Patent ID: 8493028

Claim:
A charge-balancing system comprising: N circuits each including: a first switch connected in series to a second switch; and an inductance having a first end connected between the first switch and the second switch; and a control module configured to generate control signals to control the first switch and the second switch, where N is an integer greater than or equal to 1, wherein a second end of the inductance of a first circuit of the N circuits is connected between two cells of a first pair of 2N series-connected cells of a battery stack, wherein the first switch and the second switch of the first circuit are connected in parallel to the first pair of 2N series-connected cells, wherein the control module is configured to transfer charge between the two cells of the first pair of 2N series-connected cells via the inductance until a difference between respective output voltages of the two cells of the first pair of 2N series-connected cells is less than or equal to a predetermined threshold, and wherein the predetermined threshold is not equal to zero.