I’m currently having trouble with my first mod. I chose to use a Cree XHP70.2 N4 5700k on a 16mm MCPCB along with a 17mm FET Driver and S2+ host. It seems as if the led is not receiving enough power to output any usable amount of light. I’ve tried using a Samsung 26F, 30Q and a Sony VTC5A and they all struggle to produce any amount of light (almost none). My camera isn’t able to pick up the amount of light being generated by the led, even in a pitch black room. I measured the voltage at 4.15V at the solder joints connected to the MCPCB. I accidentally cut the positive wire shorter than I intended instead of pushing the excess back into the pill. I did make sure that the solder blob was not touching the edge of the brass but is it possible that my solder joints are causing the problem? Any idea’s on how to solve this problem would be appreciated.
CRX
(CRX)
2
6v LED, says it right on the MCPCB 
So you would need two cells with a suitable 6v driver or one cell with a boost driver.
L4M4
(L4M4)
3
Just look onto the star…
6V - you need more than one LiIon cell for that LED (and a different driver) or a boost driver (don’t know if they exist that small)
Alright, I appreciate the help guys.