arranged three tiers high on one .side of
the room and two tiers high on the other in order to
economize space. Strong running boards are bracketed
out from the frames for the use of the attendants. The
plates in the cells rest on glass strips, which in turn rest
178
THE STORAGE BATTERY
on leaden legs. Connections between adjacent cells are
made by burning the plates to lead " bus-bars " ; all
copper leads are dipped in lead, as is all steel work and'
all bolts and riveted joints, to protect them from the
battery fumes.
The battery currents are controlled by a 25-H.P.,
75-volt "booster," driven by a 240-volt motor. The
field of the " booster " is wound with a series and shunt
coil. During the day, when the battery is being charged,
the series field works against the shunt field, the battery
terminal being outside the series coil, that is, between
the series coil and the motor load. In this case, if the
elevators take a heavy current, the " booster " weakens,
which prevents the " peak '* being taken from the dy-
namo, and throws it all on the battery. At night the
generators are thrown off, and the battery terminal is
changed to a position between the " booster " brush and
the series coil. In this case the field connections work
cumulatively; and if the elevators draw a heavy current,
the series coil builds up the "booster" voltage, so as to
compensate for the drop in the batteries. Thus the
lamp pressure is maintained at a constant value.
OTHER INSTALLATIONS
For the electric railway in Rome, Italy, alternating
current from the Tivoli-Rome transmission plant is sup-
plied. The pressure is first reduced by means of a
stationary transformer, and is then converted to -a direct
current by means of a motor-generator having a multi-
polar field and a single armature. The armature has
STORAGE BATTERY INSTALLATIONS
179
collecting rings on one side and a commutator on the
other. The battery plant consists of 300 Tudor cells,
with 720 kw. hr. capacity. Pressure is kept constant
by means of an automatic switching-in apparatus.
-K>
r
o^
^r
mw^Hk-
f^^t
HiliHI'W«M'^
site. JfMduXXIlJ, t9T.
Fig. ioi.
In Burnley, England, the three-wire compensating de-
vice, shown in Fig. loi, is used. The dynamo generates
230 volts. The compensator consists of two armature
coils wound on a single drum, each for an output of
200 amperes at no volts. The battery is of 120 cells,
of about 500 amperes each. The bars represent regu-
lating switches; thus balancing with only one engine
and one dynamo.
i8o
THE STORAGE BATTERY
On the Zurichberg railway, in Switzerland, gas-
engines are used in conjunction with a battery of
300 Tudor accumulators.
The diagram, Fig. 102,
shows the connections.
"There is an automatic
regulator ab, and further
a hand regulator V, for
the 90 control cells di-
vided into 30 groups
of 3 each. The cells
are in parallel with the
dynamo D^^ and D^ is
an auxiliary dynamo,
whose field coils are
placed between b and
b\ and which charges
all cells beyond a. The
excitation of D^ changes
with the number of cells
in circuit. The inter-
rupters are solenoids
with mercury cups."
Fig. 103 shows the
load curve for Berlin,
in which a represents the current curve, b the watt-
age curve, and c the charging curve. The maximum
charging current is 650 amperes, and the maximum
discharge current 1420 amperes.
Fig. 104 shows the load curve for the electric plant in
the Chicago Board of Trade, and Fig. 105, the switch-
board connections.
FI6. 102.
STORAGE BATTERY INSTALLATIONS
i8i
Secondary Batteries in Elevator Work
A growing use for secondary batteries exists in con-
nection with elevator work. Many office buildings have
been compelled to install their own generating plant,
because of the unwillingness of central station managers
to accept the load. When the character of the load due
to elevator service is considered, this unwillingness will
be clear. Because of the large amount of energy con-
« lit iu 11 la 1 a ^ i
A.M. Noon
S # ll> LL i£ L S 3 4 fi a
P.M. MidniKht A.M.
Hours
Fig. 103.
sumed, the customers require that the current be given
them at the lowest rates ; but because of the fluctuating
character of the load, which is well illustrated in Fig.
106,^ central-station men cannot afford this practice. Of
late, however, storage-battery plants have been installed,
thus changing the load from an undesirable to a most
desirable one. The battery suffices for the entire ele-
vator and lighting work, besides putting a steady load
on the engines. In some cases the storage battery has
1 Electrical Engineer, New York, Vol. 23, p. 497.
l82
THE STORAGE BATTERY
111
ZA.
I
-
1
1
1
?? j^/-.
>Tti it
«eri
es.
1
STORAGE BATTERY INSTALLATIONS
183
been installed and maintained at the sole expense of
the owners of the central station, who have placed the
Fig. 106.
meter between the battery and wiring mains in the
building and have charged only for the current actually
used by the customers.
1 84 THE STORAGE BATTERY
In some cases " recuperation," ^ as practised on the
Paris Accumulator Lines, is being employed to advan-
tage. In such cases the car, descending by gravity,
charges the battery, thus restoring much of the energy
used during the ascent.
An interesting experiment is being conducted on the
Manhattan Elevated Railway, of New York City ; that
of carrying the battery plant on the train itself, rather
than installing it at sub-stations along the line of the
road. The battery consists of 248 Chloride cells of 400
ampere-hours' capacity, the total weight being 10 tons.
The batteries are all connected in parallel by a third
rail, so that all work in unison for any variation of load
in their immediate vicinity. In this way the total
amount of battery is evidently less than if it were
installed in a sub-station. Moreover, the load on the
feeders will be the average load and steady, the battery
taking charge of the heavy load that comes with start-
ing. In this way the cost of copper for the feed wires
is greatly reduced and the pressure at the motor is kept
constant. On all curves, crossings, and in and out of
the car-barns, the third rail can be dispensed with, since
the battery is capable of doing the entire work at these
places.
The Storage Battery in Telegraphic Work
The field which, from a practical, scientific, and
economic point of view, holds the largest possibilities
for the employment of accumulators is the field but
lately exclusively occupied by the primary battery, as
1 Vide pages 206 and 215.
STORAGE BATTERY INSTALLATIONS 185
applied to telegraph and telephone stations, police and
fire alarm, and all signalling systems. Those stations
whose business is not large enough to warrant the in-
stallation of a generating plant, are fast equipping with
a battery of accumulators. The low first cost, the small
amount of space occupied, — about one-fourth of that
required of a primary battery to do the same work, —
the constancy of the E.M.F. and internal resistance, the
obviation of the troubles due to creeping salts and cor-
roding connections, are a few of the advantages which
recommend a storage battery for any of the above pur-
poses. It is a fact, as McRae has said, that "the
poorest type of lead secondary battery that is on the
market to-day is capable, if properly installed, of giving
better service than the best type of primary battery.'*
In July, 189s, 3 1 16 storage cells were performing the
work previously required of 20,407 primary battery
cells. The estimated cost of the latter, not including
freight, is $10,203.50, while that for the former is be-
tween j?8400 and 1^8500. When the element of freight-
age is considered, the difference is still greater. A
small amount will have to be added to the accumulator
cost, because of auxiliary apparatus required by a stor-
age battery installation, and not by a primary battery.
This addition will, however, be very slight, being seldom
over 1 5 % of the cost of the battery.
As regards the cost of maintenance of the primary
battery, it may be stated that this will average about
^(1.50 per year. William Finn states that "the mate-
rials consumed in a single cell of the gravity battery
furnishing current for the quadruplex circuit would, in
1 86 THE STORAGE BATTERY
the course of a year, amount, at the lowest estimate, to
$i.io." J. B. Stewart puts the cost of the gravity bat-
teries used in the "West Shore" railway telegraph
system at ;Ji.6s per annum. The maintenance cost of
the storage battery is made up of three factors : the cost
of charging current, the interest on first cost, and the
depreciation of cells. The first factor is somewhat diffi-
cult of estimation. Taking as a basis, however, the cost
at which this current could be bought from regular
electric lighting stations, it has been estimated that the
cost of current equivalent to that furnished by a gravity
cell during one year would be about 9 cents. The addi-
tion of 2.5 cents for each of the other two factors brings
the total maintenance cost up to 14 cents, as against
$1.50 for a primary battery.
According to Mr. Finn, "the elaborate series of en-
gines and dynamos now furnishing the electromotive
power in many of our telegraph offices could, in the
opinion of expert authorities, be replaced with accumu-
lators with considerable economy in capital expenditure,
and an ultimate saving in the cost of maintenance."
The great flexibility of an accumulator is one of the
main points of superiority of a storage-battery plant
oyer a dynamo.
Storage batteries are being introduced in telephone
work, the battery being installed at the subscriber's
station, and charged, when the line is not in use, from a
generator at the exchange. When a call is made, and
the line is switched for conversation, the central genera-
tor is automatically cut out, and the battery switched in.
Perhaps the earliest storage battery to be used for
STORAGE BATTERY INSTALLATIONS 187
telegraphic work was introduced, in 1892, in the Burry
printing telegraph, — the system used by the Stock
Quotation Telegraph Co. At that time electrical ex-
perts were almost unanimous in their opinion against
the use of storage batteries for this purpose. Mr.
Burry, however, believed in it, and installed one on six
months* trial. It proved to be a complete success, in
regard to quality of current, labor-saving, and general
economy.
Storage batteries are also being largely introduced in
fire-alarm work, as evidenced by the fact that 10,422
battery cells have been introduced during the last two
years, and 47 cities are now equipped with storage
systems.
The first large storage battery installed by the West-
ern Union Telegraph Co. was in its offices at Atlanta,
Ga. In this installation 700 Chloride cells perform the
work previously requiring 8000 gravity cells. This
plant includes 344 cells of 75-ampere-hours capacity;
172 50-ampere-hour cells; and 172 25-ampere-hour
cells, — all used on the main line; also 12 cells of 250-
ampere-hours capacity, exclusively for the local circuits.
These 700 cells are divided into two equal sets, which are
charged and discharged on alternate days ; the sets in
turn being divided into 8 groups of 43 cells each, which
are charged in multiple series, and discharged in series.
The cells are charged from the 500-volt mains of the
Georgia Electric and Power Co. ; two motor dynamos
being used to reduce the line E.M.F. to the correct
charging pressure. One of these, a 7.S-H.P. motor
dynamo, used for the main line battery, transforms to
i88
THE STORAGE BATTERY
iio volts; and the other, a i-H.P. for the local cells,
transforms to i6 volts. Fig. 107 shows the connections.
At Washington, the second large Western Union in-
stallation, 724 Chloride cells are used, divided as follows :
398 cells of 50 ampere-hours, 320 12.5-ampere-hour
ELECTRIC LIGHT MAINS
e.«c«.TLg
i
AUTOMATIC
CUTOUT
MOTOR r^
J
CHARQINQ
CIRCUIT
DYNAMO jS^
/
FOR
LOCAL
-1-^
BATTERy
— =^2^
] lev.
h»«-
+ • VOLTS 6 VOLTS —
i % «/ •■' \
|i|i|i|ifi|i|i[ii{i|i|i|i|i|i|i|i|i
2S 60 75 I 7S 1 75
AH. Ia.H. A.H.I A.H. IA.H.^HJ A.H.
DISCHARGINa ^ CIRCUIT
"J
I'l-H-r
^ LOCAL APPARATUS ^
-o— — — — o-
FiG. 107.
cells, and 6 125-ampere-hour cells. The main battery
of 640 cells is divided into 16 groups of 40 cells each.
This is divided into two sets, which are charged and dis-
charged alternately, as in the Atlanta installation. The
78 cells comprising the " short wire " battery are a part
of the 50-ampere-hour set. They are likewise divided
into two sets, diflfering, however, from the preceding by
being charged in series and discharged in multiple.
STORAGE BATTERY INSTALLATIONS 189
The main battery is both charged and discharged in
multiple. No transforming machinery is needed in this
station, as the charging E.M.F. is 1 10 volts. These 724
accumulators replace 7300 gravity cells.
At Albuquerque, N.M., is probably the first large
installation dependent entirely upon storage batteries.
This plant consists of 360 Chloride cells, of 20 ampere-
hours* capacity at service discharge, divided into 9 sec-
tions for convenience in charging. There are also 12
cells of 100 ampere-hours capacity at service rates for
supplying local circuits; the smaller cells being for
main line service. The cells are charged to 2.5 volts
per cell, and discharged to 1.8 volts. A resistance is
placed in each discharge circuit to prevent cells from
short-circuiting.
The cells are placed in two racks, each having three
rows of double shelving, the highest being 4.5 feet
above the floor. The total floor space occupied meas-
ures 13 feet by 5 feet. These cells supersede 900
Callaud cells. Formerly, to have increased the service
would have required an additional equipment of Callaud
cells, while now an additional service only requires
more frequent charging. The charging current is taken
from the local lighting company's incandescent circuit,
and is controlled by dynamo regulators.
At the central station in Paris, 1 1,000 Callaud cells of
the larger type were required to do the work now per-
formed by 340 accumulators. This battery is divided
into six distinct sets; two sets each of 50-60 ampere-
hour Laurent-C^ly cells, and four sets each of 60-72
ampere-hour Tudor cells. Two of the Tudor sets — one
IQO
THE STORAGE BATTERY
each for the positive and negative side — supply day cur-
rent for main line and local circuits, and to five Baudot
distributors. The other Tudor sets act as a reserve,
while the two Laurent-C^ly sets furnish current for the
night service, which is comparatively light. The cells
are placed on two strong trestles, arranged in parallel
rows of 1 5 cells each, two tiers high. All connections
are thoroughly soldered. As the charging generator
gives only 70 volts, the batteries are charged in multiple
series; three groups of 20 elements being arranged.
In the fire and police telegraph system at Wilming-
ton, Del., 470 B-3 Chloride cells, 6 ampere-hours ca-
pacity are used. They are divided into 22 separate units,
of from 7 to 30 cells each ; each of the 1 1 units having
a battery in duplicate. Current at 119 volts pressure
passes through a knife switch, a fuse, a polar and
neutral relay, and finally through lamps and resistance
coils to the six charging sets ; the lamps and resistance
coils varying with the cells in circuit. In case of re-
versed polarity, the armature of the polar relay falls on
the back stop, thus completing a circuit through a bell,
which rings until the polarity is corrected. If the
dynamo should stop, the neutral relay opens, and the
circuit is broken, thus preventing batteries from dis-
charging through the generator circuit.
In the Baltimore office of the Chesapeake and Poto-
mac Telephone Co., the outfit consists of two portable
4-volt batteries. The sets are used alternately, and
are carried by two men a distance of three squares for
charging. Notwithstanding the provision of a duplicate
set, and the trouble of carrying batteries, far more satis-
STORAGE BATTERY INSTALLATIONS 191
factory results have been obtained than with the pri-
mary battery of 80 cells, which was formerly employed.
Many have contended that the first cost and the
maintenance charge for storage batteries are so great
as to prohibit them from all use in private plants. That
this idea is a fallacious one may be readily seen by any
one who will take the trouble to look up the cost and
details of a few of the many private plants now in
existence.
In a plant in New South Wales, the total cost of
working is $35, not including the attendant's time, who
in this case is the gardener. The total cost of installa-
tion of everything except the building was Jliooo. The
plant consists of an oil engine, dynamo, and battery of
sufficient size to light 25 lamps two days in winter, or
three in summer. In a French plant consisting of a
0.7S-H.P. gas-engine and dynamo, and a battery of 85
available ampere-hours, with an installation of 25 lamps,
the total cost was only ^(440. .
For a small gas-engine plant, using accumulators, the
cost, as estimated, is:-^ Building, $2420; engine and
20 kw. dynamo (no volts), $7500; 62 cells, S72-ampere-
hours capacity, $4000; total, including switchboard ac-
cessories, cranes, tools, etc., $i5,ocx). For the running
cost, 750 lamps are assumed for 900 hours per year ;
also that 40% of the total energy is delivered by the
accumulators; 5% of the first cost is allowed for their
maintenance. With this as a basis, it is calculated that
from 12.9% to 17.1% of the capital invested will be
earned per year according to the price for gas. With
^ Elektrotechnischer Anzeiger, Nov. 29, 1894.
192 THE STORAGE BATTERY
the direct system, a 500-H.P. plant will cost about
If 47,ocx) ; with a storage-battery system, about $46,000,
the battery representing $22,500, and the steam plant
being just half the former size. The average cost,
according to the quotations from leading battery-
makers, for a battery to give i kw. for 3 hours, will
be $65, or including switchboard, instruments, build-
ing, etc., $95. A i-kw. steam plant will also cost
about $95, but if everything is considered, foundations,
flues, chimney. stocks, etc., the cost will be in favor of
the accumulator plant.
Among the more pretentious private plants may be
mentioned that at EUerslie, the home of ex- Vice-Presi-
dent Levi P. Morton, which comprises a 35-H.P. steam
engine, two C. and C. generators, of 12.5 and 25 kw.
respectively, and 67 G-i i Chloride cells. That of Mrs.
Hearst, at Sunol, Cal., comprises a twin-cylinder gaso-
line engine of 22 brake H.P., a generator, and 60 F-ii
Chlofide cells. That in Mr. Charles T. Yerkes' New
York residence is probably the largest private plant
in existence. In this installation is a 35 actual H.P.
Otto gas-engine, belted to a 30-kw. Siemens-Halske
generator — shunt- wound — and a battery of 60 G-25
Chlojide cells, 2500-ampere-hours capacity at a lo-hour
rate. The maximum discharge is 2000 ampere-hours
at a 4-hour rate. A 7.5-kw. 4-pole "booster" is also
provided.
During the erection of a large music hall in Zurich,
Switzerland, which required an installation equivalent
to 2000 16-C.P. incandescent lamps, it was found that
the night load at the central station, an alternating-
STORAGE BATTERY INSTALLATIONS
193
current station, had nearly reached its full capacity,
that the mains carried their full load, and that the day
load at the station was comparatively small. It was
decided, therefore, to install accumulators, which were
to be charged during the day, and carry the full music-
hall load at night. As only that portion of an alter-
nating-current wave can be utilized in charging in
which the voltage is higher than that of the battery,
two improved PoUak rectifiers were installed, by which
the regulation of the precise point of the wave could
be obtained by simply moving the brushes. Two bat-
teries of accumulators, in all 113 cells, of the Pollak
type were connected to the two sides of the three-wire
system; the capacity of the battery being 1528 ampere-
hours at a 4-hour rate. Current is supplied through
two transformers of 30 kw., and two auxiliary trans-
formers of 15 kw., connected in series with the others,
thus adding their 55 volts to the 105 volts of the. larger
transformers. The auxiliary transformers have ten con-
tacts on different parts of the coil, by means of which
the voltage is controlled. Excellent regulation is ob-
tained, the brushes on the rectifier being seldom moved,
and the efficiency of rectification has been found to be
about 94%. Mr. Pollak claims that such a rectified
current has the peculiar property of accelerating elec-
trolytic processes; which property has not yet been
satisfactorily explained.
A novel scheme has been proposed in France, which,
if successful, will open up a comparatively new field for
accumulators. This is to furnish all towns along or
near the river front with a storage-battery plant, and
194
THE STORAGE BATTERY
then to charge these batteries successively by means of
a floating central station. By this means many towns,
too small to have a complete installation of their own,
may be furnished with electric power with but few of
the attendant expenses.
In a paper read by Mr. B. J. Arnold before the
Northwestern Electrical Association, in St. Paul, Minn.,
the following interesting table of data was given.
DiRBcr Current
D. C. wrrH Accumulators
Alt. C.
Ebei-
feld
Ham-
burg
Barmen
Han-
over
Duftsel-
dorf
Cologne
Available power in kw. .
500
580
225
600
600
680
Expenditure in dollars per
kw
545.53
816.93
908.50
78570
926.35
693-55
Duration of working in
years
5
4
5
2
I
I
Profit, % capital . . . .
14.09
18.05
7.65
"34
7
7.2
Total energy in kw. hr.
distributed
305.794
513.183
122,026
316,114
337.285
307.074
Energy per pound of coal
in kw. hr. distributed .
140
90
181
129
71
Cost per kw. hr. in cents
distributed
570
5.18
6.85
5.02
4-54
6.65
Power utilized divided by
power available in % .
80
79
61
48
51
50
Use of Accumulators
Energy expended for
charge in kw. hr. . . .
59.573
194.733
279.506
Energy furnished by dis-
charge in kw. hr. , . .
42.584
154.836
216,561
Industrial efficiency of ac-
cumulators in % . . .
71.5
794
77.5
Loss in accumulators in %
of total energy distrib-
uted
14
II
13
At the station in Kijew, Germany, employing 72
E.P.S. accumulators, a current efficiency of 83% and
an energy efficiency of 68% is reported, for the three
years ending November, 1894. At Cassel, England, for
STORAGE BATTERY INSTALLATIONS
195
189s, the energy efficiency was 72.5%, and the current
efficiency 85.3%. At the Clichy Sector, in Paris, two
sets of batteries of 250 cells each have been installed,
with a capacity of 2000 ampere-hours at an 8-hour rate ;
one set of batteries are of the Chloride type, and the
other set, the Tudor. For the five months ending
July, 1896, the mean efficiency was 69%, the mean
daily output was 75 % of the total capacity at the nor-
mal rate, and the minimum daily output, 70% of the
total capacity at the normal rate. At Diisseldorf, for
1894 and 1895, the average output for one year was
56.5% of the total output, the total output being
31650,730 ampere-hours. The following table gives the
monthly efficiencies for the same station.
April. 64.7%
May 78.0
June 82.2
July 73-8
August 80.7
September 72.2
October .
November
December
January .
February
March .
52.7%
48.3
44.9
48.4
54.6
56.8
On the Zurich-Hirslanden railway, the introduction
of accumulators has effected a saving of 2.2 pounds of
coal per hour, or about ^(2500 per year. The coal con-
sumption on this road is from 30% to 40% less than
on a similar road where storage batteries are not used.
In Belfast the total efficiency of the station is 91%, and
the battery loss, ^.J^o of the total energy generated;
the total generating expenses are 6.48 cents per kilo-
watt-hour sold. In Edinburgh the total expenses are
3.12 cents per kilowatt-hour sold.
At present, in installing a storage-battery plant, the
196
THE STORAGE BATTERY
battery should be about one-third the maximum full-load
capacity of the station. Figs. 108 and 109 show the per
cent maximum demand factor, and the per cent load-
factor, for some English central stations, both with
and without storage-battery equipments. It may not
come Rmiss to state that the load factor indicates to
m
1^
to *"
K
Ik
z
<
S so
1
>- ^
3
Oj X
""
3
■a
a)
3 5
c
E
"2
ffi
s *"
5
«
k Batte
78
/sten
ns -»
-Non
-Ba1
ttery Sysl
Fig. 108.
what extent the hours have been filled up by work,
and the maximum demand factor assists in showing
what there is superfluous in the generating plant.
In a battery station, the maximum demand factor may,
of course, exceed 100%, as is the case in Bradford;
but in a non-battery station, never, unless its rated ca-
pacity is lower than its real capacity.
STORAGE BATTERY INSTALLATIONS
19;
In conclusion, it may be stated as a fact that in all
stations that have to meet a fluctuating demand, a com-
bined accumulator and steam plant will be found cheaper
in first cost, and cheaper and far more satisfactory in
o
I-
o
it
a
3
to
E
■A
5
1
Y
3^
5
c
3h
_ E
1 «
i
ca
1 ^
CO
'A-
h
Xf.^
ian,
9
n B
attery Sj
fster
ns —
,
• Non-I
lattery S
yste
mt-
J
Fig. 109.
running, than would be a steam plant alone for the same
work. Also that with all railways, whenever more than,
fifteen cars are to be provided for, it will be economy to
use accumulators. The same statement holds wherever
water power is to be employed in direct-current systems.
CHAPTER VIII
APPLICATIONS — TRACTION
Storage-battery traction is, naturally, the most de-
sirable method of traction in existence. The hope of
being able to do away with the unsightly overhead fix-
tures, or the undesirable and costly conduit system, and
of having each car its own unit, led many investigators
to experiment with accumulators for traction purposes.
Experiments tending to this end were carried out as early
as 1880, and in 1 881, at the Paris Exposition, two cars
were put into practical operation, with a fair degree of
success. In 1883 another car was put into operation at
Kew Bridge, London. This car was equipped with a
Siemens generator, used as a motor, and under the
seats were placed 50 cells of about 4000 pounds, total
weight. The car carried 50 passengers, and attained a
speed of about 6 miles an hour, on a level track. It is
said to have run very smoothly.
The success of these two experimental roads en-
couraged the other investigators, and in 1885 and 1886,
two roads were started, one at Antwerp, and the other
in New York.^ Roads were also started in London,
Paris, and Brussels. The cells carried were capable of
running the cars from 35 to 50 miles on one charge,
1 The New York road was constructed by the Julien Electric Co.
198
APPLICATIONS — TRACTION
199
and weighed anywhere from 2000 to 50(X) pounds. A
number of companies have taken up the subject in this
country, and several experiments on a commercial scale
have been conducted in New York, New Orleans,
Washington, Philadelphia, Dubuque, and Baltimore.
These experiments have not, however, been commer-
cially successful, and have, without an exception, been
abandoned, so that not a single road is, to-day (in 1897),
commercially operated by storage batteries in this
country, i,e, is operated independently of the storage-
battery companies, unless we except the Chicago and
Englewood Accumulator line, and the single storage-
battery car operated by the Washington Park and Spring
Grove Railway Co., at Sioux City, Iowa. It is impos-
sible to draw commercial conclusions from the reports
of cars that are under the continual supervision of
electrical experts, employed by the installing rather
than by the operating company.
In Europe, on the other hand, accumulator traction
has a decidedly better outlook, there being 12 lines,
distributed as follows: i each in Austria, England,
and Holland ; 4 in Germany and 5 in France. Besides
this, Germany has two other lines, the Hanover and
Dresden lines, run on the combined accumulator and
trolley system.
Mr. A. H. Gibbings ^ in a paper on Accumulator Trac-
tion gives a number of disadvantages attendant upon
overhead and conduit systems, which do not occur where
accumulators are used.
1 London Electrician, Vol. 34, p. 252.
200 THE STORAGE BATTERY
1. Irregular demands upon the generating plant
The station must be ready to supply, at any time, every
possible demand upon it.
2. A greater wear and tear of the machinery.
3. A greater expense in running at the station.
4. The voltage must be kept constant at all points of
the line.
5. A greater original outlay of capital. For ex-
ample, 250 H.P. is required to run 7 cars either by the
overhead trolley or the conduit system, while for the
accumulator system, at a rate of 80 cells per car for
7 cars, not more than 100 H.P. would be required.
Mr. Epstein, in replying to some criticisms on Mr. Gib-
bings' paper, claims that, notwithstanding the greater
first cost of batteries, the original outlay, in the case of
accumulator traction, is yet considerably less than with
other systems.
There are two other most potent factors in favor of
accumulator traction ; having both been proved by ex-
perience, they obtain still greater weight.
6. For the same amount of heat energy of the coal,
20% more power is applied to the axles, in the case of
accumulator traction than with the trolley system.
7. The power plant required when storage batteries
are used is only two-thirds of that required for a trolley
road.
Mr. J. Bracken, — in a paper read before the National
Electric Light Association at Niagara Falls in 1889, —
in speaking of the relative costs of horse and storage-
battery traction, said that it would cost $400x3 to pur
chase enough horses to run a 16-foot car 120 miles pei
APPLICATIONS — TRACTION 201
day, while it would cost $1500 to purchase enough
storage batteries to do the same work. Batteries, he
claims, can be maintained and replaced for one-half
what it costs to maintain horses.
Overhead wires, besides being unsightly and a source
of danger from the high tension currents used, are a
formidable obstruction to firemen when engaged in
fighting fires. One of the greatest objections to the
direct-supply system, which does not apply where
storage, batteries are used, is that of trouble at the
power-house. When this occurs, all the cars on the
line are often stopped until the trouble can be remedied.
In the case of accumulator traction, there are no ex-
ternal circuits, and lightning is therefore less apt to
play havoc with the electrical part of the equipment.
Furthermore, the " grounding " of one motor does not
affect others, and the durability of the motors is greatly
increased by reason of the low pressure used in this
system.
Although it is acknowledged by every one that
storage-battery traction is the ideal system, yet at
present the disadvantages so far outnumber the advan-
tages, that the outlook for accumulators is exceedingly
gloomy. Perhaps the greatest argument against them,
although decried by the supporters of storage-battery
traction, is the large amount of dead weight that has
to be carried. Crosby and Bell,^ in treating of this
subject, say :
** The experiences of a large nuoiJer ot electric roads,
extending over a number of years, have sho^p that the
1 The Electric Railway, Crosby and BcM, p 24^.
202 THE STORAGE BATTERY
work required per car-mile, on ordinary i6 or i8 foot
cars, is a little less than i horse-power-hour for ordinary
grades, and at a speed of 8 to lo miles per hour. As-
suming the average car-mileage at lOO, which is very
nearly a mean of the roads now running, and with two
changes of battery a day, the weight required would be
about 4000 pounds of battery for the regular service of
the car. The few cars that have been experimentally
operated with the alkaline-zincate battery — carrying
only 2500 pounds of battery — have not, at the time of
writing, been in service long enough to permit a fair
judgment of the results.** ^ Storage batteries have been
so much improved of late years that the above objection,
though still great, is less cogent than formerly. Mr. Ep-
stein claims that the weight of a car, with the storage bat-
teries, is only about 20% more than that of the ordinary
electric car. From various reports, however, the weight
is increased from 20% to 40%, — as on the new Brussels
road, — the average being nearly 30%. ^
On the other hand, Mr. Walker ^ claims that it is im-
possible to place sufficient accumulators on a fully
loaded car to enable it to start on a wet day, if the
1 The service has been abandoned but it should be remembered, in
justice to the storage battery, that the prime cause for the abandonment
of the service was not the fault of the battery itself, but rather the poor
financial management and the large amount of litigation. Besides this,
the batteries were too light to successfully cope with the work they were
called on to do, and the cars were run over old and battered track, and
over long and heavy grades.
* The proportion of the weight of the cells to the weight of the car,
should average about 1:3*5, ^^^ ^^^ ^^^Y ^^S^^ vehicles, may be as low as
1:2.75.
• l/onclon Elec. Review, May 11, 1894.
APPLICATIONS — TRACTION
203
gradient be over 5%. Since the traction coefficient in-
creases with the grade, it being four times as great on
a 3% slope as on a level, it seems that the weight of
lead accumulator, owing to its inability to discharge
with sufficient rapidity, would become so great that its
use would be impracticable. At the time of writing,
the average efficiency of the various accumulators on
the market is 3.5 watts per pound of total weight, on
a 3-hour discharge, using sealed rubber jars. Mr.
Sprague believes that storage batteries will never take
10 tons up a 10% grade until their weight efficiency is
considerably higher than at present. According to
Professor Anthony, the extra batteries which would
have to be kept on hand to draw from during the
" rush " hours would cost more than the plant it would
save.
The greater weight of an accumulator car becomes
most objectionable in the crowded portions of the city,
where it is necessary to stop and start frequently. The
method, therefore, of using them in combination with
the trolley, the trolley to be used in the suburbs and
the accumulator in the city, as in Hanover, is the reverse
of the most favorable conditions for storage-battery
traction. Where a few cars are to be used on a long
line, the storage-battery system will probably be found
to be the most economical as to cost and equipment;
but where a large number of cars are to be run, the
system of direct supply will be the best.
In 1894 Mr. Epstein published a table in one of the
London electrical papers, giving the relative merits and
costs of the three systems, — overhead trolley, under-
204
THE STORAGE BATTERY
ground conduit, and accumulator system; his data, as
far as possible, being taken from actual working. Some
of his figures are as follows : ^
For the track construction, including the overhead
and underground work, the storage-battery systems
cost $29,000 per mile; the conduit, $36,500 per mile;
and the overhead trolley, $31,400. This does not in-
clude the cost of feeders, for which an extended table
is given, covering a number of different conditions.
For car equipment and the like, using 40 passenger
cars, the expense is $5890 per car for the accumulator,
and $3550 per car for conduit and trolley roads. For
the steam and electrical equipment of the plant, $142
per ton propelled is required for an accumulator road,
$245 per ton propelled for the conduit or trolley system.
These latter figures are based upon the assumption of
2.2 I.H.P. per ton of weight propelled for the three sys-
tems. For the electrical plant, 2.4 kw. are assigned for
the overhead and conduit systems, and 1.5 kw. per ton
propelled for the accumulator road. Mr. Epstein be-
lieves that the overhead and underground systems have
an efficiency of 27%, while that for an accumulator line
is 33%.
The average life of a storage battery is about 12,500
miles, and assuming as before 100 miles per day as the
average car-mileage, the battery will have to be replaced,
in part, every 125 days, or three times per year. From
the latest reports of the storage-battery roads in Paris, it
would appear that the total life of a plate is at least
60,000 car-miles for the positive and 90,000 car-miles
* London Electrical Review, Jan. 5, 1894.
APPLICATIONS — TRACTION
205
for the negative, at which rate the positive plates will
last for about i year and 8 months. On the other
hand, the depreciation in the direct-supply systems is
rarely more than io%.
Dr. Louis Bell,^ a few years ago, made some tests on
the various systems of traction with the results given in
FT
the following table, where —-- = economic ratio = the
W
product of the commercial efficiency and the useful
weight, divided by the total weight. If better batteries
had been used, the economic ratio for the storage-
battery systems would have been at least 0.25 instead
of 0.18 as obtained. Some tests on an Antwerp road
gave 0.29.
System
EL
W
Power per Umr of Useful Work
Direct electric
Storage battery ,
Cable ....
Lx)comotive . .
0.385
0.180
0.500
0.500
2.62
5-55
2.00
1.72
In the report of a commission on the various systems
of traction by electricity, the following figures, showing
the coal consumption per car-mile, were published:^
For the trolley systems at Havre, 6.03 pounds per
car-mile ; for the accumulator system at Paris, with the
old cars, 9.2 pounds; in the new cars, where energy
is stored on the down grade, 6.56 pounds; for the com-
pressed-air line in Paris, 39.03 pounds ; for the SerpoUet
1 London Electrician, Vol. 23, p. 609.
2 Memoires de la Societe des Ingenieurs Civils, January, 1896.
206 THE STORAGE BATTERY
Steam line in Paris, J, 6 to 10.6 pounds ; for the trolley
system at Marseilles, J.y pounds, this including the
lighting of the cars and the power station.
In a paper by E. A. Ziffer,^ read before the Inter-
national Street Railway Association at Stockholm, it
was stated that in the Belpaire steam system, as used in
Belgium, the coal consumption was 5.3 to 8 pounds per
car-mile, and the water consumption, 7.1 gallons per
car-mile. In the Thomas steam system in Saxony,
the heaviest grade being |^%, the coal consumption was
7.1 pounds per car-mile; and in the Rowan steam
system, used in Denmark and Germany, the coal con-
sumption was 9.6 pounds per train-mile, the heaviest
grade being 0.5%.
Probably the largest installation for the operation of
storage-battery cars is in Paris, three accumulator lines
having been established there in 1892. The following
statistics regarding the road were taken from a paper
read before the Soci6t6 Internationale des Electriciens,
in April, 1895, by M. Sarcia. According to this report,
the cost of operation was 16.7 cents per car-mile with the
old method of placing the batteries ; that is, under the
seats of the car. By the new method, that of placing
them in a tray between the two separate trucks, the
cost of operation, including maintenance, handling,
motive-power, motormen, and maintenance of trucks
and motors, is 1 1 cents per car-mile. In the new cars,
also, "recuperation" is being used with very good
results. The controllers are so constructed that, on
descending a grade, much of the energy used in ascend-
1 St. Ry. Jour., New York, Vol. 13, p. 26.
APPLICATIONS — TRACTION
207
ing it is recovered. Fifty-six Laurent-Cely cells — the
French Chloride battery — of 230 ampere-hours ca-
pacity are used ; each cell containing 9 plates, about
8 inches square. Experience has shown that the life
of the positive plates is 8700 car-miles, at the end of
which time the active material begins to drop out con-
siderably. The plates are then removed, and the active
material is reintroduced in the form of a paste, after
which operation the plates are nearly as good as new.
By this method the minimum life of the positive plates
is 60,000 car-miles, while that for the negatives is 93,000
car-miles. The positive plate contains a central core
of antimonous lead (10%). This core is grooved, thus
constituting a series of small receivers for the active
material. The weight of the loaded car is 12.9 tons,
that of the battery 1.9 tons. The coal consumption per
car-mile, in 1893, was 12.9 pounds; in 1894,9.2 pounds;
and in 1895, when "recuperation " was used, 6.56 pounds.
The power per car-mile at the power station is 1.12 B.T.
units.
The Theryc-Oblasser accumulator has been lately
tested by the French Government. It has been found
that a horse-power-hour could be obtained with 48
pounds* total weight, in a volume of -J- of a cubic
foot, and that the battery could stand a discharge of 6
amperes per pound, the average rate being 1.36 to 1.8
amperes per pound. An accumulator line has recently
been completed between Nice and Cimiez using Laurent-
Cdy cells per car.
The Belgian Government has decided to install a
storage-battery line between Brussels and Tervueren,
2o8 THE STORAGE BATTERY
and the following advance data have been given out
concerning the road : the road is 9 miles long; the cars,
52.5 feet long, mounted on two bogies, ready for service,
weigh 42 tons, of which the battery weight is 12 tons;
the motors are compound-wound, for an E.M.F. of 500
volts ; the speed is to be 31 miles per hour and is to be
reduced to 18.5 miles on the steepest gradients.
The PoUak system is soon to be tried experimentally
in Frankfurt-on-the-Main, the batteries to be charged on
the car at the end station.
Since April, 1897, accumulator traction has been
in regular service at Ludwigshaven-on-the-Rhine ; the
mean speed being 30 miles per hour.
A line was started from Hagen to Vienna, using the
Waddell-Entz cells. This line, which was running ex-
perimentally for only a short time, was found to be so
successful that it was officially opened and accepted in
July, 1895. The road is 1.9 miles long, the sharpest
curve has a radius of 50 feet, and the steepest gradient
is 4%. Each car carries under the seats 136 accumu-
lators, of 300 ampere-hour capacity, each accumulator
containing 13 plates. One charge is intended to run
the car about 20 miles. The weight of the battery is
about 2 tons, and the weight of the car, ready for service,
about 10 tons. A test showed that a horse-power-hour
could be obtained with about 90 pounds' total weight ;
and that the power per car-mile, required at the power
station, was 1.28 B.T. units. The E.M.F. is 0.85 volt,
and the energy efficiency 60%.
A report published by a traction company in Birming-
ham, England, a company controlling four systems.
APPLICATIONS -- TRACTION
209
(horse, locomotive, cable, and storage-battery), show
the relative expenses, in cents per car-mile, for the year
ending June, 1893.^ This road, which has not paid ex-
penses since 1891, is still continued, but it is believed
a change will soon be made from the storage battery to
the overhead trolley. One reason for increased ex-
penses is the increase in wages and the price of raw
material.
•
HORSB
Steam
Electric
Gross receipts
Total cost of traction . . .
21.58
20.24
32.20
12.64
31460
22.44
32.24
33.10
The following table ^ shows the ratio of operating
expenses to receipts for five years, for the accumulator
line.
Year ending June
Operating Expenses
-^ Total Receipts
No. Car-Miles run
1891
1892
1893
1894
1895
67.13
1 1 7.81
102.56
IOI.61
I31.21
138.396
188,760
140,993
139.123
138,925
The batteries first used on this line were of the E.P.S.
type, but no data concerning them are available. The
next tried were the Epstein cells, introduced in 1892.
Twelve sets of 92 cells made an average of over i5,cxx)
car-miles without removal. With these cells the cars ran
1 Elec. World, New York, Vol. 22, p. 214.
* London Elec. Review, Vol. 37, p. 309.
210 THE STORAGE BATTERY
very regularly, and under the trying conditions of a
severe winter. The Epstein cells were run under a
maintenance contract of 3 cents per car-mile, which
amount, it is claimed, should have proved veiy profitable
to the contractor, and might have been reduced. These
batteries ran a total of i88,oc» car-miles, at a total of
28 cents per car-mile. The accumulators now in use
are of the Chloride type, and were installed in 1894.
There are 17 batteries, each battery consisting of 72
cells. The batteries weigh from 1.75 to 2.75 tons, and
are used on cars which, when filled with passengers,
weigh, without batteries, about 10 tons. The batteries
are considered inefficient when they refuse to do more
than a 2-hour run. These batteries are not bought out-
right, but are rented on a basis of the car-mileage. The
present contractors consider that the conditions of run-
ning on this line are very much against the financial
success of accumulators. The total cost for the mainte-
nance of batteries is less than 10% of the total cost per
car-mile run.
On Jan. 7, 1896, three cars went into service on a sec-
tion of a tramway between Berlin and Charlottenburg.
A car with 29 passengers weighs, complete, about 11.75
tons, — the weight of the accumulators being about 3.6
tons. The cars are equipped with 124 Schaeffer-Heine-
man accumulators, containing five positive and five
negative plates in a celluloid cell, protected by a wooden
casing. Two of the cars are in constant use and the
third is employed in carrying the batteries to and from
the charging station, a distance of 1.4 miles from the
terminal of the line. The steepest grade on the line
APPLICATIONS — TRACTION 2 1 1
is 3.6%, and 1640 feet long. The battery plates are
0.1 17 inch thick, 13.65 inches high, and- 7.8 inches
long, and are separated from each other by a distance
of 0.234 inch. The cars have been in regular ser-
vice since Jan. 12, 1896, with most gratifying success.
The consumption of energy is 4.5 kw. for a speed of
7.44 miles per hour. The battery runs regularly 6y
miles per day on one charge, consuming in that time
144 ampere-hours; the car has, in fact, run 105 miles
on one charge. The consumption per car-mile is 517
watt hr., which includes lighting the car with 7 16-C.P.
incandescent lamps. The current is brought from a
Berlin central station at about 4 cents per kilowatt-
hour, the total cost of operation, on that basis, being 8
cents per car-mile.
The Brookline, Mass., Street Railway Co. are about,
(1897), to install an accumulator line using Chloride
batteries on a 22-foot car. According to the contract
with the Electric Storage Battery Co., the latter are to
operate the road for at least six months to the satisfac-
tion of the owners, and are to pay equipment costs in
case of failure.
The accumulator line in Holland, to which reference
has already been made, lies between The Hague and
Scheveningen. This road has 7 miles of track and
runs 14 motor-cars, the maximum gradient being i : 50.
The weight of the loaded car is about 1 5 tons, and the
weight of the batteries 4 tons — Julien accumulators
being used. The maximum distance run on one charge
is 44 miles, and the positive plates remain in service,
without renewal, from 9000 to 13,000 car-miles. The
212 THE STORAGE BATTERY
cost of maintenance is 1.7 cents per car-mile, and the
cost of handling 0.46 cent per car-mile.
The Madison Ave. road, in New York City, was at
one time equipped with Chloride batteries. Sixty cells,
containing 9 plates each, were placed in a box carried
by the truck of the car. Four cars were run on this
road for about three months, but the expense of running
was found to be too great. On an experimental car in
New York City, using the Acme battery, the average
energy required per car was 1.07 horse-power-hours.
This car ran from September, 1892, to December, 1893.
The Chicago-Englewood line, which has a franchise
for 54 miles of railroad, is expected to be in complete
operation very shortly. This, the company claims, is
the first real attempt to operate a storage-battery street
railway under conditions that are in every way favorable
to success. To begin with, the power plant is of the
most modern type. The units are connected according
to the Arnold system, and will be operated at an ap-
proximately constant load. Three potentials will be
used in charging, — 150, 170, and 190 volts, — and in
this way all unnecessary loss in. rheostats, or counter
E.M.F. cells, will be obviated. The track will be laid
with 80-pound girder rails, and will be ballasted with
stone. The road-bed is practically level. Forty cars
will be run, each car containing 72 Chloride cells, of
4 tons' total weight. These cells will be capable of de-
livering 4CX) amperes at 1 50 volts, and will be contained
in a tray mounted on the truck. One 50-H.P. motor
will be used. The company expects to be able to
change the batteries in three minutes.
APPLICATIONS — TRACTION
213
A mixed trolley and accumulator system is being
tried in Hanover, Germany, the trolley being used in
the suburbs and outlying portions, in all about 13.5
miles, and the accumulator in the dense and crowded
portions, about 11 miles. Charging proceeds continu-
ously where the trolley is used, the lengths varying
from 1.75 to 5 miles, and discharging in lengths of road
varying from 3 to 7.5 miles. A car seating 20 people and
weighing, ready for service, 8.50 tons, carries 208 Tudor
batteries, — weight 2.87 tons, — of 25 ampere-hours'
capacity, at a i-hour rate. The plates are placed in
rubber jars, hermetically sealed. An additional lamp
is cut in or out, according as the trolley or battery cur-
rent is used, and another device disconnects the ground
return when the battery current is to be used.
The cost of maintenance for 1896 was 0.35 cents
per car-mile, including renewals. During regular work
only 25% of the energy is used, the remainder being
held as a reserve. With a mean of 8 charges and
discharges, an efficiency of 74% was obtained. The
following figures concerning the road may be of
interest :
Watts
Watts
Month
Kw.Hr.
Ace. Car-
MlLBS
PBR
Pound
OF Coal
Month
Kw. Hr.
Ace. Car-
Miles
per
Pound
OF Coal
Jan.
58*590
5»973
706
July
107,970
31*479
1030
Feb.
55.337
5*504
7»S
Aug.
116,856
129,989
35.026
1066
Mar.
61,633
5»93i
Sept.
40,871
1060
Apr.
83,326
17,045
Oct.
136,821
46,758
1058
May
106,765
27,010
9sl
Nov.
161,941
'^n
lOII
June
100,033
25*387
1042
Dec.
176,949
1009
214
THE STORAGE BATTERY
The results have been so satisfactory that the com
pany has decided to equip all but one of its lines with
this system. This exception is to be operated entirely
by storage batteries. The Dresden Tramway Co. have
likewise decided in favor of the mixed system. The
proposed electric railways in Ghent, Belgium, will also
use the mixed system.
A report from the road in Dubuque, which has
recently been closed, gave the total motive power
expenses as 7.8 cents per car-mile, of which the bat-
tery expenses, including shifting, cleaning, mainte-
nance, etc., was 5.29 cents per car-mile.
Mr. Manville, in discussing the relative merits of
trolley and accumulator traction, states that the cost
of running on the English accumulator lines exceeds
18 cents per car-mile, while that for the overhead
trolley lines is only 9 cents per car-mile. Although
many companies claim to be able to maintain the
batteries for 3 cents per car-mile with profit, the ma-
jority of the reports that have been received from
roads in actual operation, indicate that the cost of
maintenance is nearer 5 cents per car-mile; [that for
the Julien accumulator line, lately operated in New
York City, was 5.3 cents per car-mile. The cost of
operation, including the operating force, the battery
men, the repair-shop force, coal, oil, waste, water,
renewals, and depreciation, was 9.32 cents per car-
mile.] The experience in Brussels has been that
the cost of storage-battery traction is greater than
with horses. It may be stated as a fact, that at the
time of writing, the best efficiency of storage batteries
APPLICATIONS — TRACTION
2IS
is from i.i to 1.2 kw. hr. per car-mile, on a fairly
level track.
From a paper by F. S. Badger, on the cost of con-
struction and operation of electric railways, the aver-
age cost of power per car-mile for twenty-two trolley
roads, running from 3 to 140 cars each, and having a
length of track of from 3 to 51 miles per road, was 1.96
cents, and the average maintenance cost of rolling stock
was 1.8 cents per car-mile. The complete cost of line
equipment with underground feeders, not including
the road-bed, is about j^ 12,000 per mile of single track.
On the other hand, the cost of storage batteries is
about ;?38oo per car. It is well known that the total
maintenance cost of power plant, rolling stock, and
battery is at least 1.3 cents per car-mile more than
with the direct systems; but the smaller interest
charges, and less cost of power, should be consid-
ered. This, it is probable, will balance the extra cost.
The experiments made by M. Sarcia ^ on a St. Denis
car show plainly the value, from a financial standpoint,
of "recuperation." As before stated, by recuperation is
meant the recovery of energy on the down grades and
the charging of the batteries with it. These experi-
ments cover a period of 100 trips, during which all the
energy used was measured, as also that which was re-
covered. The motors were separately excited, and had
an adjustable resistance in the field circuit; the arma-
ture resistance being only used for obtaining a more
gradual start. By the adjustment of the field resist-
ance, therefore, the voltage of the motor, when running
1 L'Industrie Electrique, Dec. 10, 1895.
2i6 THE STORAGE BATTERY
as a generator, could be easily controlled. For the
coefficient of traction he uses that measured at the
terminals of the motor, including therefore all subse-
quent losses. Outside of Paris the Vignole rails are
used, and in the city itself the Broca rail. The coeffi-
cient of traction varies from 16,72 pounds per ton on
the Vignole rail to 34.54 pounds on the Broca rail.
With a traction coefficient of 22 pounds per ton on
a level track, and a grade of 10%, he found that ^T%
of the energy spent in mounting was recovered. With
the same traction coefficient 42% was recovered on a
4% grade, 23% on a 2% grade, and zero on a 1%
grade. With a traction coefficient of 11 pounds per
ton, he found that 23% of the energy was recovered
on a 1% grade, a result which shows the importance
of reducing the traction coefficient to as small a value
as possible.
Besides this, it should be pointed out that, while a
carefully laid and substantial track is necessary in
every system, on an accumulator line it is doubly so;
for not only do the irregularities of a rough track and
the consequent jolting injure the accumulators, but the
heavier cars pound the track in a very serious manner.
In building a storage-battery road it would be well to
follow the example given by the Chicago-Englewood
line.
In the light of these reports one is driven to the con-
clusion that not only is storage-battery traction more
expensive than other systems of electric traction, but
that unless the batteries are considerably improved it
is likely to remain so.
APPLICATIONS — TRACTION
217
In devising cells for traction purposes, many difficul-
ties arise. Owing to the heavy first cost and the in-
creased weight, the number of cells must be as small
as possible, and they must be so constructed that their
weight efficiency is high, their internal resistance low,
and their capacity large. The metal grids must be
strong enough to withstand the jolting and the oscilla-
tion, and they should be so constructed that the active
material will not fall out. The employment of distance
pieces tends to reduce the space needed for the electro-
lyte, and should therefore be avoided as much as pos-
sible. Durability and a high rate of discharge are
naturally the main requirements of a good traction
battery. In order to obtain these, it is necessary that
the conducting space should be protected from local
action. Many investigators believe, and practice has
proven their views to be correct, that the forming
should proceed from without inwards; and that the
discharge should never, under any circumstances, be
allowed to reach the support plate.
Fitzgerald believes that the reason such poor results
have been attained heretofore is that the present style
of accumulator is not adapted to the conditions of
traffic. Besides this, the weight of the electrolyte
used is far in excess of what is required. The Lon-
don Electrician^ in an editorial on Dec. 13, 1895, says:
* "It is probable that the electrical industry has yet
to produce a battery which is commercially adapted
to the conditions of traffic, and its non-existence is
one of the most serious hindrances to electrical prog-
ress, possibly the most serious of all. Although a
2i8 THE STORAGE BATTERV
real commercial traction battery cannot be said to exist,
we do not care to assert that the outlook is hopeless."
According to Fitzgerald,* a cell should be rejected
for traction purposes unless, after a trial of one month,
it complies with the following conditions :
1. The mean ratio of power to gross weight should
attain, and should not exceed, 1.2 watts per pound.
2. The weight of an accumulator per ton of traction
weight should not exceed 321 pounds, and this should
be able to supply 385 watts as an average for the whole
run; he prefers to take 1.35 watts per pound as a
minimum value.
3. The mean ratio of discharge for the whole run
should attain 0.58 ampere per pound.
" Until definite reports are received," in the words of
Crosby and Bell, "one is not justified in counting too
much on the hopeful results of the preliminary experi-
ments. An approximate statement from the Dubuque
road gave 1.5 horse-power-hours as the output required
per car-mile from the station. This figure affords a
basis for a rough comparison with the trolley system.
The average station output in the latter case is i horse-
power-hour per car-mile. Remembering that on ac-
count of the greater weight of an accumulator car
about a third more power is required to propel it, the
relative efficiencies of the two systems are shown to
be not far from those deduced elsewhere." ^
These figures give 40% for an accumulator road, and
a little less than 50% for a system of direct supply.
1 London Elec. Review, April 3, 1895.
« The Elec. Railway, Crosby & Bell, 2d ed., p. 252.
APPLICATIONS — TRACTION
219
As regards electric vehicles, the conditions are so
different, that batteries may be designed with a more
exact knowledge of the demands that will be put upon
them. That this is so is proven by the fact that electric
carriages are coming more and more into popular favor,
nearly every carriage-maker of prominence having made
arrangements for building such carriages. M. Claude,
in U Industrie Electrique, for Oct. 10, 1897, gives the
following equation for electric carriages, where M rep-
resents the weight of the carriage in kilogrammes ; j,
that of the battery; ;r, their specific energy in watt-
hours per kilogramme ; and k^ the mean specific energy
required per day for traction, k being expressed in
watt-hours per kilogramme of total weight.
k{M'\-y)^xy.
Hospitaller has figured that a mean of 100 eflfective
watt-hours per ton kilometre is required in a pneumatic-
tired, ball-bearing carriage, and Messrs. Salom and
Morris and others have arrived at the same conclusion.
Both theory and practice agree that the weight of the
battery should vary between the limits of 25% and
50% of the total weight. If lower than 25%, the dis-
tance which the carriage may cover on one charge will
be too small, and if larger than 50%, the useful weight,
that is, the weight allowed for passengers, will be too
small, and the difficulties in the construction of a light
carriage will be enormously increased. The usual
practice is to make the accumulator weight about
35% of the total, which corresponds to a speed of about
1 1 miles per hour on a level road. M. Claude estimates
220 THE STORAGE BATTERY
that the total cost per day per carriage is about ^1.63,
while the corresponding cost for animal traction is
^3.09; Bixio has figured that animal traction costs $130
per carriage per year, petroleum traction jfio6 per
carriage per year, and electric traction $96 per carriage
per year. Practice has already shown the electric
carriage to be more economical, and that it gives better
service than any other system in existence.
CHAPTER IX
CONCLUSIONS
When charging accumulators, care must be taken not
to use too high a current density. It is evident from
what has been said regarding the theory of accumulators,
that the internal resistance of a cell will be highest
immediately after discharge. Too large a charging cur-
rent, therefore, will evolve heat, thus wasting energy.
There will also be another loss by a too copious evolu-
tion of gas. On the other hand, too low a charging
rate will be found to be as bad as one that is too high,
since it tends to produce the white sulphate on the
positive plate, instead of the peroxide. Gladstone and
Tribe discovered this fact, and note it in their book : ^
" If we take two plates of lead in dilute sulphuric acid,
and pass a current from only one Grove cell, a film of
white sulphate, instead of peroxide, makes its appear-
ance on the positive plate, and the action practically
ceases very soon. If, however, the current is increased
in strength, the sulphate disappears, and peroxide is
found in its place." It is usually found that a lower
rate than one-thirtieth of the normal capacity of the cell
is detrimental.
J Chemistry of Secondary Batteries, p. 1 1.
221
222 THE STORAGE BATTERY
When the charging current is too large for the area
of the plate, "buckling" will ensue, and soon after,
short-circuiting will take place. ** Buckling " has been
found to be due to the unequal expansion of the plates.
The paste expands on discharge, and vice versa^ and it
is imperative that such expansion and contraction should
be uniform over the entire surface. In other cases,
where the current is not large enough to cause " buck-
ling," but still too large for the active area of the plate,
"boiling" ensues, due to the energy of the current
being wasted in the decomposition of the electrolyte,
instead of being used in the formation of peroxide.
Many rules have been formulated as to the best rate
of charge. Mr. J. D. Dallas believes that if the total
area of the positive plates, taken in square inches,
be divided by 20, the result will give the most eco-
nomical charging rate. Messrs. Gladstone and Tribe
found that a charging rate of 6.5 milliamperes per
square centimetre, calculated on the original surface of
the plates, was the best : this corresponds to nearly 6
amperes per square foot. The plates have, however,
been improved so much since then, that 8 amperes per
square foot is now the usual rate. Sir David Salomons^
has formulated the following very convenient rule for
calculating the best charging current. "Multiply the
total number of plates in a section by 2. The result
will be the best charging current for that section." He
also found that the injurious current for a section, that
is, the minimum current to be used, may be taken as the
number of plates in a section divided by 10. The
1 Elec. Light Installations, Vol. i, p. 98.
CONCLUSIONS
223
E.M.F. of the charging current at starting should, under
ordinary circumstances, be about 5% higher than the
normal E.M.F of the battery. When, however; the
battery has been overdischarged to a great extent,
the difference in pressure should not exceed 2%, other-
wise too large a current will flow.
It is held by many that the best method for charg-
ing is to use a constant voltage. They claim as the
advantages :
1. Less wear and tear of plates.
2. More rapid charging in the initial stage.
3. Suppression of a too rapid formation of gas,
and consequently better conservation of the electrodes,
prevention of overcharging, and subsequent useless
work.
4. Reduced voltage of dynamo.
5. Less supervision required.
It has been found that when charging at 2.3 volts per
cell, 50% of the total energy is stored during the first
hour, 75% at the end of the second hour, and 83% at
the end of the third hour.
On the other hand, it is held that this method involves
a greater first cost, and consequently greater interest
charges, and that the decreased voltage of the dynamo
is more than compensated for by the increased amperage
required.
Figs, no and in show the relative values of the two
methods of charging, — at constant current or at con-
stant voltage. They are both taken from a Gadot
cell, containing 9.35 kilogrammes of plates. In Fig.
no the battery was charged at a constant current
224
THE STORAGE BATTERY
of 10 amperes, nearly i ampere per kilogramme of
plate, and in Fig. iii, at a constant potential difiFerence
of 2'.23 volts. It will be seen that at the end of three
hours, with a constant potential difference, all but 17%
of the capacity had been obtained, while to obtain this
same capacity with a constant current required 7 hours.
In some cases the only current to be obtained for the
charging of batteries is the alternating current. In
Q.
3
— ^J- 40 r6«
15
100
^^
^
M
^
^ lU
G-
40
10
L«
-^
0.
3
00
-40
'
^
^
1
1
-_i
1
<
JW
.^
III
III!
1 1 1
— f=
i
1
i!i 1
I 1...
!
jLU-
1 1 1
z
b.
O
4
HOURS
Fig. 1 10.
such cases, a machine called a rectifier must be used
for changing the alternating to a uni-directional current.
By means of this machine, only that portion of the
current wave is utilized in which the voltage is higher
than that in the battery. It is claimed that such a
rectified alternating current has the peculiar property
of accelerating electrolytic processes, and is, therefore,
peculiarly adapted for charging purposes. It has not
yet, however, been made clear that such rectified cur-
CONCLUSIONS
225
rents really have this property. A central station in
Zurich, Switzerland, has had occasion to make use of
such a machine, with gratifying results.^
60
b
'\
a-a-A. K
b'b-=Cha
c-c— E. h
. Supplie
rging Cur
1. F. durir
1
-ent
g Charge
40
d-d=P. C
. at Term
nals duri
ig Charge
a
80
y^
90
/
/N«0
S
oe
III
e \
kA
1
1
III
!j
Q.
Q.
0.
>
$■ —
V-
1
\
<.3
M
t\~
— -j
1
tf*^
c /
\\
1
1
1
1
L 1
10
1
i
1 _
X.
W
/!
/I
1
1
1
1
1
! \
1
1
1
\^
/
/a
1
1
1
1
il. 1
\ 1 1
..Ill
1 f I«
100
o
!<<
-I
CO
<
u.
O
H 1 IH
TIME IN HOURS
Fig. III.
When a cell has been discharged below a certain
point, the excessive loss of conductivity, owing to too
large a proportion of the active material having been
converted into sulphate, will be apt to injure it, and the
^ Vii^ page 192.
226 THE STORAGE BATTERY
contact between the peroxide and the support plate may
be broken. The recharging of such an exhausted cell,
when, indeed, it is possible to recharge it at all, must
be carried on very slowly. It should be recharged
as soon as practicable, since the cell is in a weak state,
and is the seat of slow reactions, in the nature of those
occurring during discharge. When it is possible to re-
charge an exhausted cell, the current used should be at
least 30% below the maximum charging rate. Care
should be taken that the scale, or powder, which falls
off does not stick between the plates. If it were not
for the fact that the adherence of the white sulphate to
the peroxide beneath, in an exhausted cell, is very weak,
it is probable that the recharging of a battery, when in
such condition, would be impossible.
Herr Briiggeman has concluded from some investi-
gations he has made that the charging should be
stopped at the beginning of the sharp bend of the
curve; since before that point is reached the energy
lost by the evolution of gas is very small, while after
that it becomes very great. This corresponds to Salo-
mon's rule, that every cell should boil in an equal de-
gree when charging is stopped. It should be borne in
mind that this rule refers only to the regular chargings,
and not to the first or forming charge. In the latter
case the charge should be continued for at least 30
consecutive hours, without interruption. If, however,
such a run be impossible, it should be continued for
at least 10 hours a day, for 3 consecutive days; the
former method being preferable. When the evolu-
tion of gas becomes excessive, which will occur toward
CONCLUSIONS 227
the end of the charge, it is well to decrease the charg-
ing current.
With the pasted type of plate, the question of the
duration of the first charge is far more vital than with
the Plants type ; since, with the former, there is great
danger of a coating of sulphate being formed between
the active material and the grid ; especially if the plates
are allowed to stand in the acid before charging, or if
the charging current be stopped before the active ma-
terial be thoroughly formed. If this coating of sulphate
be once formed, it is almost impossible to get the plate
in first-class condition, as the sulphates insulate the
active material from the grid, and thus cause the action
to take place on the grid itself, instead of in the active
material. This applies to the positive plate, rather than
to the negative, since it is easier to reduce the sulphate
to spongy lead than it is to oxidize it
The term " boiling " does not indicate the rise in tem-
perature of a battery, but rather the great evolution of
gas which occurs when a cell is nearly charged. It is
evident that as charging proceeds the amount of sul-
phate to be converted into peroxide becomes less and
less, and the plates therefore become virtually smaller,
so that the current becomes too large for the work de-
manded of it. The result is that that part of the cur-
rent not actually used in the formation of peroxide
decomposes the electrolyte into its constituent elements.
It will be noticed that when an accumulator has been in
use for a considerable time, the gases evolved do not
produce such a milky appearance of the liquid as be-
fore. The reason for this is that the plates are better
228 THE STORAGE BATTERY
formed ; consequently a larger charging current can be
used without producing " boiling."
The color of the positive plates should be, when
formed, of a dark red or chocolate, but when fully
charged their color will be much darker, resembling
more that of a wet slate ; the negatives, although also
of a slatish color, are always considerably lighter than
the positives. To one who has become accustomed to
studying the plates, it is a comparatively simple matter
to tell the relative amount of charge that a cell may
contain.
In using an accumulator care should be taken that,
at the close of the distharge, at least 25% of the total
capacity of the cell remains unused. The best modern
practice is to leave 30%. In other words, the voltage
of the cell at the close of the discharge should be never
lower than about 1.8 volts, under load. All manufact-
urers indicate the point at which the discharge should
be stopped, and the battery should be run in accordance
with their directions. Mr. Griscom ^ gives the following
reasons why it is undesirable to run a battery lower
than about 1.8 volts.
" It should be understood that a full discharge, i,e, a
discharge to a point situated at the beginning of the
steep part of the voltage curve, is working a battery to
the danger limit, and is undesirable for the following
reasons :
" I. Regulation is troublesome.
" 2. The efficiency is low.
" 3. Dangerous molecular changes take place, as indi-
1 Trans. A. I. E. E., Vol. 11, p. 302.
CONCLUSIONS
229
cated by the changes in the internal resistance and in
the E.M.F., as well as by "buckling."
"4. Uneven plates discharge into one another after
the circuit is interrupted.
"5. The life of the battery is shortened.
" By classifying the failures and successes of a num-
ber of observations made on various batteries, the truth
dawned upon us that whenever a battery was exhausted
to its full capacity daily, its life did not exceed 500
charges; but whenever it was worked within two-thirds
of its capacity, complaints were unknown. It is only
necessary for the engineer to remember to add 50% of
the capacity, as a factor of safety, to the maximum load,
just as he allows several hundred per cent in calculating
the strength of a bridge or axle.
" This additional amount is not a dead loss in invest-
ment. It produces many countervailing advantages.
It provides a very effective and safe reserve for cases
where the charging breaks down, and it increases the
actual efficiency of the battery, which rises from about
80% to nearly 90%, when used with sufficient reserve.
And for cases where it is necessary to maintain a con-
stant potential difference, it raises the efficiency niuch
more, because in these cases the commercial efficiency
must be rated, not from the average point of E.M.F.,
but from the lowest point to which the battery falls
on discharge, and when used in this way the potential
difference drops only 2.5%."
When the plates of a cell are discharged beyond the
maximum discharge permitted, nearly all the material
of the positives becomes lead sulphate, which is soon
230
THE STORAGE BATTERY
decomposed into the higher sulphates, which ruin the
plates and cause them to " buckle " while charging.
A series of experiments has been lately conducted
with various batteries to determine in what manner
they are affected by heavy discharges. The conclusion
which has been drawn from the work is that there is
no objection, as a rule, to short high discharges, as
long as the maximum rate is not affected. It is the
prolonged discharge which is especially injurious to a
battery, since the sulphating, which then takes place, is
the cause of " buckling," especially when the discharge
is not immediately followed by a charge. If, however,
the discharge is too large, it is likely to drive the paste
out of the plates. It is the quantity of gas which is
driven from the plates at the moment of sudden heavy
discharges that causes the injury. Although all makers
give the best rates of discharge for their plates, it may
be well to state, as an approximate rule, that a good
rate of discharge is about 8 amperes per square foot
of positive plate. It is on this point — that of being
able to withstand heavy discharges — that the superi-
ority of the Plants type of plates depend. A plate
having a large surface, covered with a thin layer of
peroxide, freely exposed to the action of the electrolyte,
will be found to have a far greater capacity per pound
of plate, for rapid discharging, than is the case with
a plate having a thicker layer of active material. The
capacity of such a cell will evidently be but little affected
by the rate, and the watt-efficiency will not be nearly so
much affected by the dilution of the electrolyte in the im-
mediate neighborhood of the active material. Fig. 112,
CONCLUSIONS
231
which was taken from a Chloride plate, shows the vari-
ation in capacity at different rates of discharge.
In testing a cell, care should be taken that the source
of current be steady. A battery of cells in multiple
series will be found best, or, if that be not convenient,
a source of current of considerably higher voltage and
XM
p
1^
=
c
rr
PF
r
p
p
n
rT:
--L
T^
ri
r
p
ET
p
p
p
p
p
r
p
p
p
p
FF
.«
~
n
^
-
— -
~:
-"~hT^
--^
•^
^ 1
:z
-
1
-
=
Z
Z
—
■^
I-
—
—
""
~~
^ L.
^
_
—
_
_
1 —
_ -
'
—
_
_
. —
■-*^
_
_
_
_
_
__
«3
~
~
"
•
"" ■
■^
•
*
■^
'-
—
^
-^ —
s
—
—
)
—
—
—
—
—
^
— "
tt ^
^^^
s
S^
I w
s
_
„
^
^
_ ,
_
_
^
■f- -
_
_
_
_
_
_
^
_ ,
y
_
_
^
"
~ -
" "^
~
"
_
r_ -
■''^'~
j^
~
~
„
^
z
~
~
z
t
^
"
«> *^
~
~
~
~
11 "
_
~
r^
~ '_
zz:
'_
~
^
_
^
—
■~
~
—
^
"
s
^ -
rt
_
_
_
_
_
_-
-_
_
_
b
^
_
_
_
_
_
J
'
~
11
-
~
~
z
^
— 1
_j
10 fi? fifiiSAlo
Rate in Hours
Fig. 112.
a large resistance in series with each cell will be found
to give equally good results. The time interval should
be so arranged that about twenty readings may be
taken. The record should contain a column each for
the time, volts, amperes, ampere-hours, watt-hours, and
remarks, in which the specific gravity, temperature,
" gassing,** etc., should be noted. The specific gravity
should be measured at regular intervals, say about ten
times during the test. Three efficiencies should be cal-
culated, — the volt-, the ampere-, and the watt-efficiency.
232
THE STORAGE BATTERY
In plotting the curves, it would be well to make the
horizontal or time distances small, and the vertical
scale units large.
In comparing cells of different types, sizes, or volt-
ages, — especially where the weight is an important
factor, — the vertical scale should be made watts per
pound rather than volts. A very useful curve for gen-
eral practice is the "straight-line curve" proposed by
Carl Hering in the Electrical World, In this, the ordi-
nates are the capacities in watt-hours, and the abscissae,
the rates in watts. In obtaining the data for this curve,
the cell should be fully charged for each test, and the
discharge should be continued until the E.M.F. has
fallen — in each case — a certain fixed percentage of
what it stood a few minutes after the beginning of the
discharge; the discharge being at a constant current.
As the result is different for different makes of accu-
mulators, each manufacturer will have to determine
whether this relation approximates sufficiently close to
a straight-line function for the calculations occurring
in practice. When this curve does approximate suffi-
ciently to a straight line, it will be of the general form
watt-hours = ^ — ^ watts,
a and b being constants to be determined for each
particular type. By making the abscissae the time in
hours, the curve will resemble in general outline the
shape of a magnetization curve. The more nearly this
curve approaches to being a horizontal straight line, the
more perfect (so far as the dependence of the capacity
on the rate is concerned) is the accumulator.
CONCLUSIONS
233
Although in practice accumulators* may be discharged
discontinuously, for testing, the charging and discharg-
ing periods should be continuous, without any intervals
of rest. The most rational way to charge is to charge
at a constant voltage. This means using a diminishing
current, and as this will be found to be a difficult mat-
ter, it is better to use a constant current until the volt-
age shows signs of rising appreciably, then to reduce
the current suddenly to a lower value — taking voltage
reading for both values — and so on to the end of the
charge. M. Simon advises using a constant power, that
is, a diminishing current and an increasing voltage, the
rates being such that the product is always constant.
He argues that charging at a constant current has the
objection of taking too long, the current being weak
at the beginning and too strong at the end. With a
constant potential, on the other hand, the charge is
almost too great at first, and so small at the end that
it prolongs the time of charging considerably. A bat-
tery, in the latter case, receives, in two or three hours,
more than three-quarters of its capacity. The discharge
should be made under conditions of constant current,
using a rheostat, stepping down by small increments
for the purpose. If this is impracticable, the next best
method is to discharge through a constant resistance.
Where the tests are wanted for power purposes, it would
be best to discharge at a constant wattage. All tests
should be repeated until at least two like discharges,
under the same conditions, are obtained.
In the installation of a battery, the first point to be
considered is the selection of a room. This should
234
THE STORAGE BATTERY
be dry, well-ventilated, and of a moderate temperature ;
otherwise the evaporation will be found to be very
large. The floor must be of some acid-proof material,
and so made as to drain rapidly ; an outlet being pro-
vided for the liquid. If the floor is already put in, and
of wood, it should be covered, especially where the
battery stands, with a lead tray. The room should be
located' as near the generating room as possible, so as
to reduce the wiring cost to a minimum.
The battery should be placed in as few tiers as possi-
ble, and in such a manner that the direct rays of the sun
are not allowed to fall upon the cells. The rays of the
sun are likely to crack the glass. This is probably due
to the unequal expansion of the glass, for it has been
found that jars which are carefully annealed never crack
in this manner. Of course, the latter precaution does
not apply to large batteries, where lead-lined wooden
tanks or solid lead boxes are used. All exposed metal
work should be protected with an acid-proof paint.
When a battery is received, the elements and con-
taining-cells should be carefully unpacked, and all dust
and any foreign particles removed. One should be
sure that all insulators and distance pieces are in posi-
tion, and that the plates are in their proper alignment.
In connecting the cells, sufficient sectional area should
be provided; otherwise the various plates will be worked
unevenly, and the full capacity of the battery will not
be obtained. The most satisfactory method of connect-
ing up is to " lead-burn " or weld the positive plates of
one cell and the negative plates of the next to the same
lead " bus-bar," thus ensuring good connection between
CONCLUSIONS
235
the various plates of a cell, and also between any two
consecutive cells. If it is desired to solder rather than
"lead-burn** the electrodes, the following method will
be found to give the best results :
Strips of lead for making the joints are placed for
some time in a strong potash solution, after which they
are thoroughly washed and scraped. The electrodes
themselves should also be scraped. The two are then
held tightly in a mould, in the form of tongs, and molten
lead poured around them.
If the elements are to be bolted together, one should
see that all bolt connectors are thoroughly screwed up ;
otherwise, resistance and consequent heating will result.
In setting up a battery, it should be remembered that
plates deteriorate on standing exposed to the air. They
should, therefore, be unpacked and set up immediately
on arrival. When they are entirely connected up, they
are ready for the addition of the electrolyte, and for the
forming charge, which they should receive immediately.
In mixing the electrolyte, one should use only chemi-
cally pure acid, and always pour the acid into the
water. Before placing the electrolyte in the cells,
Lucas treats it with basic sulphide. It is then allowed
to rest for 24 hours, after which it is filtered and ready
for use. When filling the cells, the top of the plates
should be covered with the liquid by at least half an
inch, and the electrolyte should never be allowed to fall
below this point.
If it is desired to separate the plates from each other,
and no regular separators are at hand, perforated porous
paper, saturated with paraffin wax, will be found to give
236 THE STORAGE BATTERY
good service, and to be practically unacted upon by the
acid.
When glass jars are used, it is well to paint them at
the top, for about an inch, with paraffin wax to prevent
the creeping of the solution.
A new battery will never give its full capacity till after
about twenty discharges. During this time it should
be given about 25% overcharge. After that, 10% over-
charge, that is, 10% more charge than was taken out,
will be sufficient for ordinary work.
In mounting cells in cars, or in any place where there
is a liability of breakage, it is best to use the Boese
system. In this system, a set of glass cells are inserted
in a box, between which and the cells, and between the
cells themselves, is poured a melted mass of some
insulating material which, when cold, will be rigid, but
elastic, and will retain the liquid even if the glass cells
should break.
Drake and Gorham use a method for stopping the
spray from an accumulator, which it would be well to
adopt in all cases. This is to float particles of a light
substance on the acid to the depth of about \ of an
inch. In all cases where it is necessary to get at the
acid, this substance can be easily brushed aside. In
soaking up spilled acid, many attendants use either
ammonia, saw-dust, or soda; it has been found tliat
whiting is better than any of the other remedies.
Before beginning to charge a storage battery, it should
be gone over carefully, and any cell that is not up to
the standard should be disconnected and put in working
order before being replaced.
CONCLUSIONS
237
If the accumulators are to be used in a cold climate,
it would be well to adopt the device oif M. Varennes.^
He places a small incandescent lamp, covered with a
black varnish, in each accumulator. These lamps are
connected to an automatic device which puts them in
or out of circuit, according as the temperature is above
or below a certain predetermined point.
In installing plants where expert attendance is not
to be had, it is well to place in the circuit two mag-
netic cut-outs, one set for maximum current, and the
other for minimum voltage, so that the battery cannot
be discharged too low. It might be well, in some
cases, to use a resistance instead of the regulating
cells. Owing to the different lengths of time that
the regulating cells have to be in circuit, it is ex-
ceedingly troublesome to keep track of them, and
when neglected, their spraying becomes a disagreeable
feature, all of which would be obviated by the use of
resistances.
To obtain the best results in charging a battery, the
following points should be watched. The rate of charge
should be normal, except in cases of emergency. At
such a rate, unless the constant potential method be
employed, the cell may be considered, full when the
voltmeter reads 2.5 volts during charge. The electro-
lyte should be kept at uniform density throughout the
cell; when water is added, because of evaporation, it
should be added by means of a funnel reaching to the
bottom of the cell. Care should be taken never to add
acid after evaporation; otherwise the electrolyte will
1 La Lumi^re Electrique, Jan. 6, 1894.
238
THE STORAGE BATTERY
be too heavy. Hydrometer readings should be taken
regularly ; this is an excellent indication of the amount
of the charge in the battery. These readings are use-
less, however, unless the precaution be taken to keep
the electrolyte of uniform density. Fig. 113 shows the
relation between the specific gravity and the capacity,
and indicates clearly how close a guide hydrometer
readings, when intelligently observed, are.
100
90
80
«• I?
o»-
^30
20
10
X
>
P^
N
y
\
/'
.«
X
/
' \
v«.
.^
r
^t
/
\
\
/
\
/
\
/
^
usao IM) uaoo 1.190 1.I8O
Spec'rfic Gravity
Fig. 113.
1.170
ueo
About once a week, each cell should be tested with
a low reading voltmeter and hydrometer. If any cell
should read low, it should be at once cut out and care-
fully examined to see if any material has been intro-
duced which could short-circuit the cell. If no such
trouble can be found, the cell should be disconnected
from the discharge circuit and given an extra charge.
If a couple of extra chargings do not bring the cell up
to condition, and nothing is known concerning the cause
of the trouble, the manufacturer should be consulted.
CONCLUSIONS
239
Mr. Joseph Appleton ^ has devised a very interesting
test for determining the condition of cells. He takes a
plate of cadmium, mounted in a hard rubber frame,
immerses it in the electrolyte, and reads the E.M.F.
between it and the positive or negative plates of the
cell. The cadmium should be shaken occasionally to
free it from any bubbles of gas which may be formed
on its surface. The cadmium plate should be washed
with water every time it is taken from the cell. " By
this method," says Mr. Appleton, "it is possible to
ascertain at any time during the charge or discharge
whether the positive or negative plates are in proper
condition or otherwise, thus locating at an early stage
any sign of irregularity or trouble.
** During charge, the cadmium plate reads negative to
the negative plate, until the cell is about full, when the
reading should be zero ; the charge should be continued
until the cadmium reads 0.2 volt positive to the nega-
tive while charging at the normal rate."
It is best never to allow any organic matter or oxi-
dizable substance to come into contact with the peroxide
element of the battery. When cellulose is used, the
effect is to convert it into grape sugar, which is decom-
posed. The latter is converted into plumbic formiate
and carbonate, sulphate being the ultimate product It
has been the author's experience that celluloid should
be used very sparingly in cells, and never in connection
with the positive plate, since its general tendency is
towards decomposition. Others have found that when
celluloid is used for forks and bearers, it soon becomes
1 Storage Battery Engineering Practice, N. Y. E. E., Vol. 23, p. 454.
240 THE STORAGE BATTERY
coated with a shiny black coating, which is formed
from the material itself.
It is always an easy matter to increase the capacity
of a battery by mixing organic materials with the lead
oxide; but, as any such mixture is always accompanied
by a rapid deterioration of the plates, the increase in
the capacity is concomitant with a decrease in the life.
Besides this, those binding materials which are used to
harden the plates are good as long as they are not
decomposed by the current ; but this decomposition
will take place with every successive charge. It is
evident that, unless an undecomposable body is formed
with the lead oxides, the life of the plates will be greatly
decreased. Many investigators have used manganese,
either in the electrolyte or as a part of the active
material, as peroxide of manganese. All trace of such
compounds should be avoided, as the tendency is to
reduce the capacity of the battery by carrying oxygen
from the positive to the negative plate.
When filling the cells with acid, one cannot be too
careful to have the acid of the proper strength ; for, if
too strong, the plates will be found to sulphate more
rapidly, and the sulphate will be harder to reduce. It
has been found that with plates 0.4 inch thick, the
maximum capacity will be obtained when the acid is
about 1.270 specific gravity, and with plates 0.25 inch
thick, acid of 1.240 specific gravity.
Should the plates sulphate from any cause, it may be
stopped and further prevented by using Urquhart's^
remedy, which is made up as follows :
1 Electric Light Fitting, J. W. Urquhart, p. 47.
CONCLUSIONS 241
To a quart of strong solution of common washing
soda, add slowly, during agitation, 12 ounces of con-
centrated sulphuric acid. This should be added to the
electrolyte in the proportion of i : 25.
Although the best modern practice is to use as the
electrolyte nothing but the pure dilute acid, some
investigators believe that if the electrolyte be either
neutral or slightly alkaline, that the forming process
will be much more rapid. To obtain this result, such
salts of the light metals are used as will produce no
decomposition on the positive electrode, and will there-
fore not interfere in any way with the formation of the
peroxide. Luckow^ is the originator of the above
process.
In the manufacture of storage-battery plates, nearly
every conceivable shape has been tried, and it has been
found that an approximately square plate gives the best
results. The plate should not be made too deep, else
it will be subjected to different degrees of chemical
action. Where the large central station plates are
used, — approximately 15 x 30 inches in size, — some
means have to be employed to keep the electrolyte of
a uniform density. This is usually accomplished by
means of a blast of air. As to the shape of the perfora-
tions, it has been already pointed out,^ that that hole
which is larger at the centre than it is at the surface, is
the best. Many manufacturers believe that it is best
to use some alloy of lead, which is unaffected by the
chemical reactions which take place in the cell, thus
allowing the plate to be more rigid and lighter in
1 G. P., 84,423 ; 1894. 2 Vide page 66.
242
THE STORAGE BATTERY
weight than if constructed from pure lead. Mr. J. K.
Pumpelly, however, believes that all alloys of lead
should be avoided, and only chemically pure materials
used. In this view he is supported by a constantly
increasing number of manufacturers ; in fact, it is now
the exception to use alloys, except where the weight is
an important factor.
The plate should be so constructed as to be able to
expand with the active material, without destroying the
contact between the two. The electrolyte should have
free access to all parts of the active material; great
porosity is therefore necessary. Zacharias ^ obtains this
by pricking the active material with needles at the rate
of about i(X) holes per square decimetre. Many believe,
notably among them Fitzgerald, that during the con-
struction of the plates, it is best to make only the sur-
face porous, so as not to sacrifice mechanical strength.
Probably one of the potent causes for the destruction of
the plates is the gas which is formed in the pores of
the active material ; the harder and denser the active
material, the quicker will it be destroyed. It is for this
reason that the negative plates are the most difficult to
construct.
The contact between the active material and the con-
ducting plate must be good ; for if poor, a white sul-
phate will be formed at the surface, which practically
forms an insulating layer. As pointed out by Mr. Her-
ing, it is well to make the positive plates. light, cheap,
and easily replaceable. By this method, although the
life will be shortened, the great difficulty caused by the
1 G. P., 84,810 ; 1894.
CONCLUSIONS
243
gradual washing away of the peroxide will have been
settled. When the perishable parts have been renewed,
the battery is practically as good as new. This is the
plan followed with the plates used in the Paris accumu-
lator lines. The life will be soon known to the user,
and he can readily determine for himself how much is
to be allowed for amortization.
It has heretofore been the general custom among
manufacturers to construct the end plates — of the
perforated pasted type — like the other negatives, thus
giving them twice the necessary surface and capacity.
Although this decreases the internal resistance, it will
be found that the end positives discharge more rapidly
than they should, thus producing buckling. An easy
way of overcoming this difficulty would be to punch
the active material out of alternate meshes on the end
plates, leaving the plates half empty and half full.
Batteries which are constructed in this manner have been
found to give excellent service. Plates of the Plants
type, and of the grooved pasted type, are so constructed
as to have half the capacity of the other negatives.
F. Zacharias ^ has come to the following conclusions
concerning the manufacture and construction of plates :
1. No portion of the metallic frame should pass
through the paste.
2. The paste should not be retained at the upper
edge by the frame, but should be free to expand and
to form gas.
3. Whenever the frame covers the active material, it
should be perforated to allow the gas to escape.
^ London Electrician, April 17, 1896.
244
THE STORAGE BATTERY
4. The frame should distribute the current evenly,
and have a minimum weight consistent with strength
and securing the paste.
5. The frame should be so constructed that the mate-
rial on the negative plates should not lose contact, even
when disintegrated.
When it is desired to transport the battery to a dis-
tance, after having been in use, it should be taken apart,
washed thoroughly, and the plates pressed together, so
that only one face of each of the ejid ones is exposed
to the air. Each batch is then wrapped in oiled paper.
If it is not possible to do this, wrap each plate as much
as possible with the oiled paper, and stuff the intervals
between the plates with hay wrapped in oiled paper.
The battery should be set up again as soon as possible,
and then treated as though new.
If the battery is to remain idle for any considerable
length of time, it should be first given a full charge at
normal rates, and then given a recharge — till it com-
mences to boil — at least once a week. If for any
reason this recharge is impossible, the directions for the
battery used should be followed.
If by any means the connections have become re-
versed, so that the negatives assume a chocolate color
and the positives a slate color, the only remedy is to
discharge the battery completely, so that the cell gives
no E.M.F., or a very slight one. The connections are
then changed, and the battery recharged; but slowly
at first, as there is no counter E.M.F. to overcome.
When a battery has become run down, Trowbridge ^
lA. P., 551,565; 1895.
CONCLUSIONS
245
charges it, removes the negative plates, and replaces
them with zinc plates. The battery is then discharged,
the zinc plates are removed, and the lead negatives
replaced.
In connecting up cells, or on soldering connections
to the plates, thin connections, and all connections made
by soldering on the plate, should be avoided, where the
electrolyte, falling below the joint, may expose it to
the air, or to the action of electrolysis at the point
where nascent oxygen or ozone is set free.
The relatively low conductivity of the peroxide must
be considered ; if the Expansion is weak, cracks will be
produced in which a white sulphate is formed. The
distribution of current should therefore be uniform
throughout the plate. The distance between each
plate should be the same at all points, and the electro-
lyte should not be allowed to consist of layers of differ-
ent densities. A frequent mistake is made in adding
fresh acid when the specific gravity of the electrolyte
has fallen, due to heavy sulphating. The cells should
be given a prolonged charge instead. The addition
of concentrated acid to the cell is liable to rot the grids.
Sir David Salomons,^ in speaking of future improve-
ments, says :
"There can be no doubt that the improvements in
the future will take the form of a modified electrol)rte,
which, according to Mr. Robertson, must be of such a
nature as to prevent the formation of or at once break
up any deleterious substances which may be formed
during the charge or discharge." It must especially
^ Electric Light Installations, Vol. i, p. 105.
246 THE STORAGE BATTERY
break up and prevent the formation of all those lead-
trees, or fine lead-needles, which are the greatest trouble
with the batteries at present.
It is also probable that batteries will be so constructed
that the diffusivity of the acid will be greatly increased.
Messrs. Gladstone and Hibbert, in a paper "On the
Cause of the Changes of E.M.F. in Secondary Batteries,'*
in Vol. 29 of the London Electrician^ say :
" The fall of E.M.F. at the end of the discharge leaves
a large percentage of active material unacted upon.
This is mainly due to the weakness of the acid against
the plates, on account of the interstices being much
clogged, and it would be counteracted to considerable
extent if the diffusion could be increased. When a cell
has been discharged below its minimum useful voltage,
there occurs the destructive action called scaling. This
is probably due to the abnormal chemical action arising
from very weak acid. Diffusion would prevent this.
APPENDIX
Measurement of the Internal Resistance of a
Storage Cell
SHELDON
In measuring the internal resistance of a storage bat-
tery by this method, see Fig. 1 14. Care should be taken
to have the standard resistance nearly equal to that of
Fig. 114.
the accumulator to be tested; the Wheatstone bridge
should have a resistance of about 10 ohms, or capable
of carrying ^ of an ampere ; and the alternator should
give 10 or more amperes.
The contact D' should be placed successively at the
points I, 2, 3, and 4, and D shifted till the minimum
sound is produced in the telephone. Calling a, b, c,
and d the readings of the bridge wire for the points
247
248
THE STORAGE BATTERY
I, 2, 3, and 4, respectively, and r the resistance of B^
then
x^r
mange's METHOD, IMPROVED
This improvement, suggested by Dr. Perrin, is shown
in Fig. 115. The resistance should
be made equal to the normal load
of the battery, so that the meas-
urements are made under normal
working conditions. A small re-
sistance is also inserted in the gal-
FiG. 115. vanometer circuit
GRASSl'S METHOD
The following, which is given by Professor Grassi,^ is
a combination of Mance's improved method and the
methods of Hopkinson and Mathieson.
In Fig. 1 16, ;r is the accumulator having an internal
resistance x\ a^b, Cy rf, are four resistances, so determined
that bd^aCy rf being highly
inductive; G^ is a galva-
nometer; r, a standard re-
sistance; BCy a calibrated
stretched wire; and Z>, a
sliding contact.
In measuring the resist-
ance, the wire F is con-
nected successively to the terminals i, 2, 3, and 4. For
each connection, the position of D is adjusted until the
1 UElettricista, May i, 1895.
Fig. 116.
APPENDIX
249
galvanometer remains at zero, \vhcn the. switch 5 is
opened and closed. Calling e^ /, ^, aiid h the readings
on the calibrated wire BC^ for the positions i, 2, 3, and
4, we have for the resistance required
x^r
f-e
Measurement of the E.M.F. of a Storage Cell
Negrenau ^ gives the following method for measuring
the E.M.F. of cells : "The current from a standard eel
passes through a varia- s ^
ble resistance r as far I 'r^^'^^^^^^^^^
as the point a (see
Fig. 117), where the
circuit branches. The
first branch contains a
resistance r", the other ^^^* "^*
a galvanometer, a resistance ;'', and a cell connected
up in series to the standard cell. The resistances f
and r' are adjusted till the galvanometer shows a con*
stant deflection on opening and closing the first branch.
The ratio of the E.M.F.'s is then given by the ratio
of the two resistances."
Cosgrove improves this method by placing the gal-
vanometer in the first branch. This gives a zero de-
flection on balance instead of a constant deflection, and
readings can therefore be made with greater accuracy.
This second method also has the advantage that a tele-
phone receiver may be substituted for the galvanometer
if convenient.
1 E. w., Vol. 29, p. 739.
250 THE STORAGE BATTERY
FORMULA FOR THE CALCULATION OF THE E.M.F. OF
SECONDARY CELLS
In the following formula, from E. J. Wade's ** Chemi-
cal Theory of Accumulators/' ^
IV= the work in joules.
Q ss the coulombs of electricity that are passed
through the electrolyte.
If = the number of calories liberated by the recom-
bination of a unit weight of one of the
decomposed ions.
e SB its electro-chemical equivalent
c =s its chemical equivalent.
A = the electro-chemical equivalent of hydrogen
= .00001038.
J = Joule's coefficient = 4.2.
E = the E.M.F. required.
W= QE.
W=Q/eH;
therefore E = /ell
and e^ Ac;
therefore E —JhcH— 4.2 x .00001038 cH
= .0000436 ^/f.
Now cH = ^^^^ Q^ formation .
valency
^, - -, .0000436 X heat of formation
therefore E =^ ^^ ^ •
valency
1 L. E., Vol. 33, p. 657.
APPENDIX
251
Since nearly all the battery equations are expressed in
terms of the transfer of two atoms of hydrogen, or their
equivalent (that is, they are bivalent), and since
.0000436 X 46,000 _ .
2
we have E = ^^^^ ^^ formation, in calories
46,000
In the application of the above law it should be re-
membered that the effects due to variations of the
density of the electrolyte, allotropic modifications, and
alterations in the state of the substances taking part
in the reactions must be taken into account. Von
Helmholtz claims that a temperature correction will
also have to be applied, although from the result of
some investigations that have been conducted by
Preece, it would appear that the corrections are so
small that it will not be necessary to take them into
account.
Dr. Streintz ^ gives the following formula for the cal-
culation of the E.M.F. of an accumulator:
E^ 1.850 + 0.917 (5 -j);
where
S = the specific gravity of the electrolyte,
s = the specific gravity of water at the tempera*
ture of observation, and
J? = the E.M.F. required.
1 Zeit. fttr Electrotech., May 15, 1895.
252
THE STORAGE BATTERY
FORMULA FOR THE CALCULATION OF THE CAPACITY OF
A STORAGE BATTERY IN AMPERE-HOURS
It is well known that the current in ampere-hours
maintained by the consumption of any given chemically
active substance varies with the change of valence where
oxidation and reduction occur, and inversely with the
molecular weights of the transforming substance. The
combustion or liberation of i pound of hydrogen cor-
responds to 12,160 ampere-hours.
The theoretical current capacity in ampere-hours may,
therefore, be obtained as follows : Let
V= the change of valence of the ions,
IV= the sum of the molecular weights affected, and
12,160 = the capacity per pound of hydrogen.
Then capacity per pound = — '
Calling lead sulphate, which is the ultimate product at
both electrodes, the real active material, we obtain by
the use of the above formula 40.24 ampere-hours, or
80.48 watt-hours, per pound of lead sulphate, with the
lead-lead-sulphuric-acid battery.
With the lead-zinc cell, the active working substance
is both lead sulphate and zinc sulphate, and the theo-
retical capacity then obtained is 52.54 ampere-hours, or
1 26. 1 watt-hours, per pound of active working substance.
Considering the positive and negative plates as equal,
which they practically are, the capacity per pound of
working substance on either plate alone would be 80.5
APPENDIX
253
ampere-hours for the lead-lead-sulphuric-acid type, and
105.1 ampere-hours per pound for the lead-zinc type.
According to Monnier's and Gtiiton's estimate, it re-
quires 565,600 coulombs to pero^dize i kilogramme
of minium. As stated previously, Plant6 and Paget
agree on 4.48 grammes of lead peroxide as the equiva-
lent of I ampere-hour, and this corresponds to 0.158
ounce per ampere-hour. Fitzgerald has found 0.135
ounce per ampere-hour. This, it must be remembered,
is the theoretical equivalent, on the supposition that all
the active material on either plate is transformed into
lead sulphate ; that is, that the battery is completely dis-
charged. As this is not accomplished, the best prac-
tice is to allow anywhere from 0.53 to 0.86 ounce of
lead peroxide, and from 0.5 to 0.8 ounce of spongy
lead to the ampere-hour, according to the discharge
rate, thickness, and density. Fitzgerald gives as the
safest rule, and the best practice bears him out, that a
weight of 0.53 ounce per ampere-hour on each plate for
a lo-hour rate, 0.6 ounce for a 5-hour rate, 0.7 ounce
for a 3-h6iir rate, and i.o ounce for a i-hour rate of
discharge, for the ordinary thickness, and an electro-
lyte density of 1.200 will be found to afford the best
results. While, of course, these rules are only approxi-
mate and will have to be modified for different plates
and different conditions, it will be found that under
ordinary circumstances it is perfectly safe to use the
above values.
254
THE STORAGE BATTERY
K S Pfi Ph S Oi A £
Jl|1llill|l
« 2 2 o o o o o 2 2 2^
aSv^io^ aSusAy
fO 00
tinon m
ur^ioqqoqqoqq qoqqqo»ovnqqo
rot^do6dwN^^do6dcocoddwo6i-ldod
9)eij dAU
-r iBU3)e|i^ aAHoy
9Ai)i80(j JO )q2b^
• • U^ -NO
!! fo !vd I! L !!;!!:!!!! I : :
. . »0 .NO
• • • •ir>.«Q*'»*'»»' mu^ • • .
••••t^'^OO 00vO''»
NOOOtn! !00\! ! ! * '. ! ! !NO00»-"OtO
^ ^ .. ^ ^ ........ f* ^ ^ ti
Aouwoy^"^ XSiaag
jnoH
-J3MOJ-98JOH idd
spunoj ui jqaiaAV
3)»ldai03
'iPDJopunoj
J9d sjno^-dJdduiy
. vq 1^ w vq OS (^ q t^oq
juainaia jo punoj
jiad sjno^-aJ9duy
O'QQOON-OON OQ
« •vqqiot>.qsN^nir>crvio' • • • • • • tooo
\\9y-Smuye\no;y
0^O»5OO»5OOO :0(i^0fi^0(i^000OO
joj j]ina
Hh^Hh^ :hhJh^hJ :hJ .-jHhJHhj : : :^
bb
m»
B B
<<
N
\ V u
< B 2
o
^ -.S
r/2'c « «5 «2 «2 2
^ a o - rt^ 3^« a S S S S
*3fl^o22j:x«^ooooo
oJ tn 1:^
a a
OS
c5q
• a
APPENDIX
255
fe 'w 13 li^
C "TJ 73 kJ
•r «« b! »^
S
)HH
«nc3 ncj too g
I III
I bfibfi V
cu fi c a 5. S. S 2
39
M U U
III
f
a
ooN,oot^ooooooooo •^oot^^ooqqqq q qqqooo
M MM .'35 "aMM M MMM M
;;:
::::;:;;::i:i3;
• •
•
• •
:&S.vS*: :
: : :
iflvS'
:^ :5 ::«.?.::: : j 51
: :
;
: :
: : :
I I I
:^^
i :2H^ri.s^H^I
is
:
: ;
:?2
m
?S1
OMO^ rO« NOq fON OvfOvOOO ^
: 5-
:
: J
: « to
2 S,{: : 2.8 g>5 •& \ :'8 S> : : 8 2 : 8 8 : I : : J??§8 ? ?R
0P^P^C^P^C5000000P!^p!^0000Pi^000000000P<0P^
H^H-ihJH :iJ»Jh3h»j
:hh :::::::::: IiJi-jjh^-ih
■ij
.a . . S**j V V 6
Ac/5 coco flco^co^col'col'.S J J^^| 8 J| §
SPL^OlPL^pH-g 3 ^
•^-d c S,
73 tJ
all JJ8
1:2*2*293 Sr arts
256
THE STORAGE BATTERY
Mil
aStqiO)^ aSuaAy
uno({ at
q 'to^q qqq^q fosq «n q q q q q
•a TS « Ml iH
9|Vi J dAq
-WOJ iq«i9M l«»ox
9AIlISOdJO)I{8i9^
:Q ::::: :P ::::::::::: :
Jbuopy^ XSiaag
jnoH
-iSMOj-auoH JM
spuno^ in 94313^^
:8>
ai9ldai03
, 'll^DJopanod
lad sjno}{-M9daiy
moo vOMN^osr^fO .o^n*^ •©
On
)U9Uiaia JO pano j
lad uno|{-aiaduiy
^8?^:
; NO 00 44
\\9ySvmfK^noj
Q^ :p< :op^ : : : :o :oooop<oooo
ioj lima
:^-i :j
IhjHj
T3 'O
• .S .S S^ fl
o
.a
2 s
.S cr « 5 o Sj5 ^ 5 5 fi B >* 3 .2 fc 3 8 8 S a
Al>PENt)lX
^5;
§ B
o « 2
O4S ^ o o
A cti cti £ p^ H O U
M «> -
WW
si) (3
fl 2 4> «
23
?
0,0.^. CU
0. ^
fO
^11!
.
.
. . .
' ^ I
^ . . .
w • • •
.
•
. . .
I • *
• •
0.0
:
: q q
: '*
• t^u^O
: rood d
t^q
: : t^qoq q q q q q
. .00 N M iH tr>u->fO
q :qq
u^ .00 «-•
:' ;
:
: : :
: :q :
i
I
: : :
: 0. :
t^t>iq •
NO vO vO vO .
; ':
: : 0. : :
•
I I ',
i ig.:
;
;
:?.&
; ;
:&& : :
I I
1-4 r<
^
'*
On a\ »o ;
;
;
11^
"%oo !
On t^u^ ! M
^ W N : Ml
'^'^ ; ! !
-8 : : :
• q» • • • • w* • 8 o •
• t^oq foro oor^qNOvqv-^qNio^qvojt^
I"^f0^f04>»HWi-«Md»od^4>fOfOfO
: :hhhhhh-ihh : : : : :«hiJhJi-1k:ih^h-jh IhJhJhJhh
p^
c a . . .
•c -c **= -S c^^ £.
ffiM.Si S ^i ftp ^W>w^
iri i!« u I ^w ■— ' . 3i '^ tn tfl
sa
pQm
O O TJ
* '3 'd 'C
•^ -a
•§■§•
si «
-^UG 1 1917
THE PRINQPLES
OF THE TRANSFORMER.
By FREDERICK BEDELL, Ph.D.,
Assistant Profsssor of Physics in Cornell University,
8vo. Cloth. 350 Illustrations. Price $3.25, net.
This work constitutes a systematic treatise on the Alternating Current Trans-
former, and a logical exposition of the principles involved, of the most modem
methods of transformer design, construction, and testing, and of transformer
systems of distribution. Portions of the book were originally prepared with the
collaboration of Dr. A. C. Crehore. The work is suited for practical engineers
and for students in electrical engineering ; among the chapters are the following :
^an8former Systems of Distribution.
The Magnetic Circuit of the Trans-
former.
The Altem&ting Current.
The Transformer Diagram.
Simple Theory of the Transformer.
Constant Current Transformer.
Constant Potential Transformer.
iSesign and Construction.
Experimental Transformer Diagrams.
Instantaneous Transformer Curves.
Transformer Testing.
Effect of Hysteresis and Foncanlt Cur-
rents.
OPINIONS OF THE PRESS.
" To gather all this into one book, and to formulate a definite' and intelligible scheme
out of the multifarious and often contradictory material at hand, was not an easy task,
but the author has entirely succeeded. To the student and to the practical maker of
transformers the work is invaluable." — The Auiomotor,
** The same clearness of reasoning and lucidity of style which has justly rendered the
previous work [Bedell and Crehore's ** Alternating Currents "] popular among students
are apparent in this volume also." — American Journal of Science.
** Before its appearance the student was compelled to rely upon books which were
illogical collections . . . hastily thrown together m book form. [One] should recognize
the endeavor of Professor Bedell to bring order out of chaos in presenting the funda-
mental equations ... in such a clear and instructive manner."
— Professor Trowbridge, in The Electrician.
" While professedly exponent of the principles of the alternating current transformer,
the author also deals with the practical sides of the question, both as regards manufacture
and use. This part of the subject occupies the latter half of the volume; . . . the work
should be of as much value to the English as to the American electrician."
— Electricity t London.
''The work is interesting and instructive, the style is very clear, and the various
theories impartially examined; some good experimental diagrams are given, also use-
ful information on testing transformers. — Electrical Review^ London.
"... The special treatment of several problems is decidedly new. The author has
not confined himself to the mathematical and graphical treatment of the subject, . . .
but has incorporated many useful hints on the practical side of the subject. It is a valu-
able addition to the literature on transformers."^7'A^ Electrical Engineer ^ London.
THE MACMILLAN COMPANY,
66 FIFTH AVENUE, NE^Ar YORK.
Alternating Currents and
Alternating Current Machinery*
BY
DTOALO S. JACKSOH, lf.S.,
Pr^UfT ^ BUctrtcal Engintering in The University of Wiscontut
JOHN PRICE JACKSON, M.E.,
JPrqftttcr qf EUcirical Engineering in the Pennsylvania State College*
Clotli. umo. Price $3.50, net.
•* It contains much important information not to be found elsewhere, and
some which will b« especially interesting to English readers, since it chiefly
refers to American machinery." — The Electrician, London.
" The practical engineer will find in this volume an excellent reference
book. There is no padding, the tables are modern, theory is simple, and
the mathematics are not such as would stagger a person."
— Wisconsin Engineer,
** Students of Engineering and of that branch of the profession which
has to do with the construction of alternating current machinery will wel*
come this addition to the literature on the subject of alternating currents.
The student will find in this work a text-book and the engineer a book of
reference." — The Journal of the Franklin Institute.
** It deserves favor from all electrical engineers, and especially from the
higher electrical classes in scientific schools." — YaU Scientific Monthly,
" The book is up to date and conscientiously written. It may be read
with the deepest satisfaction by any earnest student of eloctro-technics."
^The Electric Age,
" We believe that this is the only text-book on the subject worthy of the
name, and it is, in our opinion, a matter of congratulation that the student
has at last at his hand something adapted to his needs."
— Electrical Engineer,
THE MACMILLAN COMPANY,
ea FIFTH AVENUE, NEW^ YORK.
Live Music Archive
Librivox Free Audio
Metropolitan Museum
Cleveland Museum of Art
Internet Arcade
Console Living Room
Books to Borrow
Open Library
TV News
Understanding 9/11