A power storage unit includes a plurality of power storage module groups connected in parallel, each having a plurality of power storage modules connected in series or in series and parallel. A plurality of temperature adjustment units is installed in each of the power storage module groups constituting the power storage unit, and cools or heats the power storage module groups. A management unit controls the plurality of temperature adjustment units corresponding to each of the power storage module groups to make resistances of the plurality of power storage module groups come close.