Does anyone have general knowledege of batteries and temperatures ..?
I had a few lights with nimh and alkalines I generally leave out on the back porch ..problem is it's now 20 degrees F...or 6.66 degrees celcius .(mark of the beastly cold)
how well or poorly will these batteries perform or am I hurting them ?
tis the season for cold weather battery tips
any help ?
On Eneloop AA´s: They will do fine
Alkalines: ughh...
http://www.candlepowerforums.com/vb/showthread.php?241606-AA-battery-tests-incl.-freezer-test
Any tests for 18650 in cold temps, say on -20°C or -4°F ?
Well then Boaz you should move down south here where it is a whole 16 degrees warmer. The info below is something I took from a backpacking website and falls right along with what I had read before
Carbon-zinc
Alkaline
Silver oxide
Lithium
Rechargable batteries
i THINK storing them at those temperatures will slow self discharge. I probably wouldn't leave them there in a real cold snap though...not sure how low those chems can go before there's damage.
Unfortunately, low temp slows discharge when you want them to do it - but depending on your use, your hand and the emitter will warm them up:)
I use a nicad drill to power an ice auger for fishing. They're pretty much useless if allowed to chill to even 40F. I have a small 'cooler' that holds two and I throw a few handwarmers in with them. They stay in there, or in my coat, unless I'm drilling. Kind of a hassle, but not nearly as bad as carrying, smelling and listening to a gas auger.
Meanwhile, my alkaline headlamp and shanty lamp perform ok - at least until it is way too cold to be fishing anyway...(although I'm probably losing a lot of capacity)
It wasn't 20 degrees it was like 34degrees but I'm sure we won't have top wait very long till it gets to be 20.
SecaRob only lives 30 miles south
I lie sometimes ..... :P
I don’t use alkaline for anything except the occassion remote control and I’m gradually changing those to NIMH but for lights that I leave in the car or anywhere else that’s cold I just spend the $ for lithium primaries.
I used to have a 2 mode light in the car (hi/lo) and had alkalines in there (2 AAA). When it was cold hi looked like low.
I’m sure you know all this already however 
20 degrees F is actually -6.66 degrees C, which is a lot colder than 6.66!
I read that nicads perform better in cold than nimhs, or no maybe it was that nimhs are damaged by the cold, which is why outdoor LED lanterns use nicads. I tried replacing one of the nicads with a nimh for quaduple the runtime, but then I read about the damage/performance, and switched it back to the nicad.
I had thought NiMH were better than nicad at cold temps but a little googling implies you are right.
Based on my personal experience w/ nicads, that would mean Nimh are TERRIBLE lol
What I can't readily determine is if Nimh self discharge is slower or faster at cold temperatures - I see sites claiming both.
Since I'll be spending at least a few days up north (as in way up north), where temperatures can easily dip below 0° F (-18° C), I thought I'd bump this thread with a question.
I know cold temperature increases the internal resistance and diminishes the capacity of lithium-ion batteries. I also know about Arrhenius law. I understand that matching cells at these kind of temperatures is even more important than usual and I know to let cells warm up and not to charge them below 32° F.
I think I understand the dangers of cell reversal so I won't be using any lights with three or more cells.
That said, what I don't know is this: are 18650s even safe to use at these temperatures? Can I leave a X8 with two protected 18650s in the car/snowmobile overnight? From what I read, LiMn/IMRs have a wider temperature range so I assume they should be safer. However, I don't have any personal experience with IMRs (yet).
I am not really concerned about the cells' capacity, as much as I am about safety and reliability. I'll have a few lights and will be bringing primaries as well, but I'd rather not discover my 18650s crapped out on me when I try to turn on a light.
Im not sure Oxy but I would say a cheap CR123 or something might be better for that kind of cold. Or maybe a dual CR123?
Oxy:
I have used 18650 cycling down to the low 20's F and never noticed any degradation in output. They also work ok when left in the car overnight down to below 10F. It hasn't been cold enough this Winter to check any colder. If it is going to be significantly colder where you are snowmobiling, I would suggest not leaving your lights out in the elements, especially not overnight. Keep a light in an inside pocket and spare batteries in pockets.
I know you are supposed to store alkaline cells in the fridge because they won't lose their energy as fast. Also likely the reason they don't work well in the cold because of the slower discharge rate. Beyond that all I know is I'd never store my lights outside except in the car. Too easy to get stolen (at least where I live).
Oxy I use CR123s for snowmobiling. I have two 501As with the Solarforce low voltage drop in. I try to keep one light in my inside pocket so it stays warm but I do leave a CR123 light in my truck and toolkit on my sled which gets down to -20F.
I have used single and double 18650's in temps below -20c easily without problem. However I am not aware if this was unsafe or not.
Great find JMc. I have brought warm 18650 lights outside into -20 and used them but never left them out it appears it's OK to leave them out in the cold and in a hot vehicle in the summer stable up to 150 is awesome.
Thanks very much for the great advice, guys! I really appreciate it. :)
For some reason, it never occurred to me to just bring a CR123A light. I use 16340s all the time but hardly ever use lithium primaries. I have a bunch but I think of them more of a SHTF item - out of sight, out of mind, I guess.
Just to be on the safe side, I think what I'm going to do is keep a CR123 light (I'll have to figure out which since I don't think I own any low-voltage drop-ins) close to my body. I'll also bring an AA light with a strobe mode (in case we get chased by grizzlies and/or for signaling purposes).
The X8 is coming along for the journey as well because I am curious to see if it works, but I think I'm going to leave it at the cabin. I briefly thought about putting my imax b6 to good use and run a discharge test in 0°F weather, but that's just a bit too geeky, even for me and it would probably make for a "fun" conversation at the airport... sigh.
Thanks again.
i've done some bicycling in almost -30c with my dry, double 18650 504b, some c2's with xml and xpg and only problem was with the 504b which was unused in an outside pocket of my backpack and it was really freezing -it wouldn't stay on
other light were used sparingly and performed very well, the 504b came to life when i got home
my advice is to keep the light (and even mobile phone!) in your inner pockets, where it will get some of your heat and just use them from time to time, it will heat up a little
funny thing was my phone (htc desire) got really cold too and it lost it's battery in hours when i had it in my hands (with gloves of course) and in outer pocket of jacket while geocaching in this cold weather
Great find!
150 degree celsius stable (storage?!?)? Or just the pcb?
I just realized I never got around to post an update. Anyway, fun was had by all and most of the flashlights I brought didn't get used at all. I'd say I used the Klarus ST-20 (2*AA) and the Sunwayman V10A (1*14500) most the time. I also brought half a dozen CR123 lights with primaries in them that mostly just sat there.
The X8 I brought along broke once when I spring came lose, then it briefly worked again after a impromptu ghetto soldering session using a jetflame cigarette lighter, until it gave in a short while later. The LED still works, the switch is fine, the solder looks okayish so I guess, it's either that or the driver. I haven't had the time to pull it and check yet and probably won't for another couple of weeks.
Oh, and janko, I have to say you're hardcore, man. :)
