Abstract: A submersible battery apparatus is set forth which has improved life and er performance capabilities. The apparatus includes a battery which has top and bottom casing ends with one of tha battery casing ends having an aperture. A housing is provided which also has top and bottom ends. The battery is mounted in the housing with the aperture in the battery casing 10 directed downwardly and facing the bottom end of the housing. The battery contains an electrolyte, and the housing contains a liquid which has a higher specific gravity than the electrolyte and is non-reactive therewith. The housing is pressure compensated so that the power of the battery is increased with increased submergence and yet gases generated by the battery are retained within the battery casing so that they will not corrode the housing and its associated terminals.