On a recent 2 hour flight I got a, "AUX VOLTS", warning message about 3/4 of the way through the flight. I have searched the manual and the forums for a possible explanation with no luck.

Consulting the .ALD file for that flight, I see:

BATVOLTS (8.5 and steady)

VOLTS (14.1 with the alternator running)

BACKVOLTS - This one starts out at 12.5 at the beginning of the flight (14:04:57), then starts dropping about 20 minutes later (14:25). It declines steadily to 7.1 volts at the end of the flight. I am not sure when the message appeared, but I believe it was around the time it dropped to 8 volts.

What is the AFS3500 trying to tell me?

john