Thank you very much, just two more questions (I hope)

1. If I get batteries with dean's connectors do I just have to get a dean's connector linked to my charger to plug the battery in?
2. Do I connect the two batteries in series, i.e. one connected to the other and then to the robot or parallel i.e. both connected to the robot together? I hope I have got these the right way around, if not feel free to correct me.