Cold Weather and Re-chargeable CR123

[skidoosh]

I'm looking at a flashlight in cr123 because it works better in cold weather.  I have read about re-chargeable cr123 with problems and warnings but many of those posts are a year or two old.  Is there any new info on re-chargeable cr123?  Thoughts?

[Heinz Doofenshmirtz]

The best cold weather cells are going to be lithium primaries.  You don't have to limit yourself to the 123 format for that either.  Energizer "Ultimate Lithium" cells have all the same advantages as 123 primaries; 10 year shelf life, leak-proof, and very high energy density.  They'll also work in a wider range of devices, and can be bought in bulk cheaply just like 123 primaries. 

Lithium-ion RCR's also perform well in cold weather.  As above, you don't have to limit yourself to the 123 format.  Many good quality lights these days that use the AA form factor can also use 14500 RCR's as well as most any other AA format chemistry.  14500's also have about a 5% capacity advantage over 16340 RCR's as well.  They also fit in li-ion rechargers better too; as most require the use of spacers with 16340's that are easy to lose. 

In my opinion, the only advantage 123 format lights have over AA format lights is that they can be slightly smaller.  But, for single cell lights, the advantage is minimal.  A Zebralight SC50 series light uses AA format cells, but is literally no bigger than 95% of all 1x123 format lights on the market.  For two cell lights, you save about an inch in overall length for a 2x123 light compared to a 2xAA light.  As a down-side, 2x123 lights can't also use a 1x123 body or 2xAA body like most modern AA based lights can now days. 

For maximum versatility, I'd recommend a 1xAA light that can take multiple chemistries, so you can use most any AA format cell, from lithium primaries, to RCR's, to alkalines in a pinch...  It's simply the best overall format for EDC lights IMO.

[jekostas]

There are also 3.0 volt lithium primaries in the 14500/AA format now, and not expensive at all.

http://www.batteryjunction.com/titanium-cr14505-craa--3v.html

$1.50 a piece, in groups of 4.

[jzmtl]

How cold?

[skidoosh]

It can hit -40 easily but average is around 0 to -20 without windchill.  I'm not using it for extended periods in the cold, usually in a jacket pocket going back and forth.

[Black Rose]

rechargeable Li-ion cells are only good to about -10C before their performance starts to suffer.

keeping the light in a pocket helps keep them warmer for short burst usage.

[jzmtl]

Yeah lithium ion will crap out at -10°C or so, others even higher. The only option you have is lithium primary, which aren't expensive if you are willing to buy in bulk.

Even if you keep it in a jacket it'll chill to ambient temp in a minute or so, those aluminum bodies lose heat fast.

[Heinz Doofenshmirtz]

I didn't know about the -10º limit on RCR's... I've never been in a situation where I've had to use a light where it's been that cold.  I think the closest I've come in recent memory was last winter, when my wife and I hiked to the top of upper Yosemite Falls in early January.  Even then, I don't think it ever got down below 0º. 

I always carry at least one fresh 4 pack of L91's in my hiking pack anyway, so once my RCR's are spent I back up with the L91's. 

I always use these for carrying spare cells;

http://powerpax.3dcartstores.com/

[Black Rose]

Even if you keep it in a jacket it'll chill to ambient temp in a minute or so, those aluminum bodies lose heat fast.

That they do. 

I walked to the scene of a small plane crash tonight, and the body of the light I had with me got freakin' cold even though it was about 4 degrees C at the time.

li-ion cell (18650) worked fine but I needed to wear gloves to hold the light.