BATTERY PACK

A battery cell module includes a plurality of battery cells stacked in a first direction, and a first groove extending in the first direction is formed at each of two ends of the first side of the battery cell module. In a second direction, the two first side covers are arranged at two opposite sides of the battery cell module. First bodies of the two first side covers are substantially parallel to a third direction of the battery cell module, and each of the first side covers is provided with an abutting part. The abutting part extends from an edge of the first side cover and is substantially perpendicular to the first body and is connected to a groove wall of the first groove .The two second side covers and the two first side covers are fastened to each other. The abutting part is inserted into the first groove.