If you are wanting to start and run your Jeep, then you can hook a 12 volt battery up to run as you are. The down side is that you'll need to remove your brake bulbs because you'll blow them the first time you step on the brake pedal. Other than that, the starter can handle the extra volts, and the generator/voltage regulator will be alright for a time with no damage. I'm a 6 volt guy along with LarrBeard. With the proper cables, you'll have more amps when starting then 12 volts. It really all depends on how you want your Jeep to be.