Have modded it yesterday, I added 2 0.2 ohms resistors in parallel with the original one resulting in 0.033 ohms (is higher than 2 0.05 ohms resistors in parallel which is 0.025 ohm).
Amp draw at the tail cap was 5+A. I’ve also put some silicon thermal glue on top of the driver hopefully it has some positive effect.
Now it has great output.
Finally re-modded my UT02 
It’s now running Narsil v1.3 (with a working switch led indicator now!!!) and a new led , a dedomed xp-g2 s4 1a .
Emitter is running at 4.4 amps and flashlight is now making 292kcd . Man , that light throws ! (And i have emitters running even higher from a single cell , @4.85 amps)
Give us some beamshots compared to U21 if possible
I will take some beamshots , today or tomorrow 
MAN! I wish you lived in the US and offered a mod service.
Say guys, one of my lights has the modes screwed up, 2 and 3rd I believe, just sort of a light nudge barely recognizable but have to double click past to get into next working mode.
I remember seeing somewhere way back down the thread a fix and or a similar issue but can’t find it and even if I did not sure if I am able or skilled enough to fix it, what would be the next best option since GB is demanding a video and I can’t take a video of this issue it wouldn’t make any sense to them and just what if I wasn’t really pressing the switch anyhow,
I am irritated with them but whatever I’d like to fix it myself, it’s an awesome light and the other one I got is perfect, maybe a point to the fix I might have noticed would be a great help, Thanks all…!
By the way GB has the UT01 for $20 and UT02 for $42 or so today so picked up a couple more 01’s, that makes 6 now, fantastic lights George thank you… again ha ha…
GB UT01
UT02 only warm $42.95
Noob question just to be sure , did you replace the original resistor with the R018 or put the R018 on top of the original ?.
replace
Thank you for clearing that up :+1:
Since all the heavy hitters are here in this thread I wanted to share something unusual about this light.
User mrheosuper has one of the early lights that show 5.8 amps using a clamp meter. This is with him pressing lightly down on the battery.
If he pushes down harder the amps drop to 3.67.
This is interesting. I wonder if the difference is because the light pressure only touches one spring and the heavy pressure touches both?
DB Custom and Tom E, do you guys think you were not pressing the battery down hard enough to touch both springs?
If not, maybe your readings might change if you pressed harder?
This is odd to me. Any thoughts?
When you compress the springs you create less resistance, the amps will lower due to the driver having to pull less current (less resistance more efficient) to maintain voltage, XHP35 is a 12v emitter, remember it is a boost driver, so less resistance makes it more efficient! So a copper wire bypass on both springs helps a lot! Also when the battery gets lower in voltage due to use or drain, the boost driver will pull more current from it, to maintain the voltage to the LED and your reading will get higher! Less amp pulled when fully charged and greater amp pull as the battery drains. That is why you should use or it’s recommended to use High drain, high amp, performance batteries.
The only way to see what is really going on is by checking the current (amp) pull at the emitter, this will also show how efficient the driver (and battery) really is too!
Same with your battery high performance, low resistant, high amp batteries will read differently than say a laptop pull or poor quality high resistant battery.
Something like that, it’s early and I need my coffee!
The clamp meter is also backwards, hence the “-” sign in front of the numbers. I don’t know if it’s true for all meters but I’ve seen mine read differently when properly connected than when reversed.
Well, i checked, there are some difference, but just only 0.2-0.3A, not too much
A good current meter wont show any changes except”-”
I was about to buy it because of the 33 USD deal, but then I read a few reviews and I really don’t like the fact the the led is underdriven. Actually I was looking for thrower bigger than my C8 (not huge like the convoy L6, still easy to carry), without spending too much, but I don’t think this UT02 will significally outperform my C8 with XP-L HI and FET+7135 driver… so what’s the point in carrying a bulkier flashlight?
I mean, the host looks awesome, but considering the 12V Led and the electronic switch, I don’t think it’s easy to swap just the driver (I wouldn’t care losing the charging if the led is driver at its full potential). The people who had the failed driver, what have you used to replace it?
Of course modding the original driver is always an option, but this particular light seems to have an easy failing driver even in stock…
I a bit confused :s what would you suggest? Also the deal is ending very soon…
Hi, I have a c8 clear convoy with blf a6, with batteries sanyo ga produces 81000 cd at 7 m, at 7 meters with the same luxometro utorch ut02 with mod resistance and liitokalas produces 119000 cd, difference is appreciable, also is a flashlight of excellent construction and Finished, that is my opinion, regards!
Is there an active coupon for the UT02?
one month ago there was a great one (lower than the price I wrote in my post above), try looking on m4dm4x website if maybe it’s still valid, if not try asking him.
Hola Gaston, como andas tanto tiempo? espero que muy bien, yo aca me habia separado del mundillo de las linternas pero es que uno tarde o temprano vuelve jaja, te hago una consulta, sabes de algun vendedor de china u otra parte que envie para aca baterias 26650? Estoy interesado en comprar un par de las Liitokala de 5000 mah o las Shockly 5500mah. Desde ya te agradezco! Saludos y espero que andes bien!!!