1990 345LE house battery System

[RBonney]

Looking for some help here. Let's back up 7 years ago I had mice under stove so I removed all the vent hoses etc and cleaned them out. As I reassembled them I noticed there was a plug laying on floor (not plugged in ) from the 12 volt panel next to the drawers.
Not knowing if I un plugged it or not so I left it unplugged.
My coach also has a inverter in battery box that makes 110 outlet power ( when I manually turn it on) and charges my house batteries so I assume the other was unplugged not to conflict with it.
So I only have 12volt when batteries are on and charged when it's plugged in to 110. My airstream camper has 12 volt power when we are plugged in without battery installed.
We are moving on to a seasonal lot and would like to run my fridge all week while we are not there but don't want to leave the batteries on all week. It seems like I put extra stress on my batteries.
Any input looking for some advise. Thanks if any one wants more details just ask.

[RBonney]

Does any one know if this 12 volt panel I'm revering too behind kitchen drawers charge the house batteries? I'm considering plugging it in to try it out. If it does charge batteries and so does the inverter in my battery tray does anyone see a problem.