Lithium Cells In a Car..

Laptops full of 18650s have lived in cars for summers on end.
Cop cars have them on mounts in full sun.
Some of the oilfield trucks out here have the same sort of setup.
Don’t know if any have had problems.
Laptops tend to have very high quality batteries that are run within “conservative” specs.
I’d worry more about cells inside a bomb-tube, errr flashlight.
Somewhere I have a temp. datalog from inside the central consul of my car. It’s been a few years but I think it maxed out at 135. Not nearly as hot as the inside or dash temp. If I find it, ill chime in again.
All the Best,
Jeff

My car is electric so tons of batteries in the floor. It has a keep-cool setting in which I can opt to use fan only or A/C to keep the cabin from overheating. I just keep it on the fan mode so it never gets above about 105 F. Even so, I use those Energizer lithiums in my car lights. Not sure if those are safer or not, but for me retaining a charge not being used for years at a time is the main priority. Now that I think about it, I wonder if those are the best choice. But whatever, in my car lights I mainly want a battery that will sit for years and still perform if needed. And not blow up. That last one is sort of an unspoken characteristic I want in all my stuff lol.

For God sakes man, where’s your sense of adventure

I expect that those odds are really, really small… and would require a substandard cell (of which most of us here would avoid). If anything, heat will degrade the lifespan of the cell… that’s probably the only real concern. But to be safer, I’d definitely use a hard lock out (e.g. twist tail cap).

It burned up in my last car.

No need to dogpile. It’s a safe default position.

However, based on test data and established precedent, it doesn’t significantly alarm me. I do keep a Convoy S2+ in my, with the battery half charged, but the reduced state of charge is a precaution for longevity, not concern for safety.

2 x cars. Caravan and boat.
ALL carry 18650 cells in Torches 24/7
for yrs.

We in Tropics (almost) up here,
but do get up to 42c on a hot day.
Most between 24 and 35c Outside.

I think they pretty safe.
AS LONG as they in good condition.
Their safety criteria is fairly strict
as they are (as stated above)
used for car power.

This topic has been discussed a few times, with passionate arguments on both sides.

It really boils down to this

I’ve kept an S2+ with a good quality battery (30Q I think) in my car for years with no issues.

I think if it’s a $10 eBay special light with the finest 8000mAh GoingToCatchFire 18650 cell then you’re asking for trouble, but if you use good quality items then it’s incredibly unlikely.

Im almost sure they are not powered off and able to wake up and turn on their fans.
Russian car drivers are probably leaders in closing their front view with different gadgets. Started with police radar detectors, then gps navigation, dash cams, rear mirrors with internal screen etc. If all this staff continuously connected to the 12v, driver never knows that batteries are dead. Im most cases they dont last more than 2 years. But yes, dangerous situations are very rare.

Considering there was a recent rash of news (at least where I live) about smartphones blowing up when people left it up in the car under the sun, “not recommend” is quite an understatement. But if you need to, you could stow it away from the sunlight.

Link?

The video is in Thai, though. I will try to find the source written in English.

Here you go. Same news, written in English.

http://thairesidents.com/local/hot-weather-causes-phone-blow-car/

:open_mouth:

Ying had a bad day, but I think Ying left her phone on the dash board of the car not the console. It could have vented and flew (possible) up to the dashboard and then went boom.

A few of those Samsung Notes burned up a few years ago.

Wow. Quite the response I got from this question. I’ve got samsung 30 Q’s and a 26650 Shockli powering 3 lights in my jeep so there all high quality batteries. There’s good points on both sides so how about I add in buying those storage bags for lithium cells and just keep the whole flashlight in it.

@SeniorXJ, your cylindrical cells are safe.

The problem with leaving cells in a hot car is longevity and cycle life capacity retention. That’s about it.

Pouch cells on the other hand, if they produce any kind of gases except during production, they are done for.

Case closed? You sound confident in your opinion. I am not second guessing, just asking what you are basing this on for piece of mind.

I consistently leave lithium cells in my car, however:

- I do have garages and also covered parking

- all glass is with window tint

- but the interior is dark/grey/black

  • temperature where I live is never too high
    so far, nothing has happened.