The electrochemical behaviour of lead, antimony and lead-antimony binary alloys has been studied as a function of sulfuric acid and antimony concentrations in the lead alloy. The investigation was performed by means of cyclic voltammetry and impedance spectroscopy methods. Cyclic voltammetry, performed between the hydrogen and oxygen evolution and over narrower regions of potential coupled with systematic variation of the scan rates and the positive or negative reversal potential, revealed more details on the oxidation and reduction processes in the potential region of Pb(II)-, Pb(IV)- and Sb(III)-containing species which give further insight into the nature of the reactions of the lead/acid battery. The impedance measurements performed in the potential range of lead oxide, in which antimony oxidation in the alloys takes place, show the decrease in film resistance with increasing antimony content.