Oli:
I’ve currently got about five flashlights and two headlights in the vehicle. All lithium ion, most will stay in there year-round. One is a Black & Decker spotlight that’s been in there since around 2012 with the two original 18650s in it. For the last 3 years I don’t use it a lot but it still seems to work okay. I’m not going to worry about extending the life of lithium ion batteries by keeping them properly stored. And I’m not convinced there’s any danger. They see from a little below zero to a little over 100 fahrenheit year after year. Edit LEDLIB Black & Decker. I’m not sure how hot it gets inside the vehicle.
I agree wholeheartedly. I’ve been keeping Dewalt 20V LI tools and batteries (basically 18650 packs) in my truck for years down in hell (South Florida summers) and I’ve never had an issue.