Whats 50,000Hr Lifetime mean in LED light?

I have a Streamlight Sidewinder LED light and the manual states as below.
C4® LED technology, white, impervious to shock with 50,000Hr lifetime.

Does this mean that after 50,000Hr of usage the LED will burn out?
I thought LEDs never burn out.

Please explain.

Thanks

I think 50,000 hr is to reach half the brightness.

Without being too technical here, will this C4 LED burn out like Incandescent bulbs do?
So does this really mean that the LED will start to burn out after 50,000Hrs?

LEDs slowly dim instead of burn out.

They could actually burn out, but that is highly unlikely and would only be cause by other electronic failures.

Has anybody actually had this happen? Especially with people on CPF who have lots of lights it seems unlikely. Maybe a night patrolman or something who's had an led light since 2004 or whenever the first single emitter lights started emerging. I've only really been in the game since 2008 so somebody give me some history lol. Seems like it's near impossible to do with emitters outside of fixed lighting products like led bulbs/fixtures. I'm going to hope some of my lights stay in good condition and maybe when I'm old and grey one day I'll realize my good old led light from 2010 or whatever is too lol. I have heard of color shifting and stuff happening, but that seems like it's probably from the emitter actually overheating rather than actually going through a 50k hour lifespan.

Put in in perspective. There are 8760 hours in a year. If an LED truly lasted 50,000 hours and running 24/7 didn't damage it you could run your light for over five and a half years before it burned out/reached half output. It seems very unlikely that an LED flashlight would ever "burn out" in normal use. Obviously parts have a MTF and nothing made by humans is perfect so of course a diode could fail. But that's a lot of normal use. Given the rate of improvement in LEDs it's hard to imagine running the same one long enough to wear it out. With higher power applications it's probably different. Almost every bulb in every fixture in my house is LED and have been for a couple years. On bulb in one room upstairs has failed/burned out. Of course, some man made devices will fail, and house lighting is run at higher voltage and amperage, and run continuously for many hours. The LED bulbs in my entry have been on 24/7 for months without issue.

What kind of bulb did you have fail? Of course the idea of led "bulbs" is overall a band-aid on the fact that LED's really should be put into properly heat-sinked fixtures, but still the really well made ones with good fins/cooling should last a long long time.

I seriously hope companies like Cree don't bow to general consumer demand for super cheap bulbs and eventually stop making the higher end led bulbs. It totally defeats the purpose of having LED lighting lol. Even the cheap bulbs that don't have good heat sinks should last a long time in the right conditions. I have a 1100 lumen Philips paddle bulb in my bathroom so it never really gets the chance to heat up much since it's usually on only briefly.

Yeah, white LEDs can overheat and start shifting blue as the phosphor degrades.

Might be good to look at old signage or old large LED signs, those are always on and should degrade much faster than in a flashlight.

LED Failure modes on wikipedia. White LED degradation paper.

I think most lights would be replaced, have the other electronics in it fail, or have a battery leak in it well before the LED dies.

martinaee said:

What kind of bulb did you have fail? Of course the idea of led "bulbs" is overall a band-aid on the fact that LED's really should be put into properly heat-sinked fixtures, but still the really well made ones with good fins/cooling should last a long long time.

I seriously hope companies like Cree don't bow to general consumer demand for super cheap bulbs and eventually stop making the higher end led bulbs. It totally defeats the purpose of having LED lighting lol. Even the cheap bulbs that don't have good heat sinks should last a long time in the right conditions. I have a 1100 lumen Philips paddle bulb in my bathroom so it never really gets the chance to heat up much since it's usually on only briefly.

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I'll have to check the package, it's a CREE one of some kind. Probably a fluke because the thing has a ten year warranty IIRC.

Keep in mind, the rating is based on ideal wattage levels and temperature limits. Running an LED beyond these levels can reduce the MTF. But even with a dramatic reduction, most lights will be obsolete (or dead) before they wear out.

The 50,000 hour rating is an estimate for running the LED at maximum rated brightness, properly heat-sinked, until it dims to 70% of its initial output. Manufactures don't test the full 50,000 hours. They test to something like 6,000 hours, then use formulas to estimate out to 50,000 hours or whatever.

If you look up Cree's LM-80 testing, you'll see results for all their LEDs. The interesting thing I note from that report, is that current (brightness) has very little effect on lifetime. It's almost entirely due to heat at the LED junction point. If you keep the LED under 85C, it will probably outlast the 50,000 hours. If you keep it down around 55C, it will essentially last forever. Temperature above 105C kills the LED much faster than the 50,000 hour rating.

The conclusion is that heat-sinking is everything, and a way for that heat to get out of the light. This is why home LED bulbs often die too soon, because they're trapped in a housing that just builds up heat. Proper flashlights don't suffer from that problem.

Just a reminder... If you kept your 50,000 hr LED on at a typical job - 40hr/wh, 50 work weeks/year - 2,000 hr/yr - it would be at, on average, 70% of it's initial brightness, with proper heat-sinking, after 25 years!

Ok, its too techy for me...But thanks. The main point is, I try my best to enjoy this light.

On my part, I've never had an LED fail. All of our in house incandescent lights that are used on a daily basis, have been changed over to LEDs and when I can, I upgrade our flashlights. The point, due to normal usage, before a light burns out, expectedly, the light will have been supplanted by a next generation or two flashlight.

Much to my wife's displeasure, I'm a consumer and will buy just to buy so as to have a new toy.........ooooo, shiny.

I wonder how much Turbo usage effects the life of tint and led quality?

I mean, lots of lights step down at three or five minute timed runs or use ATR.
Though in each case, the light is shedding some serious heat by the time them limits have been reached.

If, the led is most efficient at around the 300ish+ lumen mark, how is driving them harder at Turbo levels, effecting the life span of the dome and integrity of the led itself?
We know each uses their own idea on heat sinking, and then end users can effect heat retention through accident like turned on in pocket, or by an individuals need, where they need to keep triggering Turbo after stepping down repetitively.
Add in climate etc, but for said if this query we could assume 20c average ambient.
Are long time members seeing tint shift from continued Turbo usage on older lights or, encountering higher then normal heat output as their light ages?

Hope this is clear enough.

Another data point; there were a few reports on CPF 'back in the day' of the hard-driven LuxeonV emitter (specifically in the Surefire L4 IIRC) of significant dimming in as little as ~500 hrs of use. So most-certainly application-specific.

Kestrel said:

Another data point; there were a few reports on CPF 'back in the day' of the hard-driven LuxeonV emitter (specifically in the Surefire L4 IIRC) of significant dimming in as little as ~500 hrs of use. So most-certainly application-specific.

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Playing with excessive overdrive can shorten the life of an emitter to seconds.

itsonlyme said:

Ok, its too techy for me...But thanks. The main point is, I try my best to enjoy this light.

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Look at it this way: you'll probably die, sell the light, or lose it before the LED burns out :thumbsup:

WarRaven said:

I wonder how much Turbo usage effects the life of tint and led quality?

I mean, lots of lights step down at three or five minute timed runs or use ATR.
Though in each case, the light is shedding some serious heat by the time them limits have been reached.

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The step-downs or temperature controls and designed to keep the LED and electronics at a safe level. There should be no problem at all using turbo mode, unless you restart it after the timer steps the light down.

For LEDs like an XM-L2, you have to be running the LED at over 105C to seriously cut down its lifespan. As long as the light has a good heat-sink, you're going to get really bad burns on your hand before it gets hot enough to damage the LED.

If the light has a bad heat-sink (like some Maglites), then the body might stay cool while the LED cooks. But usually those kinds of lights aren't high output, so it's probably okay for the LED.

Kestrel said:

Another data point; there were a few reports on CPF 'back in the day' of the hard-driven LuxeonV emitter (specifically in the Surefire L4 IIRC) of significant dimming in as little as ~500 hrs of use. So most-certainly application-specific.

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Even that is better than some of the high pressure Xenon bulbs of the 80s!