Mostly OT: What's your experience with LED flashlights?



#41

(The LED's involved aren't red, but they are LED's . . . )

Most of the stubby, multi-LED, 3-AAA flashlights I've purchased seem to be undependable, and when turned on often require a sharp knock against something to (at least temporarily) get them lit again. Some of those I've purchased have been clearly El Cheapo, and others not so much. They're not of identical manufacture, but share the same basic design: six or seven white LEDs in a stubby aluminum case, with three AAA batts in a plastic insert, and the on/off button on the end.

I find it strangely amazing that several different models, from several different manufacturers, could all share a similar problem.

I started casting about for a better LED flashlight, and the one I've found that behaves flawlessly (and gives TONS of light) is one that came with a Leatherman tool ("Blast", I think) from Costco. The flashlight ("LGX 200") is a single AA model with a single, large square yellow-looking-when-off LED, and has worked absolutely without problem.

I recently bought another Leatherman ("Freestyle" knife) from Costco, because it also came with an LED flashlight -- this one a single AAA style that is more compact ("Monarch 300"). It seemed to work for a while, and though not quite as bright as the other, it's smaller in the pocket.

However, lo & behold! The newer unit is now acting intermittently, and I have to slap it to get the light to come back on.

I'm more than a little perplexed. Is there something inherent in LED flashlight design that makes them vulnerable to corroded contacts or loose connections of one sort or another? It's amazing that, as many of these as I've tried, 90% share this annoying trait.

Any insight or work-around suggestions will be appreciated!


#42

Paul,

I've had several different LED flashlights over the past few years and they are all still working today. Never a problem with them. There's one in each car and they get bounced around a lot, but always work.

I have a nice Energizer 3W LED, two AA batteries. It's all metal with a gasketed battery cap. It came with Energizer Lithium AA batteries. I use it for job site visits and it gets banged around alot - but still works great after two years. Throws out a very strong beam of light.

I think I paid about $15-20 on sale for each of the ones I have.

If you can find the Everyready one, I;d highly recommend it.

Bill

#43

Amazing timing for your question! At this moment, I'm expecting the mail(wo)man to deliver my new LD10. All I read about is how great the quality of the Fenix series is. These videos describe it.

#44

I've had a pile of the multi-LED lights, a few single LED / single AA cell units and others over the course of over six years.

The first group has no electronics. Only the current limiting of the three AAA cells and the voltage / current curve of the LEDs control the current. When the cells are new, the LEDs are bright but they taper off rapidly and you finally replace the batteries when they're too dim to do the job. They have a number of pressure contacts that have to pass current to work (two per cell, two for the cell holder, two for the switch & endcap, at least one for the front - totalling at least eleven). Those are notorious for intermittents. A cheap switch doesn't help reliability either.

The single LED / single AA cell lights are generally more reliable if made well. With no cell carrier and only one cell, they have six less failure points. But again, cheap ones can often have intermittent case-to-switch and case-to-LED connections. They do include a switching power supply to boost the single cell voltage to the 3 to 4 volts needed for the LED. But the circuitry can vary drastically in quality and efficiency.

Be aware that many flashlights run their LEDs far beyond their design specifications. The manufacturers seem to feel that degrading a LED's 50,000 hour lifetime to 500 or so is worthwhile if they can blast 3 or 5 watts through a 1 watt LED (or similar abuse in general). Apparently they don't expect most users to have the flashlight that long.

My favorites have become an Energizer 1W single AA for US$16 that fits comfortably in my pocket all the time. A Maglight 3W 3AA and a Home Depot Husky 3W 2D sit in my car. They all blow the multiLED 3AAA units away in performance and reliability.

Others may mention Fenix and a raft of others. Those are spectacularly fine, being head and shoulders above the run of the mill units found in most stores. Of course, they're priced to match. The above three I mentioned cost me under US$20 each.

You will find a whole discussion group at <http://candlepowerforums.com/vb/index.php> if you really want to dive into this head first. Hmmm - I've heard of calculator enthusiasts doing so too, somewhere...

Jim Horn, Hood River, Oregon USA (PPC 1402, etc^n)


#45

Jim you said "Be aware that many flashlights run their LEDs far beyond their design specifications. The manufacturers seem to feel that degrading a LED's 50,000 hour lifetime to 500 or so is worthwhile if they can blast 3 or 5 watts through a 1 watt LED (or similar abuse in general). Apparently they don't expect most users to have the flashlight that long."

I wasn't aware LEDs had such a short lifetime and that their lifetime could be shortened by a factor of 100 by having them run at too high a wattage. Do you think this applies as well to LED nightlights? We have 4 watt incandescent nightlights throughout our house that we mostly leave on all the time so it's easier to walk around at night, and just today we were thinking of replacing them with LED nightlights from Superstore, but if they fail in a year or less then it'll be more expensive to replace them than to purchase new bulbs for our existing nightlights (assuming you can still buy such bulbs) :(


#46

For nightlights that won't be an issue. We have a number of Feya 4W replacement night light bulbs that work fine. As such, like most LED replacments for screw-in bulbs, the 3mm or 5mm diameter bipin LEDs are run at low enough power that they should last a long time. The overall efficiency is no better than incandescents as they use series resistors to drop the rectified but not filtered 120 VAC down to the 9-11 volts the three LEDs in series use. That's nearly a 90% efficiency loss right there. But the power is so low it's not a real concern.

Haven't had one fail yet in about 6 device years of use... Of course, higher power screw-in replacements are another kettle of fish that is changing by the hour.


#47

Quote:
The overall efficiency is no better than incandescents as they use series resistors to drop the rectified but not filtered 120 VAC down to the 9-11 volts the three LEDs in series use. That's nearly a 90% efficiency loss right there. But the power is so low it's not a real concern.

Haven't had one fail yet in about 6 device years of use... Of course, higher power screw-in replacements are another kettle of fish that is changing by the hour.


Maybe for cheap night lights, and low power, the efficiency is not so good for the LEDs.

However, I splurged ($20 bucks!) for a 8 W (rated by the manufacturer) bulb to replace the 26 W fluoroescent bulb (100 W equivalent) for the desk lamp at my computer. The light output from the LED is fully adequate for desk work. I just measured the actual power consumption of both with my "Kill A Watt" meter (another handy device to have around the house) and the LED shows 6 watts while the fluoroescent shows 26 W. Unless there is a power factor that the meter doesn't handle well, this LED bulb is quite efficient. It clearly runs cooler than the fluoroescent, although the ballast in the LED base does get too hot to touch after awhile. If it lasts the guaranteed 8 or 10 years (I kept the receipt for this one!), I will be quite happy with it - light wise and power wise.


#48

Quote:
If it lasts the guaranteed 8 or 10 years (I kept the receipt for this one!), I will be quite happy with it - light wise and power wise.

Time will tell, of course. My experience with the highly-touted fluorescent replacements is that they do not last nearly as long as claimed. Sometimes barely twice as long as an incandescent. Perhaps the life claimed is theoretical, not actual "Made in China" performance.
#49

Quote:
I wasn't aware LEDs had such a short lifetime ....

What???? you think 50,000 hours is "short"?


Quality household incandescant lights typically last 1000 to 2000 hrs. Flashlights almost always are used at higher than rated voltage and will probably only last 100 or so hours.

Note that nightlights are usually run at less than rated power because they are required to give a reduced output, so they'll last at least their design life. There are 8760 hours in a year, so even if you never switch your LED nightlight off, they'll last around 6 years (probably longer). Depending on construction, LEDs could use significanty less power than equivalent brightness incandescants. They are probably the most effecient light source we have available today. What you pay for the extra initial cost, you'll probably save on energy.

Edited: 14 July 2010, 4:48 a.m.


#50

Sorry, by "short" I meant comparing cost/hour based on replacement cost and bulb lifetime, and not just bulb lifetime in hours.

4W incandescent nightlight bulbs cost about 45 cents at our local outlet and they typically last about 2 years in our house since we never turn them off. (My experience is that an incandescent bulb's lifetime is shortened considerably if you cycle it on and off frequently.) The cost/hour for incandescent nightlights thus works out to about 2.6E-5 $/hr.

LED nightlights cost about $2.50 each at the same outlet, and if they last 6 years then cost/hour works out to 4.8E-5 which is around double the cost of replacing incandescent nightlight bulbs when they fail, and if 90% of the electrical power used by LED nightlights is wasted as heat (the resistor) then not green either and what's the point using them?


#51

Oh, sorry. Of course I think cost/life is just down to production issues. Although LEDs have been around a long time, they have not really been produced for "light for the masses". White light LEDs have been particularly expensive. However, I think that as popularity grows and production numbers increase, they will come down in price (more producers will enter the market fuelling competition).

Unfortunately there's always the cheap and nasty side, and particularly with low power nightlights there's no incentive to use anything other than resistors to drop the voltage and limit the current. One can just hope that for higher power lighting, some form of voltage convertor would be used. Maybe in future houses will be wired with low voltage supplies for LED lighting.


Of course I am seeing the advantage of LED in the flash lights I have, my head lamp runs on 3 AAA which seldom need changing, one of my scouting colleagues has an incandescent headlamp requiring 3 AA that need changing on every camp. As for the 3W LED flashlight, the power consumption is the same as my old incandescent 3W torch, but the light is MUCH brighter.


Edited: 14 July 2010, 11:14 a.m.

#52

Please don't misunderstand me - the LED nightlights are less efficient than incandescents but they are so much lower in power that it's not an issue. They aren't nearly as bright, either, but are plenty bright enough for our house. Four watt incandescents have such long, thin and fragile filaments that they are notorious for failing if tapped or their power is cycled. We have automatic night lights that turn them off during the day.

If 1 watt incandescents were available they'd give enough light but would fail in no time (more so in countries with more than 120VAC - i.e. most outside the USA & Canada). As such, the roughly .6 watt LED lamps work just fine. Since they're only running at about 6mA, I expect they'll last far beyond 50k hours.

Why do LEDs fail? Two main causes: for white LEDs, the phosphors that fluoresce to make the blue LED die appear white fade with time, almost linearly with intensity. And the die reliability decreases with increasing temperature. When run at low power, that's not an issue either.

So don't worry about the el-cheapo night light replacements. I suspect they should outlast me. And hey, I'm not all *that* old...

#53

My son got a 5-pack of Husky LED flashlights for $10. They're pretty much the standard cheapo lights. But there's a "twist." Both ends are threaded, and screw/twist off. The thing is, the light end, has soldered wiring inside. You can't unscrew the end, without seriously twisting the wires, and basically ruining the flashlight. And if you do break and resolder the wires, you have to pretwist them (more damage), before returning the end to the barrel. It's a really odd arrangement.

#54

Hi.

I've ever designed and wrote an article on "Simple single cell white LED driver" which is published in the part of the appendix of "Technique to utilize the high luminance power LED " (written in Japanese)

It can operates for about 200 hours with one AA battery in a wide voltage and temperature range.

Regards,

Lyuka

#55

My experience is with the cheapest of the cheapest El Cheapo brand. 3 AAA battery cylindrical version in particular. Of course, I get what I pay for so I am not complaining.

I had a problem with the ground connection from the LED board to the metal body of the device, and had to bang the things to get them to turn on, even with fresh batteries, etc. This may be a common design feature: the ones I had used a solder pad on the back of the PCB (with a little bump of solder on it) to make contact with the rim of the cylinder. There isn't any spring or other device to keep the pressure on this connection, so it is susceptible to coming open. I dismantled my problem devices (taking the LED board out), cleaned up the solder bumps, and slammed it all back together again. They have worked OK since.

Again, I got what I paid for, and the bonus "pleasure" of using cheaply designed and constructed Chinese devices (with everything that implies) comes free.

#56

To all:

MAG-LITE 3-AA COMPACT LED !

Excellent battery life

Built like a 1970's HP-35 or 45

Doubles as kubotan if required.

This said after numerous experiences with other junk on the market. Have three of these little gems: Car,briefcase,house.

FWIW..

John


#57

I'm a Maglite fan as well. My favorites are the 2xAA model and the 3xD-cell model, and their LED models have worked fine for me w/o any problems several years now, even when banged around quite a bit.

There are certainly more "advanced" makes of flashlight out there, but the Maglite, in my opinion, is tried and true, highly effective, and utterly rugged. It's the flashlight equivalent of the Colt M1911.

#58

Mag-Lite also guarantees their lights for life/forever.

I have no experience with their LED flashlights, but we had an incandescent 2 AA mini-maglite fail, after MANY years, and sent it back to the factory (without any "original receipts" which so many places want - who knows where they are after 15 years!?). Back it came (or a new one - hard to tell which) in a few weeks, no charge (except for our postage to send it in).

As to el-cheapo multi-light LEDs, my favorite of the moment are the 9 light / 3 AAA versions given away by Harbor Freight - look for their coupons in almost any magazine (The Sunday inserts, AARP, ...). I got three, and they are all still working after several months of mild use.

I have found that many of the TV remotes we use are intermittent much of the time. A good rap fixes them. I think the currents are so low that even a little bit of oxidation anywhere in the circuit breaks the connection(s). As noted somewhere above, keeping things jiggling around (in a car or truck) seems to help.

#59

Love MagLites. Made in the good ol' USA (my apologies to the "rest of the world").

I did have a failure of a MagLite 3-D LED. Someone dropped it on a hard surface; a few weeks later it failed. (Glows very faintly).

I saw the 3-AAA ones at Home Depot; they want $40 for one. Has anyone found a cheaper price?

#60

I just bought a 2-AA, 1-LED $24 Mini Mag-Lite, replacing the incandescent Mini Mag-Lite I've had for years (one of the AA cells leaked, and is unremovable).

The light is quite bright, allowing me to see down a 13-mm portal several inches long into a cylinder head.

-- KS


#61

Karl,

Is yours the multi-mode one? I particularly like the reduced-power mode. Also, if I am ever out wandering in the wilds, I hope I remember to bring it along for the SOS mode, just in case!

#62

Karl,

The leaked, stuck battery is actually what happened to our Maglite. They still fixed it for free - they apparently have deals with the major battery manufacturers who typically warrant that if battery leakage damages your equipment, they will replace it.

Try sending it to Maglite (in Ontario, Calif, I think) and you may get a new one back!


#63

Dave --

Thanks; worth a try. Otherwise, I could keep it for spare parts, or as a tool for pounding or pressing things...

-- KS

#64

Hello!

Quote:
Any insight or work-around suggestions will be appreciated!

The only work-around I know is to throw them back into the bay and get decent ones ;-) I have experienced the same problems that you describe with various el-cheapo multi-led flashlights (one of them had 26! LEDs from which not more than 10 are still working - after a couple of hours of use.)

Now I have a couple of real good and rather expensive ones that do what they are supposed to do. Always. One is a 4D-cell LED-Maglite (single LED) that I use at home, and the others are various small ones from the German manufacturer "Zweibrueder Optoelectronics" (http://www.zweibrueder.com/ENG/startseite_1024.php) that I take with me at work (flying). They are simply the best ones - rather expensive, but money well spent. Sooner or later I will buy their top product X21 (http://www.zweibrueder.com/ENG/produkte/html_highperformance/html_Xserie/x21.php?id=x21) ... a portable car headlight. In the price range of a good HP-71B.

Regards,
Max

Edited: 13 July 2010, 3:34 p.m.

#65

I keep a wind-up LED flashlight in the car for emergencies. Never need to worry about batteries, though my daughter has a habit of taking it :(.

And here's an interesting thought. When they really perfect LED lights, their lifetime will be comparable to other building materials. At that point, we'll start to see permanent lighting built into homes and offices. By that, I mean that the design and placement of the lights won't worry about replacing the bulbs, anymore than the design of your interior walls worries about the replacement of your wallboard.

Hmm. I guess this is an OT response to an OT post.... Bad Dave! Bad! No RPL for you tonight! :)

Dave

#66

I've done a review of the excellent Fenix LD01 AAA light:

http://www.eevblog.com/2010/04/19/eevblog-78-fenix-ld01-led-keychain-flashlight-and-victorinox-minichamp-review/

You get what you pay for. The cheap ones are just poorly designed rubbish.

Dave.


#67

I use Zweibrüder LED flashlights for geocaching.
very popular are the P7 and the P14....arround 200 lumes.

#68

Hi Paul;
I like LED headlamps. When in the dark i find i usually want two hands.... I got my first about eleven years ago at REI. it's a Black Diamond (formerly Chouinard) with two low intensity LEDs and one big long distance one. It has worked flawlessly in really shitty conditions, and as i just discovered; it's made in China! I've also bought several of the multi-fixture type at the flea market for five bucks to keep in the truck, at work, or give away. The results vary. If there is a problem it's in the switch. Last winter i found a few marketed by Iron Bridge Tools at home Depot for $3.70 a piece in the bargain bin and gave away all but one. They sport a single bright LED and so far all are working...........or lost. Their idea seems sound; design a solid light with only a few good parts and it will be cheap to build and last.

The best thing for me about the multi LED lights is that they are not focused at the same spot and you get this even haze of light that is generally in front of you without one bright focused spot. I've used them for mountaineering where you start at midnight so you come down before the avalanches start. Even (or especially) cheap LEDs provide low intensity light where you are looking without ruining you vision for routefinding out past where the light shines.

Plus; their low power use/frugal nature is going to save more energy than any invention since the bicycle.


#69

Quote:
Hi Paul;
The best thing for me about the multi LED lights is that they are not focused at the same spot and you get this even haze of light that is generally in front of you without one bright focused spot.

Take a look at Zebralights. They make great no-spot, all-flood headlamps. Not affiliated, yadda yadda, just a satisfied customer.


#70

it says they have a red flood. i always meant to try red light to save my night vision.


#71

Hello!

Quote:
i always meant to try red light to save my night vision.

Not worth the effort: http://stlplaces.com/night_vision_red_myth/
In older aeroplanes, red night lighting used to be standard. Modern ones (at least those that I fly) have white cockpit lighting.

Regards,
Max

#72

Quote:
I like LED headlamps.

Speaking of which, I've done one of those too, the Princeton Tec EOS

http://www.eevblog.com/2010/03/10/eevblog-67-hacking-the-princeton-tec-eos-led-headlamp-with-a-cree-xpg/

Dave.

#73

In the no-frills one-AAA LED flashlight category, I can recommend the Fenix E01. Available online for $15 or so, it lasts for about 10 hours on a AAA battery (I use Eneloop rechargeables), weighs 14 grams + battery, outputs a bright-but-not-too-bright 10 lumens, and is very dependable. In years of use, it has never failed to turn on when I wanted it to.


#74

Quote:
In the no-frills one-AAA LED flashlight category, I can recommend the Fenix E01. Available online for $15 or so, it lasts for about 10 hours on a AAA battery (I use Eneloop rechargeables), weighs 14 grams + battery, outputs a bright-but-not-too-bright 10 lumens, and is very dependable. In years of use, it has never failed to turn on when I wanted it to.

I used to have a 10 lumen ARC-AAA Premium, but upgraded to the Fenix LD01 single AAA keychain. Having 85 lumens on your keychain is just awesome. Much more expensive than the E01 but worth every cent.

Dave.

#75

About 2 years ago I purchased the al cheapo Tesco brand LED headlamp (powered by 3 AAA) and the Tesco brand 3W LED torch (powered by 2 C cells). I use them at home and on Scout hikes/camps. They both still work perfectly.


I use the headlamp lots at home too, perfect for working on the car or lighting up the PCB I'm working on, etc. How did I ever cope without one?


Edited: 14 July 2010, 7:34 a.m.

#76

Thanks to all for your input -- I appreciate the time.

For now, I found a Fenix LD01, which seems like a step up. Three brightness levels is nice, no push button is a minor drag (two hands required to turn on -- though that's one less thing to break). And, the price was more right than some of the other fabulous-sounding lights out there.

Thanks again!


#77

If it's ok for it not to be a traditional flashlight shape, you could use a bicycle LED headlight. They're made to take incredible pounding for hours (possibly thousands of hours), mounted to the handlebars. Our road bikes with higher speed and hard, skinny tires definitely give them more pounding than a mountain bike would. I and my family of cyclists have used a lot of Cateye ones, first little halogen ones and later LED ones, stepping up as brighter and brighter models came out. We had trouble with earlier models where the various pieces of metal only pressed against each other and I had to solder them when the connections got intermittent, but it was easy to do and then they gave no further trouble. Now I have an EL-530 (see http://www.cateye.com/en/product_detail/345 ) which is a very nice, bright light considering it does not have the battery pack separate like the super-expensive HID and LED ones that practically give you stadium lighting. On those, the battery pack usually straps to the frame or takes up a water-bottle cage, which is not acceptable to us. The EL-530 however is about the size of my fist or a little smaller, and gets 90 hours from four alkaline AA batteries (although batteries have gotten so ridiculously inexpensive that I don't try to string them out that long).

Edited: 20 July 2010, 2:54 p.m.


#78

I have an earlier Cateye, the EL-510, and it's been reliable even without soldering the connections. It's a great bicycle light but I'm not sure I'd want to walk around holding it. I also have a Fenix LD01 in stainless steel (they don't seem to make this any more), it's just fantastic. I'm pretty sure that it will outlast everything else I own, me included.


Edited: 20 July 2010, 7:49 p.m.

#79

At work (paramedic) I've been using a Surefire 6P LED Defender for more than a few years. Link: http://www.surefire.com/6PDL Zero complaints. It's been dropped, smashed, handled by surly NYC cops, covered in bodily fluids and sustained multiple cleanings with hospital grade disinfectants. Zero problems. The bezel is also crenellated in case you need to use it as a weapon. 120 Lumens of beautiful output.

Off duty, I carry the Surefire ED2 LED Defender. Link: http://www.surefire.com/E2DL Slimmer than the 6P. Has _200_ lumens or 5 lumens output with a simple press of the tail cap switch. The 200 lumens can easily blind somebody for a few seconds. Bezel is also
crenellated. (I live in NYC)

Worth. Every. Penny.


P.S. Every EMT or medic I've known has always had issues with Maglites in the field, whether they were LED or incandescent.

Edited: 28 July 2010, 1:02 a.m.

#80

I've been buying those cheap 3 LED flashlights that have a small NiMH battery inside and a small DC motor/generator for recharging. They certainly aren't rugged, but I don't worry about having dead batteries when I need a flashlight.

I also have had a number of keychain LED flashlights, but many of them would turn on and run their Lithium batteries down when I'd put the keychain in my pocket.


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