Hetfield.
I am not apologising for the failures, just trying to explaine to Lyman about the system as he/she is misunderstanding lots.
Lyman. The bat switches stay selected on in flight. The breakers and contactors are controlled automatically.
The batteries will still be charging if necessary after engine start. Maintenance and flt crew check list items will determine if bat state is ok for dispatch. This is standard on all big jets. In flight the APU Bat will only be used to start the APU if NO OTHER SOURCE IS AVAILABLE.
Hope this helps.