Originally Posted by Iride01

So is there a problem with e-bike batteries bursting into flames spontaneously when not being charged or used under heavy load?

For most any of the few issues I've heard of, they were either while being charged or while in use. And this includes the electric scooters and skateboards since I've not seen much on e-bikes themselves with this problem. The few issues that weren't seem to have been the result of a fire started by some other source.