Importance of light reliability

[joema]

...No company actually test every single product in a manufacturing run....

HDS tests and individually calibrates every single light. However even this doesn't guarantee perfect reliability. You can always have "infant mortality" failures where the light fails early in its life.

The OP mentioned going into an isolated, contained area by himself and was worried about flashlight reliability. In actuality you should never go into such places by yourself. There could be hazards such as toxic fumes, or inert heavy gases like Argon. In such cases you don't cough and have a chance to escape -- you die.

In the described situation a minimum of three people should be present, one on the surface and two underground. They should be in constant communication and if the people below encounter difficulty the topside person should not immediately descend to aid them. Rather he should get other help.

No flashlight is perfectly reliable, so the emphasis should be on redundancy, not on achieving perfect reliability from a single light. Each person should have at least two lights. And in the OP scenario, there are bigger things to worry about than a failed flashlight.

 

[jssp78]

Malkoff has a 2AA for the M31. The voltage range is between .8 to 3.0
Peak has a 2AA Logan QTC in stainless.
On my 1 cell lights I have lanyards so i know I wont lose them.

 

[eh4]

Regarding the idea of an extremely reliable light, the "AK-47" of lights in AA battery variety. I've got to predict that Malkoff's Valiant Little Twisty is the light.
I do not have one of these lights, but I mistakenly ordered an M31WL led head thinking that it would fit my old SF E2E, it does not btw, my mistake.
But the led head is rock solid, beautiful warm light, regulated from 1.2-3.2 volts, been messing with it with an old minimag body.
Now the Malkoff Valiant Little Twisty is about as simple as a flashlight can get, it's made to fit Malkoff's M31 line.
I'm getting one, I can hardly see what could go wrong with the thing, looks extremely tough to me.
Just guesstimating but it looks like the M31LL head would give around 8 hours of regulated 60 lumens from two AAs with some time of fade after that.

I was typing while jssp78 was posting. great minds.

 

[jssp78]

If you have the twisty, I would opt for the one you can attach a lanyard.
I have 3 twisties, both cr123 and the 2AA. I run a M31WLL in the 2AA, a M31W w/lanyard and M31 in the other.
You could run the VME head on a Vital Gear FB2 with a battery spacer for 1AA.
The Vme also fits the E series lights. If you use a E1 you could run a M31, if you have a E2 then you can run the M61.

 

[Hogokansatsukan]

Every tool can fail. The only thing for sure is death and taxes.
I've owned several Surefire lights, non ever failed me barring a blown bulb or two, which can be nasty in the wrong place.
I probably have lights from about 20+ manufacturers ranging from JetBeam, Zebralight, Surefire, Nitecore, Fenix, 4 Sevens, HDS, Novatac, Inova, Armytec, etc. etc. I wouldn't trust a single one of them in a mission critical situation... without a backup or two.
Have at a minimum two lights for adventures like yours... better to have three. Don't let them be shelf queens either. Use them so you know the reliability of each one and test them yourself.
Just my 2 cents.
I also would not be too concerned about keeping to one battery type. It can be a benefit to have a few that take different batteries, as sometimes in an emergency, you can get some types of batteries where others you can not.

 

[marinemaster]

I have to say two most important things in a light are 1) reliability 2) battery availability
I had/have lights with reliability issues. They suck, and they did not turn on when needed most.

 

[pjandyho]

HDS tests and individually calibrates every single light.

I don't know if you actually know what production testing is all about. When I mentioned testing, I mean serious testing to see how well a product can withstand torture before it starts breaking down. You tell me that HDS actually test every single piece of their product? I doubt you would buy one by the end of the testing. By inserting a battery in there and running through a sequence of command clicks does not constitute a reliability test. It is just a test to make sure the circuitry works after full assembly.

 

[CPFBiology]

I recommend getting Malkoff Valiant Little Twisty 2xAA

You can pair that with a Malkoff M31LL for reliability and long runtime.

60 lumens and around 8hours runtime.

Malkoff is known for reliability as is Surefire and HDS.

 

[cold]

(*cough* wayy offtopic regarding selecting a flashlight...)

(I don't think anyone's suggested every light be put through every test that the prototypes were put through, but some simple tests can certainly be conducted on each light, such as turning on to test circuitry and visual inspection - which picks up a lot of issues. DOA kit sucks.)

I'd view bunker exploration as on par with caving, it's a very safe sport (deaths are very rare).

AA is a very good choice. Since you're carrying 3 lights per person, in a group of 2 you're going to need 5-6 failures to end up in a bad situation light wise.

That said, even if you did, you're not entirely out of luck. Take a lighter each with you, google around for photos of flames in bad air, they're the typical cavers method of assessing available oxygen. If you reach a CO2 high O2 low place, you'll feel it as being hot and being oddly out of breath - but may not realise if you're not looking for it. Doubles as a really crappy light source.

If it's a maze down there, consider marking your path at intersections with chalk. We lost our way in a cave recently...It's pretty exciting! But you can lose many hours. Long run time sure is important in those situations. I'm not sure if it's overkill or not, but I generally take at least 36h worth of light.

Of note is cavers often take really crappy head lamps down...You'll find many with incandescent lights, or worse...Carbide lamps. Often with only 1 spare light. And they do well enough, and it's quite accepted.


Might be worth finding a caver to go with you. They'll be more keen than you! And if there's any vertical areas requiring SRT you'll be able to make it past.

Maybe the most valuable bit of advice I've ever read regarding caving is, really tight passages going up are ok. Really tight passages going down are bad, for when you get stuck and wiggle about, you only fall deeper.

 

[pjandyho]

Hi cold,

Some interesting points you have highlighted which I have not known. Just need to clarify, is using a lighter to test oxygen level a method often used? I have no experience with bunker or cave exploration but was thinking if there is any chance there might be some flammable gases in there that could cause an explosion? Maybe some unknown natural gas leakage from the ground?

I wish I have bunkers like that to explore here.

 

[pjandyho]

How about an Elzetta ZF-L M60 with hi-lo tail cap? Looks like a super tough light. I have always wanted one but ended up buying other lights instead.

 

[cold]

...Just need to clarify, is using a lighter to test oxygen level a method often used?...

Yip, it seems somewhat rare that people use more direct means of measuring O2 and CO2.

While reputable and experienced, the cavers who were describing the symptoms of CO2 poisoning to me, and indeed took me down into such a cave, didn't really stop for a chemistry lesson, nor where chemists. So I'm not 100% solid on what's going on with the lighter, I'm guessing it's the following situation:

1. Lighter measures available O2 for combustion, less 02 higher flame.
2. There is a tendency for a relationship between high CO2 and low O2, thus the lighter serves

I can say I definitely felt something while down there, it was trivial to run out of breath, excessive sweating, but I'm not sure if that was purely symptoms of hypoercapnia (too much CO2) or hypercapnia + hypoxia (too little O2).


Hmm, just googling around, this guy seems to confirm that we're only measuring O2, he goes on to say "it is not the lack of Oxygen which is the real danger in the majority of cave atmospheres, but the elevated CO2 concentration."
http://www.wasg.iinet.net.au/Co2paper.html

 

[cland72]

<snip>
Now I want a really reliable long, lasting, tough light in the AA form. Feel free to recommend it to me, I am all ears.
Thanks guys.

Realized I didn't answer your question in my previous post. If you are willing to drop the coin, get a Surefire E2L AA model. If not, the Malkoff 2AA valiant looks tough and if it is built anything like my M61, it will last a long time. Sadly I don't know of any other AA flashlights that I personally have had a good long term experience with.

 

[kaichu dento]

I am not really looking for a bright light or thrower or high output light. I just want a backup with long runtimes, tough, reliable, small, uses AA. I think I should stick it i my bag most of us I have lots Eneloop collection too.

Unless I missed it no one has yet mentioned the twisty two level mechanically switched EZAA, which is probably one of the least likely AA lights to fail due to switch failure since it has no clicky or circuitry to fail.

Very compact and nice balance of two output levels, one of my all time favorite lights in the EZAAw version.

 

[RedForest UK]

However, the switching interface can fail on all the EZ series. I have had 3, and each has eventually lost it's low mode due to spring breaking off or somehow otherwise malfunctioning. At least you won't be left with no light, but if you lose low mode then you could be left with lots of light but not for very long.

I recommend any normal light from a decent manufacturer, e.g. Fenix E21, LD20, TK20 (very tough), Jetbeam BA20 etc, all these should do fine. You would be very unlucky to have any of these die on you and would be better prepared than most with just one of these.

To be sure, take a Fenix E01 with you for back-up, this little guy doesn't put out much light but does it for a long time and is truly bomb-proof; if there was a torture test between a Surefire LX2/E2L AA or a Malkoff and the E01 my bet would still be on the E01 as it's so simple, small (little mass for impact) and has all it's reliability bases covered (few connections, potted electronics).

To be completely safe, take a pocketful of 3 to 5 fauxton squeeze lights. These run direct drive so will give out at least some light for a long time, and are virtually indestructible. Also you can afford not only to buy lots of them, but also to carry lots around with you as they're so small and lightweight.

 

[ToNIX]

Since my life/work depends a lot on my flashlight (when working evening/night shifts), reliability is really important. That's why my light is a Malkoff. I know it won't let me down.

 

[Kestrel]

[...] To be sure, take a Fenix E01 with you for back-up, this little guy doesn't put out much light but does it for a long time and is truly bomb-proof; if there was a torture test between a Surefire LX2/E2L AA or a Malkoff and the E01 my bet would still be on the E01 as it's so simple, small (little mass for impact) and has all it's reliability bases covered (few connections, potted electronics).

A great test thread on the Fenix E01 was the Arc AAA and Fenix E01 5 Story Drop Test. :thumbsup:

 

[Stress_Test]

I can't believe Fenix hasn't come out with a AA version of the E01. My only guess as to why not is that when a light gets that big, people want more features.

I guess what I'm thinking of is basically what the Gerber Infinity(?) is, but with a modern Nichia 5mm led.


But anyway, the E01 with a lithium AAA is my choice for an always-ready backup light. Use it for a little while on rechargeables or alkalines to ensure it works with no issues, then load it with a lithum cell and put it in your pocket. Check it every now and then (or before each trip) to ensure it's still okay. One thing, I like to unscrew the head about a full turn to make sure it doesn't activate itself in my pocket. You might also want to use something fairly "tacky" for o-ring lube to increase resistance, for the same reason.

 

[kaichu dento]

However, the switching interface can fail on all the EZ series. I have had 3, and each has eventually lost it's low mode due to spring breaking off or somehow otherwise malfunctioning. At least you won't be left with no light, but if you lose low mode then you could be left with lots of light but not for very long.

Thanks for the heads up - I hadn't heard about the spring breakages although I did recall some talking about shortening the spring.

As the OP was looking for AA, maybe the hard to find Arc-AA is one of the most reliable backups?

A great test thread on the Fenix E01 was the Arc AAA and Fenix E01 5 Story Drop Test. :thumbsup:

Cool read, had my stomach in knots wondering how they would fare!

 

[RedForest UK]

There was also scout24's torture test thread, and I remember one from a while back about someone who lost his in a stream inside a cave and found it 3 years or so later on another trip. It still worked! I think that may have been an Arc AAA though not the E01 but they are very similar lights with pretty much the same circuit, LED and manufacturing process.


The new 'Rayovac Indestructible' line looks very reliable too, they are encased in rubber around the head and tail and do a 2x AA version I think (they all use XP-E I think). That may be the light you saw and were referring to earlier?