[Richard]

There are a lot of different ways of keeping the coach plugged in, and keeping both the chassis and house batteries charged. 

Newell equipped many of the coaches with an echo charger or trickle charger that takes power from the house batteries and maintains the coach batteries. 

Some leave the batteries merged so that the inverter/charger keeps the chassis batteries up. 

Sounds good, but in my case I noticed that my chassis batteries would stay charged while in storage but not really up to full charge. It took a while to sort it out, but this is what I think. I float the lithiums during the winter at 13.4. That’s lower than what I keep them while using the coach, but this is one of my strategies for battery longevity. The problem is the echo charger only charges the chassis batteries around 0.2 volts lower than the house batteries. So my chassis batteries would see 13 to 13. 2 over the winter. 

Since I am plugged in, and cheap, I chose to go the financially efficient way. I installed this maintainer on the chassis batteries. https://www.amazon.com/NOCO-GENIUS10-Ful...mREALw_wcB

It’s a NOCO Genius 10 amp maintainer. I hardwired to the parallel starting batteries and mounted the unit on the forward firewall. It is not intended to rescue a dead battery but keep the ones I have fully charged. I have been using this setup all winter. I am happy to report that the engines spins up quickly whereas when the chassis batteries were on the trickle charger, it would be a lazy start.