A few months ago I hosted a Candlepower Forums get-together at my shop in Mountain View. This was my first personal introduction to the CPF crowd so I wanted to give them something spicy to remember me by. I thought the opportunity to break one of my lights would be a good start.
I should start by saying it's a little hard to find ANY flashlight company that will impact rate their lights. At best, they are rated at 1 meter. I'm going with the slightly ambitious 2 meter height based on the video below.
So as will see, after 37 drops and some pretty massive hits, the tailcap switch finally broke. Does that mean the light failed? I don't really know. It would still turn on in momentary mode...but the switch would not latch. So, you decide. I think the bottom line is that if your own flashlight ever sees that much abuse...you probably have some other broken stuff that is higher on the priority list.
I think the main take-way should be: This light can take massive abuse. However, if that abuse just gets too massive...my light is deliberately designed for easy repair, putting in a new switch is really easy and (if you have strong fingers) can be done completely without tools in under a minute.
When I initially designed this light I was hoping it would be water resistant. Most "high end" commercial flashlights are rated for maybe 30 feet if they are really hard core. I'm not aware of any custom light that is rated for more than "splash proof" or "brief immersion."
I built this little pressure pot to test my lights. I started off with 10 feet, went to 30, went to 50, went to 100, went to 150...got bored...removed the safety over-pressure valve from the tank and ramped it up to 300 feet (130 psi). Three lights, 300 feet, 5 hours, no problems.
Crush Proof? Check.
Tried to bust it...ran over it with an SUV...didn't bust it.
Okay, I'll admit, I really ran it over about 10 times. A friend was looking at the light and said, "This thing is a tank. It's really overbuilt. It doesn't need to be this beefy." I thought...really, what if it gets run over by a car? Would you want your light to be a pancake or just shrug it off and keep on going? I suppose you can guess my sensibilities fall into the latter camp.
So I ran an Alpha over with my 4Runner, repeatedly. In the photo below the entire tire is off the ground, only being supported by the Alpha.
In a quest to find of if my light was "everything-proof" I thought it would be fun to freeze it overnight, turn the light on high until it melted itself free from the block, and inspect. It actually took about 30 minutes for the light to melt itself loose. No water intrusion. The only problem I has was that it had been so long since I lived somewhere cold...I forgot that my hand would immediately freeze to the surface of the light. Ouch.
Anecdotally, I was up in Sun Valley, Idaho this winter and left two lights in the car overnight by accident. Big deal right? Well, the overnight low was about -7 degrees Fahrenheit. That's cold, real cold. Both lights fired up without a sign that they knew the difference.
Sand, wind, dust & no wall outlet proof? Check.
10 Days in the Utah back country (with a solar charger)
Rechargeable flashlights are great, but what do you do when you can't plug it in? Go solar. I got this little solar charger (with USB port) just for this trip. I took two lights and two batteries. I'd put a battery on the charger every morning and it would be charged by mid-day. How easy is that?
The floor of this particular river valley was completely covered in the finest sand I've ever seen in my life. Powder. Like the sand you'd see in an hourglass. It got into literally EVERYTHING...except my lights. I used the Alpha with (near) total disregard for cleanliness. We camped in a shallow cave for several nights and I jammed the tail of the light into the sand and bounced the beam off the ceiling of the cave, illuminating the entire thing. Other than being cool, this made the Alpha very, very sandy.
Of course I had to swap the battery each day which meant repeatedly exposing the light to contamination. As long as you are careful not to get stuff inside the light while it's actually open, the primary seal is self-cleaning. Just wipe away any gunk that is pushed out while opening the light and you should be good to go.
Okay, so this is NOT a depth test. However, one thing that will test the seal quality of a light is being heated and cooled while submerged. As the light gets hot, the air inside the body expands and may be forced past a poor seal by positive pressure. Then, when the light is turned off, it begins to rapidly cool. If any air has escaped, the inside of the body will become a vacuum and may actively suck water into the light...if the seal is insufficient.
You can be pretty sure that the o-rings in the tailcap and head will resist this type of pressure change, but the lens seal is extremely vulnerable. The easiest way to test the lens seal is in a glass of water. Using ice speeds the change in pressure. I've done this at least a dozen times and have never had a failure...nor do I expect one :)
This test also serves another purpose, a measured run-time test. The MCE will run for 105 minutes on the highest mode and the XML will run for 65 minutes.