The Honolulu Fire Department (HFD) is warning of potential dangers from lithium-ion batteries, which are found in cellphones and laptops, cordless drills and leaf-blowers, scooters and e-bikes: If defective, damaged or overcharged, they can generate enough intense heat to start a fire.

Overheated lithium-ion batteries caused 10 structure fires in Honolulu in 2020, 23 in 2021, and 25 this year. To prevent fire hazard, HFD recommends charging tools and e-bikes with lithium-ion batteries outside of the home or in well-ventilated areas, and keeping devices away from flammables. Don’t charge e-bikes overnight, and don’t throw lithium-ion batteries in the trash.