Composition and Action of Battery
Battery consists of two electrode, cathode of lead (Pb) and anode of lead
dioxide (PbO2), and the substance called electrolyte. Electrolyte is composed of
pure water (distilled water) and dilute sulfuric acid, and the concentration of
dilute sulfuric acid is about 37%. [Specific Gravity of a New Battery 1.280]
Electro-motive force is generated by electrolysis from chemical reaction among
the water, dilute sulfuric acid and lead. The electric current generated at this
time is very small, but if electric current is passed through it more current is
generated.
That is, the process that chemical energy makes electricity and the electric
energy makes chemical energy continuously repeats.
Battery repeats this charging and discharging (electrolysis action). The substances
generated this time include hydrogen, oxygen, cation, anion and sulphate.
Among these, the biggest cause to shorten the battery life is sulphate. Sulphate attaches to the pole plates when battery is discharged, and comes off
when charged. If the battery is a new one, the action of attachment and
detachment to pole plates is very smooth, but as the battery using time
becomes long, the sulphate attached to pole plates does not comes off well.
and at the time of severe discharging, it is generated much more.[The condition
that specific gravity of electrolyte becomes low]
Severe discharge means using electricity from battery while a vehicle engine is
not started.