I called Customer Care with Hoveround and they said the little meter that shows the chair charging is just there so you don't take off with the chair plugged in. It doesn't stop moving across at any point to indicate that it's done. And it's best to plug it in at night when it's not in use even if the battery isn't dead. It won't overcharge the battery.

I can buy a handbook for $20 so that's on my wishlist for when I get some extra money.