THE BATTERY.

Press, Volume LXVI, Issue 19971, 4 July 1930, Page 6

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 tho present-day ears it iB so important that its failure will mean the failure of the entire car. On thoso cars which depend on the storage battery for tho current for the ignition system, if the battery bo dead, the engine will bo just as useless as if the petrol tank were empty. Let us see how the battery is made, how it opera tea and its care. The storage battery consists of a number of cells, called accumulator cells, each cell boing capable of yield' ing a current having a voltage of 2.1. Thus, if a six-volt battery is needed, the battery is made up of three cells, while, if twelve volts aro needed, six cells are used. 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 aro then set together, so thdt tWo 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) the positive of one to the negative of the next, Thus the cells will be in sorics. When tho battery is roady for service, a solution, called the electrolyte, made of a mixture of sulphuric acid and water, is then poured into the cells, and an eleotrlc current sont into the battery. Chemical Action. As the current enters the battery tho water of the eleetrolyte is decomposed into hydrogen and oxygen. The hydrogen will oscapo as a gas and the oxygen combine with the soft lead of negative plates, which lead will leavo this plate and be deposited In tho form of oxido of lead on tho positive plates, until no more can bo deposited. Tho battery is then fully charged. Note that the hydrogen of the water escapes, but that the sulphuric acid is not affoctod. When the battery has been charged, if a circuit be made on the outside, the roverso chemical action will take place, and electrio curront flow from the battery. In this case the oxide of lead gives up its oxygen, which escapes as a gas, and the lead is deposited back on tho soft-lead plates. Note that now the oxygen escapes, but that the sulphuric acid again is unaffected.

The relation between tbe above chemical action and tbe flow of electricity is explained by what is known aa the theory of ions. This theory cannot bo explained here, but notice how the water disappears, while the acid does not. For this reason one of tbe most important things which must be done to the battery Ts to fill it with water regularly. The water used must be distilled, so aa to be chemically pure. JHltered water will not do. Acid must never be added to the battery, even though it be years old. When the electrolyte la poured into the battery, the first thing that happen* is that much of tbe aoia is absorbed by the plates, but as tbe plates are charged they cannot hold so much of tbe acid by absorption, and so tbe acid goes back into the solution as the battery beoomea charged. Aa the acid is much heavier than the water,. tbe solution will be lighter when the battory is discharged and much of the asld has been absorbed out of the solution, and heavier when the battery is charged and the acid is back in tbe solution. This gives a means for seeing how well charged the battery is; namely, by seeing bow heavy tbe electrolyte is. For this purpose a hydrometer is used. If some of the solution is drawn out of the battery with a syringe and the hydrometer put into it, the depth to which it sinks will indicate the weight of tbe electrolyte. A battery must never be left standing in a discharged state, aa a coating will form on the plates, making it hard to charge them. For this reason, if the car is not used, the battory should be stored with a battery service station, whero it can bo charged periodically. An idle battory loses its charge.

Charge and Discharge. A battery must not be charged or discharged too aulckly, as this will generate heat ana warp the plates. On most ears the battery la 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 find the reason for the slow starting, and, if the day bo 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 is charged when the engine is running. This means that it takes about thirty minuteß of car driving at a fair speed to make up for the current used in one minute of starter use. Prom this you can judge if you are sending it back to the battery. 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 with 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 ear 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-eircut them.

Since it was announced that several prominent directors of the Automobile Racing Association (responsible for the Wash speedway scheme) bad resigned, speculation has been rife aa to the exact significance of this development In an official statement to the "Lincolnshire Standard." however, a representative of the company explains that "the directors have all formally resigned. with the object, of leaving the way olear for the appointment of a new Board. Captain Campbell is still one of the largest shareholders and is still actively interested. A new Board ij in formation, and it will be corn, posed largely of business men of bis; financial standing Captain Woolf Barnato has resigned owing to pressure of other interests."

FOR £5. ACROSS CENTRAL AFRICA. TRIP BY MOTOR-CYCLIST. The amazing economy and reliability of the modern light-weight motor-cycle have again been demonstrated in a remarkable manner by a young Englishman, who has just ridden across Africa at a total expense of £5. This amount covered all costs of petrol, oil, food, and "accommodation" for a five weeks' trip over a distance of some 8000 miles. The young rider, Mr Frank Howard, is engaged as a mining engineer lu Nigeria, and decided upon his project some months ago. For his trip be selected a British machine, and realising the difficulties of obtaining petroi, oil, and water en route he bad the machine fitted with special tanks enabling him to carry two gallons of oil, [ four gallons of water, and 17 gallons 1 of petrol.

Starting from Lagos, Lis objective was Port Sudan on the Bed Sea, and the only naps carried were those torn from a schoolboy's shilling atlas. At the outset terrifie rain caused the loss of all tools and spares, with the exception of a spar tyre and chain, owing to the carrier straps stretching. Then until Jos was reached, some 900 miles further on, rhc intrepid ridei had no means whatever of effecting the sm-'H-est repairs, so that su«h a minor fault as a sooted plug might well have meant death. At Jos, near the border between geria an 3 the French Sudan, Mr How. ard received cables from the British authorities refusing him permission 10 cross the Anglo-Egyptian Sudan. How ever, he pushed on across the interven Ing 1000 miles of Trench territory while jungle' gave place to sand, entailing tremendous strain on machine and rider. The machine, with its vast load of over a quarter of a ton, sank into the sand and for 2000 miles it was seldom possible to use top gear; mile after mile was covered in bottom gear with much physical assistance. Curiously enough, Mr Howard was I allowed entrance into the Anglo-Egypt-

ian Sudan, tad actually continued his hazardous trip as Jar as El Obeid before being definitely stopped by the authorities: This was very bard luck, as the Bed Sea was but a few hundred miles away, and the last lap would have been child's play compared with what had already been achieved. It is interesting to note that whilst monkeys encountered on the trip paid little or no attention to the machine, two Hons were thoroughly frightened, and made off at full speed.

The following remedy will be found very effectual in curing a bad leak in a radiator. Whisk the white of an ess and then pour it into the radiator so that It will circulate with the water. As soon as this reaches the leak it will harden on coming into contact with the air, and prevent further loss of water for quite a time.

KINGSFORD SMHJrSIg ' 'FLIGHT. i|| A BIG FACTOR IN THE SUCtjH The Vacuum Oil Ltd., have received a from Wing -Cororaander Kimn| Smith, it* which he states: 'j'M eiate the excellent quality which carried us safely through fog and ov«r land wish to express our appreciawoJJßH skill with which the vacuum vrenH pany process ant) refine their WH so that it stood ud to more tbaraßH miles' travel of the pistons. AWyßn the motora working perfectly,, JBH minute of our trip." ..JIM Although Plume is marketed tralia and New Zealand onl?»*WM were specially laid down this groat flight at Eiogsford Smith*® request. .