The Nickel Cadmium battery covered by this Aerospace Standard is the type which is generally, although not exclusively, used for engine starting purposes in turbine-powered aircraft and/or on aircraft with turbine type Auxiliary Power Units. This turbine starting function requires high power delivery rates from the battery for 15 to 30 seconds or more for each engine start. This same battery may also be used at lower power delivery rates, as the final redundant source of emergency electrical energy for the operation of essential flight equipment for required periods of 30 to 60 minutes.