Upgrading the battery does absolutly nothing to increase the performace of the electrical system when the car is running. All an upgraded battery will do is provide you with power when the car is off. after you start your jeep you can take the battery completly out and it will still run and give you just as much juice as when it was in. your alt runs at that point. The only reason to upgrade you battery would be 1. if you run your accessories with the engine off for long periods of time. 2. if you use your battery for heavy duty purposes, such as starting a desiel or running things like and air compessor when the engine is off. 3. If you ever run your Jeep thru things that would submerge the battery (you'll want a sealed setup such as optima) or 4. If you continually run your battery down and charge it up you'll want a deep cycle that will hold a charge better.WOW, I was thinking of buying one of the higher priced alternator's to upgrade but this looks like it could save me a lot of $$$. Would anyone recommend upgrading the battery? What's the difference between the plane stock one and an Optima? Would the red top or the yellow top work better? I'm thinking of adding a winch and 2 100watt KC's and maybe in the future some rock lights.