That's an idea. Might be able to swing installing an extra battery in the back but the terrova is gonna have to wait a while. It has a group 27 in it now but I assume if I buy one new one I probably need to get both new. The old one is three years old but still charges and tests fine. I could run them parallel for now and go in series later with a 24 volt terrova? It was awfully windy the other day though.