Analysis of gassing processes in a VRLA/spiral wound battery

An experimental analysis of the gassing processes has been conducted on a modified commercial spiral wound AGM battery. Single electrode potential, cell and battery voltage and internal gas pressure have been monitored on a modified battery at different current rates in the steady-state regime. At low polarization, the oxygen recombination cycle proceeds properly. At large polarization of the negative electrode, careful examination of the evolution both of the electrode potential and the inner gas pressure indicates that, instead of the expected adverse evolution of hydrogen gas, oxygen continued to be reduced.