AvcvsT 1, 1916.] 



THE INDIA RUBBER WORLD 



The Electric Storage Battery in the Motor Car. 



IT is estimated that tlicrc are 28,000 electric vehicles in the 

 United States, of which 20,000 are pleasure and 8,000 are 

 commercial cars. The cost of the average battery to the 

 manufacturer, for a pleasure car, is about $300, and $500 for a 

 commercial car; so that $4,000,000 is the sum expended for auto- 

 mobile batteries and $6,000,000 for commercial car batteries. 

 The average number of liard ruhl)cr jars in a pleasure car is 



Fig. 1. WiLL.\RD Vehicle B.\ttery. 

 32, and 44 for tht commercial, or a total of 1,000,000 jars. The 

 average cost is $1.50 per jar to the manufacturer; which figures 

 a total of $1,500,000 for hard rubber jars. 



There are about 1,500,000 starting and lighting batteries being 

 used in the United States, costing the manufacturer an average 

 of $15 each or a total of $22,500,000. There are three cells to the 

 average battery, or 4,500,000 jars in use, which cost the manu- 

 facturer about $1.00 each or a total of $4,500,000 for hard rubber 

 jars. 



The alcove estimates do not include hard rubber covers, separa- 

 tors and vent plugs, which would materially increase the grand 

 total of figures for hard rubber used in electric storage batteries. 



This article will cover the storage battery only as applied to 

 automobiles and commercial cars for driving, starting, lighting 

 and ignition purposes. Such batteries are also used for house 

 and railway car lighting, for lighting, power and ignition in motor 

 boats. In radio apparatus they are indispensable, and recently 

 the submarine has emphasized the importance of the storage bat- 

 tery and its hard rubber insulation in modern warfare. 



The fundamental principle of the electric storage battery is 

 best illustrated by the voltameter, a well-known instrument in 

 which water is decomposed by an electric current. The volta- 

 meter consists of a glass jar containing two platinum plates cov- 

 ered with acidulated water and connected by wires to an electric 

 battery. When an electric current is established, small bubbles 

 of oxygen collect on the positive plate, or electrode, and of hydro- 

 gen on the negative electrode. If the battery current is cut off 

 and the two electrodes connected to a galvanometer, a reverse 

 current is registered. For storage battery purposes, however, 

 the electrolysis of water was unpractical, as tl-e hydrogen and 

 oxygen quickly escape. 



Plante invented a cell in which two lead plates insulated by 

 hard rubber strips were placed against each other and covered 

 with sulphuric acid diluted with water. When electric current 

 is passed through the electrodes the water or electrolyte is de- 

 composed, the oxygen separating at the positive plate and the 

 hydrogen at the negative. The positive plate becomes oxidized 

 and covered with a coating of lead peroxide. When the battery 

 current is cut off and tlie plates connected, a reverse current is 

 established and the peroxide is reduced tn lead, while the other 

 plate becomes oxidized. 



Faure's improvements consisted in coating both plates with 

 red oxide of lead paste, which contains a smaller proportion of 



oxygen : thus the current only has to form peroxide on one 

 plate and reduce the oxide on the other. 



Many improvements have been made by modern inventors 

 toward correcting the inherent defects of the original types. 

 The most successful modern storage batteries depend on the 

 same chemical reaction as in the original Plante cell, but with 

 one notable exception — the Edison — which uses nickel-steel plates 

 in an alkaline solution, with the advantage that the battery is 

 nnich lighter, and also that the absence of the sulphuric elec- 

 trolyte makes possible the use of a metallic jar. 



Hard rubber has been found to be practically the only flexible 

 insulator impervious to the action of sulphuric acid, which is the 

 basic electrolyte in the lead storage battery. For that reason, 

 hard rubber jars, separators, vent-plugs, hold-downs, and insula- 

 tion tubes are used : also soft rubber gaskets, plugs and rubber- 

 insulated battery terminals. Descriptions of a few of the well- 

 known types of vehicle storage batteries will in a general way 

 cover the entire field. 



THE WILLAKD HATTERY CELL. 

 One of the best-known is the "Elba." A 6-volt cell type 

 ••-M-11" is shown in Fig. 2. The individual cell principle is em- 

 ployed in all types; any one cell 

 can be inspected or repaired with- 

 "iil disturbing the others. The 

 plates are the pasted type and the 

 grid is made of an alloy consist- 

 ing of lead and antimony. The 

 jar, cover, hold-downs, vent and 

 perforated separator are of hard 

 rubber; the vent-plug and sealing 

 gasket are of soft rubber. The 

 separator might be compared to 

 a piece of lace. It is honey- 

 combed with holes and, there- 

 fore, allows the electrolyte to 

 seep through evenly so that the 

 battery gives maximum service at 

 all times. The separator is 

 ridged with rubber strips which 

 protect it against wear by the 

 abrasion caused by the vibration 

 of the car. 



The plates measure 5f4 b.v 8f^ ; 

 there are 11 to each cell and the 

 discharge is 27j/< amperes for 5 

 ours. The complete cell meas- 

 ures 3^ by 6%, by 13^ inches 

 high and weighs 30^ pounds. 

 Fig. 2. Ei.b.\ Cell — Type 



.,^, ., „ THE E. S. B. CELL. 



.4-Hard R.,bber Jar. B- The-Ironclad-Exide" cell, type 



ILird Rubber Perforated Sepa- 'V-MV,' is shown m Fig. 3. The 



;?-Hard~Rubber "HoYd-do°Jns! Positive plate is of novel con- 



— l^^r'^Rubb'T Gfsli'er^^H-^ struction. It has a grid composed 



Positive Plate. / — Negative of a number of parallel, vertical 



Plate. /-Wood .Separator. ^^j^, ^^^^ ^,,^j^pj integrally with 



the horizontal top and bottom frames. Each rod forms a core 

 which is surrounded by a cylindrical pencil of peroxide of lead, 

 the active material. This, in turn, is enclosed by a hard rubber 

 tube having a large number of horizontal slits. These serve to 

 provide access for the electrolyte or solution to the active mate- 

 rial, and yet are so fine as to practically eliminate the washing 

 out of the material. The outside tubes are reinforced by leav- 

 ing the exposed edge solid, that is, without slits. 



Each tube has two parallel, vertical ribs projecting on oppo- 



