Most of the ebike fires I've looked into are caused by shoddily 'repaired' or damaged batteries while being charged. I charge my battery in a BBQ on the little 'porch' I have outside my apt or just this reason. These batteries are the same as the batteries in most of your electronics the only difference being they are probably quite a bit larger. Obviously we don't worry about charging our phones on the nightstand or our roombas in a pantry but they pose very similar danger.
