| 摘要 |
PROBLEM TO BE SOLVED: To provide battery information from a built-in microcomputer for a battery pack in an over-discharged state so as to predict a charging time and a battery operation time by feeding electric power to the built-in microcomputer in a battery pack in an over-discharged state from a battery in a non-over- discharged state. SOLUTION: A load side control unit 15 turns off a discharging switch 5, turns on a discharging switch 6, turns on an over-discharging time charging switch 10 and turns off an over-discharging time charging switch so as to feed weak current restricted by an over-discharging time charging current restricting resistor 14 from a secondary battery pack 4 to a microcomputer 1 in a secondary battery pack 3 in an over-discharged state. In this way, the load side control unit 15 can read battery information such as a battery residual capacity, a designed capacity, a voltage, a current and a temperature from the microcomputer 1 in the secondary battery pack 3. Only in the battery information reading time, the over-discharging time charging switch on the secondary battery pack in an over-discharged state is turned on, so that power supply can be minimized. |
