Came across this blog article where they freeze a flashlight in a block of ice while it's on! Seems like a good test of its cold tolerance... Check it out: http://www.pinnacleflashlights.com/blog/...nfinity-freeze/

A typical freezer is at 0 degrees F. That's not really all that cold considering how cold it can get in the winter - at least in the northern U.S. states.

Ken

bet if I freeze one of my Pelican or UKAA in a tub of water they would keep working as well. I know for a fact that a Pelican 3C or UKAA will work for at least a couple hours in -50°F conditions. On a whim we hit the light with an infrared thermometer, the surface temp of the UKAA was about -48°F and it was still functioning.

Keeping the light going when it's already on is one thing. Starting them up when they are frozen (even with access to the switch) is another. Lithium batteries are much better than Alkaline batteries in the cold.

Umm... At the risk of sounding flip, I'm not as concerned about my flashlight working while frozen in ice. I won't work frozen in ice- at that point, does it really matter?

That is like my watch being waterproof to 660 ft. If I'm at 660 ft I have more to worry about than the waterproof integrity of my watch....

I'm with Raven on this one. As morbid as it may sound, my first thought was, "well if I meet my demise in a frozen river the rescuers can find me afterwards."

Pretty cool flashlight though!

I suspect most lithium powered, rugged, waterproof lights will work while frozen.

-john

What would you like to see in terms of a flashlight "torture test". Boiling, dropping, running over with a car, hitting with a hammer? What would be the ultimate test of durability?

Me?

Personally, I'd say just rigorous waterproof testing and lots of drop testing. These are the primary real-world opponents lights will likely face and need to overcome.

Beware, boiling or squishing lights with lithium batteries would be very dangerous!

-john


Check the second picture down of the Ra Twisty. While it isn't obvious at first glance, this light actually has taken a lot of abuse. And not just by happenstance, either. Check out the diagram. The battery compartment is designed to help shield the battery from shock, and the lens has a gasket in front, behind, and on the outside. And the bezel is stainless instead of AL.

As an aside, I cracked the lens and bent the bezel on my Surefire L1 when dropping it from a ladder indoors (so, maybe 8-10ft) onto concrete. It still worked, but note the Twisty drop height was 20ft. The L1 is tough, but even a well built light starts to reach it's limit hitting the concrete. Even if the light itself survives, the impact starts to smash the battery with its own weight.