A reliable diagnostics of lead-acid batteries would become mandatory with the induction of an improved power net and the increase of electrically assisted features in future automobiles. Sparse-impedance spectroscopic technique described in this paper estimates the internal resistance of sealed automotive lead-acid batteries in the frequency range 10 Hz-10 kHz, usually produced by the alternators fitted in the automobiles. The state-of-health of the battery could be monitored from its internal resistance.

Lightweight grids for lead-acid battery grids have been prepared from acrylonitrile butadiene styrene (ABS) copolymer followed by coating with lead. Subsequently, the grids have been electrochemically coated with a conductive and corrosion-resistant layer of polyaniline. These grids are about 75% lighter than those employed in conventional lead-acid batteries. Commercial-grade 6V/3.5Ah (C₂₀-rate) lead-acid batteries have been assembled and characterized employing positive and negative plates constituting these grids. The specific energy of such a lead-acid battery is about 50 Wh/kg. The batteries can withstand fast charge-discharge duty cycles.