A battery pack is provided. In one embodiment, the battery pack includes a plurality of battery units each including at least one battery cell, a charge switch unit for connecting the plurality of battery units in parallel to form a charge path, a discharge switch unit for connecting the plurality of battery units in series to form a discharge path, and a battery management unit for controlling switching of the charge switch unit and the discharge switch unit according to a standby mode, a charge mode, a and discharge mode of the battery pack. The switching is controlled with a delay time associated with each of combinations of mode conversion between the modes.