2.22Amp, well, it’s even lower than some Xp-G2 flashlight
2.22*4V~9W, with 80% effective, i think the power of led is around 7W, Doubt it is over 1000 lumen
If the light is making 9w, the led will see .75amps at 12v. According to the data sheet, the led should make 880-1100 lumens. However, take into aciunt eficiency and losses that means only 600-850 lumens out the front depending on the flux bin.
Again, the Manker U21 specs were basically copy/pasted, so I'd expect what I posted in post #48, assuming they copy/pasted the light .
The 1,345 lumens I measured was at 30 secs in my NIST calibrated PVC light box (ok - PVC light boxes can't be NIST calibrated, but would be nice). I'm pretty confident my PVC light box is in the ballpark from testing 100's of lights in it. The lower modes though are quite a bit off in what I measured.
It sounds like 3 of 3 received so far are doing much lower in amps, much lower in output, so....
It's an electronic switch light with no power tail switch - if you did try the 2 cells, you will give the driver board 8V unless you physically block one end of the cells - tape or something. Hhmm - if you had a 26700 cell to try, but think two 26350's are a little longer.
I have a U21 and do have 26700 cells, and 26350 cells.
I really don’t get y’all, hung up on watts. Watts is an after the fact measurement of amperage and voltage. Watts is misleading, as you can get more lumens with less watts, look at Cree’s Product Configuration tool.
You don’t feed watts to the emitter, you feed amperage (current) at the voltage it will accept. Wattage shows it’s efficiency. Like statistics on a football game, a team can blow away the other team in statistics but lose by a big points spread. It’s the same way with the emitters making lumens. Voltage and current produce lumens, watts is a statistic of how efficiently it’s doing so.