Both of mine work perfectly when using Eneloops, and I haven’t tried Lithium primaries since I don’t have any. When I got my first UT01, I clipped the spring on it before I ever put the first battery in it, just so I wouldn’t possibly crush the driver. It didn’t make any difference when using a 14500, still had to break the circuit to turn it back on. Haven’t clipped the spring on my 2nd one. I had sent a PM a while back to the member who did the successful switch replacement (Lexel?) to try and get some feedback and info, but never got a response
If anyone knows the correct switch part number and where to get them, let me know and I might give that a try. Otherwise, I still REALLY like these little lights even when using Eneloops. If I had known about the “basically the same” Lumintop EDC05 at the time, I probably would have gotten that instead only because it has the magnet in the tailcap. Really handy to have that feature, just like my OTR M3 and my Olight S30 Baton have.
Yeah I think it may have been Lexel (??)… AFIAK he is the only member to have permanently fixed this problem. Somewhere on BLF is a lengthy technical discussion on it. Most of the theories behind this are way beyond my scope of understanding.
Heard back from Lexel, and the new switch that he used is available at digikey. He recommends using hot air for soldering it. Since I don’t have a hot air system for soldering, I may wait a while to try replacing the switch.
I had one little used UT01, and one unused UT01 that worked fine with 14500. I put high CRI emitters in them and started using them more. They were fine, then after a week or so, the one I used most developed the problem, so I switched to the second one, which also worked fine for about a week, and then also developed the problem.
They still work on NiMH, and I’m still using them, but I’m never buying another, and don’t suggest anyone else does, either.
My perception over the last 5 years is the Chinaman does not run new batches for problems like this unless;
1. They are red hot sellers and the manufacturer needs to run another batch anyway and they can label it 2.0 etc. as a new/better version
or
2. They get sooo many returns/chargebacks that they are Forced to fix the issue.
Usually they just come out with a new model and pretend the old problems never existed or were not as bad as some people said.
We are dealing with a low cost flashlight in this case, not a $600 smartphone which may catch on fire so the pressure is just not there for a budget brand to do anything about glitches.
That said I have 3 of them, 2 work great the other is the freak. At least they all do work and function, they are just a PITA when you just want to click and go.
Would not buy another now, but the light does have nice features and killer output.
Later,
Out of the four I bought, three still work perfectly while one needs the ‘break-the-circuit-at-the-tailcap’ treatment.
The ‘faulty’ one has become my EDC, as I always lock out my pocket light anyway. The UT-01 is still my all time favourite 1xAA light despite the odd one being quirky.
At ten bucks apiece, I still feel like I stole ’em!