Patent ID: 8692515

Claim:
A series-connected rechargeable cell device, comprising: a plurality of rechargeable cells that are series-connected, and that are divided into a plurality of series-connected cell groups placed continuously in order of connecting; and a voltage-balance correcting circuit that balances the voltages of the cells, and that is provided with: an inter-cell voltage-balance correcting circuit that performs voltage-balance correcting between adjacent cells in each of the cell groups and confined within the cell group, wherein one end of an inductor is connected between a common point between the two cells to be balanced, and the other end of the inductor is connected between two switching circuits, and an inter-group voltage-balance correcting circuit that performs balance correcting of series-connection voltages of the cell groups by AC-coupling formed with a transformer coil and a switching circuit, the inter-group voltage-balance correcting circuit including: a plurality of transformer coils each having ends respectively connected to series-connection ends of each of the series-connected cell groups, that are magnetically coupled at the transformation ratio of 1:1, and a plurality of switching circuits, disposed between the transformer coils and the cell groups, respectively, that apply a current to each of the transformer coils simultaneously by being turned ON/OFF in phase in accordance with a periodic pulse signal.