Patent ID: 8854014

Claim:
A battery charging apparatus comprising: a charging module configured to charge a battery, the battery associated with a maximum allowable current value; a voltage measurement module configured to measure a first voltage value associated with the battery; an impedance measurement module configured to measure an impedance value associated with the battery; a protector configured to send a charge stop command to the charging module, in response to the first voltage value of the battery exceeding a threshold value; a current value calculator configured to calculate, based on the first voltage value, the impedance value, and the threshold value, an overvoltage protection current value; and a charging current value setting module configured to determine a first charging current value based on the maximum allowable current value, and to determine a second charging current value based on the overvoltage protection current value, wherein the charging current value setting module is configured to set the second charging current value to the charging module when the maximum allowable current value is higher than the overvoltage protection current value and to set the first charging current value when the maximum allowable current value is not higher than the overvoltage protection current value.