Temp rise during fast charging after being heated during APU start
Hi,
Machinbird (#183):
"Temperature as trigger of cell short circuit."
This matches the model of the battery being "abused" by a fast charging (operating near or within itīs temp. limits)
The charging regime (APU batt.) could be the main BOS JAL factor. With cells probably degraded before? How many hours operated before?
Likely it was being recharged when started to fail. Or
(imo, less probable) started to runaway during or just after delivering high current to APU starter.