Resistance changes and premature capacity loss in lead battery plates

Our research work has been devoted to the identification of processes that cause premature capacity loss (PCL) in lead/acid batteries. Attention has been paid to the resistance of the active material and to the resistance of the interphase between the active material and the lead grid in specially prepared positive test electrodes, measured by an exact d.c. method. Resistance measurements performed on electrodes with grids from seven different lead alloys showed that PCL is related to increasing resistance of the active material. In contrast, PCL in electrodes having pure-lead grids is caused by the formation of an insulating layer on the grid surface, evidenced by the steeply rising interphase resistance.