[Jon Stratis]

I can speculate on a couple of reasons:
- Cost. Those batteries would be more expensive, and FIRST includes batteries in the KoP for every team.
- Safety. We've all heard stories about laptops or cell phones with Lithium-ion batteries catching fire or exploding, and that's the last thing we want in a robot! This is most often caused by abuse and physical stresses far less than our robots go through. It can happen during charging (while many people are next to it in the pits) or due to damage, such as being accidentally punctured by a robotic arm. While our current batteries can suffer some of the same issues, it's much more rare and generally speaking has a safer failure mode.