Patent attributes
A first power storage unit is a battery assembly, and is divided into battery blocks of n (n is a natural number) in number each formed of several electric cells connected together in series. When a state allowing charging with an external power supply is attained, the ECU executes an operation of resetting an SOC of a first power storage unit. The ECU controls a corresponding converter to discharge the first power storage unit with a constant current, and sets reset values for battery blocks of n in number based on battery voltages and battery temperatures exhibited when any one of the battery voltages of the n battery blocks becomes lower than a reset voltage. The ECU resets the SOCs of the battery blocks of the first power storage unit to the respective reset values thus set.