I have a 2005 Montana that came with two deep cycle batteries. One of the already went bad, started needed water every few days when we were RVing, then started getting too hot to touch. I disconnected it, using only one battery. I brought the bad battery home and hooked it up to my trickle charger. Again it overheated badly. Since we do almost no dry camping and are hooked up to electricity almost all of the time when RVing, I wonder whether I really even need the second battery. Any advice will be appreciated.