Patent ID: 8203309

Claim:
A battery pack, comprising: first and second assembled batteries as assembled batteries in which a plurality of secondary batteries are connected in series; a charge terminal for receiving a charging current for charging the first and second assembled batteries; a discharge terminal for supplying a discharging current output from the first and second assembled batteries to a load; a first charge switch unit for opening/closing a first charging path extending from the charge terminal to the first assembled battery; a first discharging path switch unit for opening/closing a first discharging path extending from the first assembled battery to the discharge terminal; a second charge switch unit for opening/closing a second charging path extending from the charge terminal to the second assembled battery; a second discharging path switch unit for opening/closing a second discharging path extending from the second assembled battery to the discharge terminal; and a control unit for executing, upon charging the first assembled battery, first charge processing of turning OFF the first discharging path switch unit and the second charge switch unit and turning ON the first charge switch unit until all secondary batteries contained in the first assembled battery are fully charged, and executing, upon charging the second assembled battery, second charge processing of turning OFF the second discharging path switch unit and the first charge switch unit and turning ON the second charge switch unit until all secondary batteries contained in the second assembled battery are fully charged.