There seems to be some confusion on insurance coverage of regular vehicles and battery-powered cars in regards to fires caused by them in garages.

Although homeowners insurance will not cover damages to your regular car, the garage would be covered under property insurance unless that vehicle was a battery-powered car which most insurance companies require to be parked outside.

http://www.motorbiscuit.com/fire-danger-underground-parking-lot-bans-electric-vehicles/