I started building my 24v. battery box. I only have the bottom together so far, But soon I will have the top and lower lip ready.
It sits just above the center foot mount and will add more support for the frame. I made the box alittle bigger than I need for the batteries so it will be easy to add larger batteries later.
You might not be able to see it very well, But I got the rear electronic board mounted back in the frame. It's the shiney area behind the batt. mount.