Abstract: Disclosed is an equalizing-charge charger includes a microprocessor, a pulse width modulator, battery cells, and equalizing charge load-control switches corresponding to the battery cells. When voltage sensors of the microprocessor detected the saturated status of one battery cell during charging mode, the microprocessor controls the pulse width modulator to stop the charging action and counts the voltage value of each battery cell to find the battery cell having the lowest voltage value, and then switches on the equalizing charge load-control switch corresponding to the saturated battery cell to discharge the saturated battery cell to the voltage value equal to the battery cell having the lowest voltage value, and then starts the pulse width modulator to charge the battery cells again, and then repeats the procedure again and again until the voltage value of the battery cells has been equalized and battery cells have been charged to saturated status.

Abstract: A multifunctional battery charger, capable of charging both lithium battery and nickel-metal hydride battery, and a method of charging battery using the multifunctional battery charger are provided. The multifunctional battery charger comprises a slot, for receiving a battery to be charged, wherein the battery is a lithium battery or a nickel-metal hydride battery; a microcontroller, comprising an identifying module and a charging module, wherein the identifying module is adapted for identifying a specification of the battery; a pulse width modulator, for charging the battery, wherein the pulse width modulator and the slot are connected to the microcontroller, and wherein the charging module of the microcontroller is adapted for controlling the pulse width modulator for charging said battery.