BuEng had designed a new lead-acid battery to resist battle damage, known as the "Sargo" battery because it was first installed on and was based on a suggestion by her commissioning commanding officer, Lieutenant E. E. Yeomans. Instead of a single hard rubber case, it had two concentric hard rubber cases with a layer of soft rubber between them. This was to prevent sulfuric acid leakage in the event one case cracked during depth-charging. This remained the standard battery design until replaced with Sargo II and GUPPY batteries in submarines upgraded under the Greater Underwater Propulsion Power Program after World War II. Each battery's capacity was slightly increased by installing 126 cells instead of 120; this also raised the nominal voltage from 250 volts to 270 volts, which has been standard in US usage ever since, including the backup batteries of nuclear submarines.