# 5mm LEDs - how long do thy really last?



## pushcart (May 8, 2010)

I have been reading some of the fade test data here - it appears that many of the 5mm LEDs fall way short of the manufacturers' claims. I realize that the auction site bargain LEDs are unbranded, so the seller specifications may have no factual basis. (I'm not maligning any sellers - they may well be passing along data from their suppliers).

Are there any 5mm LEDs with proven lifespans of 100,000 hours?


----------



## Meterman (May 8, 2010)

Just buy a bunch of different brands, operate them at 25% duty cycle and wait a bit more than 45 years to find an answer without anyone's help. 

Wulf


----------



## Bright+ (May 9, 2010)

pushcart said:


> I have been reading some of the fade test data here - it appears that many of the 5mm LEDs fall way short of the manufacturers' claims. I realize that the auction site bargain LEDs are unbranded, so the seller specifications may have no factual basis. (I'm not maligning any sellers - they may well be passing along data from their suppliers).
> 
> Are there any 5mm LEDs with proven lifespans of 100,000 hours?



It all depends on the definition of lifespan. In many applications, LEDs last well in excess of 50,000 hours. I'm sure you've come across many alarm clocks, indicators, etc that's been in service for a minimum of five years.

Lifetime can be defined as when it ceases to function completely or the performance degrades below a threshold set for the application. White LEDs driven hard run hot and the phosphor degrade fast. If the limit is no more than 10% loss in flux, I'd say a good number of 5mm LEDs driven at the current used in flashlights won't last more than a few days.


----------



## Th232 (May 9, 2010)

JohnR66 has done some fade testing of 5 mm LEDs here:

https://www.candlepowerforums.com/threads/264326

But to emphasise what Bright+ said, bear in mind that the lower the drive level, the longer the lifespan will be since phosphor degradation will be reduced.


----------



## DM51 (May 9, 2010)

Wrong forum - moving this to LED...


----------

