Battery tender & storage

I would assume you are living in Alaska in the Summer months and using the RV in the Winter months. If so your battery is subject to the high temps of Arizona. When I lived in Mesa, I found that the Summer heat was really bad on batteries. I never had a car battery even last two Summers. If you are storing your RV in either the Tucson or Phoenix areas, I doubt it will make much difference what you do. The batteries are not likely to last very long. Get the batteries out of the RV and store them in the coolest, shadiest area you can find.