Advancements in commercial aircraft batteries have been driven by changes in licensing requirements. Early model aircraft needed batteries to comply with a five minute emergency power requirement. This short time requirement was later incremented to 30 minutes and was recently increased to one hour. These requirements have changed to meet the demands of emergency equipment which, over time, have grown in sophistication and number.
Traditional flight-by-cable aircraft require emergency power mostly for instrumentation to help reach a zone were continued visual flight and landing is possible. With the advent of flight-by-wire aircraft, emergency power is not only necessary for instrumentation, but is critical to flight itself.
There is no single method for choosing a battery. The requirements for a battery will depend on many factors, including the availability of alternate sources of emergency power.
This paper will briefly describe a process for selecting, testing, installing and certifying a battery for a typical commercial aircraft.