2015 four winds 24c battery issue

[Moose and Bear]

Went to start the truck engine and battery was dead. Used emergency start and started ok. Rv is kept plugged into a 30 amp shore power connection 24/7. Use store relay switched back and forth ok when I exercised it. Kept in use position all the time. I installed a Diehard under hood battery maintainer to keep the truck battery up all the time. Shouldn't the same charger do both the truck and the living spaces as a rule? I have new batteries in both.

[Oneilkeys]

Something does not compute. If you keep your coach plugged in to 30 amps and with the use/store in the Use position, it should charge both your starting and your house batteries. You should not need any maintenance charger on your chassis battery. If you have a maintenance charger on your chassis battery and you are not plugged in, it may not keep the house batteries charged too. That is because it takes 13.1 amps to open the solenoid from the chassis to the house batteries to charge both systems. The maintenance charger may not provide that high a charge.