I have an AAA light in my car, loaded with Eneloop
I have an AAA light for my keychain, also loaded with Eneloop.
every few months, I change the battery in the car light… I have never had the light not work. It stays there during freezing winters, and hot summers.
It would be better if I used 1.5 volt Lithium Primaries, for example Energizer Ultimate Lithium, but those are expensive, and not rechargeable. That makes me reluctant to actually use the light…
They are the best choice for an emergency light left unused for years at a time…
I prefer rechargeable AAA or AA Eneloop. In my practical experience, they work even if left in a hot or freezing car, long term. With appropriate battery changes periodically.
I do not recommend leaving any 3.7volt LiIon in a car, that means no 18650, 16340, etc
I use lights with 16340 batteries for the majority of my needs, but IF I was going to leave one in a car long term, I would change the battery to 3 volt Lithium Primary, called CR123.
It is a BAD Idea to use lights with TWO CR123… Lights that use only ONE battery are safer.