Thanks Barkuti, I had a feeling you were adding resistors. I need to learn the math behind calculating that, I assume is simple ohms law.

Also this thread made me aware of CRI 80 in XHp35 HD 5000K from KD, now it has me considering that over a 5000K XHP50.2 for I light I want to rebuild.

Can you recommend a 17mm driver for the XHP35 with 2S (2*26650) ? I could probably even make 20mm work.