2. In the past couple of years, when I've used a digital camera exclusively, I have not had any problems with the camera battery freezing or loosing power quickly. The camera battery I use now is a 7.4V lithium ion re-chargeable "pack".
I supply this amount of detail so that someone else on this forum might be able to shed some light on why the smaller batteries were freezing/non-functioning at very cold temperatures...?
And, this might apply, too, to folks who use small digital cameras that take small (AAA or AA) batteries versus larger battery packs?
The issue is less battery size than the battery chemistry.
* Forget alkalines--they perform poorly in the cold
* Lithium ion (Lion, rechargable) is medium in the cold.
* NiMH (rechargable) is medium in the cold
* NiCad (rechargable) is better in the cold
* Lithium (primary cells, non-rechargable, AA or AAA) is best, but some cameras can be damaged by them. See http://www.vftt.org/forums/showthread.php?t=33776
* Fresh batteries (and freshly recharged rechargables) do better in the cold than old or semi-discharged ones.
There is some info on batteries of various technologies vs temp in http://data.energizer.com/PDFs/temperat.pdf
One strategy is to keep one set of batteies in the camera, another warm in your pocket. If the set in the camera fails, swap them.
Oh -- and to echo J.Dub's post (above), I keep my camera in a heavy-duty zip-loc bag to keep out moisture.
Moisture is the enemy of your camera in the cold--it can freeze the moving parts or fog the lens.
* Don't exhale on your camera
* Don't even hold the camera up to your face (or in your hands) for too long--moisture from your skin is likely to condense on it.
* When you move a cold camera to a warm moist place (ie under clothing, inside a heated or occupied building), keep it in a ziplock--otherwise moisture will condense on/in it.
* Chemical hand warmers give off moisture--keep the camera in a ziplock if it is near a hand warmer.
As for food, I just let it get cold. (Carry only freeze-tolerant food...) Some foods (eg chocolate) get very
hard in the cold--warm them in your mouth before biting down. (You could save a tooth or two.)