interested
Awesome! Keeping an eye on this one :)
Low Voltage cutoff is at 2.7 threshold, sorry about that.
The 4A was measured at the tailcap, I pulled the emitter and was only able to get .84-1A at the emitter, I think I need a high draw battery, or I’ll need to force PWM instead of the PFM, will do more research on it, but that means another board cut and wait time. Ugh.
Received a question in my inbox, wanted to open clarify it. If there are any questions guys, please throw them to me!
MESSAGE RECEIVE
Hi,
Are you sure you’re not direct driving the emitter from the battery? Are you able to measure/confirm ~6V voltage across the emitter?
I don’t mean my questions to sound the way that they might be sounding, but I noticed the current you showed measured in the 2nd to the last pic, and started wondering if maybe something is shorted such that the emitter is being driven directly from the battery.
Good luck!
By the “2nd to the last pic”, I meant the pic with the meter showing the current of 4.19 amps.
MESSAGE RESPONSE
Hey no worries I need skeptics 
I measured 5.9-6.4V across the output of the driver. I had already pilled up the star/driver before I thought to take pics of it. I’ll rip her apart tonight and get a pic of it, under load.
Furthermore, a XHP will not even emit @ 4.2VDC. I did try to directly solder a XHP50 to a fully charged 18650 and got nothing.
I’ll c&p this question, so others can see my answer if you don’t mind!!
Efficiency is above 90% I believe it was calculated @ 97%.
great project and thanks for sharing. I am interested; I understand it is a proof a concept atm but - if at some point in the future - you are making it available commercially or maybe via DIY platforms (i.e. Oshpark) I am willing to support/pitch in.
Once I get it nailed down I think I’ll go commercial, do a few small runs maybe 100 or so. But I wanted to share the latest revision of the board so you guys can get a picture of what I’m working with 
White ring is the 17mm ring that it is routed out at. with a 2oz pour this should be able to fully support the 3A.
Designed it this time to add a solder on spring and copper to the edge. I still am labeing it REVA. lol
You cracked the code.
You guys have me all feeling so flattered. :8) I think I’m going to go hit the lathe and turn myself a new light, I’ll do it in SS. Happy days.
After a little more reading, I am going to have to force PWM. This sucks a little bit, as my board will now need an additional ground trace. Ugh.
Any reason why this great driver shouldn’t work with a MT-G2?
You really should work with some of our driver guru’s like RMM ( Richard from mountainelectronics), led4power or wight. (Or the other(’s) which I might have forgotten at the moment)
BTW, great work!!
It will work just fine! any 6V LED will work with this, I’d have to change a resistor for forward current limiting though, but not a big deal!
Any update on this? :bigsmile:
Cant wait to see some more info/tests.
Latest update:
Sent another revision to fab, should get it next week. It uses bigger components (only one 0201), and forced PWM instead of PFM, which should (in theory) get us all the way up to the 3A. The light is in my car and I’ve got a night beam shot but it’s nothing special, you all have seen plenty of them.
Will post updated as I can!
Thanks for the update. Im looking forward to reading of future developments.
following
Very impressive! 
If the efficiency is halfway decent this should result in a substantial gain in run time over using 2 X 18350 cells in 1 X 18650 lights.
I’m going to add a dummy load on a reclaimed 18650 LG cell, If I can I’m going to “pull” this driver up to the 3A and see what run time is.