Patent ID: 8508190
Filing Date: 2013-08-13
Classification: H01M,H02J,Y02E,Y02T

Abstract:
1. An assembled battery system comprising: an assembled battery including a plurality of electric cell blocks connected in series, the electric cell blocks each including at least one nonaqueous electrolyte secondary battery provided with a negative electrode current collector formed of aluminum or an aluminum alloy; a voltage measuring unit configured to measure a plurality of voltages of the electric cell blocks; a controller which controls charge/discharge of the assembled battery in accordance with the measured voltages; and bypass circuits connected in parallel to the electric cell blocks, the bypass circuits each bypassing a current that flows from a negative electrode of one of the electric cell blocks to a positive electrode of the one of electric cell blocks when the measured voltage of the one of electric cell blocks is a negative value not greater than a threshold value, wherein the bypass circuits each include a MOSFET and a bias voltage source, the MOSFET storing a threshold voltage and having a source terminal connected to the positive electrode of a first corresponding one of the electric cell blocks, a gate terminal and a drain terminal, a drain terminal connected to the negative electrode of the first corresponding electric cell block and a gate terminal, the bias voltage source applying a bias voltage between the gate terminal and the drain terminal.