Strange Driver Performance with LED Change.

[kosPap]

Hi all! Today I modded my Rexlight 2.0 with a Q5WC from DX

But there is a curious change in performance with the new LED....When run with Eneloops there is an increase in output, while nothing has significantly changed when run on an AW 14500.

Here is a table

Now... the only explanation I can think of is that the LED Vf plays a role but why NO change with the Li-Ions?

Also, did you notice that Eneloop output has almost doubled???? And I have also verified the pattern with Alkalines too...

Note...When I removed the original LED there was NO thermal compound between it and the heatsink...Nothing. Nada...

Any clues????????

 

[Black Rose]

The driver is probably bucking down the voltage/current with Li-Ion, which would explain why you are not seeing much difference.

 

[kosPap]

hmm so it is a buck driver? or buck & boost? (but it seems too small for the task)

 

[Black Rose]

It would have to have a boost component since a regular AA only has 1.2 - 1.5v and the vF of the LED is around 3.2v.
Since it actually has modes when using the 14500, I would say that it is a boost & buck driver.

 

[kosPap]

thanks man...