Aerospace nickel-cadmium cell verification-final report

During the early years of satellites, NASA successfully flew "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 was required. 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 involved the procurement and testing of representative aerospace Ni-Cd cell designs. A standard set of test conditions was established in order to provide similar information about the products from various vendors. The objective of this testing was to provide independent verification of representative commercial flight cells available in the marketplace today. This paper provides a summary of the verification tests run on cells from various manufacturers: Sanyo 35 Ampere-hour (Ah) standard and 35 Ah advanced Ni-Cd cells, SAFT 50 Ah Ni-Cd cells and Eagle-Picher 21 Ah Magnum and 21 Ah Super NiCd/sup TM/ cells from Eagle-Picher were put through a full evaluation. A limited number of 18 Ah and 55 Ah cells from Acme Electric were also tested to provide an initial evaluation of the Acme aerospace cell designs. Additionally, 35 Ah aerospace design Ni-MH cells from Sanyo were evaluated under the standard conditions established for this program. The test program is essentially complete. The cell design parameters, the verification test plan and the details of the test results are discussed.