This paper outlines an investigation of the electrochemical behaviour of polymeric divinylferrocene (PDVF) produced by direct polymerisation of divinylferrocene (DVF) monomer on a glassy carbon substrate. The findings indicate that PDVF undergoes reversible reduction/oxidation in neutral and acidic aqueous media containing perchlorate (ClO4 −) and sulfhate (SO4 2−). The anodic peak potential of the PDVF shifts linearly to less positive potentials as the sulfuric acid (H2SO4) concentration is increased from 1 to 5M. The polymer film strongly adheres to the glassy carbon surface and is electrochemically stable when subjected to repeated voltammetric cycling in the potential range of −0.2 to +0.8V vs. Ag|AgCl. The potential of the partially oxidized film of PVDF on a glassy carbon substrate against a Ag|AgCl/KCl reference electrode in sulfuric acid solution is stable, reproducible and varies linearly with the acid concentration in the range of 1–5M. This observation may be suitable for potentiometrically measuring the state-of-charge of lead–acid batteries.