Fenix TK15 (1x18650/2xCR123A XP-G R5) Review: RUNTIMES, BEAMSHOTS and more!

Originally posted: February 25, 2011

Warning: pic heavy, as usual. :whistle:


The TK15 is new member to go with the Fenix TK11/12 family of XP-G R5 lights. So what’s different about this one? Scroll down and see. :whistle:

Packaging and extras are fairly typical for Fenix. Included with the light are a basic carrying pouch, basic wrist strap, spare o-rings and boot cover, manual, and warranty card. My sample came with the white and orange diffuser covers, but I don’t know if that is standard or not.

From left to right: AW protected 18650, Fenix TK15, TK12, 4Sevens Maelstrom G5, Sunwayman T20C, Nitecore IFE2, Eagletac P20C2-II.

TK15: Weight 131.1g (no battery), Length 147.1mm x Width 34.0mm (bezel max)
TK12: Weight 123.3g (no battery), Length 138.0mm x Width 34.1mm (bezel max)

The TK15 is about a centimeter taller than the TK12, but overall dimensions are otherwise similar.

Fit and finish are very good on my sample. No flaws in the matte black type-III hard anodizing. Knurling on the body and tailcap is about average in aggressiveness. Identification labels are clear and bright.

Screw threads are anodized for tailcap lock-out. :thumbsup: Screw threads seem to be high quality, with a square-cut at both the head and tail regions. Note the tailcap is interchangeable with my TK12 sample.

The grip ring is removable, but you have to take off the tail o-ring first. The clip is similar to other Fenix lights, but seems to lack the titanium coating send on my TK12 and recent LDx0/PDx0 series lights.

Due to the protruding forward clicky, the light cannot tailstand in stock form. But given that the tailcap sides are built-up slightly, you should be able adjust to the switch to potentially allow tailstanding. (e.g. add a washer underneath).

Note the body walls are fairly thick on the TK15, in keeping with its “Tank” family status. I imagine you could probably drive over this light with your car without much damage to the body. :rolleyes:

New from the TK12, there is a spring on the positive contact in the head of the TK15. This means that you should have no problem with any cell (although it should be said my TK12 could take flat-top cells as well, due to its slightly raised disc).

Switch is a forward clicky, with a slightly longer than typical traverse. No change from the TK12.

Like the TK12, the new TK15 also uses the Cree XP-G R5 Cool White emitter. The smooth reflector looks to be identical to the TK12 model.

Unlike some of the competition, the heads of the TK12/TK15 appear to be sealed. This means that reflector, bezel, etc is not user swappable. :shrug:

Which brings us to the requisite white wall hunting ;). All lights are on Hi on 18650 (AW Protected where available), about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall). Automatic white balance on the camera, to minimize tint differences.

The beam profile isn’t any different from the TK12, but the output has increased slightly (TK12 is not shown). Even with the Smooth reflector, the TK12 has a very even beam with no obvious rings. Like with many XP-G-based lights with deep reflectors, there is some evidence of a slightly dark centre to the hotspot (i.e. a faint donut pattern). This is only noticeable at a distance – and only if you are looking for it. It is not at all distracting in this case.

Scroll down to my Summary Tables for more specifics on output and throw.

User Interface

Turn the light on by the tailcap switch. Half-press the tailcap for momentary-on, click for locked-on

What’s new for the TK15 is that mode switching is controlled by secondary button near the head of the light. This button feels something like an electronic switch, but with a slight “click” when pressed.

When on, press and release the front button to advance through the output modes, which are Lo > Med > Hi > Turbo, in repeating sequence. The light has mode memory, and will return to the last setting used when turning the light off-on.

Strobe is “hidden” on the TK15. From on, activate it by pressing and holding the front button for at least 1 sec. Exit strobe by turning off the light off or pressing and holding the front button again for more than 1 sec. There is no memory for strobe – turning the light off and on returns you to the previously memorized constant output mode.


As with all Fenix lights of this class, the TK15 appears to be current-controlled. :thumbsup:


This is new - strobe is an oscillating strobe on the TK15. You get ~2 secs of 6.5Hz, followed by ~2 secs of 15.0Hz, in a repeating loop. I presume the idea is that it would hard to steel yourself against a rotating strobe. :green:

Testing Method:

All my output numbers are relative for my home-made light box setup, a la Quickbeam's flashlightreviews.com method. You can directly compare all my relative output values from different reviews - i.e. an output value of "10" in one graph is the same as "10" in another. All runtimes are done under a cooling fan, except for any extended run Lo/Min modes (i.e. >12 hours) which are done without cooling.

I have recently devised a method for converting my lightbox relative output values (ROV) to estimated Lumens. See my How to convert Selfbuilt's Lighbox values to Lumens thread for more info.

Throw/Output Summary Chart:

Effective November 2010, I have revised my summary tables to match with the current ANSI FL-1 standard for flashlight testing. Please see http://www.sliderule.ca/FL1.htm for a description of the terms used in these tables.

Max output has increased on TK15, relative to the TK12. Although the TK12 is consistent with most lights in this class, the TK15 not matches the most heavily driven XP-G R5 lights that I’ve seen (e.g. Armytek Predator and Lumintop TD-15).

Output/Runtime Comparison:

Note the specifications claim that RCR is not supported. However, I tested 2xRCR on the Hi and Turbo levels, without apparent ill effect. :shrug: However, keep in mind the specs do not support this configuration.

As always, Fenix efficiency remains top of class for its output levels. I note that the performance on Turbo on 1x18650 is almost an exact match for the first ArmyTek Predator on SEMI regulation.

Potential Issues

The front switch is fairly small and smooth, making it hard to find without looking for it. Using it with gloves on may be difficult.

On my sample, there is a slight indication of the well-known XP-G dark-centre effect in the hotspot (i.e. a faint donut pattern to the hotspot). This is not uncommon on XP-G lights, especially those with smooth reflectors.

The light can’t tailstand in its default form.

Preliminary Observations

The TK15 is an update to the popular Fenix “Tank” line. Like the TK12 I reviewed last year, this it is a physically robust build, but with a revised new user interface.

The main difference to the TK12 is the secondary front switch to control mode switching. I personally like this design, as it is popular with general users (i.e. it is a familiar means to control a flashlight). However, I find the TK15’s switch to be rather small and hard to access without looking for it. Although a bit ungainly looking, I would have preferred something like the Klarus of Zebralight front switches (i.e. larger, protruding, and with a textured rubber cover).

The other main difference is the output – the TK15 is driven harder on Turbo than the TK12. In fact, the TK15 is one of the highest output XP-G R5 lights I’ve ever tested – in the same category as the Lumintop TD-15 and ArmyTek Predator. :)

The TK15 also includes a “hidden” strobe mode. This strobe is unusual, as it is an oscillating med-hi frequency strobe. If you are into such things, trust me, it is quite nauseating. :rolleyes:

What hasn’t changed is the overall build of the light – it is as robust as ever, and the reflector and tailcaps seem the same as the TK12. I would say the beam is pattern is quite reasonable for a light this size, although of course it doesn’t throw as far as the larger lights with deeper reflectors. Some evidence of the common XP-G dark centre is also possible with all lights with smooth reflectors.

The other thing that hasn’t changed is that outstanding Fenix output/runtime efficiency. :thumbsup: At whatever output level you choose to run the light, you will get the best possible battery performance.

A nice upgrade to the line, the TK15 gives you an additional option above and beyond the TK11 or TK12. Whichever one you pick, you get a good, solid, sturdy light that should serve as a reliable companion.


TK15 was donated by a CPF member for review.

To follow the online discussions for this review, please see the full review thread at CPF.

Return to the master review list (at flashlightreviews.ca).

For a list of all my CPF flashlight reviews in chronological order by battery type (direct link to CPF), please see here:
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