Wurkkos WK15

The WK15 is a relatively compact, inexpensive, general-purpose flashlight running on a single 21700 battery. It features the common Cree XHP50.2 emitter.

  1. Introduction
  2. Manufacturer Specifications
  3. Package Details
  4. Build
  5. User Interface
  6. Circuit Measures
  7. Emitter Measures
  8. Beamshots
  9. Testing Results
  10. Runtimes
  11. Pros and Cons
  12. Overall Rating
  13. Preliminary Conclusions
  14. Acknowledgement


I am still working through my backlog of lights – this WK15 sample was received late last summer.

I’ve reviewed a number of general purpose 1×21700 lights by Wurkkos and Sofirn, and have typically been very impressed with the performance and build for the price. I noticed a general lack of reviews on the WK15, which seems to be a particularly inexpensive model in this space. Wurkkos agreed to send me a sample to review.

Equipped with the popular XHP50.2 emitter, available in both the neutral white 5000K and cool white 6000K colour temperatures (I opted for 5000K). The WK15 rated specs are very similar to many competing models in this space, despite its relatively compact size. Let’s see how it performs in my testing.

Manufacturer Specifications

Note: As always, these are simply what the manufacturer provides – scroll down to see my actual runtimes.

Tint5000 K
Max Output (Lumens)3,000
Min Output (Lumens)1
Max Runtime500 hours
Max Beam Intensity (cd)11,892 cd
Max Beam Distance (m)218 m
Constant Levels6
Weight (w/o battery)-
Weight (with battery)70 g
Length113 mm
Head Diameter27.8 mm
Body Diameter-

Package Details

Unlike the modern style packaging of the newer higher-end models from Sofirn and Wurkkos, the WK15 comes in fairly basic packaging. Inside I found:

  • Wurkkos WK15 flashlight
  • Wurkkos-branded 5000mAh 21700 battery
  • Wrist lanyard
  • USB-C charging cable
  • 2 Spare O-rings
  • Manual

It’s a decent package for a “budget” build, but I would like to see a holster included. FYI, Wurkkos sells an inexpensive holster (small size for ~$2 USD) that fits this light.


From left to right: LiitoKala 21700 (5000mAh), Vapcell 21700 F56 (5600mAh), Emisar D4K, Imalent MS03, Convoy S21E, Skilhunt M300, Wurkkos WK15, Wurkkos TS22, Sofirn SP35T, Cyansky P25, Nitecore P20iX, Acebeam E70.

The WK15 is a very compact 1×21700 light – its definitely on the smaller side of the lights I’ve tested in this class. It vaguely reminds me of the Fenix E35, although in a more basic build.

The tailcap is flat, with a lanyard cut-out area. It is able to tailstand stably. Tailcap threads are square-cut and anodized, with good feel. Thanks to the anodized tailcap threads, you can easily lock-out this light by a simple twist of the tailcap.

The electronic switch on the side of the head has red and green LEDs underneath to show charge status. Feel and traverse of the electronic switch is very similar to a lot of Wurkkos and Sofirn lights – it’s ok, but could be a bit tighter/firmer (i.e., hard switch covers always have some degree of play).

The light’s USB-C charging port is located on the opposite side from the switch, under a rubber cover. The cover fits pretty well – not too too tight, not too loose. I expected waterproofness is reasonable (i.e., more splashable than watertight).

There is a lot of traditional knurling on the light – not super aggressive, but more than most, producing excellent grip. Anodizing looks to be good quality for type II, with no damage on my sample. I would describe the finish as matte. Thanks to included bi-directional clip, the light will not roll on its side. The clip attaches firmly, and is good for both bezel up and down carry.

Inside, the light comes with a Wurkkos-branded standard-sized 5000mAh 21700 battery, with a slightly raised flat-top.

This is a solid little light, with good grip and handfeel. It does seem a bit more budget than the rest of the Wurrkos or Sofirn line – but that is in keeping with its lower price point.

The WK15 comes with a XHP50.2 HD emitter, in neutral or cool white tint (neutral on my sample). The reflector is fairly shallow and well textured (moderate orange peel, MOP). There doesn’t seem to be any kind of anti-reflective coating on the lens.

As expected, there is noticeable tint/colour shifting across the periphery of the beam, with a warmer yellowish white hotspot surrounded by a coolish spill and purplish shift near the edge of the periphery. This is a well-known issue with HD emitters of the XHP family, particularly obvious on the XHP50.2. The textured reflector normally helps to even it out, but I do find my sample is rather noticeable.

The bezel is flat black aluminum. So you can headstand stably, but you can’t tell if the light is on in that orientation.

User Interface

The WK15 has a straightforward user interface, and one that is similar to many basic Sofirn and Wurkkos lights.

Mode levels: Moonlight, Eco, Low, Mid, High, Turbo, and Strobe

From OFF:

  • Press-and-hold: Turns on in Moonlight mode.
  • Single-click: Turns On in last memorized mode (only Eco, Lo, Med and Hi can be memorized).
  • Double-click: Turns On in Turbo.
  • Triple-click: Turns On in Strobe.
  • 4 clicks: Activate Lock-out mode. Four clicks to unlock.

From ON:

  • Press-and-hold: Cycle between Eco > Lo > Med > Hi (in sequence).
  • Single-click: Turns Off.
  • Double-click: Jumps to Turbo. Single click jumps you back to last memorized mode.
  • Triple-click: Jumps to Strobe.Single click jumps you back to last memorized mode.

Mode memory:

Yes, for non-Moonlight, non-Turbo constant output modes.


  • Moonlight mode: Press-and-hold the switch from Off.
  • Turbo mode: Double-click the switch from On or Off.
  • Strobe: Triple-click the switch from On or Off.

Low voltage warning:

Not that I noticed.

Lockout mode:

Yes, you can physically lock out the light at the tailcap. There is an electronic lockout as well that you can trigger manually (i.e., no auto-lockout).

Battery indicator:

Not that I noticed.

Reviewer Comments:

A very serviceable and standard interface – easy to remember and use.

Circuit Measures

No Pulse-Width Modulation (PWM):







There is high frequency circuit noise on all levels above Moonlight. This is common on a lot of inexpensive lights, and is not necessarily a concern as it is not visually detectable. I measured the frequency as just over 21 kHz on all modes from Eco through Turbo (note the last trace above shows an inaccurate lower value – the auto measure feature in the oscilloscope software sometimes gets fooled by slower harmonics).


Strobe is a constant 14 Hz.


The switch button shows solid red when the light is charging. Changes to solid green when the charging is complete.

Resting voltage <3.0V

Resting voltage >3.0V

The WK15 has a two-stage charging feature, as seen on many good quality modern lights (i.e., where there is a lower initial charging rate when the cell is heavily discharged). I’m actually surprised to see it here, given the budget price. This is also a very high charging rate for the class, and will charge a 21700 cell quickly.

Standby / Parasitic Drain:

Yes, due to the electronic switch. I measured it at 1.7 mA, which is moderately high. For a 5000mAh cell, that would mean you would deplete the battery is about 4 months. But you can easily cut this current by a simple twist of the tailcap.

Emitter Measures

In this section, I directly measure key emitter characteristics in terms of colour temperature, tint, and colour rendition. Please see my Emitter Measures page to learn more about what these terms mean, and how I am measuring them. As tint in particular can shift across levels, I typically stick with the highest stably regulated level for all my reported measures.

As explained on that page, since I am using an inexpensive uncalibrated device, you can only make relative comparisons across my reviews (i.e., don’t take these numbers as absolutely accurate values, but as relatively consistent across lights in my testing).

WK15 on Hi:

The key measures above are the colour temperature of ~4800K, and a slight positive tint shift (+0.0103 Duv) to slight greenish-yellow at this temperature. I wasn’t able to get a reliable CRI (Ra) measure.

These values are consistent with the performance of a neutral white XHP50.2 emitter, and match my visual experience of this light. Note that there is a noticeable tint shift from yellowish hotspot to cooler white spill with purplish spillbeam edge, which is common to 50.2 HD emitters.


All outdoor beamshots are taken on my Canon PowerShot S5 IS at f/2.7, 0.5 secs exposure, ISO 400, daylight white balance. The bend in the road is approximately 40 meters (~45 yards) from the camera. Learn more about my outdoor beamshots here (scroll down for the floody light position used in this review).

Click on any thumbnail image below to open a full size image in a new window. You can then easily compare beams by switching between tabs.

As you can see above, the WK15 has a pretty traditional beam for this class.

Testing Results

My summary tables are generally reported in a manner consistent with the ANSI FL-1 standard for flashlight testing. In addition to the links above, please see my output measures page for more background.

All my output numbers are based on my home-made lightbox setup. As explained on that methodology page, I have devised a method for converting my lightbox relative output values to estimated lumens. Note that my lightbox calibration runs higher than most hobbyists today, but I’ve kept it to remain consistent with my earlier reviews (when the base calibration standard was first established). On average though, I find my lumen estimates are ~20% higher than most other modern reviewers.

My Peak Intensity/Beam Distance are directly measured with a NIST-certified Extech EA31 lightmeter.

WK15 Testing Results

ModeSpec LumensEstimated Lumens @0secEstimated Lumens @30 secsBeam Intensity @0secBeam Intensity @30secsBeam Distance @30secsPWM/Strobe FreqNoise FreqCharging Current <3VCharging Current >3VParasitic DrainWeight w/o BatteryWeight with BatteryCCT (K)DuvCRI
Moon11.21.2---No21.25 kHz0.17 A2.15 A1.70 mA71 g140 g---
Eco101010---No21.25 kHz0.17 A2.15 A1.70 mA71 g140 g---
Low100150150---No21.25 kHz0.17 A2.15 A1.70 mA71 g140 g---
Med550590585---No21.25 kHz0.17 A2.15 A1.70 mA71 g140 g4,8150.0113-
High1,5001,5501,550---No21.25 kHz0.17 A2.15 A1.70 mA71 g140 g---
Turbo3,0003,5003,30013,500 cd12,100 cd220 mNo1.24 kHz0.17 A2.15 A1.70 mA71 g140 g---
Strobe3,000-----14.2 Hz21.25 kHz0.17 A2.15 A1.70 mA71 g140 g---

My WK15 sample very closely matches the reported specs for this light. I know my lightbox’s relative calibration is generously high for modern high-output lights, however.

That said, my NIST-calibrated luxmeter is accurately calibrated to an absolute standard, and similarly reports very consistent peak intensity throw to reported specs.

To view and download full testing results for all modern lights in my testing, check out my Database page.


As always, my runtimes are done under a small cooling fan, for safety and consistency. To learn more about how to interpret runtime graphs, see my runtimes methodology page. Note that on average, my lightbox’s calibration seems to be ~20% higher than most modern reviewers.




Consistent with the budget price, it looks like the WK15 is using a simple linear FET driver. Performance is extremely consistent with the Sofirn SP35T – basically, a direct-drive-like pattern where the battery resistance is ultimately regulating output over time. Sadly, there is no flat voltage-regulated performance here, unlike the higher-end TS22 for example.

All that said, performance is not bad – it is just very basic. Note however that both the Hi mode as well as the Turbo mode step down rather quickly, compared to some other lights. But the flip-side of that is the light certainly lasts for a reasonably long amount of time.

Pros and Cons

The light has a solid build, with an electronic switch.Circuit is not voltage-regulated, producing a slowly decreasing output instead of flat runtimes.
The light has a serviceable basic user interface, easy to remember and use.The circuit is also noticeably less efficient than other current-controlled lights with flat regulation.
Price is reasonably low.XHP50.2 HD emitters produce well known tint shifts across the beam, with a yellowish hotspot, cool white spill, and purplish spillbeam edge.

Overall Rating

Preliminary Conclusions

The WK15 is a compact but solid light, with a decent physical build and good (if basic) user interface. You could do a lot worse for the price!

But as described above, the circuit performance is disappointing here. Similar to the Sofirn SP35T, you get a reasonable amount of light for a reasonable amount of time. But its performance just doesn’t compare to the fully-regulated competition, such as the efficient (but more expensive) TS22 in comparison. That said, the published output specs seem pretty accurate for this model, with a good range of output levels.

The XHP50.2 HD emitter is known for a lot of tint/chromatic variation across its beam, and this example is no different. I can’t specifically fault this model in that regard, but my WK15 sample is particularly noticeable.

Taken together, I find these drawbacks limit this light to a maximum 3.5 star rating on my subjective scale. This is still quite decent, and better than some equivalent models at this price point. But there are couple of others I might recommend over this. That said if you like a straightforward interface and grippy finish, this light does fit the bill for the budget class.


The WK15 was supplied by Wurkkos for review. As always, all opinions are my own and the light received the same rigourous and objective testing as all other lights that I have reviewed. At the time of review, this light retails for ~$25 USD (~$35 CDN) with battery included on the Wurkkos website here.

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