A balance correction device that is for an assembled battery including a plurality of series connected power storage cells and equalizes voltages of power storage modules that include one or more series connected power storage cells, wherein the balance correction device comprises: a plurality of balance correction units including an inductor that has one end thereof connectable to a connection point between a first one of the power storage modules and a second one of the power storage modules connected in series, a first switching element that is series connected together with the inductor and connectable between positive and negative terminals of the first power storage module, a second switching element that is series connected together with the inductor and connectable between positive and negative terminals of the second power storage module, a switching control unit that is adapted to control a supply of a current to each of the power storage modules by an on/off control of the first switching element and the second switching element to equalize the voltages of the power storage modules by exchanging electric power of the power storage modules via the inductor; wherein a first power storage module connectable to one of the balance correction units is simultaneously connectable to another balance correction unit so that it becomes the second power storage module of this other unit, characterized in that the balance correction device comprises a timing signal supply unit that is adapted to supply to the respective switching control unit of the balance correction units a common timing signal used to generate a control signal (φ) to input to the first switching element and the second switching element to on/off control the first switching element and the second switching element. a plurality of balance correction units including an inductor that has one end thereof connectable to a connection point between a first one of the power storage modules and a second one of the power storage modules connected in series, a first switching element that is series connected together with the inductor and connectable between positive and negative terminals of the first power storage module, a second switching element that is series connected together with the inductor and connectable between positive and negative terminals of the second power storage module, a switching control unit that is adapted to control a supply of a current to each of the power storage modules by an on/off control of the first switching element and the second switching element to equalize the voltages of the power storage modules by exchanging electric power of the power storage modules via the inductor; an inductor that has one end thereof connectable to a connection point between a first one of the power storage modules and a second one of the power storage modules connected in series, a first switching element that is series connected together with the inductor and connectable between positive and negative terminals of the first power storage module, a second switching element that is series connected together with the inductor and connectable between positive and negative terminals of the second power storage module, a switching control unit that is adapted to control a supply of a current to each of the power storage modules by an on/off control of the first switching element and the second switching element to equalize the voltages of the power storage modules by exchanging electric power of the power storage modules via the inductor; wherein a first power storage module connectable to one of the balance correction units is simultaneously connectable to another balance correction unit so that it becomes the second power storage module of this other unit, characterized in that the balance correction device comprises a timing signal supply unit that is adapted to supply to the respective switching control unit of the balance correction units a common timing signal used to generate a control signal (φ) to input to the first switching element and the second switching element to on/off control the first switching element and the second switching element.