Fenix TK40 Review & Comparison

Fenix TK40 Review & Comparison

First of all, i gonna give Manufacturer specifications of TK 40.

• 4 types of primary output:

Turbo (630 Lumens, 2Hrs, Default output ) ->Low (13 Lumens, 150Hrs ) ->

Mid (93 Lumens, 20Hrs ) ->High (277 Lumens, 6.8Hrs )

• 4 types of flashing output: Strobe, Slow flashing, SOS, Fast flashing

• Max beam length: 275 meters

• Central light strength: 18000 candelas

• Withstand impact from 1.5 meters

• Waterproof to IPX-8 Standard

• Included accessories: lanyard, shoulder strap, one key ring, two spare o-rings, and a rubber switch boot

• Cree MC-E LED with lifespan of 50,000 hours

• Uses eight 1.5V AA (Ni-MH, Alkaline) batteries

• 200mm (Length) x 40 mm (Diameter of the body tube) x 62mm (Diameter of the head)

• 266-gram weight (excluding batteries)

• Digitally regulated output, maintains constant brightness

• Push-button tail cap switch

• Capable of standing up securely on a flat surface to serve as a candle

• Patented structure avoid circuit damaging from reverse connection of battery

• Made of durable aircraft-grade aluminum

• Premium Type III hard-anodized anti-abrasive finish

• Toughened ultra-clear glass lens with anti-reflective coating

Fenix TK40 Review :

Initial Impressions:

Sliding the ornate paper sleeve reveals a plastic storage/carrying case. I won’t slam this too hard because I’ve already read where Fenix owned up to the mediocre design and I believe a better built case will be along shortly, if not already. It’s not that bad, however. The biggest problem I see with it is that it doesn’t close completely around the seam. Inside the snug case (besides the light, of course) is a bag with extra O-rings, rubber switch cover and a lanyard. I’m not sure who’s going to use this but there is also a giant shoulder strap. I’m not even going to comment on that!

From left to right - TK40, Wolf Eyes Sniper P7, Surefire A2

The light is big. It’s roughly the size of an M6 but with a smaller head and slightly thinner body. Speaking of thin, it certainly feels thin and light for it’s size without the batteries installed. I’m a little concerned about it’s ability to withstand “professional” abuse but only time will tell. I wouldn’t suggest a cop try and carry this light on a duty belt but it would certainly be a great light to be carried in a “trunk” bag while on patrol. Don’t get me wrong . . . this is a first impression and I’m not saying this light is a “wimp.” I was just a little surprised that it wasn’t a little thicker, due to it’s size. I get the feeling that dropping this on a concrete floor from 6 or more feet up is “gonna leave a mark,” that’s all. Sorry, I’m NOT going to try it!

Here you can see what I'm talking about where the thickness is concerned - 3D Mag on right.

The TK40 has a forward computer controlling "clicky" and is HAIII hard anodized and has non-aggressive knurling. It weighs 10.0 oz empty and 17.2 ounces with 8 nimh batteries. The fit and finish and threads are all great. In fact, the best I’ve seen on any Fenix. As I’m sure you’ve heard, the output is simply . . . . WOW. VERY impressive output, especially for it’s size (I know, I say that a lot!). This light can’t top my Mag 85 but I believe it tied or even edged out my ROP (but with a larger hotspot and much less spill). In any event, the folks who joust in the “INCAN VS. LED war” threads have a new lance with this puppy.

TK40 on left - WE Sniper P7 right

UI:

Oh boy . . . the UI is a doozy. It takes a little getting used to and even then I’m sure not everyone will like it, but it does remember the last level so that will be some solace for the folks who like simplicity. I normally do NOT like that feature (it’s why I don’t own any Olights) but on the TK40, it is most welcomed.

Okay so here goes: A single click turns it on. Like I said, it comes on in the last mode used so that will put it in 1 of 4 output levels. AFTER it’s on, and you’ve released the button, you press and hold and in short order you get the next level. Not too bad so far. If you want to explore the extra features (warning, strobe/sos haters need to turn to another station NOW) you double tap. The extra modes appear to be tied in to certain light levels, which is true of other Fenix lights. The chosen intensities do make sense so it’s not that bad but it takes a while to move around the modes to find what you want. On it’s lowest setting, double tapping gets you a beacon (a double tap gets you out of the special mode where a single tap just shuts it off). The next level up gives you SOS. The timing is a little faster and tighter than the P2D/P3D/LOD timing but it’s still not perfect. One oddity I noticed on the SOS: On my light (check this on yours) the second and third “O” (the long duration “dashes” between the short “dots”) have a slight blip of a higher intensity. It’s noticeable but not too distracting (but “Joe” noticed it right away – that will make sense later). Level three’s double tap gives you a slow strobe and Turbo’s double tap gives you a very fast strobe. I suppose this light can be used in a stress/tactical operation but you had better practice with it a lot and not mess with any other light with computer based UI. If you left it on high the last time you used it, turning it on followed by a double tap will get you your strobe. Mess that up at all and you’ll be lost and the would be strobe-ee will own you. I tried “triple tapping” it from off for the purpose of getting it to strobe immediately but that did NOT work. It needed a little pause after turning it on before the double tap put it in strobe mode.

Logistics:

There is no clip so you’re either going to need to find a big holster or go with the lanyard. Of course you can whip out the shoulder harness for maximum nerd prowess but I don’t recommend it. The body diameter is nearly identical to a D Mag so most D-sized Mag holster products should work. The TK40 can easily tailstand with good stability. There is one O-ring on each end. The reflector is deep, highly polished and has a light OP finish. The LED is well centered. The knurling is mostly for looks as it’s fairly smooth. However, the light doesn’t seem too slippery . . . the sheer size of it should keep it from slipping out of your hand anyway. The battery system was very well designed and I like it a lot (expect for a little rattling – Fenix, you need to fix that please). I would hope to see extra battery holders available but keeping them loaded will prove to be a challenge as there is nothing preventing the batteries from popping right out of the holder when not in the light. If Fenix offers extra battery holders for sale, I strongly suggest they design a little sleeve that could be left on all the time, or perhaps just slide it off right before installation. Hey Fenix, maybe you could take care of both problems if the sleeve is thick enough to stop the rattle. Now here’s the really cool part about this battery system: The TK40 can accept four or eight AA batteries. Just load two of the four slots, making sure you choose two opposite directions in adjoining slots. It is possible to mistakenly use two adjoining columns where all 4 point in the same direction. Nay nay on that – you have to choose one from column A (pointing up) and one from column B (pointing down). After that, you’re golden. Very well done, Fenix. There are “dots” on the battery tube to guide you on the 4 battery mode but I never saw them until I knew about them (I never read instructions . . . at first). With 4 batteries installed, the light comes on in all it’s glory and all it’s modes just like there are 8 batteries in there, but Fenix recommends not using turbo with 4 batteries for fear you may damage the cells. I know there have been some negative comments floating around about Fenixes decision to use AAs. I’ll give my opinion on that in the conclusion but the unique ability to use 4 instead of 8 should quell at least some of those types of concerns.

Current draw:

This was a little challenging. Somebody owes me something for this. Send me your tired old Ti light or something. What a pain. I had alligator clips, home brew insulated rods and a jumble of wires all over the place. All to find out it’s probably doing what everyone expected! First, a note on my AA nimh battery situation. I have 8 older Maha 1600ma Powerex batteries. They’ve seen little use and still read 1.4 on a full charge but they’re several years old. I also have 4 new Eneloops. My apologies for not being fully prepared. The light came unexpected. I’m working on several reviews right now and I was not expecting this one to arrive first. Dock my pay, what can I say . So with that being said, here are some measurements, which were virtually identical with 4 Eneloops or 8 Mahas.

Lo: 25ma

Medium: 250 ma

Hi: 700 to 800ma

Turbo 2.6 amps

When measuring turbo, the meter slowly climbed up as high as 3 amps right away, then settled back down to a solid 2.6A. I’ve used this meter in all of my reviews and never saw it climb like that. It didn’t stay there but went back down to 2.6. It did this with both the Powerexes and the Eneloops. Parasitic drain: Yes Virginia, there is a parasite in there and it’s sipping a constant .38ma (that's point three eight, under 1 ma) from the batteries. I had no way of measuring this with the tailcap on so if the battery is making contact with the contacts under the head, it will draw.38ma. The only way unscrewing the tailcap is going to stop this drain is if you turn it out enough to break the contact AND TAILSTAND THE LIGHT. The springs on both the negative and positive have a long reach so you’re going to have to unscrew the tailcap to the point where it almost falls off.

In the hands of “babes:”

I did this on my last review. I took a little walk over to my “non-flashaholic” neighbor’s house. Lets call him “Joe.” Okay, that’s great because his name really is Joe. He’s a mechanic but to him a good flashlight is (or was) a stock Mag. I’m slowly converting him but there is no “passion” there. This makes him a great subject to hand a light to for an opinion. His first impression was positive. Joe liked the look and feel of the light but agreed with me on the thin-ness of the tube wall AFTER I removed the batteries. He was completely lost with the UI. I had to instruct him all the way. Pressing and holding made sense to him but with the TK40 you have to first turn it on, let the button go, THEN press and hold. Joe and I both agree that pressing and holding from being on OR OFF would have been a more intuitive design. The instructions on switching through the levels are not perfectly clear on the light needing to be ON first.

The beam and white walling:

Fenix gets very high marks for the beam. I don’t know how they did it but once I got it more than 18 inches from the wall I could NOT tell it was a quad core emitter. I saw no rings or dark spots. I made a crack about a Phillips head screw slot in this thread about this beamshot but that disappears completely, never to return, once you’re more than 2 feet from the wall. The hotspot is also HUGE and the spill is very good.

Fenix TK40 PWM

Using my highly scientific test method (pointing it into a fan) I discovered no PWM on ANY power level. Either it’s using another dimming technology or I need a faster fan. Maybe I can go to the airport and stand in front of a turboprop and see if that reveals some super high frequency my house fan won’t show!

Fenix TK40 Conclusions:

There’s a lot of competition out there. There’s Tiablo, Jetbeam, Eagletac and others all pumping out some very impressive powerhouses as of late. Too bad Surefire decided just to make brochures instead of lights (oops, did I type that out loud?) because these guys are having a ball out here in the real world. So I’m thinking Fenix wanted to do something a little different and that’s why we have the 8 AA setup. I’m sure the AA’s are meant to appeal to the general public. The light is a little bigger than it needs to be and that is because of the battery tube. But the general public knows what Maglite is and to the layman, that IS a “flashlight.” The TK40 fits the hand nicely and for someone who grew up on Maglite, this will probably appeal to them more than the 18650 lights. I’ve read the arguments for and against using AAs and I feel this is just different, that’s all. It’s diverse. However, if the general public is the target Fenix wants, I’m surprised they didn’t go with a thumb switch on the body and a simpler UI. If it were me in that design room, I would have pushed for those features.

Fenix TK40 Beamshots:

NOTE about the following beamshots: For those of you looking at my older reviews, my house was painted and the color is slightly darker. The incan skews it one way and the LED the other. The real color is between the two but MUCH more accurate with the ROP. Also, to allow the P7 to show up properly, the ROP and TK40 seem a tad overexposed. However, the exposure was set the same for each distance each time.

Fenix TK40 Comparisons :