battery pack and battery pack charging method

According to various embodiments of the present invention, a battery pack is provided. The battery pack comprises: a battery which includes one or more battery cells; a balancing device which balances voltage between the battery cells; a switch unit which includes a charging switch and a discharging switch which are arranged on a large current path through which charging and discharging current flows; and a battery managing unit which monitors voltage and current of the battery, controls the balancing device, and controls charging and discharging of the battery. When the battery managing unit sense a swelling condition of the battery while charging the battery, the battery managing unit discharges the battery by operating the balancing device during a predetermined discharging time. When the predetermined discharging time has elapsed, the battery managing unit stops the battery during a predetermined stopping time. When the predetermined stopping time has elapsed, the battery managing unit charges the battery.