UKC

What's the best choice for a headtorch in cold temperatures; standard long life ones, ie Duracell, or 3000mah NiMH rechargables?

In reply to splumley:

Check the Petzl site, pretty sure there was some contraindication regarding rechargeables and LEDs.

For winter use lithium batteries. Bit dearer but last longer.

DJ

In reply to splumley:

Cheap lithiums:

http://www.7dayshop.com/catalog/product_info.php?products_id=5345

DJ

In reply to Deejay: so, those are disposable, not rechargable, but the longest lasting (and good at -20C)?

In reply to splumley:

Sorry, it's lithiums that may cause problems with some lamps:

http://en.petzl.com/petzl/LampesNews?News=159

DJ

In reply to Deejay: yeah, just read that they arent a good idea with Tikkas, not sure abuot a Black Diamond Zenix IQ though.

In reply to splumley:

According to this review lithiums are ok (near the bottom):
http://www.flashlightreviews.com/reviews/blackdiamond_zenix-iq.htm

If in doubt mail BD and ask them. If you can use them lithiums are the best choice. Rechargeables and standard disposables die in the cold a lot quicker.

DJ

In reply to Deejay: thanks for the link. I'm checking with BD too.

In reply to splumley:
I've used Lithium batteries in my Tikka XP (Petzl) for well over a year and have never had any problems. If they do indeed reduce LED lifetime, it must be several years down the line ... by which time a headtorch that's twice as good will probably cost half the price of the original one anyway!

In reply to splumley:

Lithium is generally regarded as the top performer in low temperatures. Whether its lamps or phones or whatever it's still best to have the batteries inside your jacket if you can.

What size are you talking about anyway? AA Alkalines like Duracell are about 2500mAh. Energiser, Sony and others have published capacities that are equal or higher. However, that figure isnt going to be the whole story especially when you factor in temperature.

Long wire into your jacket, LEDs, and learning to use very low light levels, will boost battery life out beyond 100 hours. That's about a week of working time in an Arctic winter. What's the problem again?

In reply to Jim Fraser: ??? Using a Zenix headtorch for climbing in the Himalayas. uses 2xAA with an advertised battery life of 4.5hrs on full beam (and presumably in optimum test conditions).

In reply to splumley:

Presumably 4.5 hours is with the maximum power long range setting. Surely you wont want to use this constantly. The more light you emit the less you will see: unless there is something wrong with your night vision or you have not yet learned how to use it.

In reply to splumley: Why not test it? stick your head torch in the freezer and check it every so often. I'd have expected normal (~2200mAh) to have lasted less time than a standard duracell but who knows what'll happen in the cold with long life rechargables.

In reply to splumley:

quite a bit on this site about temperature ranges if you poke about
http://www.abslpower.com/products/rechargeable/rugged_military/

In reply to splumley: I have a Zenix IQ and never had a problem with lithium batteries. They last forever, and are fine at extreme temperatures, -20 won't be a problem. Plus it'll be on your head which will keep it a bit warmer anyway. always worth looking after all batteries up high though.

In reply to splumley:
Another option is the new generation of nimh batteries.

The eneloop are rated as still performing well down to -10 (and will work still below that), so should be fine for Scotland.