ELECTRICAL STORAGE DEVICE

A device includes a battery module, and an inverter configured to convert a DC voltage output from the battery module into an AC voltage. The battery module includes battery cells connected in series, and a state detection unit configured to detect a state of each battery cell of the battery cells. An output voltage of the battery cells is input to the inverter without being stepped up. At least some battery cells of the battery cells are reused battery cells. The electrical storage device includes a switching unit configured to connect/disconnect an electrical connection between the battery cells and the inverter. The switching unit is controlled into a disconnected state when a voltage of the battery cells or the DC voltage on an input side of the inverter exceeds a threshold.