Abstract: A rechargeable battery array comprises a plurality of rechargeable battery cells (10)-(16) connected in series, and in equal plurality of charging sources (18)-(24) connected in series. Corresponding terminals of corresponding battery cells and charging sources are interconnected. The internal resistance of each of the charging sources is matched to the internal resistance of each battery cell. The configuration provides substantially faster charging of the battery cells than is possible using conventional battery cell array charging configurations. The invention is particularly well suited to photo-voltaic charging systems.