Review : Utorch UT01 Flashlight (XP-L V6 / AA & 14500 / e-switch)

FWIW… L - R

~.35Lumens (Quark AA-T, XPG3) - ?? Lumens, lowest program mode, Eneloop (Manker E11)

~.35Lumens (Quark AA-T, XPG3) - ?? Lumens, lowest program mode, 14500 IMR (Manker E11)

~.35Lumens (Quark AA-T, XPG3) - 15 Lumens, Fenix L1T, Eneloop - ?? Lumens, lowest program mode, Eneloop (Manker E11)

I dont have a true 10 Lumen light compare. Closest I have is an ancient Fenix L1T, its low mode is about ~15 Lumens otf

I am willing to bet that 10 Lumen-14500 spec is not the lowest program mode.

Well, light #3 has arrived this morning and this one is misbehaving. Fortunately I have the two good ones to compare to, and I may have learned something.

The drivers on these lights have two solder points showing on the battery+ side. On the two good lights, the solder points are precisely horizontally perpendicular compared to the external ‘flat’ on the head housing that the switch is installed in. On the third (misbehaving) light, the solder points are slightly off the perpendicular, being rotated a few degrees clockwise.

Now this third light does work, sort of. I did manage to get it through the programming cycle, and that seems to have remained in the drivers memory - but it’s sometimes reluctant to come on, and reluctant to shut off. Sometimes it gets to ‘low’, one level above moonlight, and then stay there. It’s definitely not working perfectly.

I’m wondering if others might check the alignment of the solder points on their drivers. It could be that the drivers need to be exactly perpendicular to the switch aperture to function properly. Unfortunately I cant seem to rotate the driver - there are no pinholes to twist by, and I can’t tell if it’s glued in or not.

thats interesting…
on both of my lights the solder points are all squared up and parallel with the flat of the switch.

My driver boards are also loose fitting and not firmly attached. I can rotate them a little and when I touch them there is some rattle. So the battery tube needs to be tight and secure… FWIW. I think its always been this way, I never paid much attention though.

Thanks. The E11 definitely looks brighter running 14500 vs running Eneloop.

Does your E11 have a neutral tint emitter?

Yeah its lowest program mode is brighter with a 14500, although in person its not as pronounced as my pics above make it appear. I really don’t believe its 10 Lumens.

I have a Ssurefire E2L Outdoorsman, its low mode is rated 3 Lumens otf.

On a ceiling bounce comparison the E11/UT01 14500 program-low is visually about half as bright as the SF.

the E11 you see in the pics above is a neutral white, but its by far the warmest “Neutral” tint I have ever seen. Not a bad thing mind you.

Cool thanks Joe

Yeah, that is really warm. I probably should have ordered CW instead. Oh well, too late now…

I did some testing on this driver today. The switch is definitely part of the problem but I believe the heart of it is the way the firmware/driver reacts to different switch characteristics. Specifically, high resistance switches without a good clean click will cause the light to malfunction. So this is why some lights will not function with the switch off center but do when the switch is rotated to center. The user is able to click the switch more cleanly and the driver is happier this way. I was able to eliminate the problem entirely using certain switches with a definitive “click”. Swapping switches back and forth, I was able to repeat the results. So this seems to be the case in my light atleast.

It looks warmer than my BLF A6 with a 5A tint

Thanks for sharing your observations and conclusions, LightRider.

I suspect that the problem with my light is somehow related to the MCU. I’d wondered about an issue with debouncing, but didn’t really know how to diagnose more fully. Or something to do with the power supply and management for the MCU.

In my case, the switch is well centered. Still waiting to see what Gearbest is going to do about a replacement before I try anything intrusive.

I think most people are using unprotected 14500 cells in UT01 because the protected ones don’t fit (easily).

An unprotected cell such as Sanyo UR14500P (second from left in the below photo) is about the same length or maybe very slightly shorter than an Eneloop AA.

I just received a new one today at the $9.99 price and it looks good. Works on alkaline and 14500 no issue. No odd behavior. I had to add a magnet to a Sanyo UR14500P though - but that’s not something new regarding battery length sensitivity.

Nice patmurris ! I use the IMR 14500 ButtonTop / WindyFire. Great fitment !

I had repaired 2 UT01 switches with one from Mouser, they worked with new switch again,
The original switch is not reliable, sometimes it works when pushed in different angle, but normal operation is not really possible when the switch develops a problem

For 14500 I advise adding a solder blob or brass button on top of the battery

If you are able to reflow things with hot air its a 15minutes repair

link to buy the switch ?

i need replace 4 of my lights too >.<

https://www.mouser.co.uk/search/ProductDetail.aspx?r=612-TL3340AF160QG

I don’t believe the problem is the switch though changing the switch can solve it. I believe the problem is how the MCU reads the signal from the switch. I just did some thorough testing on my unit and replacing the switch does not always solve the problem. In fact the problem can remain even while manually shorting the switch input by tapping two wires together. It also will not work with those really flat switches that are held together by some sort of thin plastic/tape. Don’t know how to describe them. There were some other switches that did not work as well. However, some switches work every time without a hitch. I also tested the “misfiring” ut01 switch on another driver and it works fine. It confused me for half a day at least. :slight_smile:

In general, low resistance switches with a sharp “click”, worked the best. Of course this is just one driver I have tested and others will have to check for themselves but I do think this can explain some of the problems others are having as well.

For my light, I can’t power cycle it ON-OFF-ON-OFF, without doing this…. ON-OFF-Loosen/tighten tailcap-ON-OFF-Loosen/tighten tailcap-ON-OFF-Loosen/tighten tailcap. This ONLY occurs with a 14500 cell. Eneloop works 100% perfectly.

Do you think this light is die-ing a slow death? Have you guys seen cases where a light behaves as I have described and then suddenly without warning stops working entirely?

In an earlier posts in this thread, I mentioned that my first two UT01s worked perfectly while a third does not. I have an update to that. I decided to keep the two ‘good’ ones for gifts, and struggle with the balky one myself.

Oddly enough, the more I used it, the better it worked. To begin with, it was reluctant to come on, reluctant to turn off or to change modes….it would ‘stick’ in low and need to have the tail cap loosened to regain any function. In one of its more co-operative moments, I did manage to run the programming cycle, which it remembered… (The driver board in this one is stuck tight, and I can neither budge it nor get the nose cap off; I’ve applied force to the point of fearing damage.)

After a couple of days of relentless and frustrated clicking it began working more and more consistently. Now, while still on its first lithium primary, it works as well as the other two. There remains a sense of something not being right in the switch - a feeling of two clicks ‘on the way down’ for lack of a better explanation - but it’s much better than before and it obeys all inputs without hesitation.

While I don’t doubt there might be a variety of problems with these lights, mine appears to have a mechanical issue in the switch which is somehow rectifying itself through repeated use. I’ll continue to use it. Mercilessly.

Thanks for the report, tumbleweed48.

What lightrider has described sounds like a combination of electrical, mechanical and programming issues, with the switch being a locus of electrical and mechanical issues. Your description isn’t inconsistent with that.

From your description, I see another possible component of the problem, instead of or in addition to an issue with the switch that may remediating with use. You say you are still using the same lithium primary with this light. That means that the supply voltage is declining, which could also be playing a role in the way the MCU “observes” the signal from the switch.

This is consistent with some of my earlier, crude, operations, that the problem seems to have some relationship to the type of cell I’m using, and, with a given cell, may change over the discharge of the cell.

I just looked at this more closely. With an unprotected 14500, a couple days off the charger, I’d say the chance of any click being registered, by turning on the light, after the first turn-on after power-cycling the light, is about 1-2. With a Lada NiMH a few days off the charger, the success rate is closer to 10-20, and I just had a run of 100% success, until I removed the cell and tried again with the 14500, which again only had a 1-2% success rate.

In all cases, once the light is “on” ~100% of clicks are registered for switching intensities/modes, and turning off the light.

FWIW, I’ve been able to run through the programming cycle and then disable programming mode and have the changes stick. This works even if I have to power cycle the light, do a long press to enable programming mode, power cycle, click on and into programming mode, update the settings, turn the light off, and then power-cycle it again before doing a final 10s press to disable the programming mode. Or, to put it another way, the last state of the programming ritual seems to persist even if the battery is removed.

I haven’t found that going through the programming cycle makes any difference in turn-on efficacy.