No shipping options.
Khas, how is your battery life and heat output on the X7 build with the xhp50.2?
That emitter with a linear driver gets really hot with fresh batteries and drains them really quick in my Convoy L6 compared to the xhp70.
Iām gonna order that H1-A just to try it since Iām putting my xhp70 back in the L6 and Iāll have the 50.2 plus a spare 26650 laying around. Thatās the cheap option.
If I donāt like the driver, Iāll only be out $12. Then I can order new 26350ās, a custom driver from MTN and probably a new xhp70. This is the more expensive option. Lol.
Yeah, that makes sense to me. 
Does banggood ship batteries to Sweden? If so, you might have to wait until they get back in stock. If not, then youād probably have to use an intermediary in another country to buy them and then ship them to you.
By the way, FastTech seems to have got a hold of a good deal on the LiitoKala 26650-50A cells. Use coupon BLF if buying less than the minimum bulk amount. Pity the BLF and bulk discounts don't combine. Maybe the best deal at this moment. 
Cheers ^:)
Great price, no shipping method though.
I am currently testing the driver in a Thorfire C8s, so I canāt give you exact numbers (not a numbers guy anyway )
If it tail stands on my desk it will get to hot to handle in about 7 min, but when walking the dog a lot longer maybe 15 min, runtime is at least 35 min on max with a couple of periods on a lower mode to cool down.
The F13 with the XHP35 handles the heat better with some more mass and more fins, I never put a XHP50 in the F13 though.
Now there is a 4A 6V version of the FX35 driver available
Would love to give the new 4A version a try. What would be a good host that takes a 22mm driver?
The only lights I can think of off the top of my head taking a 22mm driver are the Convoy L2 and Nightwatch NS22 Seeker. It doesnāt look like the driver has enough room to be able to shave it down to 20mm, unfortunately.
FX35 ā 22m 4A with gold plated bronze springā¦ interesting, but why just 4A maximum? Maybe the boost IC is already at the limit (TPS61088 for example). I do not see the sense resistor stack they're using in the pictures (!). The low voltage cut-off could be lower. The mode spacing is awful. On the good side, it features reverse polarity protection and a spring with high conductivity.
Cheers :-)
This is 24W to the led.
Mode spacing looks indeed not optimal.
I got the 2.5A version of the FX35 boost driver for 6V LEDs. Did a couple quick measurements. The modes are 2.7A, 1.6A, and 0.8A output current. The high mode seemed to vary between 2.6A and 2.8A measured with a clamp meter, though in general the current was stable for the range I tested, from 4.1V to 3.35V input voltage at the driver. Power input was 17.2W in high mode across all the input voltages. With the XHP70.2 I was using the efficiency in high mode was 90%.
For my application I want ~2.4A so Iām going to change the sense resistor(s). I did not take off the inductor yet, but I think I see what looks like a 1206 size sense resistor labeled R040 near the edge of the inductor. I ordered some resistors around R045. I also ordered some shorter 1microHenry inductors because I want to fit this driver in a Yootoo SD2 which only has ~3mm driver cavity depth. I will be interested to see how the smaller higher resistance inductor affects the efficiency.
Got the components from mouser and had some success with the smaller inductor.
Took the inductor off. A view of the components under the inductor. There was some thick thermal paste under the inductor. It looks like that R040 is the sense resistor.
This is the inductor I chose. Best one I could find under 2mm height. The driver fits in the SD2 now. I also replaced the R040 with an R047 to decrease the current some. Unfortunately the output current was still nearly 2.6A. Seems like that should have decreased the current, right?
Efficiency with the high mode decreased to 85%. I think I will be able to heat sink the inductor enough so it shouldnāt overheat I hope.
I tried some other sense resistors and was able to tune the output current. Maybe the stock resistor or some of mine were out of spec which caused the discrepancy/confusion.
I put in a R056 resistor which lowered the output current to 2.2A in high and 1.25A in medium, which is right around where I want them (to give me approximately 1hr and 2hr runtime modes using an LG M50T cell). Efficiency also jumped back up to 90% in high mode at 3.9V input at the driver. Some of that efficiency boost is probably from the lower losses in the driver from lower currents. But some may be measurement error; I tried to measure voltage close to the driver but maybe did not measure in exactly the same place both times.
By the way, does anyone know what that thick thermal paste is they put under the inductor? It has about the consistency of play-doh. I would like to get some as it seems pretty handy to be able to help cool some components like 7135s or linear FETs.
I wonder if BanL would answer this in his thread?
I think its called thermal putty. I found a few you might try. https://www.google.com/search?source=univ&tbm=isch&q=thermal+putty
Thanks, putty was the key word I was missing. :+1:
Hi folks,
Just got myself FX35@4A to drive an MTG2 in a slightly modded Convoy Z1
Iād love to dumb it down to 2 modes. Something like 1.5A and 4A. Or 1A and 3A for better thermals. Do you guys think its possible based on the pictures of a 2.5A 6V version from @EasyB (and a few extra below)?
The layout seems to be exactly the same.
I realize i can swap the current sense resistor, but is it possible to delete the ultra-low and low modes and maybe modify the medium one?
Deleting mode memory would also be nice. Although that would depend if it would always start in top or bottom mode.
P.S. yes for some reason the board is marked as FX-50
Ugh, sucks, no easy way out (like a jumper or removing parts)
Its all MCU controlled via the 12F683 on the first image.
Was really hoping i wouldnāt have to go bare metal programming route.
Does anyone know if someone maybe shared simple hex files for these?
Donāt see much need for something complex, like DrJones UI. As awesome as it is, it would be an overkill.