I have the same 61 lb Trojan batteries too. I remove mine and put them on a trickle charger which runs 1 hour a day. My location in Reno can get down to 5 (or lower) and I don't want to replace them every year.
My experience with 12 volt Interstate batteries is that when installed in my Monty and connected to 50 amp shore power, the converter is gentle enough that checking electrolyte levels every 90 days was more than often enough. Assuming a properly functioning multi-stage converter, I expect the Trojan 6 volt batteries to be about the same.
Our 2011 Monty stays plugged in except when on the road. Still has original battery and have checked water level just a few times, last checked about 3 months ago have not had to add water. As long as battery stays charged, I donít think you have to worry about it.
Batteries being new, if the charger is working properly you won't need to ad water during storage. Check them in two weeks and then two weeks later and you will be comfortable with leaving them 'til spring. I have a small, very small solor panel and it keeps them up all winter.
If the dealer hook your batterys up you need to double-check to make sure they did it right, when I pick mine up new they were totally wrong had to rewire everything batteries and solar system. I put 4, 6 volt Trojan with the watering system and a disconnect at the battery.
The negative cable is always the first to disconnect and last to connect.
I guess the elephant in the room is why isn't anyone recommending AGM and stop worrying about the water?
On the charging side of things (after you disconnect the negative wire), what about solar panel? I'm no fan of them working in the oilfield but if your not going to plug into the grid seems like a good application?
__________________ James & Irene Wilson Bee Branch, AR. 2017 Ram 1 ton diesel duallyCrew Cab/Long Bed 2018 Montana High Country 381TH Garage Full of Toys