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Thread: Has any here hit the 50,000 hour led life span?

  1. #1

    Default Has any here hit the 50,000 hour led life span?

    Id like to see if reaching that number before you buy another light due to better technology or what ever the case may be is likely.

  2. #2

    Default Re: Has any here hit the 50,000 hour led life span?

    Quote Originally Posted by Rasto36620 View Post
    Has any here hit the 50,000 hour led life span?
    no

  3. #3
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    Default Re: Has any here hit the 50,000 hour led life span?

    Rasto36620,

    The only thing that's really going to blow the newer LED's is the incorrect use of batteries not suitable for a particular lights voltage. Otherwise general day to day every day carry usage (Not weapon recoil for some lights) and proper battery application will provide you an LED light for a long time to use for 10-20 years if not more=)

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    Flashaholic* AnAppleSnail's Avatar
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    Default Re: Has any here hit the 50,000 hour led life span?

    Quote Originally Posted by Rasto36620 View Post
    Id like to see if reaching that number before you buy another light due to better technology or what ever the case may be is likely.
    It seems unlikely. 2000 consecutive 24-hour days of use, or 5.7 years solid. At rated current. Most people are not interested in such tests. And that isn't the life-span. LEDs are rated to 70% brightness loss. So at (xthousand) hours the LED is 30% dimmer.
    My biggest light-hog is my camera.

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    Flashaholic* PhotonBoy's Avatar
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    Default Re: Has any here hit the 50,000 hour led life span?

    I think that white LEDs are rated for 50,000 hours down to 50% brightness. They should continue to work after that time, but at still ever decreasing brightness. So at 100,000 hours, you're looking at 25% brightness.

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    Default Re: Has any here hit the 50,000 hour led life span?

    I worry about how many on/off cycles clicky switches will take.

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    Flashaholic* PhotonBoy's Avatar
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    Default Re: Has any here hit the 50,000 hour led life span?

    Yeah, the light will likely die of mechanical failure, or you'll lose it, or most likely, you just want to give it away and get something newer, trendier, brighter, etc. An LED failure is probably last on the list of problems that will do your light in.

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    Flashaholic* AnAppleSnail's Avatar
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    Default Re: Has any here hit the 50,000 hour led life span?

    Quote Originally Posted by edpmis02 View Post
    I worry about how many on/off cycles clicky switches will take.
    The clicky is probably the first flashlight part that will fail (Not counting the battery), but I don't know of a good standardized test that has been done to compare failure rates of the systems in a light. Arguing from first principles and barring unusual events, you'll lose:

    Clicky switch
    O-rings
    Contact points
    Capacitors
    Solder joints

    Long before the LED dims from age.
    My biggest light-hog is my camera.

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    Default Re: Has any here hit the 50,000 hour led life span?

    The LEDs in a few of my Inova X5 flashlights failed within a month or so. I suspect that the 55-lumen rating implies that they were being overdriven. The replacement version X5 was rated for a maximum of 31 lumens.

    I have had several LED night lights which grew dim in less than 2 years use.
    Retired engineer, author. Running Linux.

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    Default Re: Has any here hit the 50,000 hour led life span?

    Quote Originally Posted by PhotonBoy View Post
    I think that white LEDs are rated for 50,000 hours down to 50% brightness. They should continue to work after that time, but at still ever decreasing brightness. So at 100,000 hours, you're looking at 25% brightness.
    I wonder what the CREE XML's lumen deterioration rating is after just 1,000 hours. These LED's are being driven pretty hard in many of these lights with questionable heat sinking compared to what they using in the lab.

  11. #11

    Default Re: Has any here hit the 50,000 hour led life span?

    Hold on a little longer, I'm working on it as fast as I can....


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    Moderator Kestrel's Avatar
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    Default Re: Has any here hit the 50,000 hour led life span?

    Some of the older hands here might recall reports of the LuxV exhibiting a visible decrease in brightness after as little as 500 hours of use. Apparently those were driven hard enough to get HOT in some lights.

    Edit: And if anyone expects 50,000 hours of runtime from LEDs at 'CPF' drive levels, I have a 500,000 hours MTBF (i.e. 57 years) hard drive to sell them.
    Last edited by Kestrel; 04-13-2012 at 11:53 AM.
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    Default Re: Has any here hit the 50,000 hour led life span?

    50,000 hours = 5.7 years continuous under-driven lifetime ?

    -someone- has done this...speak up !!!
    posted by jh333233
    Dont cheat me, im expert in using crap light

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    Flashaholic* CarpentryHero's Avatar
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    Default Re: Has any here hit the 50,000 hour led life span?

    I get bored or my flashlights as soon as a new emitter shows lol.
    The only led that gets around the clock use is the glow mode on my PALight and I've only had them a month
    Sorry I'm not more help
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  15. #15

    Default Re: Has any here hit the 50,000 hour led life span?

    Quote Originally Posted by Kestrel View Post
    Some of the older hands here might recall reports of the LuxV exhibiting a visible decrease in brightness after as little as 500 hours of use. Apparently those were driven hard enough to get HOT in some lights.

    Edit: And if anyone expects 50,000 hours of runtime from LEDs at 'CPF' drive levels, I have a 500,000 hours MTBF (i.e. 57 years) hard drive to sell them.
    Those 500,000 MTBF hard drives are amazing too, the sales department for the Brooklyn Bridge used them exclusively.

  16. #16

    Default Re: Has any here hit the 50,000 hour led life span?

    In later years after the led house lighting is old news we'll have more examples of 50,000+ hr led performance... As much as I run my H51Fc at low and medium I'm more concerned with the 200,000 cycle rating on the switch. Also, I imagine that under driven leds will go much further than 50,000 hrs before 30 percent decline, surely it has more to do w temp and quantities of electrons and less to do w time.
    The brighter the light, the darker the shadow.

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    Default

    A member here ran his SC60w for like 6 months straight. He had 5000 hours I think. I don't think it was a full brightness, but it's still a lot of use.

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    *Flashaholic* StarHalo's Avatar
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    Default Re: Has any here hit the 50,000 hour led life span?

    I have a set of Ikea Dioder light strips (which use power LEDs) that currently have just over 8,000 hours of runtime on them; no issues thus far. I also have ten cheapie Feit LED night lights which use 5mm LEDs and have run somewhere over 15,000 hours, no change in those either.

  19. #19

    Default Re: Has any here hit the 50,000 hour led life span?

    I want to see some solid numbers too, not extrapolated crap number guessing. As mentioned before hard drives have 0.5-1 million hours MTBF, are we expecting a 1 million hours life? ofcourse not.

    I never liked the idea of making the led module not replaceable.

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    Default Re: Has any here hit the 50,000 hour led life span?

    Quote Originally Posted by entercpf View Post

    I never liked the idea of making the led module not replaceable.
    For upgrades, sure; but not for the LED running out under normal use.
    My biggest light-hog is my camera.

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    Default Re: Has any here hit the 50,000 hour led life span?

    How long is 50,000 hours?

    There are 8,760 hours in a year, so here's what 50,000 hours works out to be, depending on lamp hours of operation.

    Hours of Operation:

    24 hours a day 5.7 years
    18 hours per day 7.6 years
    12 hours per day 11.4 years
    8 hours per day 17.1 years

    Why is the life span of an LED measured as lumen depreciation?

    The life span of an LED is vastly longer than that of incandescent, fluorescent or HID lamp sources, generally lasting 50,000 hours or longer. Although the LED never really burns out, product life span is measured by lumen depreciation.

    The Illuminating Engineering Society's (IES) current standard for calculating the life of an LED as the point at which the LED reaches 30 percent lumen depreciation.

    Remember, a 100,000-hour rating is not equivalent to lamp life rating. LED life is rated where it has reached 30 percent lumen depreciation. At 100,000 hours an LED would still be operating, but at a decreased lumen output.

    What is junction temperature?

    Junction temperature is the temperature at the point where an individual diode connects to its base. Maintaining a low junction temperature increases output and slows LED lumen depreciation. Maintaining a low junction temperature is critical for evaluating an LED product's quality and ability to deliver long life.

    What can affect the LED junction temperature?

    There are three things which can affect the junction temperature of LED’s: drive current, thermal path and ambient temperature. In general, the higher the drive current, the greater the heat generated at the junction. Heat must be moved away from the junction in order to maintain expected light output, lifespan and color. The amount of heat that can be removed depends upon the ambient temperature and the design of the thermal path from the junction to the surroundings. Typically the junction temperature should be maintained below 120°C.

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    Default Re: Has any here hit the 50,000 hour led life span?



    Lumen depreciation in LEDs varies depending on package and system design. The primary cause of lumen depreciation is heat generated at the LED junction. LEDs do not emit heat as infrared radiation (IR) like other light sources, so the heat must be removed from the device by conduction or convection. If the LED system design has inadequate heat sinking or other means of removing the heat, the device temperature will rise, resulting in lower light output. Clouding of the epoxy encapsulant used to cover some LED chips also results in decreased lumens making it out of the device. Newer high-power LED devices use silicone as an encapsulant, which prevents this problem. LEDs continue to operate even after their light output has decreased to very low levels. This becomes the important factor in determining the effective useful life of the LED.
    Last edited by ledmitter; 04-13-2012 at 05:52 PM. Reason: Pic!

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    Flashaholic* yifu's Avatar
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    Default Re: Has any here hit the 50,000 hour led life span?

    Quote Originally Posted by ledmitter View Post
    I wonder what the CREE XML's lumen deterioration rating is after just 1,000 hours. These LED's are being driven pretty hard in many of these lights with questionable heat sinking compared to what they using in the lab.
    That's easy, the lumen maintainence results are here http://www.cree.com/~/media/Files/Cr...80_Results.pdf After 6000 hours of driving an XML at 2A and at 85 degrees celsius, the LED maintained 97.2% of its output. Not bad.

    And one more thing, unlike other light sources with catastrophic end of life events like incans (burn out), mercury arc (unsustainable loss of arc gap length), LEDs will not blow out after 50 000 hours, but rather loss 30% of initial output. This extrapolated lifetime would is usually done at half the maximum drive current (750mA for XPGS, 1.5A for XMLs) so the L70 lifetime would increase if the LED is driven less, or decrease if overdriven.
    Last edited by yifu; 04-14-2012 at 07:17 AM.

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    Default Re: Has any here hit the 50,000 hour led life span?

    Quote Originally Posted by yifu View Post
    the LED maintained 97.2% of its output.
    That's not nearly enough to tell the difference by the eye in a direct side-by-side comparison with a brand new copy - insanely good; not only can you pass your flashlight to your grandkids, but it'll still be just as bright..

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    Default Re: Has any here hit the 50,000 hour led life span?

    Quote Originally Posted by yifu View Post
    That's easy, the lumen maintainence results are here http://www.cree.com/~/media/Files/Cree/LED%20Components%20and%20Modules/XLamp/XLamp%20Application%20Notes/LM80_Results.pdf After 6000 hours of driving an XML at 2A and at 85 degrees celsius, the LED maintained 97.2% of its output. Not bad.

    And one more thing, unlike other light sources with catastrophic end of life events like incans (burn out), mercury arc (total loss of arcs), LEDs will not blow out after 50 000 hours, but rather loss 30% of initial output. This extrapolated lifetime would is usually done at half the maximum drive current (750mA for XPGS, 1.5A for XMLs) so the L70 lifetime would increase if the LED is driven less, or decrease if overdriven.
    Nice catch. Thanks for that. Super interesting reading.

    An XML being driven at 2A would be approx how many lumens? Any conversion numbers come to mind Yifu?

    I've always thought the 700+ lumen XML's where being driven upwards of 3A. Guess i'm wrong.

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    Flashaholic* yifu's Avatar
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    Default Re: Has any here hit the 50,000 hour led life span?

    Quote Originally Posted by ledmitter View Post
    Nice catch. Thanks for that. Super interesting reading.

    An XML being driven at 2A would be approx how many lumens? Any conversion numbers come to mind Yifu?

    I've always thought the 700+ lumen XML's where being driven upwards of 3A. Guess i'm wrong.
    Sure no problem, from Cree's lab results here http://pct.cree.com/ A XML of the U2 bin at 2A produces a typical 741.6 lumens, with a 7% variance either way. So the OTF lumens should be at least 500 lumens. The 700+ lumens XMLs are normally driven at past 2.8A, although the XML LED can be expected to output 1200 LED lumens at 4.2A, not very efficient at that current though.

    That's the reason i find it funny when people try to avoid running their lights on high for fear of loss of output. The loss after a heck of a long time is really, negligible, provided you've got a reasonable heatsinking solution, which most good lights have anyway.

    The tests on overdriving XMLs are here. The heatsink used is not very good, so the outputs could be potentially 200 lumens higher, as verified by some CPF members. It's the T6 bin BTW.
    Last edited by yifu; 04-14-2012 at 07:25 AM.

  27. #27

    Talking Re: Has any here hit the 50,000 hour led life span?

    Hold that thought............... I get back to you in about 5.7 years............................................. .................................................. .......



    {sorry}
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    Flashaholic Glock27's Avatar
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    Default Re: Has any here hit the 50,000 hour led life span?

    My SC60w has now been "On" for 443 days. Mostly on Low1, but hundreds of hours on High. 10,600+ hours. Still can't tell difference on white wall between others in same batch.

    G27

  29. #29

    Default Re: Has any here hit the 50,000 hour led life span?

    Not sure if it counts but my wife has a Sony clock radio with red LED light bars making up the numbers. She has had this light for close to twenty years and short of maybe times during a move it has been plugged in the whole time. The LEDs appear pretty dim to me at times but they are still running.

    LEDs are semiconductors. Their true failure rate should be no more or less than any other semiconductor diode, transistor or IC circuit. People have LED power indicators on items all throughout their homes and they just keep working year after year after year.

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    Flashaholic* Echo63's Avatar
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    Default Re: Has any here hit the 50,000 hour led life span?

    Quote Originally Posted by Kestrel View Post
    Some of the older hands here might recall reports of the LuxV exhibiting a visible decrease in brightness after as little as 500 hours of use. Apparently those were driven hard enough to get HOT in some lights.

    Edit: And if anyone expects 50,000 hours of runtime from LEDs at 'CPF' drive levels, I have a 500,000 hours MTBF (i.e. 57 years) hard drive to sell them.
    I had a lux V in an L4 die after maybe 400 hours of use
    It got pretty hot though, and i think one of the screws holding the heatsink to the head was loose - which halved the transfer capacity of the thermal path from the led to the outside world (maybe more)

    I think a mehanical failure is more likely than a led that has reached the end of its life
    (i believe my failure in the l4 was heat related caused by a mechanical failure)
    And i dont think Leds will reach their rated lifespan at CPF type drive levels - maybe in things like the LL malkoffs
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