ENERGY STORAGE DEVICE

The invention discloses an energy storage device, comprising: a housing provided with at least one connector; and a battery module arranged in the housing, the battery module including: a plurality of batteries; a battery rack accommodating the plurality of batteries; at least one bus arranged on a surface of the battery rack and connected to the plurality of batteries; at least one connecting rod connected between the bus and the connector; and at least one insulator sheathed onto the connecting rod. The insulator is provided with a bridging portion, two side pieces, and two inward protrusion portions. An opening end is formed between ends of the two side pieces. The connecting rod passes through the opening end and is sheathed by the insulator. Therefore, the battery module of the present invention has low cost and simple design.