I have a powerchair and mostly recharge it every night. I am not sure it needs it, but I rather be safe. I would guess that you will not be staying in motels (where you could charge it), but an alternative might be a campground. There are travel books that show all the campgrounds across the country (or probably you could get the same information on the internet). There are plug-in places with the campground and you can get a shower too.
An alternative suggestion is this. It is only supposed to take my electric wheelchair about two hours to charge fully. All these StarBucks have lots of outlets for computers. Why not go get a nice long relaxing cup of coffee and charge the chair–just discreetly plug it in. Or recharge when you are eating at a restaurant. For that you might need to ask permission, but probably it would be granted if you were spending money at the restaurant anyway and they were not at the peak of activity where the plug in spot might be in the way. When I was thinking about this, I thought that might be a nice way to ensure that there were a couple of resting hours built into each days schedule.
WithHope for cure of these diseases.