Review: BTU Shocker (3 x XM-L T6 NW | 3 x 18650)

BTU Shocker (3 x XM-L | 3 x 18650)

Reviewer's Overall Rating: ★★★


Battery: 3 x 18650
Switch: Tail switch, Reverse clicky
Modes: 4: Low, Med, High, Turbo
LED Type: 3 x XM-L T6 3C (NW)
Lens: Glass
Tailstands: Yes
Price Payed: Introductory price $150 (retail price $180)
From: FF
Date Ordered: November 2012


  • Bright (CW U2 would be even brighter)
  • Insane throw (about 80kcd as NW)
  • Ability to choose DRY driver for even more output
  • Very solid build
  • Available as NW
  • Good runtime with three cells
  • Current regulated -> No PWM on any mode
  • Well spaced modes
  • No blinky modes
  • Tailstands well (and can be used to illuminate the whole room )
  • Good thermal characteristics - temperature raised only to 53°C during a 1h25min run indoors (ambient temp 23°C)
  • Great design & build quality, also in battery carrier
  • Lanyard is long enough to be used as a handle
  • "Lanyard handle" is not cold in low temperatures (it was -18°C yesterday when I was testing this - yes, it's about 0°F)
  • Flat bezel
  • Comes in a nice box, lanyard included, very good for gifting!


  • Not exactly lightweight at 1200g
  • No option for lock-out

Features / Value: ★★★★

The light comes in a plain black box which contains the light itself and good long lanyard (and optional & extra DRY driver)

Features are good: Four well spaced, current regulated modes. No blinky modes, that would just annoy the user.

UI is pretty normal: Reverse clicky tail switch, with working memory. The light always starts on the last mode used.

Turbo mode has an automatic step-down feature: If the turbo mode is used over 3 minutes, the light steps down to High mode to prevent overheating. If you still want to continue with turbo, you can go back to turbo with a single half-click.

Value for money: Good!

Design / Build Quality: ★★★

Design is very nice. You can think of TK70, but much shorter. Short, thick, good handle, and large head for maximal throw.

Color of anodizing is good in my eyes and to top of it, bezel is flat. Just I like'em!

The anodization is very good overall, and glass lens looks & feels nice and durable. It doesn't seem to be AR-coated though.

Let's see some details..

Cooling fins, serial number, and just about perfect knurling in the body:

Tailcap switch, or actually only the rubber boot covering the real switch, which is integral part of the battery carrier. Tailcap has also two holes for attaching the lanyard.

Here we can see the switch, which is indeed attached to the very well built battery carrier.

Four basic parts of the light: Head, body, battery carrier, and tailcap.

All threads are square cut and anodized. Here's threads of the head, note how long those are. Very good for durability!

There is also dual O-rings to make sure that the light is water proof.

Tailcap threads are not only sqare and anodized, but also well lubed. Good job at BTU factory! Dual O-rings also here.

The battery carrier is very well built and feels secure for heavy use. Even larger cells, like XTAR 18700s, fit well.The tail end has the switch:

..and the other end as two springs, delivering the current to the head / driver:

All of the springs feel suitable for the job of delivering high amperage. The springs inside the carrier are reversed, which feels like a good solution. They are also soldered very well.

Positive terminals are covered with copper plates:

Heres the business end. Looks great! Emitters are well centered and reflectors spotless.

Thick plate holding the driver can be screwed out pretty easily, allowing access to a screw holding the reflector tightly in place:

Closeup on the driver. Says "LD-34"

Here's the reflector. It's made of aluminum and pretty heavy.

Under the reflector we can see three emitters glued to hefty heat sink and wired in series with beefy leads. Plastic centering rings make sure that the emitters stay perfectly centered also in the future.

Here's the whole light disassembled in a group shot:

The included lanyard is long, thick, and robust enough to be used as a handle. This made it easier to carry the light, especially in cold conditions when metallic body can make your hands cold in a short time.

Some measurements:

Length: 204mm

Head diameter: 106mm

Body diameter: 50mm

Body wall thickness: 4.5mm

Tail diameter: 54mm

Lens diameter: 94mm

Lens thickness: 3mm

Reflector diameter: 42mm

Reflector depth: 47mm

Weight: 1203g with 3 cells (= ready to use), 1062g without

..and here's some pictures confirming the measurements:

Compared to other lights:

Three three emitter lights from the front:

And the bottom line in the quality: Nothing to complain! Very solid and well built light.

Battery Life: ★★★★

Good! Three batteries and good mode arrangement with low enough low will allow very long runtimes.

I measured the tailcap current and got results of 3.6A on Turbo, 1.8A on High, 0.6A on Med and 0.05A on low.

This would give almost 1.5h runtime on High, 4.5h on Med, and over 52h on low!

Light Output: ★★★

Let's make this clear: This light is "only" about as bright as the NW King, if we compare only lumens that is.

But when we take the throw into account, this light wins, hands down. Even as NW, this BTU pushes out very respectable amount of candelas: 80kcd (after 30s, measured at 4m and calculated back to 1m), which is four times as much as my NW King does!

Thermal sag & runtime graph: (with XTAR 18700 2600mAh cells)

The first three minutes are on turbo, rest of the graph on high. This runtime test was done indoors, with ambient temperature of 23°C, without any additional cooling. This light seems to be well regulated and handles the heat very well.

This light has a low voltage warning (blinking the light with low level), which kicked in at about 1:22. Battery voltage after a slight rest was 3.2V.

I estimate (ceiling bounce + "known" references) the light output to:

- way over 2000 lumens OTF on turbo

Please take these values with a grain of salt. I have been underestimating OTF lumens in my last tests (like 650lm for 3.0A driven A8). It's time to get an IS, for sure.

White wall beamshots (1/400s, f/4, ISO80, WB: Daylight)

Beam angle:

Compared to King

High with low exposure to show differences in throw: (1/2500s, f/4, ISO80, WB: Daylight)

Left: King NW, Right: BTU NW

High with even more reduced exposure (1/2500s, f/8, ISO80, WB: Daylight)

Outdoor beamshots (1/2s, f/4, ISO200, WB 5000K)


BTU Shocker Turbo:

Compared to Skyray King NW High (mouse over for BTU Shocker Turbo)

Compared to Thrunite TN31 Turbo (mouse over for BTU Shocker Turbo)

Summary: ★★★★

I have always wanted to have Fenix TK70, but it's too long for my taste and uses D-cells, which I don't like. This light provides the same insane throw levels in a much shorter form and with lighter 18650 batteries.

This is a very throwy multi-emitter flashlight with solid build for anyone who needs a durable work horse, which put out generous amount of neutral white lumens.

Verdict: Highly recommended!

The End (pun intended):

Thanks for reading & watching. Hope you enjoyed the review!

I just want to say, before even reading the review, that I’ve been refreshing “recent posts” since I saw you received this light (well…i slept for a few hours), thanks! :beer:

I can’t wait for mine. Epic

Thanks for the awesome (as always) review =the=

Great review, and the BTU looks great :slight_smile:

This is monster, this is not a light :D!

Now, how about some outdoor beamshots?!

Thanks, the, for review!

great review.

very nice light. only thing I’d do different is make the emitters mechanically fastened, rather than with adhesive…

as much as I like the side switch on the tk75, if I were in choosing one or the other, I’d go with the BTU, because it is more user serviceable…

Nice review on a sweet light! ;)

Your lux readings are way off from others I've seen (as high as 130+k). Is it because yours isn't running the DRY driver? Just being NW compared to CW shouldn't make a difference of almost 50k.

Well.. My reading for stock TN31 CW is about 95kcd.

But there are couple of reasons for this low reading:

- I measured with the original driver (DRY driver would read higher for sure)

- This light is NW

- I measured at 4m, which is too little for this kind of throwers

- my meter might read a bit low(?)

Thanks! Looks like one well made light. That head is HUGE.

Product link in OP is wrong. Otherwise a teriffic review. Thanks. :slight_smile:

Much thanks for the review.
I was really surprised at the size, it’s the same height as the Thrunite TN31.
Seeing how short it is, and looking at the weight, it must be built like a tank.
I agree with JohnnyMac, I think you numbers are conservative.

That pill does no have many threads reminds me of the TK35 clone.

its not a pill, afaik - just a driver holder. emitters are mounted on integral part of head.

Great review -the-. Sorry I don't follow the general enthusiasm for this $150 light, 80kcd isn't impressive for the price, and the output is just at King's level. Given the hype that this was called "super thrower"... hmmmph... not quite there. Maybe beamshots will tell a different story, but right now I'm not too impressed.

my guess is that we see <$100 by summer

Thanks for informing me. Fixed. :)

Wow - great review as always, the

Would be interesting to see the difference a CW makes.

Well, it looks like the Shocker is a win in my book. Thanks for ‘the’ review, the! While 80kCd is less than I expected, that’s still up there with the good throwers in the price range, and evidently build quality is right up there as well. A 9.4cm UCL or AR window would net even more output. Not to hassle you or anything, but I’m guessing you tested out measuring lux at further distances like 10m?

If you aren’t impressed, tell me the other 18650 multi-xml that throws even half this well for the price. Xtar S1 at 65k and $200?