Sofirn SC18/ Wurkkos WK03 small review + runtime + teardown (partially)

LED Flashlights – General Info 18650 Flashlights
1

This is my first review and neither my english is good, nor is my test equipment. Please don’t expect to much :wink:

First a size comp: SC18(18650) - SC21(14500) - SP35(21700)

This is quite a nice light for that price point: strong SST-40 LED, 1800lm, 2A USB-C charging, battery indicator, super compact factor and weight. On the second view, you will notice, where they were cutting costs. E.g. the anodizing is even worse than other sofirn lights regarding durability.
But overall I think Sofirn exactly meets their goal: a simple quality light for non flashaholics.

What I like:

  • price point
  • very compact
  • bright
    +USB C (my thicker cables fit, unlike at SC21)
  • moon: hold from off is as long as with Anduril, not as forever long as with SC21 or SP35

Neutral:
o no glass lens
o FET driver (expected in that price range)

What I dislike:

- dropin instead of unibody

  • CW LED

My attempt to disassemble the light:
To unscrew the head I heated up the light a bit in Turbo and took a bike tube to grab the housing and head.

There is no glass lens in front of the optic -> scratches are preprogrammed
The LED and driver are sitting in an thin dropin.

It’s press fitted and I didn’t try to remove it, because of lack of suitable equipment.

What I found out is, that the MCU is from fremontmicro and the charger IC is a 3A one, that charges with 2A actually.

Following a runtime chart.
Take the absolute values not to serious, because I only calibrated my DIY Lumensphere roughly.

full High test with Sofirn 3Ah cell. It turned off at 2.7V as it should. drop at 158min, because I measured the voltage.

It seems like, there is no ATR in High mode. It runs really hot. At the end, I could touch the body only as long as 2 seconds.
Also, when I turned on the fan, the light didn’t react to it and rising the output (unlike SP35, whose temperature was alway 45-46°C).

In Turbo, there is a stepdown, but the light didn’t behave different with cooling (120mm PC fan 13V). It was a little bit brighter and/ because it ran around 15°C cooler.
I’m not sure if there even is a working ATR, or when it do regulate sth.
*According to Sofirn this could be a problem with first batch and will be
fixed in 2nd batch in October 22. *

Turbo isn’t fully DD, but around 72%. Frequency is 21kHz in all modes—> no flickering :slight_smile:
Measured over a 3mOhm shunt:

Modes:
Off: 3.5µA
spec measured tailcap
Moon: 3lm 2.5lm 8mA
Low: 100lm 75lm 0.2A
Med: 350lm 285lm 0.8A
High: 800lm 630lm 1.8A
Turbo: 1800lm 1220lm 4.5A
Turbo 0s: - 1400lm -
1 Thank
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Sorry, no one photo?
Could you please measure the current in different modes?
Thanks

3

off current is 3µA -> almost nothing. I am going to try measuring the current. The problem is the voltage drop over my multimeter. But maybe my lumen measurements do help:
Moon: 3/ 2.5
Low: 100/75
Med: 350/ 290
High: 800/ 650
Turbo 1800/ 1400(turn on) -> 1280 (30s)

But these values could be off, I have to calibrate my sphere better

4

Thanks for joining the party, Luminance!

I frequently play a video game where my character is known as "The Luminary."

5

Thanks, it looks like something like 5A on turbo, maybe 1.5A on high and 600mA on medium. You need two thick and short wires connected to multimeter instead of the default thin probes for true current values.

Maybe this dropin isn’t so bad as it is press fitted and the light get hot when used.
ATR now works as stepdown in turbo mode.

I ordered wurkkos w03 to try. Just for fun, I like the UI.

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Hi, raccoon city. Nice to now. I chose this name, aiming at the SI unit cd/mm2

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yes, I have a stepdown at turbo to. Could you test if your light steps down on high, mine does not. As it can be seen in the graph

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I just ordered it yesterday so it may take 2 weeks of even longer when I get my wk03)

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The SC18 uses a 1 minute turbo timer + ATR at 43°C if you continuously reactivate turbo.

What’s the ambient temp for the test? I reviewed this and at 20°C it maxed out at 54°C at the head and 50°C on the body. This is perfectly fine, but for places that are warmer it could become an issue if one isn’t smart enough to manually reduce the level or hey sit it down somewhere. Although in use, would it actually heat up as hot as you saw, not likely since the air is moving around it and your hand conducts heat better than air sitting on your desk.

Your lumen measurements in comment #3 are very close to mine, some are exactly the same. My tube is calibrated with maukka lights, so you may not need to change anything.

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Is the switch led controllable?

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Not within the UI. You need Anduril UI

12

Great job on your first review. You answered all my questions.
Thanks for taking the time to make it! It is very helpful.

13

Thank you for the review!

Is it possible to remove the head? Is the body tube attached to the head by a threaded or press-fit connection?
I would like to modify the driver to have button standby light.
This has deterred me from buying so far, as well as the fact that the button seems to protrude too much. It is problematic to all the time lock out the button.

In the meantime I realized that the body and head are probably one piece and the shelf is holding the driver down.
It’s incorrigible, uncustomizable. :cry:

14

I would have to Retest my SC18, but if I’m remembering correctly — your numbers are close to what I measured

15

It happend that I didn’t get a notification about new replies, sorry. I received a new unit and can confirm, that it regulates the temperature to around 45˚C, although the pcb has the same date marked (22.05.17). Good to now, that my numbers seem accurate.

16

It seems the driver is not current regulated in turbo mode?

17

yes, it’s only an pwm fet driver. No current regulation in any mode

18

Not in any mode?
Too bad.
I was about to get one, i like the TIR fresnell optic.

19

viele danke

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Thank you for putting this up Luminance. I really appreciate it! Good stuff!