Practical influence of float and charge voltage adjustment on the service life of AGM VRLA batteries depending on the conditions of use

The service life of VRLA batteries is normally determined by three main limiting factors these being positive grid corrosion (often linked to water loss), active mass degradation and active mass sulphation. Considering these limitations several parameters such as frequency of discharge, temperature, temperature dispersion and commissioning must be taken into account in order to adjust correctly the float and recharge voltages. This paper reviews such parameters both qualitatively and quantitatively and attempts to indicate how and why to adjust the charge and float voltages to optimise the use of AGM VRLA batteries according to the environmental conditions.