DA 42 accident

"C J Campbell" wrote ...

According to the article, the battery was so dead that it could not excite
the alternator -- the alternator needs some current in order to start.

I'm sorry, but the quoted article seems to point more at the main battery as
the culprit.

Without the buffering effect of the main battery, the current spike of the
gear retract was supposedly enough to decrease the voltage on the ECU bus
and cause an ECU reset.

There is a discussion whether the main battery was connected to the battery
bus at all. Judging from the electrical diagram, if the battery is flat
there is no way to activate the battery relay to get the main battery
connected to the battery bus.

If the excitation battery had been the culprit, I guess an alternator
warning light would have been very visible.