# 18650 light and sub zero weather



## K31Scout (Nov 3, 2014)

After doing a lot of reading here I ordered a Zebralight H600FwMkII. I bought it mainly for hikes in the woods after dark coming and going to hunting stands and fishing streams spring summer fall. I also want it for plowing snow on my ATV in the winter and it can get very cold here in northern Michigan. What can I expect with the 18650 battery in freezing weather? 

The ATV has headlights but the plow up front blocks them.


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## mobi (Nov 3, 2014)

This is not based on research or experience and doesn't really address your question. Seems to me, though, that flipping the light on high for a few seconds should toast up the battery, so freezing should not be a issue while you're using the light. If you keep the light in an inner-pocket when it's off for an extended time, I think you'll be good to go.

Here's a CPF comment that may be relevant.

another comment:


> i have used good li-ions in 32*F and they acted weak, but did everything i wanted to do, sorry i did not do a chart, i just walk at night in as low as freezing and it works.i have Deep freezed, operating li-ion lights at about -14*F with 18650 and the coin cell light, and they kept working in the deep freezer , i left them in untill they were at the temp of the freezer, after pulled out they got wet bad from condensation.
> 
> there have been reports here of freezing batteries with protection curcuits has caused a protection curcuit failure, so it should be noted that freezing isnt nessisarily a good thing, for a battery designed mostly for room temp operation....



Thanks for bringing up this issue. It's a concern even for those of us in milder winter climes.


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## markr6 (Nov 3, 2014)

Most of my backpacking trips are somewhere in northern MI. I like to get out at least once in the deep winter too. Never had a problem with my H600wII, even down to 3°F. In fact, after some moderate use I still get 3 blinks when returning...so a good deal of battery left.

I also run with it at least every other day in the winter. But I'm sure the constant use for 30-45min and body heat help out there.


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## mcnair55 (Nov 3, 2014)

What does it say on the instructions of temperature range?


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## thedoc007 (Nov 3, 2014)

mcnair55 said:


> What does it say on the instructions of temperature range?



No 18650 I have seen has detailed info about operating temperatures. I have belt carried 18650 lights down to -15F, and never had a problem. Body heat and even a basic holster will keep it a little warmer than ambient. Basically, from what I have read, lithium-ion cells have trouble delivering full current when very cold, but they don't stop working at all. And as they warm up under use, the ability to deliver more current will improve also. So unless you have truly extreme temps (I wouldn't want to bet it works well at -50F), I think it is a non-issue.


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## K31Scout (Nov 3, 2014)

The light will definitely be on top of my head over my hat catching all the wind so I don't think there will be much body heat to warm it up. How about one of those shake it up hand warmer pouches rubber banded around the battery compartment?


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## ven (Nov 3, 2014)

If the light is kept on your person before using,turned on so its relatively warm to start,then mounted,the cool air if anything should aid the light on a higher power level whilst driving..............just a different thought. :thumbsup:


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## markr6 (Nov 3, 2014)

K31Scout said:


> The light will definitely be on top of my head over my hat catching all the wind so I don't think there will be much body heat to warm it up. How about one of those shake it up hand warmer pouches rubber banded around the battery compartment?



I think the warmer would be a bit extreme, but I guess you could try it if you find the cold to be a problem. But like ven said, it should warm itself enough on medium or higher.


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## Norm (Nov 3, 2014)

Lithium/Lithium-ion cold weather performance search.

Norm


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## meti (Nov 3, 2014)

thedoc007 said:


> No 18650 I have seen has detailed info about operating temperatures.



Just look in the datasheet. NCR18650B, for example, are rated for -20 +60 °C during discharge


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## mcnair55 (Nov 3, 2014)

meti said:


> Just look in the datasheet. NCR18650B, for example, are rated for -20 +60 °C during discharge




Well done,that made me smile,very few ever think of reading data sheets.


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## K31Scout (Nov 3, 2014)

-20C is about -4F so I should be good. We got to -30F last winter for a week or so but it doesn't snow much at that temp. I need to spend some time at the Battery University! I'll post a report in January sometime.


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## meti (Nov 4, 2014)

It's the temperature the battery need to reach. When you are actually using it, thanks to the heat of the light itself, or if you are storing it near your body, it doesn't reach -30F...


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## d1337 (Nov 4, 2014)

mobi said:


> This is not based on research or experience and doesn't really address your question. Seems to me, though, that flipping the light on high for a few seconds should toast up the battery, so freezing should not be a issue while you're using the light. If you keep the light in an inner-pocket when it's off for an extended time, I think you'll be good to go.



Your first sentence literally made me lol.


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## jorn (Nov 5, 2014)

The tesla is using a couple of tousand 18650's. And they do just fine during winter. If there was huge problems with 18650 and cold, no one in Norway would have owned a tesla. But i see one almost every day. 

Winter has begun....Hate the crappy snow outside....I miss summer....


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## inetdog (Nov 5, 2014)

jorn said:


> The tesla is using a couple of tousand 18650's. And they do just fine during winter. If there was huge problems with 18650 and cold, no one in Norway would have owned a tesla. But i see one almost every day.
> 
> Winter has begun....Hate the crappy snow outside....I miss summer....


More like just under 7000.


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## gofastman (Nov 5, 2014)

Based on my experience drilling holes in snow for downhill ski gates, I have found that as passé as NiCd is, it completely stomps all other current chemistries available when the temp drops below 0°F. I'm not sure if that really helps you. But I plan on trying to get a head lamp that will run on them for winter hiking


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## Edwood (Dec 7, 2014)

I've used my 3400mAH AW 18650's in 15-20F weather without a noticeably large drop in runtime. I'll be using the same set up and batteries soon in hopefully much colder weather in my next expedition.


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## Sno4Life (Dec 10, 2014)

I use my Zebralight H600 mkII with Panasonic 3400ma Li-ion Batteries in Minnesota for snowblowing (42" thrower on a lawn tractor) and have gone down to we'll below zero with this light for several hours at a time. On turbo, which is what I use it at most of the time, and this light stays very warm at all times during continuous use, and works very well even if off or lower for a bit. Get 2 batteries and you will be unstoppable.


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## den331 (Dec 12, 2014)

i have a ncr18650b on my tk75 fully charged. last winter i went out for a walk using my tk75 . it won't stay on turbo. the temperature that time is -15C


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