The video title is wrong. It’s an eScooter, not an eSkateboard.
This could be China or Singapore or Hong Kong. We don’t know.
The type of battery? Unknown. But I wouldn’t be surprised if they were cheap generic Chinese batteries.
The scariest part is actually the chain reaction that occurs after he pulls the plug out of the AC outlet. Common sense says that without juice flowing in, everything should calm down. The opposite happens.
Never charge overnight. And get a fire extinguisher that can handle LiOn battery fires. Failing that, have a bucket of sand nearby.
August 2, 2018 update: Exploding eScooter Identified