Holy crap. That's a whole series of bad ideas extremely well executed. That guy probably has never seen what a lead acid battery can do when it explodes. He keeps hiding away from the hot metal but in the path of ~half of those batteries. Ignorance is bliss.

That's low voltage lightning :)

See also (as posted elsethread): https://www.youtube.com/watch?v=RoGbrgOhPes