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. The battery generally consists of a group of plastic jarred cells contained within an enclosing battery case. They are electrically connected in series with each other and usually terminate in an electrical connector mounted in the case front wall. The battery case may be secured to the aircraft structure by any of a number of clamping techniques.
This SAE Aerospace Recommended Practices (ARP) covers the definitions, functions and broad application guidelines of modern aerospace vehicle electric power management systems. As aerospace control systems have become more sophisticated and autonomous, the electric power subsystem no longer is just a generation and distribution bus control system. New electric power systems include integration of individual load logic control, protection, generation, distribution, and load management. This system can report to a higher level control system, typically a vehicle management system, or can be an autonomous system within itself reporting and responding to operator commands.