Longevity of LED at 50% brightness

[kirby]

If I turn the light on at 50% of its max brightness most of the time, would the LED last longer then if it were turned on at its max brightness most of the time?

If so how much extra life if a LED is only turned on at 50% brightness?

Thanks.

 

[zipplet]

I'd vote and say it would last longer, based on some testing done on 5mm LEDs a while ago (if someone would post the thread URL that would be appreciated, I don't have it).

How much longer is a good question :candle:

 

[precisionworks]

Cree discusses that here:

http://www.cree.com/Products/pdf/XLamp_Reliability.pdf

 

[RODALCO]

I have fitted many thousands of red leds in kWh meters as potential indicators, to check if a phase failed, and a meter reader could report a blown fuse in case of CT meters.
That project started about 20 years ago and a lot of these meters are still in service 24/7, survived power surges and the LED's never failed.

Ok, most of these were the 20 and 15 y.o. type leds running at 5 mA at 240 Volts ac. via a 47 k ohm resistor 2W, a 1N4007 diode and a 1N4448 antiparrallel diode.
Now for indicator lights at streetlight and hotwater contactors in the poco, I fit 5000 or 10000 MCAD blue , red or white LED's as ON-OFF indication. same set up as above with no faillures.

These LED's are underdriven and last the time allright well past the 100,000hrs (11.4 years) with no visible reduction in brightness.

 

[zipplet]

Ever noticed that PCs seem to overdrive the power LED? I've had a couple of machines that after 2 years or so, the power LED was pretty dim.