| 摘要 |
PROBLEM TO BE SOLVED: To prevent over-discharging and overcharging of respective unit cells and avoid restriction as much as possible due to variations in the capacities of respective unit cells on the charging capacity of a battery formed by connecting respective unit cells in series. SOLUTION: The terminal voltage of a battery 38 formed by connecting four unit cells 21 (1) to 21 (4) in series is divided by a voltage dividing circuit 40' formed by connecting resistors 23a, 24a, 25a, 39 in series. A logic circuit part 67 turns on the switch 35 of a discharge circuit 33 for a unit cell 21 whose internal terminal voltage is higher than mean voltage based on the output signal of comparators 27 to 41L for permitting its automatic discharge and ultimately attains roughly equal terminal voltages for all the unit cells 21 to resolve variations. When the ambient temperature is detected by a thermistor 61 and is at the prescribed temperature or less, the logic circuit 67 prohibits the cells 21 from discharging upon receiving the output signal of the comparator 62. |
