Characterization of degraded nickel cadmium cells

Various cells were cycled until degradation and then tested to determine the electrochemical characterization of the cells with regard to charge control. A constant voltage charged to a temperature-biased voltage, using up to an 8-voltage limit was used for the evaluation. Graphs show severe discharge voltage degradation with cycling and periodic capacity discharge; voltage extremes for cells with and without periodic capacity discharges; voltage extremes for cells with high rate discharge; voltage-temperature levels used for charge control; end of charge current and discharge voltage for 5 percent DOD cycling; cell capacity following 5 percent DOD cycling; and the end of discharge voltage and typical charge current profiles for the 20 percent DOD cycling.