Nickel-hydrogen cell test program summary

Three prototype 50 ampere-hour (Ah) nickel-hydrogen cells of the Air Force Wright Aeronautical Laboratories (AWFAL) design were cycled to failure. A summary of the life cycling tests and failure analyses of the cells are presented. The cells were cycled in a simulated low earth orbit regime at depths of discharge ranging from 25 to 80 percent. Trend data, such as end of discharge voltage and cell capacity, was recorded during test. Cells 1, 2, and 3 completed 17167, 2473, and 10080 charge/discharge cycles, respectively, prior to failure. All failed due to internal shorts, and were disassembled to determine cause of failure.