The Toyhauler has a Norcold model N621 propane / electric refridgerator. (There is a recall for certain serial numbers of this model but not mine.) The trailer has an onboard charging system (under the kitchen) and a 3 matched battery bank RV/Marine (I think they are group 24) on the tongue behind the propane tanks. Batteries came with the trailer, previous owner claimed they were "new" but frankly, we bought in the Spring & the trailer was not in use over the winter so most likely a season old at that point. I'm no longer able to set up a primitive camp, so we are setting up a day camp & RVing in the parking lot of rendezvous... totally off the grid. But sound carries so even as quiet as the 1000 Honda is, we only run when we are at the camper during daylight hours... and we spend as much time as possible in the primitive camp. Last year, at this event, the fridge ran happily on propane for a couple of days... then began having trouble restarting. The other loads are water system & hot water, a scant few lights, I manually lit the burner and we ran it on the 1000w Honda generator which seemed to be barely able to carry it. I bought a new sparker but it seemed to work ok in the yard, so I have a spare. I had nephew look at it but did not see a fault.While we were using / working on the trailer, it was plugged in & powered up so charger was working. During the inactive period, I've had a timer on the power so the trailer had power for a few hours each day... all winter. Since there little to no use, I thought the batteries should be fully charged. I started it on propane... (dockside off) fridge seemed to run but now a C code showing which means "low volts" to the refridge. I moved the power to on all the time, yesterday. It's pouring rain right now... frustrating my desire to check the battery voltage.I'm thinking the batteries have likely croaked though it could be corroded cables? How long do you guys expect from RV batteries? I am considering adding a 45W solar charger (Harbor Freight $159)... to charge silently during the daylight. I've been impressed with how little light it takes to charge the dashboard maintainer I use. Any other ideas, guys?

i unplugged the fridge from AC power so it would stay on propane.

Yours is a Norcold isn't it? There should be a mode setting for LP to force it on propane. I typically leave in on LP unless I'm hooked up to AC then I use Auto so when the power drops away fridge flips to LP modes on its own.

Yes, there is a setting on the Norcoold to keep it on LP... but previously I had to shut it on/off repeatedly so just simpler (KISS!) while I was outside with the cover off to leave the AC cord unpluged. My 1000 Honda would barely run the fridge or charge the batteries (RV + scooter) but not enough power to do both so I was taking no chances. I suppose I could print out the manual.