Cyclon Enersys (Hawker) 0819-0010 D-Cell 4 Volt/2.5 Amp Hour Sealed Lead Acid Battery Per unit weight, the power provided bypure lead products offers the greatest high-rate power density for your energy dollar. CYCLON battery's greater volumetric power allows engineers to consider more energy-supporting features. Compared to competitive lead products (offering up to 200 full cycles), pure lead-tin batteries provide 50% to 200% greater full cycle capability. CYCLON product will deliver up to 300 cycles (100% DOD, C/5). Conventional sealed-lead batteries vary greatly in specified standby life: from three to six years at 20C, C/20. CYCLON Single Cells, however, offer a ten-year design life at 25C, C/5, to 80% of rated capacity. High stable voltage delivery - The high stable voltage delivery of a pure lead-tin battery results from its low internal resistance. The flat discharge voltage profile of our batteries, similar to Nickel Cadmium. Since CYCLON Single Cells and Monoblocs emit minimal to no gassing under normal charging conditions they are safe for installation in offices, aircraft cabins, hospitals or any other environment occupied by human beings.