Study of Nickel Hydrogen Battery Discharge Performance After Charge and Stand at Warm Temperature

Spacecraft batteries are normally installed in the discharged condition. It may be necessary that they be charged and trickle-charged prior to launch in an environment different from that in which they are intended to operate; i.e., an environment in which the heat generated during charge and trickle charge is radiated to space. The purpose of the testing described herein was to determine the battery capacity achieved after treatment at prelaunch conditions as a function of charge rate, charge temperature, trickle charge temperature, and time. In this testing the discharge in every case was performed under simulated space thermal conditions. Charging was performed with a variety of battery starting temperatures, and heat dissipation was limited to that expected to be encountered under conditions of cooling with an air manifold. At the worst conditions of test, that is with 24°C (75°F) cooling air at the battery baseplate, 80 percent of the rated capacity was obtained.