Battery acid is a strong acid, meaning that it can completely dissociate into its component ions in water. When dissolved in water, sulfuric acid forms hydrogen ions (H+) and sulfate ions (SO4^2-). These ions are what carry the electrical current in a lead-acid battery.
The chemical reaction that takes place in a lead-acid battery during discharge is as follows:
Pb(s) + PbO2(s) + 2H2SO4(aq) → 2PbSO4(s) + 2H2O(l)
During discharge, the lead and lead oxide electrodes in the battery are converted to lead sulfate, and the sulfuric acid in the electrolyte is consumed. This reaction generates water, which is why the electrolyte level in a lead-acid battery must be periodically checked and topped off as needed.
Battery acid is extremely corrosive and can cause severe burns if it comes into contact with skin or eyes. It is also toxic if ingested, and can cause damage to the respiratory system if inhaled.
For these reasons, it is important to handle battery acid with care and to always wear protective clothing, gloves, and safety glasses when working with it.
