ACCELERATED LIFE-CYCLE TESTING AND ANALYSIS FOR EARLY FAILURE PREDICTION USING 2 TYPES OF LEAD-ACID-BATTERIES

A sample of 12 small, single cell, lead/acid batteries from each of two manufacturers was subjected to continuous charge-discharge cycling at 50-degrees-C. Reduction of battery capacity to 60% of the manufacturer's rating was the failure criterion. Cycles-to-failure data followed a Weibull distribution, indicating wearout as the failure mode. A Weibull characteristic life of 93 and 580 cycles was found for the cylindrical and flat plate batteries tested, respectively. An early way to detect an inferior battery from among batteries of the same type is suggested. It was found, using an early cycle, that a cell with a comparatively low voltage at end-of-discharge is relatively likely to fail earlier than other batteries of the same type.