Failure Mode of the Positive Plate on Charging Voltage in Gel Type Valve Regulated Lead Acid Batteries

Cycle life test was carried out to evaluate the failure modes of the gel type nth batteries at currents and DOD. When the batteries were charged at constant voltage of 2.40 V and 2.50 Vi respectively, cycle lift was over 1,000 cycles. The batteries lost 426.4 g and 391.2 g of electrolyte far each case after the weight measurement. The battery charged at 2.50 V was shown to have a better cyclic performance than charged at 2.40 V, and the amounts of electrolyte loss was proportional to charge factor. After cycle test, the micro-structure of positive active material was completely changed and the corrosion layer of positive grid was about . Failure mode of the positive plate of the gel type battery was a shedding of the positive active material, and the cause of discharge capacity decrease was found to be a electrolyte loss.