Your post makes no sense!
Did they just plug it in every 300 miles for 30 minutes, an hour, two hours? Did they have pre-positioned charging stations just for the run? Did they have the capability to quickly replace the batteries at logistically coordinated locations?
Not to be snarky but I have a history of professional endurance road racing back to 1995. I think I know a thing or two about endurance racing logistics because I have seen a thing or two about racing logistics. Two Rolex champion teams 2003 and 2011.
Does that make any sense to you?