EXTENSION OF BATTERY LIFE VIA CHARGE EQUALIZATION CONTROL

The primary difficulty in charging storage batteries is in attaining process regulation that allows fast charging while avoiding destructive overcharging. This paper presents a two-level approach to controlling the charging process. A general background discussion of batteries and charging problems is followed by the presentation of a novel recirculating charge equalization technique that enhances the uniformity of batteries made up from long serial strings of cells. Next is a brief description of a straightforward means of embedding equalization within an outer-loop supervisory control that maintains a fast charging rate while providing overall protection against overcharging. Simulation and experimental results confirm the applicability of the equalization control technique.