Development of a lithium ion battery that will meet the requirements of all three aircraft, F-16, F-18, and F-117, is on going at the SAFT Research and Development Center in Cockeysville, MD. Seven high power cells, type HP47178, are connected in series to provide 28VDC and a C rate capacity of 16Ah. This cell pack fits into the smallest volume of the three aircraft, which is the 7.5 Ah lead acid box used on the F-18. Cell construction consists of spiral wound thin electrodes in a cylindrical steel case. The case negative design employs a center hole for improved thermal management. The battery containing cells with low temperature electrolyte meets the required F-16 duty cycle at temperatures from −20°C to +71°C. At −30°C the voltage is marginal. Lower temperatures down to −40°C will require heaters. The weight and volume of the lithium ion cell pack is considerably less than the nickel cadmium and lead acid batteries that would be replaced.