ok i have an XP-L in a noctigon, and tried several drivers, bypassing the switch, etc. even direct drive from a Laptop Pull 18650 to the emitter, (Connecting the cell DIRECT short-path through two #20 wires + AMP meter to the and LED on Noctigon on a heatsink)
and i can’t get a load reading of any higher than 1.97 amps. Is the XP-L emitter limited to what amps can be shoved through it even direct drive from a cell with even heavy #20-gauge wires? or is the emitter i have in this case just weak?
I have not however tried to direct drive it with a 20R or 25R samsung as those cells can reap out some high amps.
Maybe it’s unusually high vf ?? Did you try a 2s driver?
Not yet.
its a modified Single-Head DST im testing this to increase throw output, & using a single 18650 cell body.
I tried both a FET driver and a Nanjq 105C 3.06A driver for the single 4.2V cell set up. I never thought the Cree XP-L needed a higher voltage than 4.2V to drive it harder for more amps. (even the emitter Direct driven with two wires from a good 2100mah 18650 cell at 4.15 volts yielded only a hair below 2 amps draw.
That was the only thing I could think of apart from the led being dysfunctional somehow. Of course, I’m no guru H)
Assuming no issues with your testing method, I’d say you may have a dud of an emitter or a dud of a battery. I would expect around 2.5amps on a good laptop pull, 4+amps from a 25R/similar.
It could also be the DMM giving a low reading if that is what is being used.
Boy, I hope you just have a defective led.
Cree: Try our New XP-L! Now with higher vf.
The DMM is a Fluke pro model. I tested that with a 12 volt car battery and a 100W halogen and it read plus 8 amps.
I tried several cells, same results.
The lower the voltage the higher the resistance matters for the same amount of current, so first make sure of your readings on 4v sources, 12V is much higher voltage, less resistance and a car battery sure does not have issue with delivering currents like most 18650 have.
I just tested another modded light i have with a Q-Lite driver ( 8-7135) and XM-L2 on a single 20R cell and it read 3 amps.
Have you measured the Vf yet? I'd be curious to know what that is on your particular emitter.
How is the Vf measured on the emitter?
^ One DMM probe on each side of the emitter while it is running.
ok will check that later. Thanks