A battery spacer, a protection assembly for electric core, and a power battery are provided. The battery spacer comprises a spacer body. The spacer body comprises: a tab passing area located in a middle portion of the spacer body, the tab passing area being adapted to receive an end of an electric core of a battery; and receiving areas adjacent to ends of the tab passing area along the spacer body. The spacer body and the tab passing area provide an end wall, two side walls, and a top wall configured to surround each of the receiving area. At least one tab aperture is formed in the tab passing area and penetrates the spacer body.