Lithium/Lithium-ion cold weather performance

One of the most predominant reasons I got into lithium powered flashlights was there cold weather performance, I ended up consuming much more battery power than I accounted for and switched to Pilas for most of my lights.
My question is this.. Do the rechargable Lithiums have the same cold weather performance as primary cells? If there is a difference is it significant?

Thanks!
David

Hello David,

LG Chemical is shooting for 70% of initial capacity at -10 C.

Tom

Thanks Tom.
So I guess it's back to primaries for my lights that see the cold.. I have tried to convince myself they were the same, but it's getting pretty cold out there and I don't want to take chances..

Hello David,

I don't have comparisons at the same temperatures, however, Duracell seems to indicate that at a 500 mA current draw, their DL123 cells will give around 67% of their capacity at 0 C compared to 20 C.

This would tend to indicate that the Li-Ion cells may outperform the primary cells, by a small margin.

Tom

That is great news, somehow I missed that when I read through..
Thanks for taking the time to post those results Tom .

In my experience, both lithium-ion and primary lithium batteries will outperform everything else when it really starts getting cold outside. Alkaline cells perform the worst.

A really easy test is to take several identical flashlights and load them up with the cells you'd like to use in the cold. AA mini-mags work great for this, since you can get AA's in every chemistry. Stick them in your freezer for a few hours, then try and compare them to one that is at room temperature, and note the difference. The lithium one will win, every time!

I do a lot of work outside, daily (no way to get a submarine inside!), and I use lithium powered flashlights almost exclusively now. I've convinced a lot of people at work to get lithium lights too (or use lithium AA's in their beloved minimags), and they've all been really happy with their choices, both LED and incan.

Chris

Here's a related story that happened to me a few years ago.
I took my wife and her sister camping in Yosemite.
We hiked 6 hours up Half Dome near dead winter and
camped out. When we woke up the next day there
was 6 inches of snow. The trail was covered with snow.
Lucky us we had a GPS that we used to track all the way up.
However on the way down the GPS wouldn't power up for
more than 1-2 minutes. I took out the spare cells
popped them in and still no tracking. Bummed were we.
Really bummed. I thought those cells were brand new.
Well, we totally got lost - it was still snowing - and we didn't
have a compass. It was terrible. I felt like we were going in circles
in the middle of nowhere. The only way the three of us kept
warm was constantly arguing with each other about which direction
to take.

Suddenly it dawned on me. Those cells were alkalines.
And it was like 20 below zero. So I stuck those cells
down my pants (kids don't try this at home) to try to
warm them up. Boy were they cold! Finally we got the
GPS to work and we found our way down.

Lesson learned: pack lithium AA's during winter

For HIGH consumption devices, would the battery (and bulb and other stuff) heat up the battery itself, and therby change the "specs" of discharge at the low temps?

in other words, when they test this stuff, they try and get the battery to the low temp and KEEP it there, when in normal use a battery will heat, and be heated. Pluss your hand might be on the item , and such.

would the "self heating" of the battery during discharge improve the "specs" in high consumption devices? (and other stupid observations
or would that be inconsequential?

ex: cant get the item to function, use body heat to get it started up, then the batteries own charateristics (depending on insulative containment) would keep it warm a bit?

and we didn't
have a compass. It was terrible. I felt like we were going in circles
in the middle of nowhere.

Click to expand...

I love my GPS but I always carry a compass. Not the compass on my watch, not the compass on the GPS but a genuine magnetic needle compass.

The only way the three of us kept
warm was constantly arguing with each other about which direction
to take.

Click to expand...

LOL

Nice idea in theory, but it would be rather hard to accomplish in practice, especially with metal bodied flashlights... brr!

Chris

VidPro said:

For HIGH consumption devices, would the battery (and bulb and other stuff) heat up the battery itself, and therby change the "specs" of discharge at the low temps?

Click to expand...