I have an FF E01, yep, might be interesting.
The #'s posted were just on the single GOLISI. Think the 4 EFEST test was slightly lower results. Yea, could have been over the top, or the old EFEST's lost some power over the years, not sure.
I found the SFT40 on a mcpcb for sale. But I can’t find a driver for it. Any recommendations for 8-9 amps? Also, where to buy? (sorry, I’m a noob) Constant current/single mode is OK. I don’t need extra features. I’m also planning to run with an off-line power supply instead of batteries, if that makes a difference.
Hmmm, thanks for the testing djozz. Maybe Nitecore will use these on their next iteration of P12 and MH series. Would certainly be amazing. Hopefully they bring back the guarded tail-switch and the amazing rubber mode button in the next P12. The P12GT was absolutely perfect and every iteration after that has sucked. Exposed tail-switches (that’s less of a gripe, I can live with a light that can’t tailstand but meh), and the part where they REALLY messed up was in the side switch (which is also the on/off button on their lights without a tail-switch). That button is nearly impossible to find in the dark. It’s the same color as the rest of the light and you can’t feel it. Anyway, this LED seems promising. Might just try modding my old P12GT with this… after I get it fixed that is. I think the P12GT uses a MOSFET driver, would this LED work with that? (I’ve never modded a light before, newbie here so be easy on me 
) I know Nitecore uses a lot of proprietary components and they’re a pain to get open, etc. (saw a thread once where someone opened up a P12GT, wish I had the link). Maybe I should just get a C8 and play with that first.
I see it being compared to the SBT 90.2, are they that similar? I have a Thrunite Catapult V6 and that has an XHP35 HI in it, would the SFT40 be a good upgrade for it? I can already see how modding lights can be a rabbit hole into which I could easily fall…
exact same question and scenario for me too…
Had it on my Convoy Z1, looks very bright and great laser beam!
I put SFT-40 in BLF A6 and in WildTrail D80v2. I measured almost 27kcd throw from BLF A6 with SFT-40. 116kcd from D80v2.
“Details are in ”What did you mod today” thread”:What did you mod today?
They are not that similar, except in their luminance (candela / sqaure mm), and their beam profile looks similar regarding the large hot spot. the sft40 is a great upgrade
I was comparing triple SFT-40's with a single SBT90.2, but 1:1 comparison, the SBT90.2 at 5700K has a better temp (warmer) and better tint, less green. I still think in raw throw (kcd), they are very close when both are driven hard (SFT-40 about 9 amps, SBT90.2 about 20-24 amps), and for those extra amps you get more lumens with the SBT90.2. They are both 3V, but a XHP35 HI is 12V, so a straight emitter swap in a 12V LED light is out of the question - more serious modding is needed.
Hmm not that similar how? Is there a size difference or is it just the voltage difference, being that the XHP35 HI is 12V and the SFT40 is 3V? Thanks for mentioning it’s a great upgrade 
Now I’m even more interested. Will likely end up doing it once I learn more. I’ll of course post it on the forum if I do, so that others may do the same if they wish.
Ok, so I’d basically just have to change out the board for another one that’s 3V and install the emitter there yes? So for example, buy an SFT-40 or SBT-90.2 and also get a suitable, 3 volt board and then just install the LED on the board and solder that to my flashlight? Or do these LED’s come preinstalled in suitable boards that I could just “drop in” my flashlight? Basically remove the old one, and solder the replacement in. The SFT-40 would be easier to drive on a single cell light like my Catapult V6, but I do know of a 26650 cell that outputs crazy current (like 45 amps) that I could purchase if I did go the SBT route.
I apologize i was in a rush and didnt finish my thought. the sft40 is aa good upgrade, but it is similar to the xhp35 HI in its design and beam shape. BUT - MORE Importantly - and to further TomE's point, you cannot just drop a sbt90.2 or sft40 in that catapult. and there is no "board" replacement like you were aksing about, it requires chaging the DRIVER in that Catapult so you can run the sbt90 or sft40, or any other 3 volt emitter for that matter. The xhp35 Hi is a 12 volt only emitter, so the driver running voltage is different. so that mod is more involved becasue well you have to find an appropriate driver first (not too hard) bu tthen remove the driver and set the new one in. its more of a pain, and that catapult with xhp35 HI is a pretty nice light, i would say this.
Your better off doing what im doing and buying an astrolux FT03 for aroud $35 shipped, it already has a sst40 mcpcb (the board the LED sits on) so all you need is a heat source and a soldering gun and you can VERY EASILY instal a sft40. once mine comes in i will be doing it, i will try to make a couple short videos of how i do it, if you think itll help?
Anyway good luck and feel free to ask questions. just always remember different voltage (3volt, 6 volt, 12 volt) all need didfferent drivers. and drivers CAN BE a pain in the but to replace, and just finidng the appropriate driver can be tough too. So try to avoid the driver swapping mod in the beginning unless you are buying some convoys and just want to practice it. BUT, LED swaps are easy. and most fun LED's are 3volt (fortunately for us!)
Yes, my mistake, got the words mixed up, meant to say the driver but the word wouldn’t come to me so I just called everything board lol. Why is it such a pain to replace drivers but not the LED boards? I would assume it’s likely the removal process? I could imagine stubborn retainers and things like access being an issue, but other than that it should be a case of just soldering the wires off of the LED’s mcpcb, taking out the old driver, putting the new one in place and then resoldering the wires onto the pcb (3 volt, since the Catapult’s literally the only light I own that uses a 12 volt emitter, I do have a Nitecore EC4S that uses a first gen Cree XHP50, but I’m sure it’s the 3v, 5000k version). Or in the case where you’re replacing both the driver and the LED, I assume the LED already comes mounted in some mcpcb varieties u can choose from, so all you’d need to do is gut the light then drop in the new LED/pcb and solder the driver wires to the pcb then seal everything back up?
And yeah, I’d definitely appreciate a video of you doing the mod, or even just a write-up. (although after doing some writeups myself, I think a video is much easier since all you have to do is record the process and upload that, no having to upload pictures to imgur, copying links, writing down many paragraphs, organizing everything, etc) but whatever is more convenient for you!
I’ve never modified a flashlight before, never even cracked one open, in fact, but I AM handy! I’ve always been a tinkerer, I’ve taken car engines apart and repaired em, as well as taken off transmissions and reinstalled them, done other mechanical work and I was also an aircraft structural mechanic for several years in a Lufthansa MRO. All my work was on the Airbus A320 fam. (so A318’s, A319, A320’s, A321’s). They’re all basically the same, just shorter or longer and they have different door layouts (the longer one would have a door in front of the wing and another behind it vs the rest having them pretty close together) anyway that’s enough derailing, I got some new cells in today and just tried them out a few hrs ago and I’m very impressed. Could only try the 21700’s because the 18650’s didn’t work on my lights because they’re too short AND flat-tops. I think if I just solder a nice blob on the tops I should be good, though. Just need to get my soldering iron back from a friend, texted him tonight n he told me he burnt out my old one so we’ll see how quickly he gets me a replacement. Or maybe I’ll just go out and buy one tomorrow and bill him for it for being a hog hehe, I’d asked for it back several times before.
Anyway, the cells in question are Molicel P26A’s for the 18650’s. They’re INR’s rated for 2600mAh and they’re rated by Mooch for 25A. I think Sony VTC6A’s do 20A but have slightly higher capacity. I went with the Molicels cuz I wanted to try something different and they were a little over 4 bucks a pop.
The 21700’s are the Molicel P42A, 4000mAh minimum capacity and tested by Mooch at a whopping 30 amps continuous, and up to 40A at a 75* cutoff. Anyhow, I tested these in both my Lumintop D2 and my Nitecore MH10S and holy crap, after not even a minute on turbo on the Nitecore, the head got HOT as hell. Definitely not gonna wanna use these cells at full whack for extended periods of time, would likely fry most LED’s I think. Wish I had measurement equipment so I could quantify the difference and share my results here, but it’s very noticeable, specially in how hot the light gets so quickly. Maybe I’ll get the gear eventually if I’m so inclined some day. Thanks for all your feedback btw.
Just went back through this thread to read what i missed the first time.
I reflowed the SFT40 in a EA01 (sst40), single emitter, TIR optic. It REALLY increased the visual throw. by a lot. I will have to measure but it is a very worthy upgrade. I still need to bust out the lux meter i bought and have never used....
Only weird thing (i guess)- i bought to Lishen 5000mah 21700 that are rated for 9.6 amps i think, to try and control the amps that way.. well the first time i turned on and went to turbo there was some nasty Angry Blue happening..
I set max ramp to 120/150 and just stopped using turbo (honestly not a big difference between 120 and turbo anyway) and no angry blue and it has been fine.
Now that battery voltage has dropped due to use, no angry blue happening in Turbo anymore..
I need to disassemble and make sure i tightened down the mcpcb screws enough and also need to test the mcpcb for flatness - something i didn't do when i originally reflowed the sft40 on the original ea01 sst40 board..
It made me wonder - is there any good way to control amp output on a light like the EA01 beside the battery you are using? although i do suspect i got angry blue because of a lack of heat sinking going on due to bad mcpcb contact with the shelf or not an acceptable contact due to screw tension..
You can lengthen and reduce the gauge of the LED wires. Adding resistance lowers amps.
Yeah, and purposely using bad (steel) springs.
Ok good to know, thank you. But nothing on the driver itself?
Well, nothing that simple to the driver itself. Theoretically you could find a lower performing FET but that has other risks.
I'm cautious about downgrading springs. In lowering the amps to 8 or 9 for example, that's still a lot of amps for cheap springs and I'd be concerned about melting them, as I've seen/done before.
thanks Tom. Also about lengthening / reducing diamter of springs- just removive the driver and solder on new springs, right? That's the best way?
Don't ask me - I'm saying I would not degrade the springs. If anything, I would add thin bypasses. I don't trust springs unless they are from Hank or are "Blue" springs.
sorry about that- that was a typo- I mean WIRES, not springs.
if I want to lengthen the wires, I would remove driver and desolder existing and solder new onto it? Is that the best way?
Wow melting ? 
was it quite thin ?
I mentionned this thinking about the one in the H600 IV, 0.8mm, steel and quite long, about 50mΩ, it gets quite hot (the light draws 6A which a nearly empty cell) . I was thinking shorter and thicker steel spring would do if that exists (because 50 mΩ would be too much).
For lengthening wires, AWG22 is 0.53mΩ/cm, 24 is 0.84mΩ/cm, depending on the resistance needed it could get quite long.
I should add the SFT-40 in my DD calculator ( Graphing Calculator - GeoGebra ) since it has a lower Vf than the SST-40, it helps see the effect of added resistance (but without knowing the current it’s difficult to estimate the light’s resistance)