Apparatus for charging a portable terminal in a radio-telephone system which allows a telephone conversation to be conducted while the portable terminal is being charged. In one embodiment, the charging apparatus includes an alternating current (AC) adapter for converting an AC power source voltage into a predetermined AC voltage, a rectifying circuit disposed within the portable terminal for rectifying the AC voltage provided from the AC adapter and converting the AC voltage into a direct current (DC) voltage, a charging circuit disposed within the portable terminal for receiving the DC voltage output from the rectifying circuit and charging a battery of the portable terminal with the DC voltage, and a charging current control circuit for controlling the amount of charging current applied to the battery.