Originally Posted by DirkW

If you want to race, you're basically limited to 2S. (3S would probably be better, but is usually not race legal anywhere, so not an option for most people, including myself).

For a 2S on such a heavy vehicle like a Short Course Truck, especially if you use a powerful motor, you should go for a good quality, high capacity (7000+) lipo with at least a decent (preferably high) C-Rating. So don't got (too) cheap there.