Wearing out leds

[22hornet]

Hello,

Why this poll?
As most of us, I have several led lights that I like a lot. The problem is that I mostly find myself using only my "lesser" lights in order not to wear out the more expensive ones or those I can't replace (like my colored led ARC AAAs)

This because we sometimes read things like leds that are overdriven and will only be useful for a limited time. Nothing near as long as the sometimes claimed 100.000 hours.
White 5mm leds seem not to last as long as colored 5mm leds or 1 watt or larger leds. But the 5w luxeon (L4/L2) seems to be shortlived as well.

I just want to know how many of us have already experienced a led that has really, visibly become dimmer over time with hard (or normal) use.

Thanks for your cooperation,
Joris

 

[22hornet]

... so there actually are people who have been confronted with a decline in output with their led lights.

I wonder which brands are more prone to degradation than others... I really have no idea.


Joris

 

[Gunner12]

It's mostly overdriving a LED that causes it to dim quickly. A 80 milliamp rated white led(smjed?) overdriven at 125 milliamp degrades quite a bit in 120 hours. There was a chart but I can't find it right now.

Edit: Here's the old thread with charts,

 

[greenLED]

There was a chart but I can't find it right now.

Look for threads started by Newbie.

 

[cave dave]

I'm pretty sure my original ARCAAA LE from 2002 is dimmer and more purple now. I'm comparing it to a CMG U Infinity from the same era which has seen much less use.

I've also has a Fauxton light burn out the LED in short order.

 

[frasera]

hard to test.
i know they dim from 25-50khrs?
thats up to 2000+days of testing if you wanted to prove it
or 25 thousand sets of batteries assuming 5 hours per set
i just assume the flashlight will be obsolete before i care i guess

 

[LEDninja]

LED nite lites get very dim in about 6 months, totally useless in about a year.

 

[Flying Turtle]

I've definitely noticed it in LED nightlights. It also seems to have occured in my old 3 LED Peak Matterhorn which has seen many hours used with a diffuser as a mini lantern.

Geoff

 

[frasera]

hah guess its led night lite buying time

 

[LEDninja]

hah guess its led night lite buying time

I am now using WARM WHITE versions of these:
http://ledmuseum.candlepower.us/fifth/1wbulb-1.htm
Much better colour. A little brighter than I need. The underdriven Luxeon should last a lot longer than the 5mm LEDs in most LED nite lites.

 

[paulr]

I believe the degradation mostly comes from the phosphor wearing out and the epoxy envelope yellowing. Phosphor is only an issue for white leds, i.e. it won't affect your colored-led Arcs. Not sure about the epoxy but I suspect it's mostly an issue for higher-powered leds rather than 5mm leds run within spec. Main thing I notice about my own Arc AAA (my former edc) is that its blue cast became more and more noticible, but I think that's because I became more aware of it as neutral-white leds became common, rather than because the led itself shifted in color.

 

[cbxer55]

I have one of them LED Lenser's with the 5 whites and one central red.
One of the whites started getting dimmer, than flickering, then completely gone. Fortunately I only use it around the house or I would be pissed.:scowl:
Otherwise I have a Surefire U2 that is 1.5 years and still no problems.
And a Fenix P1D-CE that just requires a bit of lube now and then to function right.

 

[glockboy]

I got the Surefire L5(5w luxeon), I used it for 3 years, got over 2000 hours on it and it's still bright.

 

[TigerhawkT3]

Oh, how I WISH that I had the opportunity to use my lights that much.

 

[TorchBoy]

It's really hard to tell. I have a pair of matched torches, but I don't use either very much. They are being overdriven, since I measured 450mA through 9 LEDs. They would make a good test.

I had my first and only burnt-out LED last Sunday. It didn't look good to start with, being dimmer and greener than the others in that light.

 

[WildChild]

LED nite lites get very dim in about 6 months, totally useless in about a year.

I have 2 nite lites (5mm). 1 runs continously since 1 year and I cannot tell if it has dimmed or not. To me is is still as bright as it was, or almost. The second only runs at night and it is still as bright to me as 1 year ago. They don't look overdriven at all.

 

[adirondackdestroyer]

I have 2 nite lites (5mm). 1 runs continously since 1 year and I cannot tell if it has dimmed or not. To me is is still as bright as it was, or almost. The second only runs at night and it is still as bright to me as 1 year ago. They don't look overdriven at all.

Same here. I have had two LED nightlights that have run continously for around 1 year and as far as I can tell haven't dimmed at all. I bought them at Lowes and they came two in a package for $6.

 

[RebelXTNC]

I have been running two Woods-brand LED nightlights for something over 6 months, 24/7. I "think" the white one is a little dimmer, but still pretty bright. The blue one seems unchanged. These use an LED that looks similar to the one in a RiverRock 2xAAA light.

 

[carbine15]

Look for threads started by Newbie.

I miss Newbie.:sigh: