THE BATTERY

Sun (Auckland), Volume IV, Issue 1020, 10 July 1930, Page 22

THE BATTERY

TO GET EFFICIENCY CARE TO BE TAKEN The storage battery may seem to be an insignificant unit of the automobile, but on most of the present-day cars it is so important that its failure will mean the failure of the entire car. On those cars which depend on the storage battery for the current for the ignition system, if the battery be dead the engine will be just as useless as if the petrol tank were empty. Let us see how the battery is made, how it operates and its care. The storage battery consists of a number of cells, called accumulator cells, each cell being capable of yielding a current having a voltage of 2.1. Thus, if a six-volt battery is needed, the battery is made up of three celis. while, if twelve volts are needed, six cells are used. CHEMICAL DETAILS Each cell is made up of a jar, generally of hard rubber, in which are two sets of plates, positive and negative These plates are made of lead, in the form of a grid. In the grid of one set

of plates a paste of grey spongy 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 grey plate, then red, then grey, etc., all the red plates being connected to a common binding post, and likewise the grey. The plates are kept from touching by separators. made either of specially treated wood or porous rubber, and are then placed in jars. The jars are then covered and sealed and the plates of the various cells connected, tho positive 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 current sent into tho battery. HANDY HINTS One of the most important things which must be done to the battery is to fill it with water regularly. The water used must be distilled, so as to be chemically pure. Filtered water will not do. Acid must never be added to the battery, even though it be years old. 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, the battery should be stored with a battery service station, where it can be charged periodically. An idle battery loses its charge. CHARGE AND DISCHARGE A battery must not be charged or

discharged too quickly, as this will generate heat and warp the plates. On most cars the battery is charged at about a 10-ampere rate, which is the maximum safe charge. When the selfstarter motor is used, however, a current of an amperage from 150 to 250 will flow, which will result in a very quick discharge. Therefore, if your engine does not start promptly, do not use the starter constantly, but stop and give the battery a rest. It would be well to And the reason for the slow starting and, if the day be cold, to give the engine a few preliminary turns by hand before switching on the ignition. Note that when the starter is used the battery is discharged from fifteen to thirty times as fast as it js charged when the engine is running. This means that it takes about 30 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 sending it back to the battery. KEEPING IT CLEAN - Care must be taken to keep the top of the battery clean. Before filling with water it would be well to wipe the top of the battery before unscrewing the filler caps. If the smallest pieces of iron or copper, etc., get into the battery quite a portion of the plates will be coated -n*th an iron or

copper sulphate, and so be put out of service. It is advisable to rub the lead terminals with a cloth on which is some vaseline, as this will protect them from being corroded 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 to get between the plates and so short-circuit them. RETREADING TYRES An excellent opportunity for motorists to save 60 per cent, of their tyre bills is furnished by the AUvanx Ty-re-pair Company. The Advanx Retread process more than doubles the life of the tyre at very little cost, and an Advanx job carries with it a new tyre guarantee. The new tread is designed to ensure mileage, safety and comfort. MOTOR ACCESSORIES SALE All moLorists must be interested Id tho huge sale of motor accessories th-at is being conducted by the United Motor Supplies Company, the accessory and spare part specialists, Upper Queen Street. A full range of accessories and parts for all makes of cars is being sacrificed at very low prices.