A battery spacer, an electric core protection assembly having the battery spacer and a power battery are provided. The battery spacer includes: a spacer body; a plurality of protrusions, each protrusion protruding from an inner surface of the spacer body, extending in a longitudinal direction of the spacer body, and formed by recessing a portion of an outer surface of the spacer body; a plurality of grooves formed in the outer surface of the spacer body, each groove corresponding to one of the plurality of protrusions respectively and formed by recessing the portion of the outer surface of the spacer body; and a plurality of liquid guiding slots formed in the outer surface of the spacer body and extending from the grooves to an edge of the spacer body respectively.