# Need suggestions for best focusable headlamp for working in a mine!



## blueboy9 (Sep 16, 2008)

Hello all!

I work underground in a mine in Canada and I'm looking for a headlamp to replace the one we're given as it's heavy(lead-acid battery worn on our belt) and has a long cord that gets in the way often.

As you can imagine, its VERY dark down there in some areas so it has to be of appreciable brightness and clarity. The most important thing for me is the ability to tightly focus the beam up to ranges of at least 50 meters(165 feet) for spotting and lighting up hazards at a distance. The bulb type doesn't matter to me, and price isn't really an issue. Durability is a consideration as it can be wet and dusty at times.

Thanks for any help you can give me!

BB


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## Yucca Patrol (Sep 17, 2008)

If I were you, I would get a StenLight, as it is a VERY durable and bright headlamp made for cavers and would be very suitable for mining. It does not have a focusable beam, but it is VERY bright and VERY durable.

For a very tightly focused beam, you'll probably want a very bright thrower flashlight in addition to your headlamp. Too many good ones out there for me to suggest a specific light, but others probably have some good ideas.


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## vtunderground (Sep 17, 2008)

Another vote for the Stenlight! It's pretty expensive, but it's the best headlamp available right now. I can't think of many more headlamps tough enough to spend 8 hours every day underground.

http://www.stenlight.com/


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## JohnB (Sep 17, 2008)

If you are working in a mine is there a requirement for the light to be explosion proof?


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## PeterC (Sep 17, 2008)

My thought too (about it being explosion proof).

I think the terminology is "Intrinsically safe".
In practical terms, this means that the lamp and battery system should be sealed to the extent that any sparks inside wouldn't be able to ignite an explosive mixture (gas or dust and air) on the outside.

I would expect that these sorts of apparatus usually require formal certification. Depends upon the regulation in force at the mine.


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## blueboy9 (Sep 17, 2008)

I think as long as the lamp is sealed with no ignition sources exposed to the air it'll be ok. Its a copper/zinc/gold mine so there's no methane or other gases to worry about.

I'll take a look at the Sten, can you also suggest a headlamp that's focusable? I've looked at some of the focusable Xenon headlamps, how are they for brightness at a distance?


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## Marduke (Sep 17, 2008)

I'm almost positive that Canada has nearly the same regulations as the US on the matter, meaning any headlamp will have to be intrinsically safe and meet some sort of regulator guidelines as to what that is.

A good place to start would be MSHA approved lights.


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## blueboy9 (Sep 18, 2008)

If the wires are insulated and the bulb is sealed from the environment, they're considered safe to use in our mine. 

With that said, does anyone know of a focusable headlamp that can illuminate a spot at a distance of 10 or more meters?


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## vtunderground (Sep 18, 2008)

Most of the newer LED lights have such good beams (bright spill beam with a tight, very bright spot in the middle) that there's no need for focusability. I think almost any headlamp with a reflector (as opposed to an optic) and a Seoul, Cree, or Rebel LED should meet your criteria for brightness and usability.


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## Gunner12 (Sep 19, 2008)

blueboy9 said:


> If the wires are insulated and the bulb is sealed from the environment, they're considered safe to use in our mine.
> 
> With that said, does anyone know of a focusable headlamp that can illuminate a spot at a distance of 10 or more meters?



10m should be no problem for most of the headlamps you read about here. How much runtime? Also would you like to have multiple modes(low, high etc)?

If it is completely dark, a pure flood Zebralight(essentially close work only) might work(though not well).

:welcome:


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## PeLu (Sep 21, 2008)

blueboy9 said:


> does anyone know of a focusable headlamp that can illuminate a spot at a distance of 10 or more meters?


A Scurion does a fantastic job there, but is not sold in northern America. 
As it also does not have external contacts (unlike a Stenlight), it should be intrinsically safe, but is not certified for it. 
The headpiece is of about the same weight as of a usual miner's lamp and the battery box with battery equals the cable in weight.

The floodlight is wonderful for working and the spot is quite good at distance. 

Another option might be the BiSun. As you can use an intrinsically safe headpiece, it will be safe (but not necessarly certified).


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## RGB_LED (Sep 22, 2008)

:welcome:. How about the Petzl Ultra headlamp? This headlamp is pretty rugged as it's main customer would be adventure racers but it's versatile and allows you to use an extension cord and it also has a couple of battery options as well. The only drawback is that it's quite expensive. They recently started selling them at MEC here...

Good luck with your choice and let us know what you decide to go with.


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## mdocod (Sep 22, 2008)

Most modern LED headlamps, have a fixed focus beam. They generally have a tight beam in the center, with a nice useful spill beam around the central spot that makes up close work very doable. 

LEDs in reflectors, will have much stronger spill beam compared to the incan in a reflector you are used to using. With LEDs, depending on the design of the reflector 40% or more of the light coming out the front can be in the spill light around the central beam (depending on reflector design), plenty for up close work, whereas on incans, often the amount of light in that spill beam is more like 25% or less. 

You will probably find that almost any headlamp utilizing a MODERN (read, NOT a Luxeon) LED emitter will out-perform the headlamp that you have been issued... In fact, the low and medium modes on these modern LEDs will suffice for 75% or more of underground activities. 

But, it's important that whatever you pick out, have enough runtime to last you through the day. Ideally, that means on 1 set of batteries, but if you think swapping batteries while down there isn't a problem then let us know as this is going to influence what options are on the table. 

A few things to take into consideration:

1. Do not use a CR123 powered headlamp in a mine, as CR123s, while generally safe, have a higher chance of randomly exploding while being discharged than most other cell chemistries. And obviously, you need something rechargeable if you are going to be using it daily, CR123s are way too expensive to be using 8 hours a day... 

2. Li-ion rechargeable should be considered fine, especially if you pick out a headlamp that comes with them pre-installed with charge controls and cell protection all built in.

3. Any multi-AA headlamp can be used with NIMH cells for recharge-ability. Since you will be using it every day, and want the investment to last, I would suggest Sanyo brand Eneloop NIMH cells. They are definitely some of the more reliable cells out there, and will deliver hundreds of useful cycles before they need to be replaced, some NIMH cells barely make it to 100 cycles before developing problems. Another huge factor is a good quality charger, as this will really maximize the performance and life you get from your rechargeable cells, do a little research, and check out chargers from MAHA, La Crosse, AmsMann, Accupower,... Something with individual channel control, and if possible, a capacity readout and cell testing capability, so you can always know that you are going in with GOOD cells that are ready for the day. 

--------------------------


On a side note, you should absolutely be holstering some sort of hand-held light as a backup. A 2xAA powered Fenix, or Olight, or something like that would probably not be a bad choice. 

Eric


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## blueboy9 (Sep 22, 2008)

Thank you for all the suggestions and information! Lots more to headlamps than I thought.

I'm leaning towards the new version of the Petzl Myo XP. With a single super bright bulb, the max distance and battery life are extremely appealing. I can change batteries when I'm down there, I carry a backup flashlight at all times. 

Does anyone have this lamp that can attest to the range it boasts? (97m)

I'm also interested in the Petzl Zoom Halogen, Micro, and Myo 3 Noir. All three of these Petzl models have the focusing bezel that I'm looking for. Does anyone have any experience or opinions on these?


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## SureAddicted (Sep 22, 2008)

LED Lenser H7

140.2 Lumens
2.9 Watt (3) AAA Batteries
84 Hour Battery Life
528 Feet Effective Range (160 metres)
Advanced Focus System with hinged position beam
Variable Light Control Technology (VLT)
Coast Lifetime Warranty

DONE


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## Marduke (Sep 22, 2008)

SureAddicted said:


> LED Lenser H7
> 
> 140.2 Lumens
> 2.9 Watt (3) AAA Batteries
> ...



84 hours 

More like 2-3 with NiMH


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## SureAddicted (Sep 22, 2008)

Marduke said:


> 84 hours
> 
> More like 2-3 with NiMH




I've gotten more mileage than that from alkalines.
I suppose you have the figures to back it up.

EDIT Having checked another source, its up to 50 Hrs runtime.
I still have the original batteries in mine and its still going strong after about ~12 hrs.


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## Marduke (Sep 23, 2008)

SureAddicted said:


> I've gotten more mileage than that from alkalines.
> I suppose you have the figures to back it up.
> 
> EDIT Having checked another source, its up to 50 Hrs runtime.
> I still have the original batteries in mine and its still going strong after about ~12 hrs.



So you honestly think you're going to get 140 lumens out of 3 little AAA cells for over 12 hours (or 50, or 84...)??

Try doing a little math for the figures. Assuming you can squeeze every possible drop of power out of an AAA alkaline cell, you _might_ get 4.3Wh out of 3 of them. If you believe their own 2.9W claim, that's only 1.48 hours. In reality, being driven that hard, you will only get a fraction of the available energy out of the cells, meaning even less runtime than that.

LED Lenser has a LONG history of absurd brightness and runtime claims. They keep doing it because it works, and lures in uneducated consumers who take the fictional specifications at face value.


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## SureAddicted (Sep 23, 2008)

Marduke said:


> So you honestly think you're going to get 140 lumens out of 3 little AAA cells for over 12 hours (or 50, or 84...)??
> 
> Try doing a little math for the figures. Assuming you can squeeze every possible drop of power out of an AAA alkaline cell, you _might_ get 4.3Wh out of 3 of them. If you believe their own 2.9W claim, that's only 1.48 hours. In reality, being driven that hard, you will only get a fraction of the available energy out of the cells, meaning even less runtime than that.
> 
> LED Lenser has a LONG history of absurd brightness and runtime claims. They keep doing it because it works, and lures in uneducated consumers who take the fictional specifications at face value.



Well, how do you explain the runtime I've been getting so far?
EDIT If it did only last the runtime you say it does, I would of taken it back the next day.


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## Marduke (Sep 23, 2008)

SureAddicted said:


> Well, how do you explain the runtime I've been getting so far?



Constantly diminishing output, which is not noticeable over that period of time. That and decreased initial output (far below claimed).

This is what a 3xAAA direct drive light runtime really looks like for a 3watt light on alkalines

http://www.flashlightreviews.com/reviews/mxdl_3watt.htm


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## RGB_LED (Sep 23, 2008)

blueboy9 said:


> ...I'm also interested in the *Petzl Zoom Halogen*, Micro, and Myo 3 Noir. All three of these Petzl models have the focusing bezel that I'm looking for. Does anyone have any experience or opinions on these?


Whoa! That is taking me back a few years! I still have a Petzl Zoom Halogen - my first headlamp - but it's now sitting in storage. 

It's a sturdy light and very simply designed but, as with all halogen lights, it casts a very yellow beam, the brightness diminishes very quickly as it's not regulated and the reflector leaves a lot of rings and other artifacts in the beam. If you don't mind the trade-off of having regulated light but less depth perception and contrast, then you should consider staying with LED's as they are more efficient and the regulated light alone is worth it. My two cents.


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## SureAddicted (Sep 23, 2008)

Marduke said:


> Constantly diminishing output, which is not noticeable over that period of time. That and decreased initial output (far below claimed).
> 
> This is what a 3xAAA direct drive light runtime really looks like for a 3watt light on alkalines
> 
> http://www.flashlightreviews.com/reviews/mxdl_3watt.htm



So my understanding is direct drive lights have no circuitry?


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## Marduke (Sep 23, 2008)

SureAddicted said:


> So my understanding is direct drive lights have no circuitry?



LED Lesner's "Variable Light Output Technology (VLT)" in the H7 consists of a variable resistor. In the highest output, it's essentially a direct drive light.

Big whoop, >100 year old technology.

Their standard for battery life is a theoretical maximum time that the system will operate, meaning if you look very closely at the LED you _just might _see a few photons still being emitted, with the end of actual "useful runtime" having passed several DAYS prior.


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## mdocod (Sep 23, 2008)

[edit in] I poked away at this response on and off over the last few hours, looks like a few other people have already made the point I was going to make, I'll leave the post in place though. conclusion is I am in agreement that a direct drive 3AAA powered light with a rheostat slapped on the bottom is nothing fancy or special. [/edit in]

Don't you love when manufactures list an output on high with fresh cells, and a runtime on low, that takes into account diminishing output down to some meaningless level of illumination..

If my math is correct, in order to get 84 hours of runtime from 3AAA cells, the LED would have to be driven, on average, around 12mA give or take, that translates to a few lumens. The LED would have to be operated below it's efficiency peak to stretch out to 84 hours on these 3 cells. If it were 3AA cells it could be ~12 lumens for 84 hours, which is a more useful amount of light in a mine/cave. Either way, the point is that the numbers on the H7 are deceiving. Big surprise right.

Basically, for what you are planning to do with this headlamp, I have to suggest an AA powered headlamp for the larger energy storage, and AAA headlamp isn't going to be practical when run at high output levels for extended periods of time.

Something to consider, just about any headlamp or flashlight that uses 3 cells, (alkaline/NIMH etc) is likely not going to have built in regulation circuitry, they are almost always a simple circuit consisting of a resistor, (or a few resistors for different modes, or in the case of the H7, probably a variable resistor, which has been given a fancy name, the "VLT").. While this is not a bad design, it means that the light will dim through the run. When you walk in the cave in the morning on fresh cells, it will be bright, by the time you leave at the end of the day, it will be dimmer. The advantage to this design, is that it extends the runtime of the light considerably, as the cells drain, the current across the LED just keeps on dropping to a lower and lower level, and increasing in efficiency as it goes. This is a good thing for extended runtimes, but not so great if you want consistent performance. A good way to ensure that you are getting a light with a regulation circuit is to find one that runs on either 2 or 4 AA cells. (or some other number of cell, but not 3). 

Eric


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## SureAddicted (Sep 23, 2008)

I totally understand mdocod, and thanks for explaining it. I had a gut feeling that the advertised runtime was exaggerated by LL, but what surprised me was the 2-3 hr runtime given by marduke. If i was only getting 2 hrs of runtime, I wouldn't have it in my house. I just found one short review online which the guy got 8 hrs at full brightness, I've been using mine for ~12 hrs, 60% at full brightness.


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## uk_caver (Sep 23, 2008)

mdocod said:


> Something to consider, just about any headlamp or flashlight that uses 3 cells, (alkaline/NIMH etc) is likely not going to have built in regulation circuitry, they are almost always a simple circuit consisting of a resistor, (or a few resistors for different modes, or in the case of the H7, probably a variable resistor, which has been given a fancy name, the "VLT").. While this is not a bad design, it means that the light will dim through the run.
> ...
> A good way to ensure that you are getting a light with a regulation circuit is to find one that runs on either 2 or 4 AA cells. (or some other number of cell, but not 3).



Though that might work as a rule-of-thumb, it's certainly not universally true.
Even cheap single-power 3-cell lights could be using linear regulation with AMC7135s or similar, and multipower 3-cell lights may well be doing PWM control of a 7135 for the lower power levels. There certainly seem to be cheap controllers working that way being sold on DX/Kaidomain, and a light using one would have reasonably regulated output up to the point where the cells were fairly flat, when they'd effectively drop into direct drive.

Also, it's possible for lights using 1, 2 or 4 cells not to have a constant output. Switching regulators, even those specifically targeted at LED use, aren't always constant current.


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## Marduke (Sep 23, 2008)

uk_caver said:


> Though that might work as a rule-of-thumb, it's certainly not universally true.
> Even cheap single-power 3-cell lights could be using linear regulation with AMC7135s or similar, and multipower 3-cell lights may well be doing PWM control of a 7135 for the lower power levels. There certainly seem to be cheap controllers working that way being sold on DX/Kaidomain, and a light using one would have reasonably regulated output up to the point where the cells were fairly flat, when they'd effectively drop into direct drive.



True, but that's not LL's style. Their idea of progress is going from a single drop resistor to having a rheostat (variable resistor), or having several different value resistors so that you have low modes.


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## Marduke (Sep 23, 2008)

SureAddicted said:


> I totally understand mdocod, and thanks for explaining it. I had a gut feeling that the advertised runtime was exaggerated by LL, but what surprised me was the 2-3 hr runtime given by marduke. If i was only getting 2 hrs of runtime, I wouldn't have it in my house. I just found one short review online which the guy got 8 hrs at full brightness, I've been using mine for ~12 hrs, 60% at full brightness.



Ok, so let's take your 8 hours at face value. Again, if you assume the perfect AAA cells with 1000mAh at that current draw (fat chance) and 100% circuit efficiency (no possible), you would be driving the LED's at only 125 mA, which is less than 1/2 watt of power. That's a far cry from the 3W claimed, and would be in the 20-25 lumen range.

So, which do you prefer to believe? They can have the brightness, or the runtime, not both (or in LL's typical style, they have neither as advertised)


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## uk_caver (Sep 23, 2008)

Marduke said:


> True, but that's not LL's style. Their idea of progress is going from a single drop resistor to having a rheostat (variable resistor), or having several different value resistors so that you have low modes.


I don't disagree with that, it's just that the variety of the market has resulted in a great mix of power controls on various battery configurations, so generalisations can be tricky.
I'd also agree that AAAs are a pretty poor power source for a serious headlamp that's expected to be regularly used as a main light for long periods.

A rheosat would seem like a bit of a leap backwards, especially since mechanical things tend to wear out. Even cheap unregulated PWM with up/down buttons would seem better, though personally I don't see the point in continuously variable power anyway.
A few well-spaced fixed levels is really all most people need, and having fixed levels makes it much easier when trying to get some idea how much power is being burnt.

I'd love to know how they work out an 'effective range' of 160 metres.

Looking at the UK distributor site,
http://www.ledco.co.uk/index_faq.asp
I noticed the following:



> LED's are incredibly energy efficient because they generate almost no heat. A standard LED uses only 0.1 watt, and our new, ultra-bright power chips use between 0.8 and 3 watts. This allows all the electrical energy to be used to generate light.


Which is, of course, complete nonsense, and is written either by someone who knows nothing about LEDs, a stranger to the truth, or an astonishingly poor translator.


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## Yucca Patrol (Sep 23, 2008)

uk_caver said:


> I'd love to know how they work out an 'effective range' of 160 metres.
> 
> 
> > It probably means that someone 160 meters away in complete darkness can see your head lamp is turned on even if you cannot see them.


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## Marduke (Sep 23, 2008)

Yucca Patrol said:


> uk_caver said:
> 
> 
> > I'd love to know how they work out an 'effective range' of 160 metres.
> ...


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## blueboy9 (Sep 23, 2008)

Myo XP or Myo 3? Does anyone have any experience with the 3? I'm curious about the brightness of the Xenon bulb when focused into a tight spot.


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## SureAddicted (Sep 24, 2008)

Marduke said:


> Ok, so let's take your 8 hours at face value. Again, if you assume the perfect AAA cells with 1000mAh at that current draw (fat chance) and 100% circuit efficiency (no possible), you would be driving the LED's at only 125 mA, which is less than 1/2 watt of power. That's a far cry from the 3W claimed, and would be in the 20-25 lumen range.
> 
> So, which do you prefer to believe? They can have the brightness, or the runtime, not both (or in LL's typical style, they have neither as advertised)




Do you seriously think I'm going to recommend a headlamp that only lasts for 2-3 hours? Come on Marduke, now your starting to insult my intelligence, and that aint cool.


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## Marduke (Sep 24, 2008)

SureAddicted said:


> Do you seriously think I'm going to recommend a headlamp that only lasts for 2-3 hours? Come on Marduke, now your starting to insult my intelligence, and that aint cool.



The math speaks for itself. If you got 8 hours of constant brightness from 3xAAA, it was no where near 140 lumens. LL didn't magically find a way to get over *FIFTY TIMES* more energy out of AAA cells than what is there, despite their claim to have done so.

Don't believe me. Believe the math, believe the runtime graph, believe the other knowledgeable members who have said the exact same thing.


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## ToTo (Sep 24, 2008)

mammut got a new headlamp which is completely focusable
but not regulatet
and i think its ipx6 as ever
heres a link:
http://www.mammut.ch/en/productDetail/1060340_v_001/X-Zoom.html


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## hopkins (Sep 25, 2008)

This Swiss made 'Scurion' headlamp has 2 beams, a spot and a flood.
and wow is it cool looking ehh! All for only 348.00 Euro's.
If I worked in a mine I'd have to have this baby.

http://www.scurion.ch/ms/index.php?lamp


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## blueboy9 (Sep 28, 2008)

I ended up buying a Black Diamond Spot. The focusable xenon's and other lights were not nearly as bright as the Spot. It even seemed brighter than the Petzl Myo XP. I would've purchased the Myo if they had post-recall units available but they didn't. Since using rechargable batteries is a must for me, the Spot won out.


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## mdocod (Sep 28, 2008)

You'll be swapping cells a lot with that headlamp running AAAs (not much capacity), but it will be nice and light weight. Best bet is going to probably be eneloop AAAs for long term reliability.


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## Marduke (Sep 28, 2008)

Sounds like you compared to the old Myo XP. The 2008 version is 2x as bright, and runtime is no comparison to the short usage 3xAAA format.


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## blueboy9 (Sep 29, 2008)

The BD Spot performed adequately today underground. The bright setting had useful illumination up to about 15m and the 3 LED setting was sufficient for walking around. It was noticeably dimmer after about 4 hours of intermittent use.

An '08 Myo XP sounds like it'd be perfect if it is indeed brighter and longer lasting.

Can anyone tell me if NiMH batteries are safe to use in the older Myo XP's? Some sites only specify Lithium ion batteries as being problematic, some say you shouldn't use any rechargeable.


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## PeLu (Sep 30, 2008)

blueboy9 said:


> Some sites only specify Lithium ion batteries as being problematic,


 No, LiIon was never an option. The warning was not to use LiFe AA cells, as they have a higher voltage.


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## uk_caver (Sep 30, 2008)

blueboy9 said:


> Can anyone tell me if NiMH batteries are safe to use in the older Myo XP's? Some sites only specify Lithium ion batteries as being problematic, some say you shouldn't use any rechargeable.


Petzl's recent warning 
http://en.petzl.com/petzl/LampesNews?News=222
is about rechargeable cells, and by implication, is effectively almost entirely about NiMH cells, since hardly anyone would be using NiCd these days.

As to NiMH being safe to use, I suppose that depends how rigidly you define 'safe'. Reported problems don't seem to be very common, and even allowing for only a fraction of incidents being reported, the real number of problems still seems likely to be very small.
It may be that some or even most/all of the problem lights actually had visible signs of cable wear before anything happened, and so a user may be able to significantly reduce the chances of a short circuit by regular inspection.

Also, if Petzl sold a very large number of lights and had a handful of reported problems, it could be that some other light made by another company and sold in rather smaller quantities isn't any more reliable, it's just that the number of problems isn't enough to have been noticed.

Finally, in some circumstances, a light with a very small risk of a short circuit (which may be guarded against to some extent by inspection and removal of cells when not in use, or breaking the circuit by inserting a tab of paper in the battery pack) may be more acceptable than another light that is rather more likely to stop working if it gets a drop or two of water in the case.


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## mdocod (Sep 30, 2008)

As I was saying in one of my posts above, most 3 cell lights are not regulated. This has the unfortunate side effect in many of the designs of not being compatible with AA lithium cells (even the 1.5V variety sold at the grocery store) because the lithium chemistry actually has a higher operating voltage than the Alkaline cells that the light is designed around. 

However, NIMH cells are almost ALWAYS going to be just fine for use in any light designed for alkaline cells. As Cave Dave has pointed out, they are pretty much just covering their own @$$es by recommending against the use of NIMH cells because of a few limited issues. 

If the "spot" was only performing at a level of adequate and you would like more, then perhaps looking into 3W options would be worthwhile, just make sure it uses one of the new modern emitters beforehand. And ideally, 4AA cells or more (if you're not sure, ask first). 

Eric


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## hopkins (Sep 30, 2008)

Sometimes on the News we see miners with a helmet mounted headlamp...
and there is always a power cable leading to a belt mounted battery,
likely a SLA (cause its so big). Anyone hear of fire hazards for these systems?
Tons of regulations for miners.

I've been thinking that the Petzl NimH battery ban for the Myo series is
due to its headlamps getting stuffed/crammed/squeezed into a backpacks
repeatedly which fatique's the cable into failure. Miners don't have to do this
to their helmet lamps.


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## uk_caver (Oct 1, 2008)

Going a bit off-topic, typically, the cables for mining lamps are thick, strong and resistant to damage.
The classic UK mining lamp is the 'Oldham', and the cable for that lamp has a nylon core which is tied off to the inside of the case at each end to take tension, and the electrical wires are spiral wound around the core so that even if the core attachment fails and the cable is pulled, the wires won't break.
Additionally, there's a fuse in the battery box to protect against large currents flowing in the case of a short circuit.


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## adirondackdundee (Oct 1, 2008)

i own a nuisance wildlife company....we spend alot of time in attics...our preffered headlamp is princeton tec apex,there 3 different models,4 settings, has (in our opinion) the longest lasting and brightest light available on the market in the led lines.

http://www.princetontec.com/?q=node/67


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## TMorita (Oct 1, 2008)

mdocod said:


> As I was saying in one of my posts above, most 3 cell lights are not regulated. This has the unfortunate side effect in many of the designs of not being compatible with AA lithium cells (even the 1.5V variety sold at the grocery store) because the lithium chemistry actually has a higher operating voltage than the Alkaline cells that the light is designed around.
> 
> However, NIMH cells are almost ALWAYS going to be just fine for use in any light designed for alkaline cells. As Cave Dave has pointed out, they are pretty much just covering their own @$$es by recommending against the use of NIMH cells because of a few limited issues.
> ..
> Eric


 
Well, yes...

AA alkalines batteries are rated at 1.5 volts, and AA lithiums are rated at 1.7 volts. So AA lithiums will kill a light designed for AA alkalines unless the light has proper regulation.

AA NiMH cells are rated at 1.2 volts, so the an unregulated light will be noticeably dimmer on AA NiMHs. The AA NiMHs have a flatter discharge curve than the Alkalines, so the light output should not drop as much over time, but the intial light output will be significantly lower.

Toshi


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## degarb (Oct 4, 2008)

Marduke said:


> LED Lenser has a LONG history of absurd brightness and runtime claims. They keep doing it because it works, and lures in uneducated consumers who take the fictional specifications at face value.



I can't hold back much longer. Thanks for reminding me. LedLenser are big fat liars. They should be banned from selling their stuff, until simple true specs can be put on package. Goes for all manufacturers. (led type and bin, current flow, time to 50%, lumens, beam angle, corona angle, and throw; is this too much to ask?) 

Best to learn the math and what type of led they are using. And stick with rebel 100 or rebel 80, cree q5 or higher, or Seoul.

Speaking of which, Stenlight look great except only Lux 3. Hello, this is nearly 2009! And, a bit too pricey. Oh yes, and the two heads look like in series, meaning no separate controls per head...Hello, again. This is nearly whole point of two heads, control. (However, some lux 3's are red bin's and good with color rendering, which is good for earthy colors.)

Also, I would add, 1. Cannot emphasis enough need a backup in dark. 2. xrc's seem to have 15% or more throw than xr-e with same optic, per Coleman packaging. Think, 1 Xr-c plus one rebel or high cri souel 3. might consider making own light or modify one for a third the Stenlight price, except might be difficult to make it super rugged or intrinsic. 4. In a cave, you may consider temp and color rendering to get brightest perceived light. Also, looking for gold, you probably need good color rendering, perhaps toward red. My Browning Rebel 100 Nitro (modified power supply for full day use) is very pinkish, compared with any other light, and has excellent color rendering. I've 2 other rebel 80's, both are better at color rendering than my Cree's, lux1's or Seoul, but worse than the rebel 100. Ideal, is the Zled or new bin of the Cree.

Just my two cents. Which I believe is lower now on the weaker dollar.


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## kokesh (Nov 29, 2008)

Got one H7 today. I'll write something about the running time, it seems like a fairy tale to me also, we'll see.

Does any of you have NiMHs in H7? Just don't want to burn it since it is new


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## Stromberg (Nov 29, 2008)

SureAddicted, do you have a lux meter or how did you get the 60% brightness figure? If you have, you can do your own experiments about LL brightness during battery drain. I'm 100% sure that you will find out just what the guys have been telling. LL is known for gross exaggeration in both runtime and brightness. You just can't get more energy out from the battery than what's inside them and that is exactly what would be required if LL's claims were true. 

It is true that 3AAA with direct drive(or driving led with series resistor) can give longer runtime than fully regulated circuitry, but it _always_ comes with constantly diminishing output. Sometimes this can be an advantage, but usually not. Especially if near 100% brightness is required.

Ps. do you remember the address where someone claims to get 8hrs of full brightness out of LL? I'd be really interested to find out his testing methods..


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## SureAddicted (Nov 29, 2008)

kokesh said:


> Got one H7 today. I'll write something about the running time, it seems like a fairy tale to me also, we'll see.
> 
> Does any of you have NiMHs in H7? Just don't want to burn it since it is new




Yep, eneloops. I haven't done a rumtime....yet.


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## SureAddicted (Nov 29, 2008)

Stromberg said:


> SureAddicted, do you have a lux meter or how did you get the 60% brightness figure? If you have, you can do your own experiments about LL brightness during battery drain. I'm 100% sure that you will find out just what the guys have been telling. LL is known for gross exaggeration in both runtime and brightness. You just can't get more energy out from the battery than what's inside them and that is exactly what would be required if LL's claims were true.
> 
> It is true that 3AAA with direct drive(or driving led with series resistor) can give longer runtime than fully regulated circuitry, but it _always_ comes with constantly diminishing output. Sometimes this can be an advantage, but usually not. Especially if near 100% brightness is required.
> 
> Ps. do you remember the address where someone claims to get 8hrs of full brightness out of LL? I'd be really interested to find out his testing methods..




I was going by other flashlights that I have set to ~80 lumens, it wasn't an accurate setting, but it was pretty close. I hear ya, i know LL grossly exaggerate figures, but what I do know is that the H7 lasts more than 2 hrs on high as others have suggested that it wont. 8 hrs sounds a bit much, and it was the only review at the time when I bought the H7. I'd like to also know what method was used to determine the runtime. I am using NiMH, so runtime should be longer than alky's. My guess would be 3-4 hrs, I'm going to have to do a runtime one of these days.


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## yowzer (Nov 30, 2008)

Stromberg said:


> It is true that 3AAA with direct drive(or driving led with series resistor) can give longer runtime than fully regulated circuitry, but it _always_ comes with constantly diminishing output. Sometimes this can be an advantage, but usually not. Especially if near 100% brightness is required.



It all depends. For my use (Backpacking, and nighttime hikes and SAR missions) long run time is more important. I can live with a slowly dropping brightness level 95% of the time -- your eyes adapt. Most headlamps are aimed at the outdoors market, where people don't want to have to carry lots of extra batteries. 

If you're, say, a plumber and want some extra light when working under a sink, I can understand why you'd want a regulated headlamp. 

The average person, though, isn't going to be wanting to change batteries every few hours, even if they are money-saving rechargeables. (The average headlamp user probably doesn't hang out here.)


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## Stromberg (Nov 30, 2008)

SureAddicted said:


> I was going by other flashlights that I have set to ~80 lumens, it wasn't an accurate setting, but it was pretty close. I hear ya, i know LL grossly exaggerate figures, but what I do know is that the H7 lasts more than 2 hrs on high as others have suggested that it wont. 8 hrs sounds a bit much, and it was the only review at the time when I bought the H7. I'd like to also know what method was used to determine the runtime. I am using NiMH, so runtime should be longer than alky's. My guess would be 3-4 hrs, I'm going to have to do a runtime one of these days.



Going badly off topic, but..


You really need - at least - a lux meter if you want to make accurate measurements. Human eyes are not good measurement devices because eyes and/or brains adjusts to slowly dimming lights so that the difference is not easily visible. And to my knowledge human vision is also logarithmic, so that barely detectable brightness differences between two light sources can be actually quite big in lux scale. 

Another thing you should notice is the fact that NiMh's are better than alkies in high current draw devices. This is good when the device - such as high power flashlight - has modern current regulation circuitry. But if that flashlight relies in series resistance(this seems to be the case in many models of LL), or is pure direct drive without any additional resistance, alkies can give longer runtime than NiMh's due its higher voltage. Nominal voltage in alkies is 1.5V where NiMh's is 1.2V. When the batteries are getting depleted, total voltage of 3 NiMh's can drop quite fast below leds threshold voltage -> led dims significantly or shuts down completely, whereas alkies keep on going(with light dimming all the time..) thanks to the higher voltage. 

Here is good explanation of how different batteries behave in different situations:

http://www.flashlightreviews.com/qa/batteries.htm


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## uk_caver (Nov 30, 2008)

Given a choice, I think the best option for a 3-cell light is one that starts off in regulation, and then drops into direct drive when the cells approach exhaustion.
That still gives you a good long tail at the end, but also a predictable brightness through most of the cell life, and also means the light doesn't start off with excessive brightness on fresh cells in order to still be bright enough some way down the line.


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## converge (Nov 30, 2008)

I have had the LL H7 a couple of months now. I have not really measured the battery life with clock but I´d say using decent NiMHs it is about 1 hour at full power. Then the output gets low quickly.

So far I have no lux meter to check is the output getting weaker all the time from the beginning but it looks like it's staying the 1 hour very bright and the a quick dimming so maybe there is switching regulator inside.

So the runtime is lousy - it should rather be built for having 3 or 4 AA batteries.

Brightness is very good to my opinion and focusing also works pretty well. The flood position is very usable. It is not completely the same brightness everywhere but quite ok. On spot throw is really good to my opinion.

Also the "1%...100%" power control is quite useful.


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## kokesh (Nov 30, 2008)

So math and physics were not defeated by LL  
Is there chance to get 3AA box with regulator somewhere?

Something like the original which is on H7, but for AAs...


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## converge (Dec 1, 2008)

Math seems to match well to the real life. If there is altogether 800mAh * 3,6V in the battries and the led is driven with 700mA - it's about an hour at full power and then there is only the quickly dimming tail left.

I got curios and Checked is there a regulator inside LL H7. I disassembled the battery box and looked in. And yes there is but I'd say it's a linear one that only regulates the current until the battery voltage drops close to the led forward voltage. It can not help by boosting the led current up beyond that point but dimming will start. I'd attach a small image here of the regulator but after insert image I can not see it on "preview post", something goes wrong.

I'd also like to get a decent waterproof battery box with holders for head strap or belt for 3 or 4AAs. I wonder if someone is selling those?


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## kokesh (Dec 1, 2008)

I guess that for my driving in minus temperatures, I should definitely have AA box with dimmer, I guess that little AAAs on my head will freeze quite quickly if it gets really cold. Today I took my H7 for the first time for longer run - driving snowmobile, digging it out many times, etc. in forests and wide open areas and I must say, that it stayed very bright all the time (I guess not 100%, but very reasonable). I used it mostly on full power for at least two hours. Before, I've used it maybe for one hour of high-power.

So altogether it runs on original batteries for something like 3hours until now. I'll write how it looks in next days.

I am still puzzled about using NiMHs, I'll try to find some dimmable 3x AA box.


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## degarb (Dec 1, 2008)

uk_caver said:


> Given a choice, I think the best option for a 3-cell light is one that starts off in regulation, and then drops into direct drive when the cells approach exhaustion.
> That still gives you a good long tail at the end, but also a predictable brightness through most of the cell life, and also means the light doesn't start off with excessive brightness on fresh cells in order to still be bright enough some way down the line.



Hmmm. Do many regulators do this?

How about a button we can push to take the light out of regulation? Such a bypass switch may be cheap to include in a build. 

This would sure settle alot of arguments between people that insist on regulation, and people like me who like direct drive 3 or 4 cell + variable pot that have yet to use a regulated light that didn't have short runtime, finicky with perfectly good batteries, and unreliability.


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## uk_caver (Dec 1, 2008)

If a linear regulator is designed for low dropout and low minimum resistance, one way of looking at it would be as a postponed direct drive which limited the maximum power on fresh batteries.

Personally, I reckon the simplest way to conserve battery power is to have 2 or 3 usefully different power levels, so light isn't used when it's not needed. However, I do do things where demand for light varies widely, and direct drive would be no real use to me. Other people may have different demands.

Mind you, I suppose I did end up making my own controller, partly because I couldn't find anything that did what I wanted, and partly because I wanted a project.


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