[review] Wurkkos TS21 21700 light, 4000K!

Would changing it fix the problem or just make the LED dimmer?

The stock resistor is 0.1K ohms, 0402 size, where it normally is 5K to 20K. I swapped it for an 8.2K ohm and the drain went from 13.5 mA to 1.3 mA, but 1.3 mA is still too high - shouldn't be that high. I get under 0.2 mA with many switch LED's, sometimes 0.2 to 0.3, but 0.4 should be the max. The stock setup was way too bright, on mine now it's reasonable, noticeable in bright room light.

Any chance of this bug getting fixed at the factory? The WK30 has got me back in to the flashlight craze once again and seriously looking at other Wurkkos offerings.

The TS21 has the ground work to be a great light. Just needs some tweaking. Anduril 2 is cool. The manual memory is the cat’s meow. For me it has just enough mass to run a decent lumen level without overheating yet it is small enough to be pocketable. A little short in the throw department but hey, it’s a flooder.
Wurkkos needs to address the bugs. So far I have not seen any movement in that direction. Hopefully future models will upgrade.

Are you talking about the high mode?
I use the low mode and I like it. It kinda looks steampunk-ish or like a hot piece of metal.

Would the higher resistor make the low mode useless/barely visible considering it’s already dim?

the reply we got from the engineer is the bug can not fixed except change the switch button

For which bug you are talking about? For blue led or high current drain from resistor to amber LED in switch. First can’t be fixed yes without change of charge controller, but second one there is proposed easy solution from Tom_E. 1.3 mA high drain current also come from high quiescent current of charge controller.

Third bug - battery check in simple mode does not read correctly.

High drain current needs to be fixed; other bugs can be lived with. Is the high drain because of the controller or the resistor or the combination? I do understand that changing controller might be costly but the OEM of that controller should take the responsibility for the high drain and fix the design and offer flashlight manufacturer credit for the update.

Wurkkos - changing a resistor value is simple, and it will reduce the switch high mode super high parasitic drain.

With the 8.2K resistor I used, the switch low mode is still visible, though I'd like it brighter - we don't have much control over the amperage difference between low and high - just the way the ATMEL MCU supports that built-in feature.

In that case, Terry should talk again with the Wurkkos engineer and see if one can ECO the resistor change. That should be done as soon as possible. There is lot of latent demand for the TS21 with low drain. I am holding off my purchase just for that.


I poked around for switch covers on Aliexpress, and while there are a variety of sizes and depths, didn’t find a direct replacement for the ~10/11mm covers that Sofirn uses.

I’ve been informed that a drain fix is in the works.

The spurious lighting isn’t harmful, but I’d hope that it prompts a reconsideration of the related (and IMO sort of frivolous) power bank feature, or at least more thorough testing before for all bugs before mass production is initiated. The industry already relies on public betas of sorts, but it shouldn’t be carried out by paying customers unless they’re willing.

This will be great news! Now all I need is the coupon code for the new Blue one!


Thanks for the nice thread. I’ve just bought a Thrunite T2 which I love because it is a very (very) bright & floody light, but the green tint gives me a headache. That Cree XHP 70 is a true green monster :confounded: . Came across this thread, got the Champagne 4000k TS21, now having a lot of fun with Anduril. I was very disappointed with the TS21 rapid step down at first, but now that the temp has been set to 60, it is night and day better.

FWIW, I’ve set the two lights next to each other and taken sequential pictures with my Canon in raw, manual settings, 5000k white balance, to follow their step downs during a 40 minute period. The Wurkkos, if still not as bright, could at least now keep closer in brightness to the T2 (which as mentioned is incredibly bright and floody). When it comes to color accuracy, there simply is no comparison between the 2; Wurkkos is so much better. Following are pictures to show off the beautiful tint of the Wurkkos 4000k. Very highly recommended!

Out of curiosity, I also measured external temp. After a 40 minute or so continuous run, Wurkkos measures 50 C at the head, and thrunite 45. Not bad at all.

Beam shots at 5000k WB

BTW I searched but couldn’t find: how to do voltage calibration? Take out battery after full charge, measure with my Rat Shack voltmeter, then set internal voltage to same value?

What are some of the reasons for doing this? So light doesn’t shut down/step down too soon if internal voltmeter is erroneously low? Thanks.

For the same reason that thermal calibration is performed — to ensure that the light’s internal sensor measurements correspond accurately to the true values. Take a measurement, then apply the configuration.

It was a feature added to Anduril 2’s advanced UI, and allows one to apply a correction factor as needed, via an additional 7H click sequence when in the battery check mode.

The T2 has piqued my interest, but too bad about the tint, proprietary cell, and price.

Not so! This is a better design. I would be much more interested if the switch was LARGE and proud and rubber. As others have said, coloring the lock ring is a good option for style.

Yes, the switch of TS21 finally decided to change to rubber ones

Ok done - thanks. Rat Shack measures 4.16V at full charge, flashlight says 4.1, so I did 8 clicks for +.05V. Feel good lol.

Yes the Thrunite T2 is an incredibly bright and floody light. And it seems to do it with ease. I think because the floody character makes the light output spread smoothly and evenly all around. If I walk into a small room in my house and point the T2 to the ceiling, it’s as if I’ve turned on the ceiling light. Too bad about the green, it’s overwhelming. BTW the Thrunite body with its more shallow cut doesn’t look aggressive but to me feels much better to hold than TS21 body with its deep valley and peak cut.

Because I am used to the T2’s prodigious output (for such a tiny light), I have had to set my TS21 to always one click start at Turbo level. :innocent: For those not ready with manual: with light on, double click to Turbo level, then 10 clicks to set Manual Memory. Now your TS21 will always start with one click at Turbo, regardless of last level. I love manual memory, makes life so simple, just like an old flashlight lol.