Patent ID: 7633268

Claim:
A charging apparatus comprising: a battery pack which includes a plurality of battery cells, cell voltage detection unit for detecting a cell voltage of a battery cell to output a cell voltage detection signal if a detected value is equal to or greater than a cell voltage threshold value, and a temperature sensor for detecting a temperature of the battery pack; and a charger to which the battery pack is freely removably mounted, the charger including a power supply circuit for charging the battery cells of the battery pack, pack voltage detection unit for detecting a pack voltage across two terminals of the battery pack, and a charging control circuit for controlling the power supply circuit, wherein if a detected temperature from the temperature sensor exceeds a temperature threshold value, the charging control circuit performs a first mode charging that a constant current charging is switched to a constant voltage charging when the cell voltage detection signal is received from the cell voltage detection unit, and, if the detected temperature from the temperature sensor is equal to or smaller than the temperature threshold value, the charging control circuit performs a second mode charging that the constant current charging is switched to the constant voltage charging when the cell voltage detection signal is received from the cell voltage detection unit or a detected pack voltage from the pack voltage detection unit becomes equal to or greater than a pack voltage threshold value, whichever occurs first.