I googled "insurance fire caused by gasoline in garage" and found https://cpsc.gov/content/consumers-warned-against-storing-gasoline https://cpsc.gov/content/co

I googled "insurance fire caused by gasoline in garage" and found https://cpsc.gov/content/consumers-warned-against-storing-gasoline https://cpsc.gov/content/consumers-warned-against-storing-ga... as the third result. "CPSC also warns consumers that private storage of more than a limited amount of gasoline (usually five gallons or less) is illegal in many areas, and subsequent fire damage may not be covered by insurance policies." although IANAL, storing a large quantity of lithium ion batteries seems likely to be considered negligence, which is generally not covered under insurance.