Patent ID: 6437540
Filing Date: 2002-08-20
Classification: H02J

Abstract:
A battery pack using a battery comprising one or more cells as a power source and for connecting power to an external host device, said battery pack comprising:charging/discharging means connected in series to said battery and used for charging and discharging; current detecting means for detecting the charging/discharging current; voltage detecting means for detecting voltage; and temperature detecting means for detecting temperature, wherein at least charging state, discharging state, charging stop state and discharging stop state can be selected by controlling said charging/discharging means based on the charging/discharging current, the voltage, and the temperature as detected, and it is turned from one of these states to another state, and state transition information is transmitted to the external host device, and wherein said charging/discharging means comprises a charging switch for charging said battery and a discharging switch for discharging said battery, said control means is operated in such manner that it is turned to the charging state or the discharging state when said charging switch and said discharging switch are both turned on and charging current or discharging current higher than a preset value is detected, it is turned to a charging stop state when the charging switch is turned off and the discharging switch is turned on, and it is turned to a discharge stop state when the charging switch is turned on and the discharging switch is turned off.