You really shouldn't use a car charger on any of these. Any time something clicks on or off in the car, there is a surge in the power before the regulater can handle it. That will drastically shorten battery life. Keeping extra batteries is best. I have 3 pairs for my Snow Wolf and plan on getting more. I like to let the batteries rest for an hour or so before charging and the same after charging before using. Any batteries can be dangerous, and high output 18650's aren't nice when they go so I do my best to limit the risks. Using the mod while charging creates surges as well, not something I would want to risk. An extra $15-20 for a charger and some extra batteries could double or more the life of the batteries, saving you money in the long run as well as keeping you safer.
I really was not aware of any if this. I heard there where risks, but I assumed that if the quality of the product was what it should be then I shouldn't worry to much. I currently have a dual battery charger that's maybe 3 years old that was the best at the time (from what I was told) with over charge protection, so I should be good with that one. I really don't mind swapping batteries, especially if it will prolong battery life and help with safely. I'll drop the charging port requirement or at least not charge and vape since there seem to be a consensus against it.