Near Earth Asteroid Rendezvous flight battery performance-boost charge response of super-NiCd following extended trickle charge flight storage

After 14 months of in-flight trickle charge, the flight battery of the Near Earth Asteroid Rendezvous spacecraft was boost charged in preparation for a possible discharge. During the boost charge, anomalous current-voltage behavior was observed, prompting the ground test of flight-lot cells that had been in night life simulation. The night boost regime was duplicated on the ground cells and exhibited a similar current-voltage response. Ground test cells were then discharged for capacity measurement demonstrating no capacity degradation after flight simulation. The anomalous current-voltage behavior is attributed to nonfaradaic charging and depolarization from boost charging.