I got over my apprehension and wired the batteries up for 24 volts. I was running at 12 (If you wire two 12 volts batteries in parallel, you get 12 volts but twice the run time, if you wire them in series you get twice the voltage.) My motor controllers are made to handle 24 volts. He's got a lot more power this way. In fact, when the batteries are fresh he goes too fast. And taking sharp turns I could tip him over. I'll have to watch that.
Here's some video in front of the house.
A few issues have come up in the driving around. I raised the front caster about 1/2" because it was riding too low on the carpet and I moved the caster a bit forward. But now you can see the footshell tipping up and shifting around. When I have him flipped over next, I'll have to shift that caster back under the leg and snug up the foot shell. I want a long wheel base, but shifting out away from the legs puts strain on the foot shells. Maybe I'll try two casters in the front foot shell. The problem with casters is that the movement is herky jerky when they are oriented one way and then you turn sharply another way. It takes a thrust and probably creates an amperage spike for the motors to get him moving from one position to the other. But short of having a steerable front wheel, I don't seen an alternative.
The dome is rattling a good bit. I've only got three screw mounting posts. I think I need rubber spacers or something in between to let it rest evenly. The inner ring on my dome hoop was welded crooked to start with and the wrong size, and it got bent around while I was working on the dome. I'll have to work on that.
I have also been looking at salvaging the charging and switch system out of the scooter chassis to use in the R2. I'd like to have an easy plug and play charging system, but I'm a bit over my head on the electronics right now. I'll figure it out in time.