Abstract: A protective cap affixed to a dry cell to be removed before use includes a disc-like cap covering the exposed electrode at one end of the cell. Axial protrusions on one face of the disc extend through holes in the end face surrounding the electrode, the protrusions being deformed while in a plastic state so as to be not removable without breakage. The cap is removed by fracturing the protrusions with a rotary motion. In another embodiment a single annular flange fits in an annular groove around the electrode. Yet another embodiment includes axial and radial projections to adopt to the specific form of battery case design. A further embodiment includes a two-part cap with one externally threaded and molded onto the electrode, and the other internally threaded and screwed onto the first. Removal is effected by tightening the second which breaks the first loose.