A battery having an outer casing and an anode/cathode assembly within that casing, wherein the anode/cathode assembly includes plural anodes and cathodes and electrolyte therebetween. The battery has a pressure relief feature associated with the casing and a channel preservation element sufficiently rigid to preserve at least one gas passageway to the pressure relief feature under conditions of anode/cathode assembly warpage. Thus the gas in the passageway will not become impeded by anode/cathode assembly warpage.