Equivalent mass of H₂SO₄ in lead storage battery is (M=Molar mass)

${\mathrm{SO}}_{4\left(\mathrm{aq}\right)}^{-2}+4{\mathrm{H}}_{\left(\mathrm{aq}\right)}^{+}+2{\mathrm{e}}^{-}\to 2{\mathrm{H}}_2{{\mathrm{SO}}_4}_{\left(\mathrm{aq}\right)}$

for 2 moles of H₂SO₄ = 2 mole electrons

                ?             =          1 mole electrons

${\mathrm{E}}_{{\mathrm{H}}_2{\mathrm{SO}}_4}=\frac{2\mathrm{M}}{2}=\mathrm{M}$