An apparatus for charging a battery of an electronic device is provided. The apparatus includes a battery configured to supply power to the electronic device; a charger configured to charge the battery according to a set charging voltage (V_SET) and a charging current (I_SET); and a controller configured to set the V_SET and the I_SET, and receive an output value of the charger or the battery during charging to re-set the V_SET if the output value corresponds to a pre-set reference range.