TK75 vs BTU Shocker - Let the battle begin! (NEW UPDATE ON POST 125)

My brother just received his Fenix TK75 this week. So we took it and and my BTU U2 Shocker outside to play a little. Noticing the similarities between the two lights, we just felt it would be fun to do a full test on both lights together.
So we got both lights and loaded them up with freshly topped off 3400mah protected Keeppower 18650’s. 4 for the Tk75 and 3 for the BTU. We then did a full lumen test of all 4 levels on both lights in my lightbox. Then we got both lights out and did a lux test at multiple distances. And lastly we took the lights out on a deserted park road to see how far they truly threw.
Anyway, we actually got some surprising results. I think most know I’m a big BTU fan. Well I will say the TK75 held its own and then some. Check these results out -
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FENIX TK75
Turbo (start up) - 2960 lumens
Turbo (30 sec.) - 2925 lumens
High - 1240 lumens
Medium - 468 lumens
Low - 28 lumens
Lux Reading - 94K (from 50m)
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BTU Shocker U2
Turbo (start up) - 3050 lumens
Turbo (30 sec.) - 2880 lumens
High - 2160 lumens
Medium - 928 lumens
Low - 68 lumens
Lux Reading - 124K (from 50m)
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So the TK75 actually had a slight edge over the BTU at 30 sec. It appears to have very good regulation. The TK dropped about 25 lumens right away and then just dropped very slow after that. The BTU dropped about 100-125 lumens right away and then dropped pretty slow after that.
And as a note - we have used this lightbox and meter combo for a good 50 lights, and about 30 of those being ANSI rated. So I’m very confident these numbers are pretty spot on. Don’t know if my brothers TK75 is a healthy binned U2 light or if all the TK75’s read a little high like his, but his light has my full respect. Basically what it means is these two lights are very close in power on turbo. High is quite a lot higher on the BTU though - almost double. To counter that the TK75 can retain its turbo a good time longer. Though the BTU after Turbo kicks down, it can keep a 2100+ lumen high until the batteries are depleted. So it’s a give and take with both lights after turbo. Also nice to see both lights have useable low levels. Meaning sub 100 lumen which is fine for walking a dog, etc. Not like some big lights that have 250 or more lumens for a low.
Now for the throw, the BTU was a noticeable victor with its bigger head and deeper reflector. But again the TK did very well. 124k vs 94K. In real life throw testing, with the BTU we were able to get readings of .2L at a distance of 700m. and .1L at 800m. The TK75 made .2L at 600m. easy enough, but could only do .1L at 700m. So basically the TK75 should do 600-625m in real life throw depending on conditions. And the BTU is pretty much a true 700m thrower.
As a side note we had my brothers TN31 out there along with my dedomed SR90. His TN31 also made the 700m, I’d say just a tic easier than the BTU did. And the dedomed SR90 made 800m without issue, but couldn’t quite get the .2 needed for 900m. to “make it”. The air conditions, I would consider slightly on the poor side with a good amount of humidity and bugs in the air.
Physically the TK75 is much lighter and I have to admit, more practical for everyday use with the side clicky. The BTU has a nice heft that I prefer, and has a good 80-90m more throw. The TK75 does have a AR lens where as the the BTU doesn’t. Though it appears to not hurt the BTU much. The BTU is about an inch longer and the bodies are almost the exact same diameter. The head is bigger on the BTU a fair amount.
So to sum it up, I feel both the BTU and TK75 are awesome lights. Both put out just under 3000otf. Both can throw 6-700m. I couldn’t be happier with my BTU and he is very pleased with his TK75. Both are winners in our eyes. Both are beasts!
We didn’t do any beamshots tonite. We will in the near future I promise. But here are a few photos of the two together.
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NEW UPDATE ON POST #125 - Video test for 22min turbo runs. Also has BTU testing with and with out lens
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NEW UPDATE ON POST #125 - Video test for 22min turbo runs. Also has BTU testing with and with out lens

Is it my screen or does the Tk75 have more shiny reflectors than the BTU? the BTU reflectors look like very slight orange peel, while the fenix look smooth.

Thanks for this. Very nice info and comparison. Awaiting the beamshots with everyone else.

Both are smooth polished reflectors, but the TK75’s are SUPER smooth - almost like glass.

Nice job rd,I have been on the fence about which one to get and with the $50 store credit that is offered at FF,It's hard to turn down.I like the BTU alot,although the battery carrier seems crappy I'm sure this will be my next purchase.Thanks and waiting for those head to head beamshots.

If TK75 get better lumens in Turbo mode than BTU, TK75 is already the winner by a lot. Look at the size of BTU, it should not let TK75 get close to its performance at all. And still doesn’t out throw TN31, I am really disappointed with it, TK70 2200 lumens is already so close to TN31. Why a 2880 lumens BTU still can’t manage to beat TN31. Something is wrong with the torch. It doesn’t perform as it should be judging on its drive circuit and size.

Thanks for taking the time to do this and sharing it with us!

Very nice comparison by the way. Thanks for the effort. :slight_smile:

Oh No! This comparison makes me want to get TK75. I must resist. RC40 is at the corner.

I agree and disagree about the TN-31because I just exchanged mine and the one I was sent got spanked by the original one I got.Lux was definitely lower on the new copy,in fact the old one washed out the new at 100 ft no problem and white wall test was just a crushing.It just shows even the same light can be different,and I was very surprised and confused by the results.Lux differences in multi emitter lights have been tricky to figure out just why they are lower than single emitter lights,so I get what you are saying about the TK75.

Maybe this makes the BTU should drop at least $30 on its price. :stuck_out_tongue:

Truthfully at most distances they look pretty close. The TK75 wasn’t as spotty as the BTU and made finding the hot spot at distances trickier. However the BTU offers more flood to go along with its slightly tighter spot.

You sir are mistaken. The BTU is a light that throws 700m and puts out 2880otf at 30sec - nothing is wrong with the torch. And beating a TN31 isn’t exactly an easy task for triple led lights. And the BTU does 124K vs the 126K I got tonite with the TN31 - both super close.
I respect anybody’s desire to get the TK75 - it’s a bad arse light. I like the BTU better, but I assume many will prefer the Fenix name and its lighter weight. To each their own you know. But to say there is “something wrong” with the torch is quite simply wrong. That’s a fact.

I actually suspect because I am suspicious guy, that current new TN31 are not using good material compare to old one. Thrunite is definitely doing engineering change if the price reduce from 200 to 139. I grabbed the first batch of discount where they at first plan to have limited 20 units only. Later Thrunite extend the discount until now. So I suspect new batch is not similar to old batch. Heat will affect XML performance by a lot. Both ILF and my TN31 out throw TK70 slightly, so I expect the very hard driven and U2-ed BTU to out throw TN31.

Maybe it is the reflector and AR lens that let TK75 win this time. Every parts play a role.

I was on the shining end meaning I held the lights and got the best view obviously and believe me both lights lit up the whole road and surrounding area for hundreds of yards. I have to say the BTU looked like it threw a little farther and was slightly floodier. I personally do not see anyone being disappointed in either one of these beasts.

I am stating the fact. BTU is heavier so heat sinking should be better, driven harder so output should be higher, but the fact it is not. So something is wrong with it. If Fenix drive harder and put U2 in their TK70, it will beat TK75 easily.

I have to say I wonder what a BTU would be like de-domed,I don't have the nerve to do it but it would be interesting to see what happens to the beam.Sorry if I'm going a bit off topic,I have never seen this done.

The TK75 did not win in throw. Was short by about 30k and almost a 100m. The TK did have a slight lumen edge and did still throw its butt of considering it has a smaller reflector. Again it’s a great light.
And my brothers TN31 is a fairly healthy example with it’s consistent testing in the mid 120’s. And ever test I’ve done on the BTU also puts it solid in the mid 120’s. But I still give the TN a slight edge since most tests done together put it a couple k in the lead. Of course 2k at those distances is equal to perhaps 5m.

If you go with the TK75, you won’t regret it. Again I love my BTU and wouldn’t consider trading my brother lights, but its mostly a personal taste thing. I actually prefer the beefier feel of the BTU. But likely most people would prefer the lighter weight of the TK75. And if you intend to use one of these for long carry at work - the TK75 is the obvious winner there.

The TK75 weighs less than the BTU by a fair bit and is even lighter than my TN31. To me it feels good in your hand. It is a very well thought out design.