A storage battery has at least battery banks, switching units, a charging terminal, a discharging terminal and a battery management unit. The battery banks form a bank structure. Each switching unit electrically connects a group of the battery banks with either the charging terminal or the discharging terminal, and disconnects the group of the battery banks from the charging terminal or the discharging terminal. The battery management unit instructs the switching units to electrically and simultaneously connect one or more battery banks to the charging terminal during charging, and to electrically and simultaneously connect one or more battery banks to the discharging terminal during discharging.