Thanks so much for the explanation. Makes way more sense now. I've got rosin core solder so I'm going to try it out now.
I too believe this may be causing some of the issues. My UT01 would not work with any of the alkaline batteries I had on hand, the battery tube is too short and the spring bottoms out before the tail cap makes contact with the end of the tube.
The unprotected Sanyo 14500 worded well. Tried the alkaline’s and just jumped from the rear of the battery to the end of the tube and they all worked.
As others have mentioned, a small diameter wire formed into a circle that fits around the outside edge of the spring and the tail cap will fix the problem, for my light anyway.
Worked like a charm. 60 seconds of work. You, sir, are a gentleman and a scholar.
Received mine recently (3D) finally had a few minutes to play with it. Installed a regular Alkaline primary cell and it worked great, real nice tint, switch works fine and all modes are working, I switched many times through all 4 levels and back to off, plus 2 clicks for hidden strobes with no problems.
The memory mode (long press from off) only memorizes L-M-H modes, it does not memorize Moonlight, I guess you wouldn’t need that because a single click always enters moonlight anyway.
I haven’t tried a protected 14500 because I didn’t want to crush the driver, don’t have any shorter unprotected right now. I also have some NIMH I will check their length and try later. My 14500 protected 750mAh AW is only slight longer than the Alkaline, will try that one later after I do a paper clip mod in the tailcap.
I also didn’t try programming the levels yet.
The last good AA/14500 light I bought was an Olight S15, but it was only available in CW and its greenish blue tint is pretty ugly. This UT01 NW tint is far better for my liking. The Olight has a much larger reflector and a tighter hot spot, the UT01 in comparison is thinner, shorter and more compact. I’m really liking this light so far!
OK I tried the programming, there’s nothing in the user manual about programmable output levels but I got the instructions from the review thread: Review : Utorch UT01 Flashlight (XP-L V6 / AA & 14500 / e-switch)
The reprogramming function appears to be working but it’s kind of confusing, it went through the sequences as described in the review but there were only 3 programmable modes instead of 4, apparently High is not programmable?
It says in the review “Light has programmable output levels for every mode” but after I set levels for 3 lower modes it just goes to high and is no longer auto-ramping, then I have to single click to get to strobe (to turn off in strobe as described in the review instructions). I have to spend some more time with the programming.
In programming there are 3 levels to chose from, anyone know what the factory default levels were?
Maybe they don’t want people messing with that since nothing in the manual about it?
Mine was able to program all 4
How recently did you order yours? (I ordered mine on Dec. 19th)
I have got one ordered in December - 3 levels to choose from.
Thanks yasenf! So it seems they have upgraded to remove programming for HI.
I’m wondering if they changed it because when it first came out some people were complaining of low maximum output, only to discover the default programming for HI wasn’t set to the maximum level.
Months ago.
OK thanks, yours was apparently before the change. yasenf and I ordered in December – both only 3 modes that were programmable: ML-LOW-MED.
has anyone found their UT01 tint was seriously warmer than expected?
I purchased the 5000k model and I would put it closer to 4000k.
I have a U6-3A (5000k - 5200k) convoy S2+ and my UT01 is much much warmer.
Yes, as has been reported here by many others, the 5k version is pretty far from 5k in reality. Mine seems to be even below 4k.
Yes a good bit warmer than my Convoy S2+ XML2 4C (4300-4500K) which is was the warmest light I own.
I’m guessing it’s maybe around a 5C. http://flashlightwiki.com/images/f/f6/Ansiwhite.jpg
In a side by side comparison it makes the 4C Convoy look white, and I always thought it was quite yellowish, but I think I’m starting to like warmer tints sometimes.
Thanks Beam0 
:+1:
Yeah its definetly alot warmer than i was expecting. Convoys 5000k is my sweet spot at the moment.
Do you have the 6500k version of the UT01 aswell? Can anyone tell me the approx tint of that version?
Yes it’s VERY warm to me because I’m also a “5000k kind-of-guy”, but I’ve been itching to try a warmer tint so I’m happy with it.
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I do not have the 6500K version. And I was wondering the same thing, if the CW version is actually more towards NW, but I kind of doubt it is.
Ok, thanks mate. I have one in 6500k on its way to me, ill let ya know when i receive it.
Mine is also ~4000K, which I generally don’t like that much, but somehow it fits this light. I saw nice reds and generally vivid colors with it - I like how it turns out so much, that it will be a keeper.
As soon as my UT01 arrives I will measure it. Of course I ordered NW. I feel something that will be similar to the UT02 that I got a few days ago. From the measurements, 4350K came out instead of 5000K. The measurements are done with the eyeone Pro calibrator, so it is a fairly accurate measurement. I also get a spectrum of timbre.
UT02:
I feel the same, it has nice color rendering. Sometimes I like a warmer tint using around the house inside late night when I’m sleepy, also in a movie theater etc., anytime colder white could be somewhat “offensive” to the eyes.
Also I only ran mine on an Alkaline primary, I’m wondering if I’ll see slightly different or cooler tint with higher output when running it on 14500.