Alternator charging flaw
2015 ACE 29.3
Setup: trombetto contactor and BIRD.
While dry camping the house batteries ran down. Knowing the genset would not start with dead house batteries, I started the engine to charge the house batteries so I could start the genset. Still could not start the genset. I drove to next stop (300miles), still had dead house batteries.
Here is what I found:
Engine batt voltage was 14.4 (engine running). House batt voltage was 4 volts. The trombetto contactor will not close unless it has 8 volts on the house batt. Hence, the alternator will never charge the house batteries if they are less than 8 volts because the contactor will not close.
I made a short jumper cable out of 8GA wire and heavy duty batt clips to connect between the lugs on the trombetto contactor so I could start the genset if this scenario arises again.