The apparatus of charging a rechargeable battery includes a voltage detector which detects a voltage value between terminals of a rechargeable battery, a current generator which generates current for charging the rechargeable battery and outputs the generated current to the terminals of the rechargeable battery, and a controller which controls the current generator based on the voltage value detected by the voltage detector. The current generator outputs a first current for which a direction thereof between the terminals of the rechargeable battery is constant, in a charging period of the rechargeable battery, wherein the first current comprises direct current, and a second current for which a direction thereof between the terminals of the rechargeable battery is periodically reversed, in an intermittent period of the rechargeable battery.