A system including a first cell, a second cell, a first switch, a second switch, an inductance, and a control module. The first cell and the second cell are connected in series to each other and respectively output a first voltage and a second voltage. The first switch and the second switch are connected in series to each other and are connected across the first cell and the second cell. The inductance is connected between the first switch and the second switch, and between the first cell and the second cell. The control module generates control signals to control the first switch and the second switch, and to transfer charge between the first cell and the second cell via the inductance until a difference between the first voltage and the second voltage is less than or equal to a predetermined threshold. The predetermined threshold is not equal to zero.