dead battery on toad

I can't remember how many Saturn's that I've own over the years, and towed behind my RV. I never had any battery problems towing my Saturn's. I would run the engine in my Saturn for 10 minutes before and after towing and, every time that I would stop for a meal, I would start the Saturn engine for 10 minutes. I also made sure everything was off on the dashboard of the Saturn while towing and the key on accessary. I'm not into unhooking fuses!