From your link which you obviously did not read.
“Once I ran out of charge in the parking lot at the Haleakala Visitor Center, I was able to recharge the battery using regenerative braking by descending down the volcano. I got back to 42 percent charge on the way down!”
Dang! You must be right. I forgot about the steep hill.
I would trade in my 2016 gas guzzler for an EV, but here in California I will never get it back. And after 2035 when they stop selling ICE cars,this heap will be a valuable antique.