A battery system having at least one battery string of more than two batteries connected in series, a charge equalization circuit, a relay matrix, and a balance controller. The charge equalization circuit is capable of equalizing the charge on any pair of series connected batteries in the at least one battery string. The relay matrix is operatively connected between the charge equalization circuit and the at least one battery string. The balance controller controls the relay matrix such that at least one battery characteristic of at least one battery is sensed. Based on at least one sensed battery characteristic, the balance controller controls the relay matrix such that the charge equalization circuit is connected across at least one pair of series connected batteries in the at least one battery string.
