Please provide a definition of “spontaneous”, and how many EV batteries fall under this category of self-immolation. I’ve been part of a drone/quad copter racing group for a long time, and the vast vast majority of failures occur due to improper charging. Many people charge their drone batteries in cinderblock enclosures or metal ammo cans. Those batteries are crashed, dropped, overheated and otherwise suffer abuse that cars shouldn’t though they can
suffer the same fate if damaged.
I really don’t see EV batteries being any more of a risk
than ICE vehicles when it comes to fires. The irony is that we in this group are more likely to suffer a fire per capita than a production line car. DIY wiring, combining non-standard components, DIY fuel systems, high stress use, and quality control is only as good as individual skill. How many DIY supercars go up in smoke vs the tens of thousands of boring domestic vehicles?
At any rate, there’s no more reason to fear EV than ICE - however, if I ever build a house, the garage will absolutely not be directly attached to the house. Garages are always a higher fire risk due to everything we discussed. Sparks, engines, fuels, chemicals, vapors… it’s all there.