Need Mobile Robot Battery Advice

Hello all,

I recently bashed together a Mario Kart Balloon Battle style robot for my robotics class.

The full rundown can be found at

My question is, based on what I have created, what rechargeable battery would everyone recommend for this project in a class?

My current 9.6V RC car batteries are quickly outliving their usefulness and I will need to replace them shortly.

Any and all feedback is welcome.

Do you mean that the 9.6v batteries are at the end of their life, or do you mean that they are good, but don't have enough capacity. {1}

In either case, what capacity have the batteries {2} and how long can they drive your robot ? {3}


Note that there are 3 questions here