The Wrangell sentinel., 1923-08-09
HOW THE STORAGE
 BATTERY OPERATES
Operator Must Guard Against an Excessive Rate of Charge
 or Discharge.

long and tedious process to get oxide of lead on the positive plates by means of numerous charging and dischargne cycles. The oxide, which is the active material, Is manufactured chemically and applied to the plates.
 The body of manufactured plates IS cast from lead in such a manner as to leave the surface honeycombed. h this honeycombed surface of the plates Is forced a paste, formed by mixing litharge-lead-oxide with sul- phuric acid. After the plates are as sembled with separators between they are placed in containers in an electro lyte consisting of 20 per cent so- lution of sulphuric acid. The lead body of storage battery plate simply acts as a holder or container for the active material. The active materials | In a lead storage battery are the lead peroxide on the positive plate, the sponge lead of the negative plate and the sulphurlc acid electrolyte. When a storage battery is discharg' ing. that Is, while a current Is being drawn from It, chemical action takes l place in the battery. The lead per oxide of the positive plate and the sulphuric acid of the electrolyte react to form lead sulphate and water. Aclu Is more dense than water, so that when fully charged the electrolyte has a density of 1.275 to 1900, which means that the electrolyte Is 1.275 to | Is times as heavy as an equal volume of water. As the battery Is discharged and water is formed by the chemical action, the electrolyte becomes less dense. Finally, when the density drops to 100 to 1.150, the battery reaches a point when charging Is nee essary. Thus the density of the cleo trolyte Is a measure of how much en- ergy, or how fully charged the bat tery Is.
 The voltage of q battery is also an indication of the degree of charge. A fully charged battery should have an open circuit voltage of 2.2 volts per cell.
 The voltage per cell should not be allowed to drop below Is before re- charging.
 When storage battery Is put on charge. direct current Is forced through the battery. The chemical reaction that takes place during the charging process is just the reverse of that which takes place during the process of dlscharging. That is to say, the lead sulphate and water formed during the discharge are converted back into lead peroxide and sulphuric acid. The formation of sulphuric acid during the charging process causes the density of the electrolyte to increase. The density of the cleo trolyte of fully charged battery is between 1.275 and 1900. while the open circuit voltage per cell is about 2.2.
 Of course, a storage battery Is not 100 per cent efficient, which means that the total ampere hours delivered to the battery during the charging pc riod will always exceed the total am- pere hours drawn from the battery during the discharge period. The voltage per cell and the specific grav- ity of the electrolyte are the criterion of the degrees of charge in the battery However, due to the fact that some of the lead sulphate is not readily con verted into lead peroxide and sul- phuric acid, 1t Is necessary at times to give the battery an over. charge That is, the charging cur. rent should be allowed to flow after the battery has reached the charged condition. until after several hours of constant charging, there is no In. crease in the voltage per cell or the density of the electrolyte.
 The value of the charging current Is determined by the manufacturers and should not be exceeded. An ex- cessively high charging current will cause an increase In the rate of de- terioration of the plates. Every time e battery is charged or discharged a certain amount of active material on the plates crumbles and drops to the bottom of the cell. Assuming the same operating con- ditions, the life of a storage battery Is | certain number of charges and dis charges. An excessive rate of charge or discharge will cause the battery to heat, buckle the plates, and result in an abnormal amount of crumbling of the active material In the extreme case of a short circuit. the plates of the battery might be buckled to such an extent that an internal short cir cult is formed in the battery. To guard against short circuits 1t Is well when using a lead plate storage bat tery to install a fuse in both battery leads right near the terminals of the battery. Don't under any condition spark the battery by placing q pair of pliers or a screw driver across the terminals. This will eventually ruin the battery.
 The water will evaporate out of the slectrolyte of a battery and should be replaced. Always add enough dis tiled water to keep the electrolyte at least 2 quarter of an inch above the