Battery voltage has dropped to almost nothing. Could be converter is shut off, so start there. Check output voltage of converter on 12 volt terminal strips. If it shows over 13 volts, then check at battery posts. If it doesn't show the same there, look at the connecting wires.
In my case the negative feed to the battery at the converter terminal strip was loose, preventing the battery from charging.
Mike
2012 Winnebago Impulse Silver 26QP
2005 16.6 Double Eagle
2018 Jeep Wrangler JK
previously Snowbird Campers,
Triple E Motorhome and Fifth Wheel