US Patent 8154250 Battery charging controller and battery module using the same

The present invention discloses a battery charging controller for achieving a balanced battery charge. The battery charging controller includes a voltage divider, a switch module and a balance circuit. A reference voltage generated by the voltage divide is used to determine which battery unit in a battery module has an insufficient voltage lower than the others, so that the balance circuit controls the switch module to allow a larger current to charge a lower-voltage battery than a higher-voltage battery, so as to result in substantially the same voltage for each fully charged battery of the battery module.