Discharge and Charging of Lead-Acid Battery
When a lead-acid battery is discharged, the electrolyte divides into H 2 and SO 4 combine with some of the oxygen that is formed on the positive plate to produce water (H 2 O), and thereby reduces the amount of acid in the electrolyte. The sulfate (SO 4) combines with the lead (Pb) of both plates, forming lead sulphate (PbSO 4), as shown in Equation.