Hey did not say how big the robot would need to be, the kind of battery will depend on size of the robot, how long he wants them to last, if he wants them to be rechargeable, etc...use Sealed Lead Acid(SLA) batteries
Well the OP assumed we would know already somehowHey did not say how big the robot would need to be, the kind of battery will depend on size of the robot, how long he wants them to last, if he wants them to be rechargeable, etc...