At discharge, the lead is converted into lead sulphate (a white powder in the open air) while the sulphuric acid content decreases in the acid solution (i.
The following mainly analyzes the lead-acid battery short circuit caused by excessive charging current, charging voltage of a single battery exceeds 2.4V, internal short-circuit or partial discharge, excessive temperature rise and valve control failure, and summarizes the treatment methods of lead acid battery short circuit as follows:
When a current is being drawn from the battery, the sudden drop is due to the internal resistance of the cell, the formation of more sulphate, and the abstracting of the acid from the electrolyte which fills the pores of the plate. The density of this acid is high just before the discharge is begun.
Why is the discharge state more stable for lead–acid batteries?
The discharge state is more stable for lead–acid batteries because lead, on the negative electrode, and lead dioxide on the positive are unstable in sulfuric acid. Therefore, the chemical (not electrochemical) decomposition of lead and lead dioxide in sulfuric acid will proceed even without a load between the electrodes.
Normally, as the lead–acid batteries discharge, lead sulfate crystals are formed on the plates. Then during charging, a reversed electrochemical reaction takes place to decompose lead sulfate back to lead on the negative electrode and lead oxide on the positive electrode.
Sulfation , which means the formation of PbSO 4, is another serious problem with lead–acid batteries. Normally, as the lead–acid batteries discharge, lead sulfate crystals are formed on the plates.
Lead-acid storage battery will lose part of its capacity due to self-discharge. Therefore, before lead-acid battery is installed and put into use, the remaining capacity of the battery should be judged according to the battery's open circuit voltage, and then different methods should be used for supplementary charge for the battery.