A system and method of charging a battery pack in a state in which a battery management unit (BMU) is stably woken up. In one embodiment, the system of charging a battery pack includes a battery including at least one battery cell, a connector electrically connected to the battery and a battery management unit electrically connected to the battery and to the connector, the battery management unit to control charging and discharging operations of the battery, wherein the connector includes an auxiliary power supply terminal to provide a path of supplying auxiliary power to the battery management unit when a total voltage of the battery is less than a wake-up voltage of the battery management unit.