Higher Vf of Q5 Crees. Fact or Myth?

[jirik_cz]

In various threads I still read over and over, that Cree XR-E Q5 have higher Vf than lower bins. Is this still true, or it was only problem with early batches?

 

[Jauno]

I wonder this too.
Am i right about this:
higher vf -> more voltage from battery needed to keep output flat-regulated.
One li-ion (3.7v) may not be enough.

So this vf thing might be reason why my Wolf-Eyes Q5 is not so good regulated as i expected.

 

[lyyyghtmaster]

I just measured a herd of CREE P4s I still have:

3.34, 3.43, 3.46, 3.56, 3.65, 3.79, 3.83 V, all at 1.00 A.

This averages to 3.58. At the same conditions, the one Q5 I have tested measured 3.61 V. I'm waiting on 5 from DX. Once they arrive, I'll post the results.


LED cowboy 1: A herd of CREE P4s? It's not a herd, it's a bunch.
LED cowboy 2: Bunch a what?
1: Bunch a P4s.
2: Of course I bunched a P4s, there's a whole herd of them right
over there on my workbench!