Wurkkos FC12 first impressions

Got a FC12 from Wurkkos for testing (thanks again) – here’s a quick summary of my first impressions:


  • Bundled 3000 mAh 18650 was at 3.64 V.
  • FET driver with 30 kHz PWM except turbo and moon (moon might be just a resistor?).
  • Measured the battery with 4.22 V after internal charging.
  • Switch PCB has a diode (Vf = 0.1 V measured with a multimeter). It is used for charging when the switch is off. The charge controller has to take this diode into account, otherwise it will under/overcharge the battery. Haven’t checked if it works in all scenarios correctly (switched on/off, switching wile charging).
  • LED is switched off during charging. It turns on if you unplug the charger.
  • The small, but deep reflector results in a small spot with bright spill. Nice for outdoor use.
  • Gets hot quickly and ramps down from turbo to about 25% in just 30 seconds if not cooled.
  • Moon and turbo are not included in the normal mode sequence. Only smooth ramping is from low to turbo (without moon).


  • The ribs / knurling are unexpectedly nice. Good grip without being sharp or rough.
  • I really like the SFT-40, although it is CW and low CRI. No noticeable tintshift between low and high and doesn’t appear green.
  • Forward clicky – usable for momentary light!
  • Shortcut to moon if you hold the side switch when turning it on. Small detail, but very useful. Otherwise you don’t have any control of the light output when you turn it on. Requires both hands for many people.


  • It’s long! Usually you can control flashlight with two switches like this: Thumb at the rear switch, another finger at the side switch. Often not pleasant, but it works. Not with this light.
  • Smooth ramping is linear regarding duty cycle, not visual. Low levels are too fast, and high levels too slow. In stepped mode the four levels are well spaced.

Suggestions for improvements:

  • Only normal levels are memorized, not moon or turbo. If you like to get full output when switching on the light, you have to use smooth ramping and ramp up all the way (which is the same level as turbo). Would be great if turbo is memorized in stepped mode as well.
  • Apropos memory: If strobe is memorized as well, it might be even useful. Now to get strobe, first turn the light on with the rear switch, then press the side switch three times.
  • In smooth ramping you change the brightness by holding the side switch. But in stepped mode its a short click of the side switch. Currently holding it does nothing, so it would help to make it consistent and change the levels either by clicking or by holding.
  • Make it shorter! 10-15 mm would help a lot.


thanks for the review :nerd_face:

I don’t understand the chart. Did you start with turbo and the lights ramps down after a minute? Why would a runtime chart have a zigzag like that?
Looks more like a lumens/brightness chart and the zigzag is the ATR doing its thing.

Mine didn't come with a manual. I see the website shows a picture of one. Can you make the manual available for dowload?

Btw, even though the size is a bit too long, shaky to tailstand, I am glad I bought one - nice LED, nice beam profile, nice looking light. The purple ano sparkles

Yes, it is “ATR doing its thing”. I can’t measure the runtime on full turbo because I can’t cool it enough.

Thanks for the review!

ATR regulation needs some PID…

Where i can update a manual for a download, maybe someone could help?

Ask the website team of wurkkos.com. Manuals should be provided for download on the product pages. It cannot be much effort to place a download link in the description section

I like the tint of my FC12. Pure white with no green and the color is maintained even in the low levels.

Purple ano is perfect.. i need to read the manual - can you only turn it on with rear switch? if so this is annoying. Also, it is much longer than i thought. the beam and light are very nice, but i bought this for the wife (even though i love the purple ano and WOULD edc it..) but she is not a fan because it is too large for her to carry around during times she might actually carry around a flashlight (hiking, camping, night time outdoor events).. so maybe ill take it on but i prob wont use it, or she will keep it and use it once a year.. just a little disappointing.. my own fault i bought it "on the spot" and ASSUMED it would be sc31- sized.. i should know better than to not look up the dimensions of lights i've never owned.

Try this:

But of course you have to twist the tailcap to turn the light off. My solution is a driver swap. It will be getting a gchart 1616 MCU driver, 20 mm, losing the charging though, but running the very latest Anduril 2. I'll configure A2 to support the tactical tail switch (power switch comes on at last used level), so can be used with either the tail switch or not. If you turn it off at the side switch, the switch LED still stays on (using the green switch LED, not RED).

They used a lot of glue, completely covering the outer ring of the driver and shelf it sits on. Had to use a hammer and solder pick to tap it loose, no damage accept the vertical board came loose from the round horizontal board.

Traced out the switch. They used all red wires with Chinese labeling. I'm replacing them with color coded 30 AWG.

Awesome Tom!!

Where can i get the Gchart driver?? Can i buy one somewhere?

Dude, Gchart really is the man! that guy does some fantastic things! And so do you!, because you're showing us this mod! haha.

And is that just a regular sc31 pro ( or similar) tail cap? i think i saw those on Aliexpress for like $2 ? is that the one? https://www.aliexpress.com/item/1005001291432719.html?spm=a2g0o.cart.0.0.51833c00UXdjzQ&mp=1

Thanks again Tom

The gchart driver - I got one (think he does too) on OSHPark. Don't think he's selling them and I'm not, so... So you can buy the board and parts and reflow. But for me, the jury is still out - still trying to get it working. Having a couple of problems, mainly the MCU is difficult for me to reflow, others are doing better using a stencil, etc.

That's a SC31B tailcap, not a SC31 Pro, but they are interchangeable (just tried it). so Yes - that tailcap should work, as well as a SC31 Pro tailcap. Can't actually test right now because my FC12 is dis-assembled.

The Pro tailcap has a lanyard hole so it's slightly longer. However a FC12 tailcap can't thread on a SC31B or SC31 Pro.

Got ya. Thanks Tom

I’d be so happy with this light if it did away with the rear switch and could be turned on/off with the side switch. Fumbling around with 2 switches just ruins it for me which is a shame because I really like the beam performance, color style etc.

Actually any 20 mm driver for e-switch would do. I got FET+1's that can run Anduril 2 in 20 mm sizes.

There has been an allusion to an FC11 2.0 in the works.

Love the sft40, good hotspot and spill.
Great light overall.
Fix 2 things:
Get rid of the useless sideswitch and make it the same length as a S2 with ramping, all at the tail switch!
Keep it simple.

Not possible to just reflash original MCU?

Not for me or anyone else I'm aware of. Typically they use PIC MCU's, but who knows - not worth reverse engineering, then again, I'm not too good at that. Others here know hardware wayy better than me.