A battery assembly comprising a main body and a cover, wherein the main body is provided with a battery compartment with an opening, one end of the cover is rotatably mounted on the main body, and the other end is provided with a locking assembly, an end of the battery compartment close to the opening is provided with a limiting part, the cover is locked to the main body and covers the opening when the cover is rotated to a position where the locking assembly is coupled to the limiting part, the main body is further provided with at least one elastic assembly, the at least one elastic assembly elastically abuts against the cover when the cover covers the main body, and an outer periphery of the elastic assembly abuts against a side wall of the cover facing the limiting part when the cover is rotated to expose the opening; wherein the main body is provided with a receiving groove for receiving the cover, the receiving groove comprises a small-diameter section and a large-diameter section, the large-diameter section is provided with the limiting part, one end of the cover is provided with a rotatable part, the rotatable part is rotatably mounted on the small-diameter section, the elastic assembly is provided adjacent to an intersection of the small-diameter section and the large-diameter section, and the outer periphery of the elastic assembly abuts against a side wall of the rotatable part facing the limiting part when the cover is rotated to expose the opening; wherein the elastic assembly comprises a fixed base provided with a receiving hole, an elastic member mounted in the receiving hole, and a limiting head connected with the elastic member, the fixed base is mounted on the main body, the limiting head is partially slidably mounted in the fixed base, the limiting head abuts against the fixed base when sliding to the end of the fixed base, the cover abuts against the limiting head when the cover is coupled with the main body, and a side wall of the rotatable part facing the limiting part abuts against the outer periphery of the limiting head when the cover is rotated to expose the opening; wherein the rotatable part is further provided with an avoidance groove corresponding to the elastic assembly, the limiting head abuts against the avoidance groove, the limiting head slides along the avoidance groove and is ejected from the receiving hole when the rotatable part rotates, characterised in that the limiting head is disengaged and completely ejected from the receiving hole, and abuts against a side groove wall of the avoidance groove facing the limiting part when the cover is rotated to expose the opening. wherein the main body is provided with a receiving groove for receiving the cover, the receiving groove comprises a small-diameter section and a large-diameter section, the large-diameter section is provided with the limiting part, one end of the cover is provided with a rotatable part, the rotatable part is rotatably mounted on the small-diameter section, the elastic assembly is provided adjacent to an intersection of the small-diameter section and the large-diameter section, and the outer periphery of the elastic assembly abuts against a side wall of the rotatable part facing the limiting part when the cover is rotated to expose the opening; wherein the elastic assembly comprises a fixed base provided with a receiving hole, an elastic member mounted in the receiving hole, and a limiting head connected with the elastic member, the fixed base is mounted on the main body, the limiting head is partially slidably mounted in the fixed base, the limiting head abuts against the fixed base when sliding to the end of the fixed base, the cover abuts against the limiting head when the cover is coupled with the main body, and a side wall of the rotatable part facing the limiting part abuts against the outer periphery of the limiting head when the cover is rotated to expose the opening; wherein the rotatable part is further provided with an avoidance groove corresponding to the elastic assembly, the limiting head abuts against the avoidance groove, the limiting head slides along the avoidance groove and is ejected from the receiving hole when the rotatable part rotates, characterised in that the limiting head is disengaged and completely ejected from the receiving hole, and abuts against a side groove wall of the avoidance groove facing the limiting part when the cover is rotated to expose the opening.