Temperature Effects on CR123 Cells

Now that summer is almost here… I thought it would be interesting to see what effect cold temperature has on the Lithium CR123 cells. /ubbthreads/images/graemlins/grin.gif

We recommend lithium cells for cold weather use, so here is a look at how they perform in the cold.

Harry N sent me some Varta cells with instructions to check them cold. Thanks Harry.

I did a normal room temperature run at 0.5 and 1.0 amps, then took cells and put them into my freezer. I checked the temperature of the freezer at 0 F., and let the cells sit there overnight.

I have a cold pack that I formed to cradle the cells for testing and pulled them from the freezer and immediately tested them. I put a hot pad around the cold pack/cell to keep the temperature stable.

The test at 0.5 amps is really strange. The cell temperature was trying to increase, and it seems that the chemistry was unable to keep the reaction going. Very strange graph, it jumped around a lot. At the end of the test, the cell temperature was 56 F.

The test at 1.0 amps also showed some quirks. There was a dip about 2/3 through the test, then it is as if things recovered a bit, then it dropped off, then the slope tapered off. All of these changes seem to be temperature related. This test was a lot smoother than the 0.5 amp test, but the cold temperature still seems to take its toll.

At the end of the 1.0 amp test, the cell temperature was 77 F.

While lithium chemistry is more reactive at higher temperatures, it does a pretty good job at low temperatures as well. It seems that lights with higher current draws perform better than lower current draw lights, and you may notice some flickering with a low current draw light.

Here is the data.



Tom

Hi Tom - I think maybe we have too many warm weather people here on the forums - wait till January 2006 hits Maine again, then this info will be really interesting.

Thank you very much for conducting this testing - a couple of quick observations / questions.
- I was hoping to determine from this test if the Varta cells are the same as the ones from their parent company (Ray O Vac). It appears that the results are within +/- 5% of each other - is it safe to conclude anything or is this just within the general cluster of "good quality cells" ?

- The 0 F results are quite interesting, and show that the cells can generate enough heat to get moving on a cold day. - nice to know. I have wild ideas about what is going on in the 0.5 A results, but nothing with any factual basis.

- It is nice to see that the cells retained approx. 90% of their room temperature WH performance at 0 F overnight.

- Now we just need to figure out a good way to get them down to (-40 ).

There is a local store that sells dry ice - I will experiment with methods of holding this temperature range and let you know.

Interesting results!

[ QUOTE ]
I have a cold pack that I formed to cradle the cells for testing and pulled them from the freezer and immediately tested them. I put a hot pad around the cold pack/cell to keep the temperature stable.

[/ QUOTE ]
I don't understand the experimental setup. So you had some sort of coldpack (icepack?) to keep the batteries cold? But, then, why a hotpad or by that do you mean insulation?

Whenever you feel like testing some Lithium AAs, let me know. I will be happy to provide the Energizer and BatterStation Lithium AAs for testing.

[ QUOTE ]
- Now we just need to figure out a good way to get them down to (-40 ).

[/ QUOTE ]
Crushed ice/salt will get you down to and hold temperatures approaching -20C (-4F).

Very interesting. Having lived in warm climates for most of my life I had never really thought about cell performance under cold conditions. That changed last weekend when I went camping. I took my old Petzl Zora with brand new alkies and a 123 light. I had both lights out on a table. Just a little before midnight I went to bed and the Zora wouldn't even light up! The lithium light worked just fine. I stuck the Zora in my sleeping bag and within 30 minutes or so it worked again. Temperature was around 35 F.

Hello Harry,

/ubbthreads/images/graemlins/popcorn.gif

(I have always wanted to use that Graemlin... /ubbthreads/images/graemlins/grin.gif )

Tom

Hello Dave,

Sorry I did not explain my set up well. Let me try and clarify...

I wrapped the battery in a 10" by 4" 3M Nexcare First Aid Reusable Cold Pack. I then put a hot pad under the cold pack and over the cold pack as a "blanket" to keep things cold. I was going to use a towel, but had the hot pads handy.

Hope that clears things up.

Tom

Thanks for clarifying the experimental setup. One more question, the pictures I have seen of the West Mountain Radio CBA that you are using look like this:
http://www.westmountainradio.com/Image/CBA.jpg
Do the batteries being tested go in some external holder that is then connected to the CBA via the Red/Black wires shown in the photo?

Hello David,

That is what I am using.

I have an 8" pigtail of 13 gage wire that plugs into the Anderson Power Pole connector. I soldered #4 copper washers to the pigtail ends and hold the cells in a Quick-Grip clamp for testing. The clamp is tightened to about 12 pounds of force to get a good - low resistance- connection. Hook up the temperature probe and you are ready to go.

Tom

I have lined up a number of the components to do the basic temperature control part of the testing,
- Home built very well insulated container
- sealed bags for the cells / flashlights
- 50/50 mix of antifreeze and H2O (for heat capacity)
- Dry ice

Now, the missing part - finding a small thermometer that will go down to (-40 ). This temperature is of course not very common locally, so the only thermometer I have found here is one with an almost 6 inch dial at Walmart. Apparently, Hg based thermometers are not routinly sold to the public anymore.

Anyone have access to a small (as in either stick type or 2- 3 inch dial) thermometer that will go to at least (-40 F or C) ? I can make the big one work, but it requires some changes to my setup.

My DMM has a temp probe, but only to (-4 F).

Hello Harry,

I'll keep an eye out. I live in a warmer area and have not had much need for measuring cold temperatures.

Perhaps a thermocouple?

Tom