Is there precedent for a single battery in service aboard an aircraft?
Good point.
The ACE (Actuator Control Electronics) backup Batteries are also Li-Ion. Much smaller than a main battery and only designed to last about ten minutes. As far as I know there have been no reported problems with these, even the one that got charred by the APU battery at Boston.
The 777 has a similar ACE backup battery. I wonder if it too is Li-Ion?
