An inline resistor is not a bad shout. So quick maths: if your drawing 20A then assuming batteries are powering at 8.4v then total circuit resistance is ~0.42ohm. To get ~13A total resistance should be ~0.64ohms meaning you need to add a resistance value of ~0.22ohm.
The issue is that the resistor could need to dissipate as much as 5-10W. I don’t know of many that can do that and fit inside the flashlight body. The ones that do exist are expensive. Wire on the other hand is cheap and easy and can dissipate a fair amount of heat if it is silicone and long enough.
The best option is to use a regulated driver obviously. The stock L6 driver should be able to work as long as you don’t want more then 7-8A.
Wow! Nah, I don't believe in limits or thin wires 
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Ok, here's some details. It's a TA Convoy L6 triple channel using a SIR800DP, 20 AWG wires, 20 AWG spring bypass. It's got the Simon SMO reflector.
On 2 LK 5000's at 4.17V, I got 18.0 amps on the clamp meter.
Lumens: 8,940 @start, 8,090 @30 secs. Throw at 5m: 186 kcd (862 meters)
There is no black hole, well under 1 foot to a white wall there is, but nothing further away than 1 foot. It's got the usual new LED yellow around the hot spot. Could be the 3B tint, or just the nature of the LED's with our typical reflector designs.
The thing gets hot, maybe the hottest I ever felt after 30 secs. I didn't let it cool down much before getting the throw readings, and it was getting darn uncomfortable holding it for the 30-40 secs or so.
Is this thing usable? Well for a few moments, yes. I had two EVVA unprotected 4000K cells I tried. They were at 4.05V and I got about 11A on the clamp meter, and maybe about 6,800 lumens at start.
Surprisingly, ramping seemed to be working ok, but as has been pointed out, there's not many steps in the ramping table at the high levels, so it jumps bright fairly quick at the end.
That resistor is compact it is build to be mounted on a heatsink with a screw
Just tried it outside - too much power to point around the block, so just hit top of telephone poles and tree tops, and down on the lawn. Even outdoors at 68F it's hot quick. Funny, it seems so much brighter than a 9,000 lumens flooder like the MT03. Even off the ceiling, the hot spot is extremely bright, or shining it down on grass, it's blinding.
Impressive, since it seems to survive at that current you could limit the power by simply adjusting the max pwm in the firmware (ideal would be to add some voltage compensation as was discussed before).
I was think'n, well hoping, these new LED's can handle the amps, but I think it's a nice "feature" the heat keeps you from running it too long anyway. I just got an MT03 and measured it at 9,010 lumens @30 secs, but even though the head diameters are about the same, the MT03 seems to handle the heat pretty well. Of course it's got to be more efficient because of the 3 XHP70's - guess that's the big difference. I'm not sure what the MT03 does in amps though.
XHP70.2 P2-1A 17.15amps 8.2v with a BLF-FETDDSIR800 20awg driver spring bypass with 1.2’’ long 20awg Leads 2 x26650 Basens in a Jaxman X6 Hunter with a L6 smooth reflector.
8000+ lumens Tom? It’s a really Big Bright Floody Freaking BEAM!! :cowboy_hat_face: :+1:
I Wonder How Long it will live at 17-18 amps!!! 
What do your neighbors think about shining all those massive lights in that direction for your beamshots?
I think mine are use to it by now, only had one person at the end of the road say enough with the flashlight. And I wasn’t even shining it towards his house. The next door neighbor doesn’t care he knows I’m keeping the raccoons away from his rabbit pen. I think k the people across the street think I’m crazy probably but they have never said anything. She’s always outside smoking or talking in the phone so they definitely see them.
I was just curious I see beam shots from members in the area they have and wonder if their neighbors ever say anything
My neighbors, never a peep, not even when I fire up one of the drag bikes and do burn outs in the middle of the night, but I would only do that on weekends Friday/Saturday nights, most of them would be right there, drinking my beer, my neighbors are COOL! 
heheh you need cool neighbors with the wicked mods you do kawi
8 and 9 thousand lumens! Woo boy, that’s sounds good to me.
I didn’t care for the xhp50.2 I tried in my L6 at 9-10 amps or so. It wasn’t any brighter than the sliced dome xhp70 at 7 amps. I think the 5000k color temp was not to my liking, as well.
But a P2 bin in 6000k sounds like something I need to try.
With the amp readings, my first measurement was 17.25 A, but the 2nd readings was actually higher at 18 A. I attributed it to the hold I had on the wire to the top edge of the battery tube (14 AWG I think), or some how the amps go up with the heat, not sure.
I have seen just over 22amps with the SD75 board on the sink directly hooked up to a 2S2P battery carrier with 4 VTC5a’s, and it still works, so a 2S set up might be the way to go, until somebody tests it, no sense running it past it’s useful out put. The heat this thing throws off is amazing, the host might be getting hot fast, wonder how hot the board is getting?
Notice I kapton taped the heck out of it, wasn’t worried about shorting off the reflector, machined the reflector so I have plenty of clearance, just that red wire de-soldering itself :person_facepalming:
Better to error on the side of safety, I guess, it is a beast of an emitter that’s for sure!
It is also the only thing stopping me (2S2P carrier) from putting this emitter in this thing, Beast Light needs a Beast emitter! 
Is someone able to mod a Acebeam K60 with driver mod and XHP70.2.
And has someone a power supply witH 20A to test the LED and measure Lumens.
I have been wanting to test the 50.2 and 70.2 for awhile but just have not been able to free up the funds to get my hands on them. I think djozz mentioned he was thinking about testing them, don’t remember if he is or not though.
I got bored so I did a few non scientific/ professional tests.Checked a few 2S 26650 and 20700 battery set’s in the JX6Hunter 70.2 P2-1A
All straight off the charger at 4.20v
KP26650 15.15a
Basen I 16.20a
PEfest 4200 16.65a
Basen II 16.70a
Sanyo 2700A 19.70a
IJoy 2700 20.20a
Topped them off again, and I measured LUX at 2M just to see “IF” it made a difference in LUX readings, just to check the out put in my light with bypassed tail cap. And to see if LUX topped out in between? It didn’t, not from my very rough checks!
KP’s measured 38,000lux
Basen II/ Purple Efest4200’s 44,400lux
IJoy’s measured 51,500lux
Even at 20 amps the LED did not turn blue, pretty amazing! :person_facepalming:
20 amps is basically the same as 10 amps to an XP-L2, which from my own testing, it can handle.
So the real issue is heat, at over 125W worth of heat, it is pretty insane for almost any host. Particularly for the amount of light you get. An XHP70 can make around 6500-7000 lumens and only needs about 80W to do it.
The real benefit is the higher efficiency at lower outputs. It should work great with buck drivers, although they will most likely need to be run in 12V mode to keep the amperage down. For example the GT driver should work great with the xhp70.2 in 12V mode (or 50.2 for that matter)
The "lux" numbers are all directly off the meter at 2m? So x4 for converting to candela, so 44,400 lux is 178 kcd. Think that's about right compared to mine. You have an L6 SMO reflector in that light, I believe what you said earlier?
This is good cause it indicates at 18A to 20A, throw, and therefore lumens, is still rising, at least initially assuming you are taking readings at 30 secs or so.
Thanks for the info!
I assume this was in a flashlight host, right? No big heatsink and fan cooling?
If so, these lux measurements you took were probably within a few seconds of turning it on right?
Unless you had the LED cooled extremely well, the output will drop dramatically the hotter it gets, because a flashlight host sucks for dissipating heat.
Most people wait for the output and heat to stabilize before recording the numbers, which usually takes ~30sec.