Low temperature 18650 batteries

What's folks' take on the new "low temperature resistant" 18650 batteries?

I see Panasonic have the NCR18650F and Nitecore just launched the NL1829LTP / LTHP.

I regularly camp weekends in temperatures around -10c/14f and I'm wondering if these things will grant me a bit more juice over the course of the weekend, as opposed to just running my Eagletac 3500s (with slightly reduced capacity due to the cold)?

The low temp batteries seem to all be 2900mah but I'm sure folk on here will be able to offer some better insight once you take discharge currents and other factors into account.

fyi, the usual weapon of choice for these trips is a Nitecore HC50.

Hello, and welcome to CPF

Your post above has been approved, but the thread was moved to the Batteries subforum

I'm probably wrong, but I seem to remember seeing somewhere where the IMR formulation has a better cold temp performance, and the fact that you say all the ratings are around 2900 mAh seems to bear that out. That is about the capacity level of IMR cells. I'm sure if I'm wrong someone will correct me on this. Of course, you could always just keep the cells on your body, and the extra warmth should allow you to get all you can out of them.

Seems that the Nitecore is just a rewrap of the Panasonic cell. I've found a datasheet of the Panasonic cell, but they don't specify which chemistry.
So far Nitecore did not respond when i asked if there is a reseller in EU, maybe the cell is new and did not got through all sales channels.

If the Nitecore is a re-wrapped Panasonic, then they are NCR-LiNiCoAlO2. With added safety features (circuit protection and pressure release valve, going by their website). Is that chemistry a good or bad thing?

This is getting too complicated for me already :thinking:

Might just stick with keeping my current 18650s close to body heat when camping.

That's as good as others, i see no problem at all. Protection is also adding safety features, so safety+++.
I did not encounter yet a situation where a normall cell would not do its job properly, but i did not use the light in low temperatures for long times. Camping will be another situation tough, some lights may stay away from your body.

The first time I noticed a problem was hiking at night with an NCR18650GA. I believe it was 11°F when I started. I noticed when I switched to max output on my Zebralight H600w, it would only last for about 1 second then step down. It wasn't a problem since I didn't need anywhere near that output, but just an observation when messing around with different settings.

I bet if I ran it on high while holding it the high setting would have heated up the battery enough to sustain itself. Not something I would want to count on, though, if that was necessary.

markr6 said:

The first time I noticed a problem was hiking at night with an NCR18650GA. I believe it was 11°F when I started. I noticed when I switched to max output on my Zebralight H600w, it would only last for about 1 second then step down. It wasn't a problem since I didn't need anywhere near that output, but just an observation when messing around with different settings.

I bet if I ran it on high while holding it the high setting would have heated up the battery enough to sustain itself. Not something I would want to count on, though, if that was necessary.

Click to expand...

Indeed, the step-down could be caused by the initial big voltage drop when cold (where IR is higher - see the initial droops in the 0°C and -10°C curves below). Once self-heating kicks in the IR (and consequent droop) will decrease, so the problem may disappear. Often one needs to fiddle a bit to exploit self-heating in cold conditions.