Thank to all for their opinions and suggestions. I manage my life so that it is spent as close to 75 degrees as possible, and most often stay in campgrounds with hookups. However, sometimes I have to travel for a few nights in cool weather and dry camp along the way. That is why I need a little more reserve in the old battery bank. I have no idea why the dealer installed a dual purpose battery, as he never has before. He is over a thousand miles away, so I won't be running to him for a replacement. I don't mind spending $100-$200 for an upgrade but I am not interested in spending much more for full blown solar setup.