When a lead-acid cell is recharged, the H₂ ions move to cathode and SO₄ ions go to anode. The following changes then take place.

At Cathode: PbSO4 + H2 → Pb + H2SO4

At Anode: PbSO4 + 2H2O → PbO2 + 2H2SO4

At Cathode: PbSO4­ + H2 → Pb + H2SO4

At Anode: PbSO4 + H2O → PbO2­ + H2SO4

At Cathode: PhSO4 + H2O → PbO2 + H2SO4

At Anode: PbSO4 + H2 → Pb + H2SO4

At cathode: PhSO4­ + 2H2O → PbO2 + 2H2SO4

At Anode: PbSO4 + H2 → Pb + H2SO4

At Cathode: PbSO4­ + H2 → Pb + H2O

At Anode: PbSO4 + H2O → PbO2­ + H2O