Low temperature Lithium cells?

dragosios

Newly Enlightened
Joined
Apr 29, 2011
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Stockholm, Sweden
I saw at Nitecore's site that they have a new Low Temperature High Performance lithium cell. Model NL1829LTHP.
They claim that it will retain its performance even at -40 celsius, which is more than respectable.
Anybody tried these cells? I recently moved in a nordic country and ... well ... winther just started, may be good to have.
 

iamlucky13

Flashlight Enthusiast
Joined
Oct 11, 2016
Messages
1,139
I haven't seen those before, and fortunately, live in an area where I don't have to worry about temperatures that low.

However, I happened recently out of personal curiosity to go digging for information on what batteries NASA used on their Mars rovers, which also encounter very low temperatures. The cathode and anode chemistry is pretty typical (ICR, I think), but they had a different electrolyte than normally used in order to handle lower temperatures.

One of NASA's rover has been using these batteries daily for roughly 14 years, so even early generation low temperature cells can apparently be quite reliable if well-made and properly cared for.

It looks like Nitecore has some basic performance data on their site, which is very good to have:
http://flashlight.nitecore.com/BATTERIES/18650/NL1829LTHP/

They say ~90% capacity at 0 Celsius. I think that's a bit better than regular lithium ion cells do at 0 C, but the real performance loss happens below 0 Celsius. The performance table indicates they're ok to use at 1C discharge at -20 Celsius, and can expect around 83% nominal capacity, so you're probably ok up to around 1000 lumens at that temperature. That's good. A Sanyo NCR18650B datasheet indicates around 65% capacity at that temperature and discharge rate, and really significant voltage sag. The Sanyo might actually do worse at lower discharge rates because it appears to recover due to self-heating in the graph I'm looking at, and of course, that's as cold as the Sanyo can go.

At -40 Celsius, they seem to suggested a limit of 580 mA (0.2 C), which would be about 200 lumens from a typical flashlight.

I don't see anything said about temperature for recharging, so I assume your should warm them up to at least 0 Celsius before recharging, like normal lithium-ions

These seem like a reasonable option if you have to store any of your cells in places where the temperature might go below the typical -20 celsius rating of normal lithium-ion batteries.
 
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