Q4 & 5 Break-In Improvement?

[jayflash]

The two Cree Q4 and one Q5 Fenix lights that I just got, produced more output at the same current consumption after a little use, the next day, then right out of the box. I should have calibrated my meter, first, but it has been stable and accurate. It's not the lithium cells. The improvement lies with the lights or a poor connection with my light measuring set-up.

What do the experts speculate?

 

[SteveDavis]

I'm not really sure where this comes from, but from the lifetime data I've seen from many suppliers, there is a small increase in performance at the beginning of life before the long slow fade in performance thousands of hours later. This is happening at the die level, and seems pretty common for InGaN LEDs (blue, green, white).

 

[jayflash]

Thanks for the info, Steve.

 

[WeLight]

While Q4 and Q5 have distinct differences in output, because they are yielded that way the efficiency of the constant current drivers used from torch to torch are more likely to vary than the led and may seek to limit the current/vf to restrain likely thermal rise. The Fenix are nice torches but have limited surface area so there will always be a trade between output and how long you can hold a firestarter