 U-Boat Worx was the first submarine manufacturer who applied Lithium-ion batteries in her submarines with classification by DNV GL.Pressure tolerant Battery technology – U-Boat Worx developed a pressure tolerant battery system with an increased capacity of 350% when compared to lead-acid batteries used non U-Boat Worx submersibles.The technology has been tested to 13,000 feet and stores a total of 62 kWh on compact battery modules.