To provide a battery protection device for processing a regenerative current in which, in the state where a battery can receive the regenerative current, the regenerative current is received, in the state where the battery cannot receive the regenerative current, inflow of the regenerative current is blocked but power feeding to a power line is enabled and the regenerative current is perfectly prevented from flowing into the battery.
The battery protection device comprises: a regenerative current receiving battery relay 3 which is connected in parallel with a diode 10 for causing a drive current to flow from a battery 4 toward a motor 8, and guides a regenerative current generated from the motor 8 to the battery 4; a regenerative current discharging relay 1 for guiding the regenerative current from the motor 8 to a discharging member 2; and an electronic control unit 5 in which a previously stored threshold value for a temperature of the battery at which the battery cannot receive the regenerative current, is compared with a temperature of the battery 4 and when it is determined that the temperature of the battery 4 is lower than the threshold value, the regenerative current receiving battery relay 3 is brought into a shut-off state from the completion of the determination, thereby controlling the regenerative current discharging relay 1 into a conducted state.
KURAISHI MAMORU
MAKISHI WATARU
