Aerospace nickel-cadmium cell verification-an update

Over the past twenty-five years NASA has successfully flown "NASA-Standard" nickel-cadmium (Ni-Cd) Cells manufactured by GE/Gates/SAFT on a variety of spacecraft. In 1992, a NASA Battery Review Board determined that the strategy of a NASA Standard Cell and Battery Specification and the accompanying NASA control of a standard manufacturing control document (MCD) for Ni-Cd cells and batteries was unwarranted. As a result of that determination, standards were abandoned and the use of cells other than the NASA standard became more accepted. In order to gain insight into the performance and characteristics of the various aerospace Ni-Cd products available, tasks were initiated within the NASA Aerospace Flight Battery Systems Program that involve the procurement and testing of representative aerospace Ni-Cd cell designs. A standard set of test conditions has been established in order to provide similar information about the products from various vendors. The objective of this testing is to provide independent verification of representative commercial flight cells available in the marketplace today. This paper provides an update on the progress of verification tests being run on cells from various manufacturers. Data from this program will establish the performance characteristics of the cells produced by the various vendors. It will also provide baseline information for comparison with future cell lots. The design parameters for the cells being evaluated as part of this program, details of the verification test plan, and the test results available to date are discussed.