Energy storage device and energy storage device box thereof

The utility model discloses an energy storage device and an energy storage device box thereof, the energy storage device box comprises a box body, the box body comprises a box body skeleton and a side plate assembly installed on the box body skeleton, the side plate assembly is an integrated structure, the side plate assembly comprises a bottom plate, a first side plate, a second side plate and a third side plate, the first side plate, the second side plate and the third side plate are sequentially connected and arranged on the side edge of the bottom plate, the energy storage device box further comprises a first side cover and a second side cover, and the first side cover and the second side cover are installed on the outer side of the first side plate and the outer side of the third side plate through clamping structures respectively. The energy storage device box is formed by assembling a plurality of components, the welding workload can be reduced by adopting the box body, meanwhile, the side plates are i