| 摘要 |
PROBLEM TO BE SOLVED: To protect a battery against an overcharging operation when the constant- voltage control operation of a charging device is not operated and when the safety circuit of a battery pack does not function by a method wherein the charging device is provided with a battery-voltage detection circuit and with a charging-voltage detection circuit and a charging operation is stopped when their detection voltages exceed respective preset voltages. SOLUTION: When a secondary battery 4 is charged, a charging-current-and-voltage control circuit 2 performs a constant current operation on the basis of the detection voltage value of a battery-voltage detection circuit 5, and it is shifted to a constant- voltage control operation when a battery voltage reaches a set voltage. At this time, when the constant-voltage control is not operated, when a safety circuit 3 installed inside a battery pack does not function and the battery voltage is increased further and when the charging-voltage detection value of a charging-voltage detection circuit 15 exceeds a set value, a charging stop signal is sent to a charging stop means 12 from a second comparison means 11, and a charging operation is stopped. In addition, when the battery-voltage detection value of the battery-voltage detection circuit 5 exceeds a set value, a charging stop signal is sent to the charging stop means 12 by a third comparison means 14, and the charging operation is stopped. |
