# 5mm LED fade testing continued



## JohnR66 (Mar 4, 2010)

Thanks to AT&T discontinuing Web hosting, all the links to my charts will soon be broken.:thumbsdow With new hosting, I will continue the updates to the lumen depreciation tests here.

Nichia GS: After 3000 hrs at 30ma it has dropped to 76% of initial output. The drop started before 1500hrs and has been a steady, almost a linear decline. I expect it to drop below 70% at around 3500hrs.
3-18-10 update: 3384 hrs. The GS seems to have stabilized. Perhaps it is not done just yet. This will be interesting.
4-19-10 update: 4152 hrs. The GS dropped a little. it is now at %72 of initial intensity. It is in danger of dropping out of the test soon.
5-18-10 update: Nichia GS: Output has dropped to below 70%. It lasted 4,800 hrs at 30ma. At 15ma, I'd expect life to be at least 20,000 hr. *Test completed.*

Radio Shack 276-0017 neutral white 30 Deg LED. After 3000hrs at 30ma, there has been a small decline, however it is still at 102% of it's initial brightness. When a decline starts after thousands of hours of steady state output, means it has began its decent into the valley of the dim LED. It is too early to estimate when it will drop to below 70%.
3-18-10 update: 3384hrs. The RS LED also seems to have stabilized (slight brightness increase).
4-19-10 update: 4152hrs. Not much change. Steady as she goes!
5-18-10 update: 4848hrs. This LED shows no quit. Steady state.
6-18-10 update: 5592hrs. Slight drop but still above initial intensity.
8-19-10 : 7080hrs. No change from last measurement.
10-10-10: 8328hrs. No change. LED has been in overdrive for almost one year now. At half current, life is at least 4x, so it would last at least 4 years at 15ma. Since the LED has spent the last 4 months at steady state, I'd venture to guess that it will last 50K hours at normal drive currents.
10-26-11: 17472hrs. LED remains above initial brightness after 2 years. At this point I consider the test over.








Cree 503C-WAS-CBADA151 This part no. specifies a wide brightness and tint, but they all have been about the same brightness and tint (sample of 110 pcs). After 2000hrs, it has been a roller coaster ride of luminance, but at least it has not started to decline. The blue line is an older Cree LED. The newer 503 series is brighter and longer lasting.
3-18-10 update: 2328 hrs. The Cree just wants to get brighter. Interesting.
4-19-10 update: 3096 hrs. Notable drop, but it is back at initial output. Not sure if it is fading or just a momentary dimming. Odd how the LEDs vary over their life. I have seen this oddity in other tests not performed by me.
5-18-10 update: 3792 hrs. Trend seems to show it is now on the decline but still at 92% of initial intensity.
6-18-10 update: 4536 hrs. Falling fast and now at 70.5% of initial output. It is safe to say this LED will drop below 70% in the next couple of days. Interesting fade characteristic as compared to the GS. The GS started loosing intensity just before 1,500 hrs and slowly declined. This Cree gained intensity which peaked around 2500 hours and then started fading at a higher rate.
6-22-10 update: 4632 hrs. As expected, the LED has fallen into the 69% range. The reason for fading seems to be the discoloring (slight darkening) of the epoxy and/or the phosphors above the die. I doubt the die itself lost output. At 15ma, I'd expect the LED to last at least 20K hrs. Like the GS, this is excellent life for a 5mm LED. *Test completed*.







jtr1962 was kind enough to send me some surface mount LEDs for testing. These are tiny, but with masking tape, they are fairly easy to solder onto a perf board (the kind with the ring of copper around the hole).





The Osram LW E6SG PLCC4 (on Left in above photo) has been cooking at 39ma for 1680hrs and has been pretty much steady state. These have a nice near neutral white tint.
3-18-10 update: 2088 hrs. Very slow but steady decline
4-19-10 update: 2855 hrs. Now steady state. For 39ma, this LED has held up well.
5-18-10 update: 3551 hrs. Remains steady state. Amazing LED to handle 39ma so well.
6-18-10 update: 4295 hrs. Seems to be starting to descend.
8-19-10: 5783hrs slight gain in output. So, after falling a bit, it has stabilized.
10-10-10: 7031hrs. Slight drop. Still at 86% initial intensity.
10-26-11: 16175hrs. LED fell to 80% of initial brightness. At 39ma for nearly 2 years and well above 70% of initial brightness, the LED is made for the long haul. At this point, I consider the test over.

The smaller Nichia (not charted yet) is just a bit less bright and cool white. It is testing at 30ma and after nearly 600hrs has not changed
3-18-10 update: 984 hrs. Now added on chart. starting to decline.
4-19-10 update: 1752 hrs. After starting to drop, it has regained steady state output.
5-18-10 update: 2448 hrs. Starting to decline. Now at 80% intensity.
6-18-10 update: 3192 hrs. Dropped below 70% of initial intensity. Not bad for such a tiny LED. *Test completed.*






This is a reminder of how pathetic those cheap ebay/Chinese LEDs are. This one fell below 70% in about 3 whole days at 30ma





I decided to make it easier on the cheapo ebay LEDs. I tested them at 12.5 ma. They lasted about 500 hrs. Hey! that is 3 weeks of use!

I point out this junk because they end up in many products from cheap flashlights, to "shower head" PAR styles lights, landscape lighting and under cabinet lights. A new Menards store opened nearby and some LED lights on display were faded in 1 month!






Coming up: I have some Fox Group 360nm UV LEDs on the way and I started testing some Cree low dome 5mm 110 Deg LEDs.


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## Erasmus (Mar 5, 2010)

Thanks for posting your observations


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## Evilsizer (Mar 6, 2010)

good stuff, done testing on any other LEDS?


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## JohnR66 (Mar 6, 2010)

Evilsizer said:


> good stuff, done testing on any other LEDS?



If you check this LED subforum over the last year and a half, I have tested many LEDs, from 3mm to 4 pin flux style. Most from ebay. Compared to the LEDs above lasting several thousands of hours, they all are junk. Only the flux style LEDs gave a few hundred hours of useful life.

The 1/2 watt multi chip LEDs from ebay were the *worst junk I have ever seen*. Tested at only 70% of max current, one type nearly went dark after only one week.

To put it another way, nothing really interesting to see in those old tests.

I am self employed and business sucks now, so I'm not making any money. I rely on people here to send samples to test. When I do get some extra money, I buy LEDs, like the Crees and the Fox Group UV LEDs.


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## Phaserburn (Mar 6, 2010)

I was in Wally World last night, and saw the Coleman 2AA 5mm leds light. What I hadn't noticed before was that they are using 5 5mm Cree leds (stated on the packaging). I would be interested in getting one of these (around 15 bucks) if I could tell if it was using the old or new Crees. Any way of knowing? I'm hoping for a light reminiscent of the Inova X5 but using 2AAs.


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## JohnR66 (Mar 6, 2010)

Phaserburn said:


> I was in Wally World last night, and saw the Coleman 2AA 5mm leds light. What I hadn't noticed before was that they are using 5 5mm Cree leds (stated on the packaging). I would be interested in getting one of these (around 15 bucks) if I could tell if it was using the old or new Crees. Any way of knowing? I'm hoping for a light reminiscent of the Inova X5 but using 2AAs.



You can tell the type of LED if you can look directly down into it while it is on. Underdrive it so the LED is very dim and safe to look at. All the 15 Deg 503C LEDs I have (110 pcs) have a rectangular blue die that shows through the phosphor. I can say this is true only for the bin I have. Here is what the die looks like. I photographed it through a blue filter to help it stand out. On the OLDER LEDs, the phosphor appears to be too thick to see through.


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## Phaserburn (Mar 6, 2010)

Thanks, I may have to try that out. I wonder what Coleman is driving those 5mm leds at.


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## Dave_H (Mar 7, 2010)

Good of you to do this service JohnR, makes sense that people
who want specific LEDs tested drop a few in an envelope to you,
assuming you can take them all  Would be neat to see a shot of
your test area with all other lights turned off, if indeed you need
any other lighting in that area. 

I don't have immediate application of your results but it sure is
an eye-opener. Anyone doing a retrofit like jtr's fluorescent night-light
would be better not using self-fading LEDs (sort of like self-splitting
pants...).

Any comment on Ledshoppe LEDs...are they in the same category
as eBay?

Incidentally, these are fade tests but do you see any other early
failure modes besides outright dying? Some cheap 5mm devices go
into a rapid flicker mode, before they die, although some temporarily
recover; thermally related, could it be intermittent bond wire
heating/cooling?

Dave


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## JohnR66 (Mar 7, 2010)

Thanks Dave! I have not tested Ledshoppe LEDs. If they are cheap, beware.

All the LEDs I have tested just faded. I didn't see any flicker or go out. I did notice that cheap LEDs tend to be more sensitive to static electricity (ESD). I tested some by zapping them on purpose. Some would flicker or not light after the ESD damage.


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## Evilsizer (Mar 7, 2010)

JohnR66 said:


> Thanks Dave! I have not tested Ledshoppe LEDs. If they are cheap, beware.
> 
> All the LEDs I have tested just faded. I didn't see any flicker or go out. I did notice that cheap LEDs tend to be more sensitive to static electricity (ESD). I tested some by zapping them on purpose. Some would flicker or not light after the ESD damage.


how cheap would be to cheap? i bought a few led's from electricgoldmine site and some where 1.49 and one i got was .99c, the .99c one was a 5mm led, the others cost up where 8mm+.


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## JohnR66 (Mar 8, 2010)

Evilsizer said:


> how cheap would be to cheap? i bought a few led's from electricgoldmine site and some where 1.49 and one i got was .99c, the .99c one was a 5mm led, the others cost up where 8mm+.



$10 for 100 or ~$18 for 50 is what I paid on ebay for 5mm white LEDs. The 50 I paid $18 for were a bit better, but still faded much too quickly.


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## JohnR66 (Mar 10, 2010)

Testing Two Cree C535A-WJN-U0-Wf-29 5mm low dome 110 Deg white LEDs. Continuous drive is 30ma and 39ma. Light meter tested at 20ma (typical for all my tests).

These are neat little LEDs. The short epoxy dome makes them fit into tighter spaces and the wide angle beam makes them great for low power wide angle use. Max rated continuous drive current is 25ma as stated by Cree's datasheet. Since I got so many of them, I tested one at an abusive 39ma. It is fading quite a bit, but you should not take this as a lifetime result. Follow the 30ma curve which shown pretty much steady state.

These LEDs seem to be twice as bright as the Nichia and Osram surface mount LED tested above. This could be due to the true beam angle of these LEDs.

If you were to force me to make a negative comment, the tint bin of "Wf" specifies a really cool white light. At least it is free of blue, violet or green tints of some cheap LEDs.

3-18-10 update: 384 hrs. LED at 30ma is steady state (slight increase), while the LED driven at 39ma has fallen to 1/2 light output and has dropped out of this test. This shows how overdriving a LED can shorten its life dramatically. The overdriven LED started to fade after only a few days. Actually both LEDs are overdriven since the spec sheet give 25ma as max continuous current. I got some of these in a little less cool white Wm bin. Quite nice!
4-19-10 update: 1152 hrs. Slight increase in output. I was concerned of how long the LED was going to last with the other fading at 39ma. At 30ma, which is 5ma over the rated max, these are quality LEDs.
5-18-10 update: 1848 hrs. Very slight decline but still above initial output.
6-18-10 update: 2592 hrs. Gentle decline continues. At 95% of initial output.
8-19-10: 4080hrs. It has fallen to 59.6% of the initial intensity. I estimate that it dropped below 70% at 3,500hrs. At half current, the LED will last at least 14,000hrs. Since the same LED would last only 1/10th as long at 39ma as it did at 30ma, I'd say it probably could exceed 20K hrs at 15ma. Definitely a good LED where you need a low power wide angle light. *Test completed. *









I made a little board using 8 LEDs. Two in series for 4 circuits paralleled and limited by one resistor. Vf seemed close enough and I don't want to waste resistors. 9 volt Vs. Makes a nice little nightlight, if not a bit bright.





I'm not sure if the CPF member wants to be named, but he said that he appreciated my tests and sent me thousands of these LEDs for free. I couldn't believe it! I had to check to be sure he hadn't made a shipping error. I told him I really appreciate what he did for me. I don't have much money, but when I get some extra, I go blow it on LEDs. I guess I'm a LEDaholic of sorts, so this was a great gift from someone I didn't even know.

I have sent many of these LEDs to another member who is going handle giving them away + the cost of shipping to interested CPF members. He will make it known when the LEDs will be available when he is ready. I would become quite overwhelmed if I tried to handle this myself.


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## JohnR66 (Mar 14, 2010)

*Nichia GS vs. Cree*

Has the Nichia GS met its match?

A CPF member (who wishes to remain anonymous) sent me some Cree 5mm white LEDs: C503C-WAN-Cb-Wp-29 which are bighter and are warmer in tint than the Crees I was raving about a few months ago. Here is my review of them vs. the Nichia GS C0w bin.

Relative intensity at .5 meter:
GS: 23.2
Cree: 22.1
The bullet shaped lens of the GS focusses a bit thighter for an edge intensity. This is so close that you would not be able to tell the difference.

Since I don't have an integrating sphere, I filed down the dome of the LEDS so it was flat just above the bond wires. I polished them to be clear again. This normalizes the output so I can compare the light output more accurately. I then tested the LEDs at different currents to see how they compare.






At 20ma they are essentially the same brightness. The GS starts to open a gap at 30 ma and increases from there. So at higher currents, the GS outperforms the Cree.

Here are the beam shots. Cree on left. Same current on both.





Nichia GS advantage:


tight focus with some spill
high brightness
excellent lumen increase at overdrive currents
long life (has not dropped out of test after 3,000hr at 30ma
overall close to neutral white tint of C0w bin
silver plated copper lead frame for best heat dissipation at overdrive currents
Nichia GS disadvantage:


currently not available to some markets (US) by normal means
weird oblong "angry blue" center with yellowish halo
Rather expensive
Cree C503C advantage: (of bin listed above)


brightness on par with the GS
much better beam than GS (slight yellow halo, but no "angry blue" center)
low price for a quality LED and good availability
long life (perhaps will outlive the GS)
Cree C503 disadvantage:


brightness does not increase as much as it does with the GS with overdrive currents
steel lead frame not as good at dissipating heat under overdrive conditions
Conclusion
There is no clear winner here. The LEDs are both high brightness (for 5mm) and have a long life and are not very cool in tint.:thumbsup: The GS has the advantage of being brighter at overdrive currents and that is fine for flashlight use. Unfortunately, Nichia chooses to make them hard to get at reasonable prices in some markets. Some are put off by the blue beam center.

The Cree's pice/performance, availability and cleaner beam put it a notch above the GS for me. It may be different for you depending on your use. Cree's C503D LED should be even better, but I have not tested any yet.


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## JohnR66 (Mar 18, 2010)

All LEDs under test have been updated with latest chart data. I added any comments after "3-18-10 update" entry.

Some interesting things are brewing in these tests.


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## JohnR66 (Mar 29, 2010)

*Nichia GS Vs Cree: Part II*

I now have the brightest bin of the Cree C503C series white LEDs
C503C-WAN-Da-Wn-29 (Da bin is the brightest)
Vs.
GS C0w (brightest bin of GS)

At 20ma the Cree is a hair more intense. The GS overtakes as current increases. In the 20 to 40ma range, they will appear to be the same brightness visually although they have quite different beam profiles. Given the price, availability and better beam characteristics of the Cree, it is the clear winner here. If you are going to push the current above 40ma, the GS is still the LED to beat.

Axis: X=ma, Y=relative intensity





If you're not happy with the angry blue beam of your light with the GS LED, this is the upgrade LED. Tint bins of Wn or better will not be too cool white.

Cree C503D Db bin is even a brighter LED, but I have yet to get my hands on any for testing.


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## jtr1962 (Mar 30, 2010)

*Re: Nichia GS Vs Cree: Part II*



JohnR66 said:


> Cree C503D Db bin is even a brighter LED, but I have yet to get my hands on any for testing.


Db is out? The data sheet I have only goes to Da. If so, then that would be one amazing LED!

One of these days I'll lumens test the Nichia GS you sent me, as well as all the Crees. Just going by your results, it's entirely possible the Cree is 100+ lm/W at 20 mA. I remember the Nichia GS's I tested a while back nearly broke 100 lm/W, but I think the ones you sent are even brighter.


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## JohnR66 (Mar 30, 2010)

*Re: Nichia GS Vs Cree: Part II*



jtr1962 said:


> Db is out? The data sheet I have only goes to Da. If so, then that would be one amazing LED!
> 
> One of these days I'll lumens test the Nichia GS you sent me, as well as all the Crees. Just going by your results, it's entirely possible the Cree is 100+ lm/W at 20 mA. I remember the Nichia GS's I tested a while back nearly broke 100 lm/W, but I think the ones you sent are even brighter.



jtr, According to the 503D datasheet the Db bin is 39,500 to 46,100 mcd
http://www.cree.com/products/pdf/LEDlamps/C503D-WAN.pdf
It should outperform the GS at 30ma and under and probably tie it a 40ma. Given the Cree's better beam, flashlight manufacturers using the GS should take a hard look at these newer Crees (Wm bins or warmer).

I'll send you some of these Da bins I got from you know who. They are quite nice. As for the top bin of the 503D series, I don't know if they are in the wild yet. Not sure why Cree has both the 503C and 503D. Binning seems the same except that the D has the one higher brightness bin.


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## jtr1962 (Mar 30, 2010)

*Re: Nichia GS Vs Cree: Part II*



JohnR66 said:


> jtr, According to the 503D datasheet the Db bin is 39,500 to 46,100 mcd
> http://www.cree.com/products/pdf/LEDlamps/C503D-WAN.pdf
> It should outperform the GS at 30ma and under and probably tie it a 40ma.


I see now-it's 503D, _not_ 503C as I thought. Also, the Db bin might well outperform the GS at _all_ currents, not just lower ones. I noticed a trend looking at your charts where it appears the higher-binned Crees have less droop at higher currents. This isn't unexpected. A more efficient LED will make less heat. Droop is partially related to die temperature. A cooler die obviously means less droop.



> I'll send you some of these Da bins I got from you know who. They are quite nice. As for the top bin of the 503D series, I don't know if they are in the wild yet. Not sure why Cree has both the 503C and 503D. Binning seems the same except that the D has the one higher brightness bin.


Thanks! As I said, when I get a free day I'll be lumens testing everything you sent me. I wouldn't be surprised if the Da bin finally breaks the 100 lm/W barrier for small LEDs. Power LEDs surpassed that a while back, but I"ve yet to test indicator-type LEDs which manage 100 lm/W or more at rated current.


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## coors (Apr 9, 2010)

I just became interested in the 5mm LEDs, recently. Found this thread today and I must say thanks a whole lot, for all of your time in sharing this information. I suspect that you're also the guy on Youtube that has some 5mm comparison reviews. Just yesterday I purchased the RadioShack 2-pack of #276-0017 5mm LEDs, that were so highly touted in the Youtube review. I put one in a Chinese clone of the PT EOS headlamp, replacing the red 5mm LED, which was driven at 20ma:






This Radioshack LED's neutral tint is really nice, in my opinion. For reading a book, it's 7000mcd and 30degree angle of output is just "perfect". However, walking around outdoors last night, I found myself wanting a little more output/flux. I could see fine to navigate but there was a notable lack of detail in the topography. 
I've searched for the C503D-WAN and found them listed on Cutter's site: http://www.cutter.com.au/proddetail.php?prod=cut926 . However, it looks to me as if you can end up with a tint ranging anywhere from 4600k-15000k. Is there no way to buy these Cree 5mm LEDs at a more specific temperture bin than this? I did order some of the Cree C503C-WANs, from Digi-Key, but again there was no way to order a specific tint. Is this why some folks order large amounts of the 5mm LEDs, so that they can sort through them to find the desirable tint?


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## JohnR66 (Apr 12, 2010)

coors said:


> I just became interested in the 5mm LEDs, recently. Found this thread today and I must say thanks a whole lot, for all of your time in sharing this information. I suspect that you're also the guy on Youtube that has some 5mm comparison reviews. Just yesterday I purchased the RadioShack 2-pack of #276-0017 5mm LEDs, that were so highly touted in the Youtube review. I put one in a Chinese clone of the PT EOS headlamp, replacing the red 5mm LED, which was driven at 20ma:
> 
> This Radioshack LED's neutral tint is really nice, in my opinion. For reading a book, it's 7000mcd and 30degree angle of output is just "perfect". However, walking around outdoors last night, I found myself wanting a little more output/flux. I could see fine to navigate but there was a notable lack of detail in the topography.
> I've searched for the C503D-WAN and found them listed on Cutter's site: http://www.cutter.com.au/proddetail.php?prod=cut926 . However, it looks to me as if you can end up with a tint ranging anywhere from 4600k-15000k. Is there no way to buy these Cree 5mm LEDs at a more specific temperture bin than this? I did order some of the Cree C503C-WANs, from Digi-Key, but again there was no way to order a specific tint. Is this why some folks order large amounts of the 5mm LEDs, so that they can sort through them to find the desirable tint?



Sorry to be slow. I have not been around lately... When replacing the red with white, remember the forward voltage (Vf) of the white is much higher and can result in very low drive current depending on the driver of that light. The RS led has a lovely color temp, but it does not match Cree and Nichia GS led in overall output, plus it's wider beam means low intensity.

The highest bins will probably be cooler as warmer tints tend to be less bright. I looked at cutter's C503D and the best bins range from 28 to 46 cd so it is kind of a crap shoot of what you will end up with, although these are quite bright.

I have C503C-WAN-Cb-Wp-29 (28.2-32.9 cd) warmer bin of cool white.
Also, C503C-WAN-Da-Wn-29 (32.9-39.5 cd) cooler but brighter.
Either way, your within Cutter's brightness range offering.
Also, Nichia GS C0w bin brightest and warmest of cool white bins

I can send some to you some for free (+$2 for shipping). PM me.


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## coors (Apr 12, 2010)

Thank you for your reply. Yes, you're right, the forward current is now 10ma since putting the Radioshack LED in the light. The current limiting resistor seems to be 470ohms for the 5mm LED's seperate circuit:







Also, the voltage in that circuit is 2.94 volts (3.98v at the battery with the load of the #276-0017 LED and the 470ohm resistor). The packaging for the RS LED states a forward voltage of 3.3v-3.6v (max) and a forward current of 25ma. Is that enough information for me to be able to choose a proper resistor for this or another 5mm LED with similar vf ? Is there some kind of online calculator for this kind of thing ? I'd like to end up with a forward current of 20ma. 
Thanks for the LED offer. Sure, I'd be glad to get some 5mm LEDs to experiment with. Will send a PM.


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## JohnR66 (Apr 12, 2010)

Is this a 3 cell light with run cells run down? 4 volts seems odd. I would test with new cells.

That appears to be a 47 Ohm resistor. The right most number is the multiplier and at 0 means add no zero to the two numbers, or multiply by 1. (if it were a 1, it would be a 10 multiplier (add one zero) meaning 470 ohms)

Sounds like there is another voltage drop somewhere (driver transistor, perhaps?) because at 10ma, the voltage across the LED and resistor would be around 3.5 volts. If this were the case, the LED could work with no resistor. If the voltage is 4 volts (LED+R) with new batteries, and LED is 3.5 volt at 30ma, a 16.7 ohm resistor can be used (15 ohm closest). This LED has lasted 3,500 hours in my test at 30ma and is still going, so it is okay to drive at 30ma.


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## coors (Apr 12, 2010)

JohnR66 said:


> Is this a 3 cell light with run cells run down? 4 volts seems odd. I would test with new cells.


This is a 3-cell, but I'm using Eneloops in it. They are fresh off the charger.



> That appears to be a 47 Ohm resistor. The right most number is the multiplier and at 0 means add no zero to the two numbers, or multiply by 1. (if it were a 1, it would be a 10 multiplier (add one zero) meaning 470 ohms)


Thanks, for the correction! Yes, this is a brand-new new facet of flashlights for me (electronic component speak).



> Sounds like there is another voltage drop somewhere (driver transistor, perhaps?) because at 10ma, the voltage across the LED and resistor would be around 3.5 volts. If this were the case, the LED could work with no resistor. If the voltage is 4 volts (LED+R) with new batteries, and LED is 3.5 volt at 30ma, a 16.7 ohm resistor can be used (15 ohm closest). This LED has lasted 3,500 hours in my test at 30ma and is still going, so it is okay to drive at 30ma.


Thanks, for calculating the required resistor for me! If I happen to find a 15 ohm (marked 150) resistor on a board in my saved junk electronics box, should I scavenge it to use or should I use a brand new resistor ?
Thank you, very much, for your help with this project of mine!


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## JohnR66 (Apr 12, 2010)

You can piggy back a 22 Ohm resistor with the one in the circuit (parallel) or remove the 47 and put in a 15 ohm. Whatever works for you.

Glad to help, John


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## coors (Apr 13, 2010)

John,
I found a 15 ohm smd-type resistor on a discarded mother board and exchanged it for the 47 ohm resistor, even though I ordered some new ones from Digi-Key last night. This one has "15R0" printed on it. It tested 15 ohms resistance and with the RadioShack LED allows 27ma forward current in the circuit:






The brightness is much improved, now! Thank you, once again, for taking the time to steer me in the right direction.


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## coors (Apr 17, 2010)

John,
I found these http://tinyurl.com/y8x6vkt on eBay and if they are legit, then these would be ideal for my own purpose. They seem to be very overbuilt/robust, so they may actually emit 60,000-70,000mcd @ 100ma. If so, any idea what the output at lower current values, like 30ma, would be like?


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## Evilsizer (Apr 18, 2010)

not sure if john would agree but IMO this is better quality LED then those ebay ones.
http://www.goldmine-elec-products.com/prodinfo.asp?number=G17255
its 8mm vs 5mm but i haven't found 5mm LED's that are claimed to be that bright (per the ebay link). talking about what i was told is old LED tech compared to Cree/luxeon. With the 8mm one you could sand a bit off of the sides to make it 5mm.
this might be more up your ally since its 5mm and be brighter then what you have now.
http://www.goldmine-elec-products.com/prodinfo.asp?number=G16402


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## Dave_H (Apr 18, 2010)

coors said:


> John,
> I found these http://tinyurl.com/y8x6vkt on eBay and if they are legit, then these would be ideal for my own purpose. They seem to be very overbuilt/robust, so they may actually emit 60,000-70,000mcd @ 100ma. If so, any idea what the output at lower current values, like 30ma, would be like?


 
You have to be careful with specs....these give Absolute Maximum
of 100mA, which would be closer to 0.35W, not 0.5W as advertised.
And this is at 25C which is not realistic for even low-end power
LEDs, especially if the ambient is (say) 30C. Regardless, these may
be good at lower currents.

Don't believe the 100,000 hour lifetime. That's almost 11.5 years
of continuous use.

Dave


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## Dave_H (Apr 18, 2010)

Evilsizer said:


> this might be more up your ally since its 5mm and be brighter then what you have now.
> http://www.goldmine-elec-products.com/prodinfo.asp?number=G16402


 
Not sure what's the difference (except price) between these, and
ones Ledshoppe sells for $0.08 each in qty 100's. With this pricing
and spec'ing, they are mostly suspect (note the common 100k hour
life claims).

Dave


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## Evilsizer (Apr 18, 2010)

Dave_H said:


> Not sure what's the difference (except price) between these, and
> ones Ledshoppe sells for $0.08 each in qty 100's. With this pricing
> and spec'ing, they are mostly suspect (note the common 100k hour
> life claims).
> ...


well on some of Gold mines pages they claim to use high-end or quality brand LED's. such as liteon to name one, i would assume the cheaper China leds wouldnt last as long as say the one i linked to. though i dunno since i dont have a cheap china made one of about same specs to compare to the 10mm 256k MCD led i linked to. 

honestly i really dont know how much of a difference there is between the two. one may use higher quality material for it to last longer then the cheaper china made ones. i say someone on here say if you can get 50 for 15 or 100 for $30-$50 for LED's, then they are the cheap LEDs to be avoided. that is though why i said if john would agree, guess you can say i respect he opinion for the short time i have been here. im sure there are others i would as well. just haven't looked deep enough in this forum yet.


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## JohnR66 (Apr 18, 2010)

Sorry guys, my experience with those ebay multi chip LEDs are worse than with the 5mm ones. Some so called .5 watt ones nearly went dark after a week of testing at much LESS than 140 ma rated current. The phosphor/epoxy above the dies had actually turned dark!:laughing:

Heat is going to be a problem with these indicator style multi chip LEDs. If you need more light, go with good quality 5mm LEDs in a group or go with power LEDs.

I can't comment on the LEDs I haven't tested. Given the performance of the new Crees and how long they last at such a low price, my money is with them.


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## JohnR66 (Apr 19, 2010)

It has been about a month since last update. LEDs metered, graphs updated and comments made.

*If anyone has LEDs that they would like to be life tested and can donate a couple, PM me. I would like to test the following:*
3 and 5mm LEDs from manufacturers other than Cree and Nichia
non white ebay LEDs (is it just the phosphors they use that suck?)
Medium power LEDs and flux style.
XP-G and other 1000ma LEDs (tested at 1500ma)
Thanks!


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## coors (Apr 19, 2010)

I have 10x of these enroute: http://tinyurl.com/yynchmj If you'd like, I can send you a couple. PM me, if interested.


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## JohnR66 (Apr 20, 2010)

coors said:


> I have 10x of these enroute: http://tinyurl.com/yynchmj If you'd like, I can send you a couple. PM me, if interested.



Coors,
Sure, I would like to test them. They are likely reselling the cheap Chinese stuff, but you never know.
Thanks, John


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## JohnR66 (May 4, 2010)

*Warm white ebay LED tested.*

Special thanks to CPF member Coors for providing some for testing.

These are sold here: *http://tinyurl.com/yynchmj *and are advertised as a "Warm soft white LED" 16,000mcd. My meter reading indicates that they are pretty accurately rated (by converting frequency output to millicandelas by using a multiplier). Beam is pretty narrow, ~15 Deg.

Calling them warm white is a little inaccurate. As you can see here, next to a true warm white LED, the subject LED (left) is quite yellow. It is strong in the green-yellow-orange part of the spectrum and weak in the red and blue. To me, it looks pastel yellow (or **** yellow if you prefer). All three samples I received were like this.







The "Fade Test" at 30ma reveals something interesting. It is lasting longer than all of those "55,000 mcd super bright" cool white ebay LEDs I tested, but after only a week it appears to be in decline. Unless it stabilizes, it can drop out of the test too soon to be considered a long life 5mm LED.

Update 5-10-10: LED has dropped below 70% of initial light output. Life at 30ma is 265 hours. Life at 15ma would be estimated at around 1,000hr. This LED is suitable for battery applications as long as current is kept below 20 - 25 ma. It is not recommended for continuous duty use. Test completed on this LED.





Summary:


Bright for a "warm white" led, accurate intensity stated.
More yellowish white tint than true warm white.
Okay life for battery use at 25ma or less
Not recommended for continuous use given the short life.


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## coors (May 5, 2010)

John,
Thank you for the update. That's too bad that these are fading so quickly, as I've really been enjoying the tint from these. I can see more details in the foliage, etc. outdoors at night, with these ones. I can verify the yellow color in your image is accurate, as I have Firefox color management enabled and holding the light that I'm using one of these in, shone on a white wall from 10" or closer is exactly what your image shows. However, when getting out past 10" I'm getting a more neutral tint, with no discernrible yellow. Here's the headlamp that I'm using this LED in:






Here's the main LED (neutral K2-TFFC) beamshot, which I just took (from 5', daylight white balance):






and here's the warm white 5mm, which you're testing (from 5', daylight white balance):


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## JohnR66 (May 6, 2010)

Coors, it may be that the LED generates so much light in the yellow green band that it works great for night vision. What drive current are you using with this one? If you run it at 20ma, it might well last over 500hrs. Unless you are a heavy user, it could take years to rack up those hours on a battery powered light.

Walking by my test setup this morning, the LED looked dim. It could be my eyes. I'll have to check it tonight to see where its at. If it has fallen below 70%, I'll leave an update in the thread.


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## JohnR66 (May 10, 2010)

Test update on WW "ebay" LED. Test complete. Chart updated. See review above.


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## JohnR66 (May 18, 2010)

5-18-10 test updates. Graphs have been updated and notes added.

Most notable, the Nichia GS has dropped below 70% of initial output at 4800 hours with a 30ma drive. Test has concluded on this LED. A moment of silence for GS :mecry:


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## 2009Prius (May 19, 2010)

Great thread with very helpful info! Thank you so much!


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## jtr1962 (May 19, 2010)

I continue to be amazed at how well the Osram LW E6SG is doing. At 39 mA it should be cooking but it's holding steady. Given this kind of performance at 39 mA, I can only imagine how long they'll last at the 20 mA I'm driving them at. Some nightlights I modded with these LEDs are now up to 8000 hours with no signs of dimming.


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## JohnR66 (May 19, 2010)

Hey jtr, haven't seen you around much lately.
I suspect they'll do 40K -50K hours at 20ma as long as they don't get too warm from clustering several together. IIRC, you had them in a series string with some space, so they are probably good for a few tens of thousand hours.


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## jtr1962 (May 19, 2010)

JohnR66 said:


> Hey jtr, haven't seen you around much lately.


Quite busy actually lately. A lot projects to do around the house, and also I'm getting back into cycling and my other great hobby, trains. I still check out this place almost every day, but don't post as much as I used to.



> I suspect they'll do 40K -50K hours at 20ma as long as they don't get too warm from clustering several together. IIRC, you had them in a series string with some space, so they are probably good for a few tens of thousand hours.


Yes, that sounds about right to me. I'll let you know in about 5 or 6 years.


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## JohnR66 (May 24, 2010)

Deal Extreme white LEDs tested!

Special thanks to new CPF member "2009Prius" for sending me some DX LEDs for testing.

DX 5mm white LED sku 1106. 2009Prius noted that the older LEDs he got from DX were brighter than the newer ones. He sent me samples of both. The brightest was 20 cd (not bad) and the dimmest 14 cd (not so good). Image below shows a Cree 5mm 24 cd (Wk tint bin) 15 Deg on the left vs the 20 cd DX on the right. All the DX LEDs are very cool white with blue/slight violet look to the eye. Beam is consistent.







Next LED is the DX 10.5mm white LED sku 3190. This LED has a bullet shaped epoxy lens that focusses the beam to a tight circle. You can kind of see the bond wires in the beam. Because of this tight focus, it is very intense. One scored a 62 cd, the other was 54.3 cd. Yes, this more intense than the Nichia GS or Crees. It is NOT making more light, just the tight focus with little spill cause this. They are cool white, but not as blue as the 5mm DX LED.





These LEDs are now in "fade" testing to see how long they will last. My recommendation pends the outcome. However, I can conclude that 5mm are nothing special since it is outdone by a Cree that is not even near the top brightness bin and are very cool white. Note: meter readings made @ 20ma drive.

Update 5-30-10: The 10.5mm LED has faded to 58% of initial output after only 6 days (144hr). Given this performance, I cannot give any recommendation for this product. It is garbage. The 5mm LED is also fading. It is at 88%, which is better than the ebay LEDs I tested before, but far inferior to the quality LEDs I tested that are lasting thousands of hours.

Update 6-2-10: The 5mm DX LED has faded to 69.9% of initial output after 192 hours at 30ma. Seems to be a bit more purplish tinted now. It lasted longer than the cheap ebay LEDs did, but lasting only a week is not going to get it any recommendations from me.


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## JohnR66 (May 30, 2010)

Update to DX LEDs posted. They are just more of the same cheap rubbish.


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## JohnR66 (Jun 2, 2010)

If anyone is still following this, the DX 5mm LED has dropped below 70% and is out of the test. More rubbish...


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## csshih (Jun 2, 2010)

thank you for the testing, John. :thumbsup:


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## TorchBoy (Jun 2, 2010)

Sure am still following it. No graph for the DX LED? Would you mind another test at, say, 10 mA? You imply it could make a big difference:



JohnR66 said:


> 5-18-10 update: Nichia GS: Output has dropped to below 70%. It lasted 4,800hrs at 30ma. At 15ma, I'd expect life to be at least 20,000hr. Test complete.



These fade rates remind me of the promises that came with CDs, that they could be run over by a truck and still work fine. We later found that even a tiny longitudinal scratch (as opposed to a radial one) could make a track unreadable. What happened to the 50,000 - 100,000 hours that's so often claimed for LEDs?


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## TorchBoy (Jun 3, 2010)

Does PWM affect fade?


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## JohnR66 (Jun 3, 2010)

TorchBoy said:


> Sure am still following it. No graph for the DX LED? Would you mind another test at, say, 10 mA? You imply it could make a big difference:
> 
> 
> 
> These fade rates remind me of the promises that came with CDs, that they could be run over by a truck and still work fine. We later found that even a tiny longitudinal scratch (as opposed to a radial one) could make a track unreadable. What happened to the 50,000 - 100,000 hours that's so often claimed for LEDs?



I didn't bother graphing them because they turned out to be an uninteresting product. Halving the current will quadruple the life. Not an exact or scientific study, but my testing of the ebay LEDs at lower current shows much improved life. One lasted 3 days at 30ma and around 20 days at 12.5ma (it could have been too far overdriven at 30ma though). I'd expect 6x or more life at 10ma for the DX LED.

The lifetime claims are useless without defining test parameters.
100,000 hrs at what amount of light output? At what current? and so on.

Life on a PWM would depend on RMS current. As long as there isn't an insane crest factor, I'd expect the LED to last the same as steady state current at a given drive current.


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## 2009Prius (Jun 5, 2010)

JohnR66 said:


> If anyone is still following this, the DX 5mm LED has dropped below 70% and is out of the test. More rubbish...



Sure I am following with enthusiasm.  I try not to post too many simple "thanks" posts that tend to dilute the information density, especially for this great thread. 

I do have graphs of some DX LED measurement curves if anyone is interested. I don't have a light meter or any fancy instruments, just some crude home made stuff. I run 3 LEDs at a time and when I do measurements I temporarily unplug the current limiting resistors:




The power comes from a small AC to DC brick adapter and through a linear voltage regulator.

The LED output is measured with a simple photodiode with reverse voltage 5.35V (doesn't seem matter much at the current level I am dealing with), sense resistor is 22K ohms, and about 15 + 1/8 inch from the LEDs:




The reverse voltage comes from batteries, also through a voltage regulator. The green index card provide a background to center the LED light spot onto the photodiode. Then I gently move the LED around to try to read the maximum photocurrent via the sense resistor.

If you think this crude setup is still worth something then read on. Here is the data I have so far:





Before I found this forum I saw DX overdriving their keyring flashlights and thought I could do the same with the DX 5 mm LEDs. As you can see I soon discovered 60 mA is no no and even 40 mA is too much. Then I pulled out the LED from the flashlight hoping it would be somehow more robust. I was wrong of course. The DX 5 mm LED degrades even at 17 mA. I am still following it just out of curiosity - would it go all the way to zero? I also bought two pieces of wide brightness bin Cree 5 mm LED from Digikey (the only kind that is available from them) and put one of them to test at 27 mA. So far it's holding up. At 15 inch the beam profile looks much less regular than the round shape of the DX LED beam. At first I was excited with the higher photocurrent reading but then I realized the photodiode is less sensitive in the blue (DX LED tint) than in the green (Cree tint) so I won't read too much into it.


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## JohnR66 (Jun 7, 2010)

Nice work Prius. I think you found the same as I did. Cheap LEDs fade fast. I think any 5mm LED will not last too long at 60ma though. good LEDs will last thousands of hours at 30ma and tens of thousands of hours at 20 ma or less. 40ma and more the LED can start succumbing to the heat quickly.

From my findings I have come up with a recommended max drive currents for low power (5mm) LEDs, 30 Deg Ambient, single device:

Long duty (1 - 10 hours a day): 30ma
Extreme duty (10 - 24 hours a day): 15 - 20 ma

Flashlight duty: LED should be checked at flashlight's designed operating current to see how long it lasts. because a LED that lasts thousands of hours at 30ma may fade quickly at 40ma (look what happened to the low dome cree I tested above as a good example).

De-rate for high temperatures or clusters.


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## JohnR66 (Jun 19, 2010)

Another month down! Charts updated and notes added. Another LED dropped out of the test and still another one will shortly.

The test LEDs are operating in an upstairs room that gets hot in the summer. I don't have the room for them elsewhere. Over the last month it has climbed into the upper 90s in there on sunny days. While not the ideal situation for testing, it might be a better real world situation. LEDs tested over the summer months may show somewhat reduced life.

Minor update, 6-22-10: The Cree 5mm white dropped below 70% and is out of the test


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## saabluster (Jul 2, 2010)

John I have been lurking in your thread for a while now I should have said it already but excellent work! I have some Nichia Raijin superflux if you'd like to test them. I have fallen in love with these things. Just PM me and I'll drop some in the mail for you if you'd like.


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## JohnR66 (Jul 2, 2010)

saabluster said:


> John I have been lurking in your thread for a while now I should have said it already but excellent work! I have some Nichia Raijin superflux if you'd like to test them. I have fallen in love with these things. Just PM me and I'll drop some in the mail for you if you'd like.



Thanks Saabluster :thumbsup:
With all the tests concluding, I have only three LEDs still running. I could use new LEDs to test.
PM sent


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## Nil Einne (Jul 4, 2010)

Excellent work! Interesting to see how fast many actually fade.


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## JohnR66 (Aug 19, 2010)

More updates to the tests...
I stopped updating unless something interesting happened. It has been two months. Well, another LED has dropped out of the test. See the earlier threads in this post for the updates.

My test bench is in sort of a semi finished attic space. With the high temps we have had all summer long, it has been reaching 100 degrees in the attic with the hottest day at 105 Deg F so far. The little LEDs have been taking some extra abuse from this heat. While even temps would be ideal, this will more represent real world use of the LEDs. I don't have any space for this downstairs.

Saabluster finally got some Nichia Raijin flux LEDs to me. I started them testing and will put up a review at some point. One thing is for sure. For a low power LED, these little *******s are bright!


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## ama230 (Aug 19, 2010)

cant wait!!!


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## saabluster (Aug 20, 2010)

JohnR66 said:


> More updates to the tests...
> Saabluster finally got some Nichia Raijin flux LEDs to me. I started them testing and will put up a review at some point. One thing is for sure. For a low power LED, these little *******s are bright!


 Glad to see them getting to step up to the plate. Yeah they are some pretty special LEDs. It is amazing how much abuse they can take. With my special heatsink I could run them happily at about 6 times their rated max current! Of course I'm sure the epoxy would give way in short order at that level but there was no angry blue or dipping in output. They even have higher surface brightness than the XP-E R3 until a little over 100mA. Can't wait to see the results.


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## JohnR66 (Oct 11, 2010)

I have updated the charts and comments for the RS and Osram LEDs. These LEDs were definitely made for the long haul. I (we?) really need to find out where RS is getting them from.

I am also testing some 3,500K warm white 3mm and 5mm (5mm is inverse cone) LEDs. If they turn out not to be junk, I'll post more information as they could be a good source for WW LEDs for under 20 cents a piece.


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## doctaq (Oct 11, 2010)

john, would you be interested in testing some cheapo chinese 3w leds?i am getting an order in of reds and warm whites, probably take a month to get here


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## JohnR66 (Oct 11, 2010)

doctaq said:


> john, would you be interested in testing some cheapo chinese 3w leds?i am getting an order in of reds and warm whites, probably take a month to get here



Hi,
Yes I can test them. I wonder how these Chinese power LEDs stack up. The smaller ones sure don't. :shakehead


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## doctaq (Oct 12, 2010)

ive been using an older batch for about a month now, although driving to about 300ma, i guess they beat 5mm so far


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## doctaq (Oct 17, 2010)

leds are in, send me a pm as to what to do now, including shipping and packing, i dont have any padded envelopes on hand


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## JohnR66 (Oct 26, 2011)

*Re: 5mm LED fade testing wrap-up*

Here are the final results of some LEDs I've been "fade testing" for a couple years:

Radio Shack 276-0017 (sometimes shown as 276-017). After TWO YEARS of continuous testing at 30ma, the LED has not faded below initial brightness. Amazing for a 5mm LED. I am 99% sure these are made by Everlight 334 series 5mm LEDs. I also found that the LED contains an ESD zener diode protector.

Osram surface mount LED. It has been under test for about 23 months. It has dropped to 80% of initial output. Considering it has been driven at 39ma with little heatsinking, it too is a quality product. The graphs have been updated in the OP.

Cree CLM3C series: These are low power "grain of rice" sized surface mount LEDs with excellent brightness (twice the intensity of the Osram LED above at the same current). I started testing it in July and 3.5 months later it is still above initial brightness. There are no graphs for this one.

I have decided to end the testing on these LEDs. Who knows how long the RS and Osram LEDs will continue before dropping below 70% of initial intensity.

I have tested some ebay LEDs and other cheapo white 5mm LEDs to see if they are improving any since my initial fade tests of three or 4 years ago. The answer is NO! They still have overblown specs and some faded below 70% of initial brightness in less than 1 week. junk remains to be junk. :shakehead

Thanks for following my fade tests on low power LEDs!:thumbsup:


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## jtr1962 (Oct 27, 2011)

Thanks for the updates. I was wondered just the other day how the Osram LED is fairing. Those are pretty amazing results. That explains why the nightlights I modded with 25 of those LEDs each nearly 21 months ago are still going strong ( and they're on most of the time because we often forget to turn them off). Based on your data, it certainly looks like 100,000+ hours to 70% when driven at 20 mA is possible.


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