Hi fellow BLFers,
There is a questioned that had troubled me for quite a while.
could not get any relevant information on the site.
wondering that CREE stats that its lifespan is approx 50000 hours runtime.
is there implications whereby the led is being fed with 20ma vs 2amps?
if we use our light in 20lm low mode, as a night stand, does it constitute to the depreciation of lifespan as the same as running it on High 200lm?
Thank you for your time.
A few things here, first an LED has a much longer life that 50k hours actually, 50k hours is the rating of when the LED will drop to 70% of its original output. LEDs don't bun out, they just get dimmer over time. Also, 50k hours is a very long time, if your flashlight was on 24x7 it would be 5.7 years. 12 hours a day puts you over a decade, by then LEDs will have advanced so far that what you have now will seem archaic, you will probably already have replaced your light 2 or 3 times over with new technology before 50k hours passes.
I frequently see claims of up to 100,000 hours for Cree emitters...so I'm guessing that the extra hours come from running it on Med or Low
No, they are from the manufacturers of the flashlights, Chinese hours, kinda like Chinese lumens.
So true.
Thanks for the breakdown into really reasonable and practical life example.
Maybe I had been too engrossed into specs. CREE must have some sort of test equipment for running the lights to speed up their life cycle to test the 50k hours.
So it does not matter whether i run it at 20lm or 200lm. The result on lifespan is negligible.
Can i say that bro?
Br,
Tom.
Lifetime mostly depends on temperature of the led, if it gets hotter the lifetime will be shorter.
All I can say is this. I own 50+ flashlights. Some of them I use (and abuse) quite often, some others are just standing on a shelf. I fried some of the drivers already, but I didn't manage to kill a led so far.
Design of the head looks similar to the TM11.
Ok. Thanks for the info. Appreciate it.
Ok. Thanks for the info. Appreciate it.
CREE states >94.1% of the initial lumens in 6000 hours of use at 2A.
There is a lot of data offered by CREE. Unless the current and temperature is specified, that 100.000 hours is a useless "rating"
Taken from CREE, http://www.cree.com/~/media/Files/Cree/LED%20Components%20and%20Modules/XLamp/XLamp%20Application%20Notes/LM80_Results.pdf
Tested at 105C ambient? They planned to use these where again?
No wonder CREE emitter sells... these are pretty good stuff.
The case is 105C and they only tested at 1500mA, this means that the die is about 116C (The die inside the led is rated for 150C).
I think Cree is successful for a reason. They are simply astounding. I believe I'll be buying more of P60 drop in. Knowing that I could change out the faulty LED is reassuring.
The question I'm asking is due to the fact I bought a few non replaceable manufacturer lights. The thought of USD20 shipping fee to and fro manufacturer is haunting me.
UF drop in that bros here highly recommend are only 15 at manafont.
Even 36,000 hours is 4+ years of CONTINUOUS-ON usage. That's like 50 years or more of real usage.
I (think I) read somewhere that the 50k number really refers to when all of the lights will fail and that it tells nothing about when an individual light will fail.
In other words most will fail around the 36k range, the last one will fail by 50k and some can (will) fail well before that.
LEDs do not “fail” lifetime ratings are based on percentage of initial intensity.
At a cost of $7 for an XM-L I really don't care if I drive one at 6A and it lasts only 1 year. I will replace it. Just sayin'...
Very true indeed.
Drivers… Switches… Ano… Batteries, even charger will give up before the LED in casual use.