Cool, thanks for reviewing this light.
Measuring the amps at the tail will do.
Exactly
Think I’ll give this one a miss.
Don’t have the equipment to measure output or amps at tail.
We don’t know if any other flashlights have any problem.
We will see…
For reference, and comparison, does anyone know what the stock Manker U21 pulls?
From Tom E ’s review i remember 5.45 amps in turbo .
Ohhhhhh. That’s why those numbers were being quoted. Sorry. I thought that was AFTER he modded it.
No, it's in the review thread OP and I'll stick with stock #'s, etc. for the OP.
"On Turbo, measured 1.08A at the LED (16 AWG patch wire, UT210E clamp meter), and 5.52A at the tail with a EFEST IMR 26650 5200 mAh cell. "
Ouch. I really hope giorgoskok’s results aren’t the norm then. Guess I’ll find out tomorrow night when mine arrives. I don’t know how to measure that, but at that much of a difference, I’m sure eyes will tell me when sitting side by side with my U21 (that I was hoping to be able to send back if this could replace it).
So far It’s three out of three that’s low in amp draw :
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
This is what I measured on the Manker U21, CW 1A:
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.
Hhmm. Would be interesting to compare against the stock Manker U21 driver:
Removed the driver this morning . It’s the same driver you posted Tom E .
I looked for weak connections or something suspicious but i found nothing .
So , stock numbers : Amps at the tail : 2.65A / Amps at the emitter : 0.7A / ~70kcd intensity (meter i a bit under-reading)
As a last step , i checked the sense resistor . It was the same R050 as Tom E’s driver , Screenshot by Lightshot .
I added another R050 on top of the existing one , and it was pulling 5.7A from the battery .
I let the light run for 10 mins without any issue . Charging cell now for more tests …
PS . I have already contacted gearbest to check the production with the factory .
Also UT01 came today , at least this is working properly .
Nice looking light. 
They claim its 1300L, are those ANSI Lumens or just a ball park number? (looks like the latter)
Curious… how much wattage does the XHP35 need to reach 1300 emitter Lumens ?
How is the PWM ?
How did you get the UT01 so quickly?… hope mine comes soon to CA, USA.
I think it only needs 800mA to 1A to reack 1300lm .
Pwm not visible , i’ll try to test with oscilloscope (if i have access this week) .
UT01 was sent with dhl .
It depends on the flux bin, but in this light it would probably take 14-16watts