Patent ID: 7365952
Filing Date: 2008-04-29
Classification: H02J,Y02E

Abstract:
1. A battery pack including at least a battery cell and a protection circuit for shutting off overcurrent discharge to a load, said protection circuit comprising: an integrated circuit including a overvoltage detection unit; a discharging shut-off switch controlled by the integrated circuit and connected in series with the load; a diode wired in parallel to said discharging shut-off switch; and a shut-off holding unit connected between the battery cell positive terminal and an external negative terminal of the protection circuit, comprising (a) resistor block of resistance larger than 1 kΩ and smaller than 200 kΩ; and (b) a detector in parallel with the resistor block for detecting voltage between an external plus terminal and the external minus terminal, wherein, the overvoltage detection unit detects an abnormal discharge of the battery caused by shorting or connecting a low resistance between the external plus terminal and the external minus terminal, the discharge shut-off switch opens in response to a abnormal discharge, the shut-off holding unit maintains the discharge shut-off in the open position, and said discharge shut-off switch closes to recover discharge upon detection by the shut-off holding unit of a predetermined voltage between the external plus terminal and the external minus terminal of the battery pack.