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Show LESSON NO. 77. Care of the Storage. Battery. The storage battery may seem to be an iniigni:lcarit unit uf the automobile, but on most of the present-day carB it is so important that its failure will mean Iho failure of tiie entire car. On those cars uhicn depend on the storage battery bat-tery f'.r tiie current for the ignition system, sys-tem, if the battery be dead, the engine will be just as useless as if tho gasoline tank were empty. Let us tee how the battery is made, how it operates anil its care. Tiie storuyc battery consists of a number num-ber of cells, called accurnula tor cells, ea-'h cell being capable of yielding a current cur-rent having a voltage of 2.1. Thus, if a ;-vnlt battery Is needed, the battery is made up of three '-ells, while if twelve voils are m-eded, six cells are used. l-iach cell is made up of a jar, generally of hard rubber, in which are two :-pis of pla les, positive and pegath e. These plates are made of lend, in the form of a grid. J n the grid of one set of phi trs a paste of gray. Hpongy lead is forced, while in the other set a paste of red oxide of lead is forced. The plates are then set together so that there will be a gray plate, then red, then gray, etc., all and the lead is deposited back on t':e soft-lead plates. Note now that the oxygen escapes, but that the sulphuric aeid again is unai-fc-f ed. Thfc relation between the above chemical chem-ical action and the flow of electricity is explained by what is known as the theory of ions. Tills theory cannot be explained her-;, but I want you to notice how t::e water disappears, while the acid docs not. For this reason one of the most important im-portant tilings which must be done to the battery is to fill it with water regularly. regu-larly. Figure 1 shows the level at which the solution must be maintained. It must not come higher than This, as it will cause a short circuit. The water used must be distilled, so as to be chemically chem-ically pure. Filtered water will not do. Acid must never bo added to the bat-terv. bat-terv. even though it lie years old. When the electrolyte Is poured into the battery the first thing that happens is that much of the acid is absorbed by the plates, but as the plates are charged they cannot bold Sfo much of the acid by absorption, ab-sorption, and so tiie acid go?s back into the solution as the hattery becomes charged. As the acid is much heavier than the water, tho solution will be lighter light-er when tiie battery is discharged and much of the acid has been absorbed out i FiO. i Flo. L the red plates being connected to a common com-mon binding .post, and, likewise, the gray. Tho plates are kept from touching touch-ing by separators, made either of specially spe-cially treated wood or porous rubber, and aro then placed in the jars. The jars are then covered and sealed, and the plates of the various cells connected, the positive posi-tive of one to the negative of the next. Thus the cells will be In series. When the battery is ready for service a solution, called tho electrolyte, made of a mixture of sulphuric acid and water. Is then poured into the cells, and an electric elec-tric current sent into the battery. As the current enters the battery the water of the electrolyte is decomposed into hydrogen and oxygen. The hydrogen will escape as a gas and the oxygen combine com-bine with the soft lead of negative plates, which lead will leave tills plate and be deposited in the form of oxide of lead on the positive plates, until no more can be deposited. The battery Is then fully charged. Note that the hydrogen of the -water escaped, but that the sulphuric acid was not. affected. When the battery has been charged, if a circuit be made on the outside, the reverse chemical action will take place, and electric current flow from the batter;-. In ths case tiie oxide of lead gives up "its oxygen, which escapes as a gas. of the solution, and heavier when the battery is charged and the acid Is back in the solution. This gives a means for seeing how well charged the battery is; namely, by seeing how heavy the electrolyte electro-lyte is. For this purpose a hydrometer is used. If some of the solution is drawn out of the battery by a syringe and the hydrometer hy-drometer put into it, the depth to which it sinks will Indicate the weight of "the electrolyte, Thus, In Figure 2, the top of the liquid comes to the mark 1200, indicating indi-cating that the solution is 1.2 times the weight of water. The following table gives the amount i of charge for the various readings and I the temperature at which the solution will freeze: 1120, discharged: freezes 20 above zero. 1160, three-quarters discharged; freezes at zero. , , e . . 1210, one-half discharged; freezes at 20 below zero. - 1260, one-quarter discharged; freezes at 60 below zero. 1275 to 1300, fully charged. A battery must never be left standing In a discharged state, as a coating will form on the plates, making it hard to charge them. For this reason, if the car Is not used in the winter, the battery should be stored with a batterv service station, where it can be charged period- icatly. An id! battery loses its charge. A battery must not be charpred or dls-: charged too quickly, as this will generate heat and warp the plates. On most cars the battery is charged at about a 10-atnpere 10-atnpere rate, which is tho maximum safe, charge. When, however, the self-starter motor Is used, a current of an amperage from 150 to 250 will flow, which will result re-sult in a very quick discharge. Therefore, if your engine does not utart promptly, do not use the starter constantly, but stop and give the battery a rest. It would be good to find the reason for the slow starting, and, possibly, if the day be cold, to prime bv pouring some raw gasoline into the cylinder through the compression cocks. Note that when the tarter Is used the battery Is discharged from fifteen to thirty times as . fast as it is charged when the engine is running. This means that it takes about thirty minutes of car driving at a fair speed- to make up for the current used in one minute of starter use. From this you can judge if you are using current faster than you are sending send-ing it back to the battery. This Is very often the case in winter. Care must be taken to keep the top of the battery clean. Before filling it with water, it would be well to wipe the top nf the battery before unscrewing the filter caps. If the smallest pieces of iron or copper, etc., get Into the battery quite a portion of the plates will 'be coated with an iron or copper sulphite, and so be put out of service. It is good to rub the lead terminals with a cloth on which is some gasoline, as this will protect them from being corroded cor-roded by any acid which might be spilled. In taking the battery out of the car, or putting it back, care should be taken ! to keep it in a vertical position. Some sediment may be in the bottom of the jars, and tipping them may cause this sediment sed-iment to get between the plates, and so short circuit them. cause t a sharp knock. All cars start hard in cold weather. Priming is one of the best methods to accelerate easv starting. Also it is- a good plan, oh very cold mornings, to warm up the intake manifold with a hot cloth or by flooding it with hot water. I have a forty ampere storage battery bat-tery that I use for lighting onlv. How often do yon think this ought to be recharged? re-charged? E. H. Mathews. That depends upon how long the lamps are burned and on the size bulbs used. Probably once in two weeks would be enough under ordinary service serv-ice conditions. How many passenger cars will be manufactured in 1918,? Tom Wilder. No figures ar0 available and I do not believe the National Automobile Chamber Cham-ber of Commerce will make anv statement. state-ment. Perhaps the total may "reach a million. Production was not radically cut down until the quota for the firs't half year had been turned out. |