A minute or two is probably what it takes to discharge to 4.0 Volts, and so your current will drop.
It may be better to start with a battery that is already discharged to 3.8 Volts, because that’s where the voltage starts to stay the same for a longer time, just slowly dropping.
But hey, do as you see fit.
I done hundreds of diy FET drivers and some Texas Ace one so I know how they behave. I am looking for permanent solution of restricting FET driver current, and since Djozz mentioned that some kind of resistor can be added to driver circuit I would really like to know what type of resistor and where should I place it in a circuit?
If someone wants to run Osram WF with FET driver just use low current 18650 cell and don’t bypass springs. But however that is not proper and safe solution. Proper solution for FET drivers would be current restriction on FET driver. It should be doable but I don’t know how.
I’m sorry l.i. but although I produced the AK-47 hack back in the days, which was purely an extension of comfychair’s work, I’m not very knowledgable in drivers, not like Texas_Ace or Lexel or DEL or wight.
The idea of putting an extra resistor in this hacked driver is not a really practical one because it would have to be a big one that can handle 5A current.
Maybe if you can guarantee buying a large amount of them, you could ask Simon from Convoy Flashlight to produce a batch of his 5A drivers with high-med-low without memory?
Yes I could. But what should I do with hundreds of AK47C1 drivers(also ordered from Simon) ? 
I would try to place big resistor on driver cause I pot drivers anyway. Can you suggest me proper resistor for this potential current restriction FET driver mod?
The added resistance is going to be in the 0.05 to 0.1 ohm range I think.
These are two resistor mods I did for the 2mm WF. Added resistance was about 0.1ohm. For the 1mm WF it should be a bit less.
I wonder…would it be possible to adjust PWM as battery discharges to maintain something closer to constant current?
I think it’s possible. Some discussion here.
Finally someone with a will for FET solutions 
Is there any way to put some kind of resistor on a top of a driver and where would you put it? I pot drivers so it would be nice if I could merge resistor with a driver for permanent bond :+1:
You would put the resistor anywhere in the main current path. The challenge is the heat dissipation. It will be producing between 2 and 5W depending on what current you choose (5 to 7A), and that is a lot for a small resistor so it will get very hot.
has anywhere got stock of these yet? Also does convoy do a 4040 gasket or are we stuck with reaming out the 3030 ?
EasyB,
Can it fit to 17mm diameter? Can I cut it to fit if needed? I have aluminum and copper plates as potential heat sink for resistor and when I merge everything with potting compound it will look like it is made from one piece and whole driver should act as a heatsink.
But if it generates serious heat at 5A (more than 60 celzius) that could be problem…
The extra heat is not large compared to the total heat from the LED. The risk is that if the resistor you choose is too small or not heat sinked enough it will burn up. You will have to look for resistors that will fit in your lights.
Can you link me some kind of big but no to big resistor that could be bent into 17mm diameter please. I really don’t know what to order? Pretty please… 
Use a square file, only cuts out the necessary corners.
Anyone have any leads on this chip yet? Seems impossible to find, but some people have gotten their hands on it.
I haven’t heard anything about it, but apparently they have another boost family emitter 0.5mm² named HM I think.
Okay, so the ‘boost HX’ is basically the 2mm² white flat with a 4040 footprint.
So the 1mm² white flat with 4040 footprint will probably beat it in throw (like with the 3030 sizes)?
@Jerommel
Yes. Boost line seems to take a given chip and move it up one package size/class. This probably didn’t mean much for the 1mm² chip but should for the 2mm² . Where 1mm² saw a ~10% “boost” in current handling, I would expect 15-20% for the 2mm² . This might close the gap entirely between these two. The choice between would then be based on your host/driver/runtime restrictions.
@Fat_Controller
Interestingly the If vs Vf curve maxes out at 8A (despite 6A rating)! That should mean we have a bit of overhead there I would imagine…
EDIT: Looking at the datasheet for the 1mm² (Boost HL) it appears they did the same thing. If vs Vf goes up to 4A and max rating is 3A. If overhead is proportional then the HX should be good for 12A. We’ll still just have to see if the HX ever shows up.
PS: Interesting to note as well, the HL product page notes it’s “not for new designs”. I wonder what why? Is there a successor already?