New operational strategies for gelled-electrolyte lead/acid batteries

Gelled-electrolyte and flooded-electrolyte lead/acid batteries are cycled according to a new schedule that is based on partial-state-of-charge operation. With this strategy, the energy delivery of gelled-electrolyte batteries increases threefold, compared with that expected under traditional cycling procedures. In addition, overcharge is reduced by an order of magnitude. This provides charging efficiencies of up to 99.5%. Under the same duty, flooded-electrolyte batteries fail prematurely due to degradation of active-material at the bottom of the positive plates. This limitation is induced by increased active-material utilization as a result of acid stratification. The phenomenon is termed 'localized PCL', and is explained in terms of the uniform theory of PCL that has been developed by CSIRO.