Batteries/Nickel-hydrogen page 051013
A 50AH, 11 cell, Common Pressure Vessel (CPV), Nickel-hydrogen battery will provide the main power for the Mars Reconnaisaance Orbiter
High-Capacity Nickel Hydrogen Cells
Cells with capacities of 350 Ah have been developed for use in government and commercial satellites. They have been qualified for use in geosynchronous orbits for as long as 15 years. Cells have electrochemically impregnated sintered nickel positive electrodes, single layer zirconium oxide cloth separators, platinum-catalyzed hydrogen electrodes and a nickel alloy pressure vessel.
NASA Tech Briefs
December 2001, p. 38