Battery Discharge

[skline01]

Had my 2017 Thor ACE in Ford for warranty work on gas gauge. Vehicle sat in lot for about a week while they did the repair, this included a weekend. When I arrived on Monday to pick it up both the house and chassis batteries were dead. They didn’t have the coach plugged in to power and had not pushed the store switch BUT with all major items drawing power that I can think of turned off I was very surprised that the house batteries were dead, let alone the chassis. Any thoughts, ideas or suggestions

[16ACE27]

If not in STORE I can easily see why the house batteries were dead, but the chassis battery should not have been dead unless you have other issues.

[Trkyte@msn.com]

Invertors are usually the culprit. Make sure it is powered off. Even with no load it still uses power.
Class a's also usually have a bi directional relay that will tie both chassis and house battery together depending where the charge is coming from. Sometimes it gets confused and doesn't release
My class c has a time delay that only operates with engine charge. I have never (knock wood) have both discharge and leave coach unplugged for up to a month.

[skline01]

Thanks for the responses. I will put a new question out about the bi directional relay.