I just checked the KD page (about time, huh?) and it lists (max) output voltage at 23v (3.28v each - not enough to do the rated 2.8-3A). To shove 3A thru 7 XML2s should take around 24-25v, well within spec for the 9x version (max output listed at 30v).
Ummm, yep, ahhh..... Hhmm - I just did a quick order check and I bought this one from IOS back on April 5th, but I believe the same specs apply. So comfy, you think this worked at 2.6A per LED for the stock XML's then, but can't get that high on XM-L2's? Guess the Match's charts may have the answer? Boy.... I feel so stew pid and impo-tent.... 
Weird - I thought others did the same mod, hhmmmm...
Probably, but I don't have a handy chart for the XML. The Vf difference between them isn't that big, but when you take that difference and multiply it by 7 it's a lot.
edit: Also, it's very likely the 9x driver won't be able to do the rated current into 9 XML2s for the same reason. It'd need to output 31-31.5v.
You are definatally on the right track! I tested a KD 9x 5 mode on a string of 7 mx-l the other day, and I measured drive currant to 3.1-3.2A. I dont know what happens when the driver heats up, though.
the driver goes kaput…. the beast 7 LEDs driver went kaput on me after I put the light on HIGH mode for 15 mins :_(
Running how many of which LEDs? I'd imagine if you used it for long with it doing its absolute max voltage, it wouldn't be too good for it.
Ok, well, did the dirty deed - the 7X LED 3 mode driver with 6 XM-L2's now in the J18:
6.42A tail on 3 fresh TF 26650's (yes, TF's): 6,425 lumens at start, 6,113 lumens @30 secs
Wow - it is bright now and didn't drop a whole lot. Well, some may say 300 lumens droppage in 30 secs is a lot, but that's only 4.9% - I got much worse when running 7 LED's.
gotta play with it a little bit before she blows, but the beam pattern, even with the center LED missing, doesn't look bad at all. Probably lost some throw, but sheer, brute output will make it throw - I'll measure that next.
Edit - Ok, throw is 68 kcd measured @5m, again, pretty steady - might have a winner here. Probably should go back, take it apart and measure voltage though.
I ordered the 9X 5 mode driver from KD, so dunno - if this one survives, I may just leave it as is and upgrade the stock J18 same way with 7 XM-L2's. Side by side, the stock J18 looks pathetic compared to the this 6 LED super J18 
.
Mod'd one with green trim, stock one with blue and orange:
The 6 XM-L2's doing over 6,100 lumens:
Crude side beamshot:
Dog is curious, but obviously can detect and goes for the brighter light .
Loving your work Tom E.
Thanks Mrs - I am soo far behind on my own work - took like 6 months to get to this. This is a burner though, but outside in 15F, not so bad... First J18 I did was straight driver swap, but DayLighter got it and the driver died in 15 minutes on high he said - he's FEMA and volunteer EMS, so he actually has a practical use for these things. At the time I used the thermal pad the driver came with from IOS, but don't think it's enough. Really don't know if the potting I did on this one is any better, but would like to see, but afraid to run it for any decent amount of continuous time.
Didn't even swap in an AR lens yet. I got one, so will try it, along with maybe better cells to see if any improvement in output. Certainly for 30 mins of continuous output, you probably would drain the cells, and the driver be heat protection based backing down on amps.
New measurements --
- swapped in KeepPower 26650 protected cells at 4.17v, 41.7v and 4.15v -- 7.37A tail measured. These are from e2fieldgear.com - cellguy (thanx!)
Lumens: 6,834 @start, 6,582 @30 secs
- then swapped in a CNQ/FFL AR lens, HD 2010 size. Stock J18 lens: 2 x 58.75mm, AR: 2 x 57.9mm. Probably did not let it cool down enough.
Lumens: 6,970 @start, 6,691 @30 sec, throw: 75 kcd measured at 5m
Wow! I think this light is crank'n now. Still, only with 6 XM-L2's.
6,691 lumens OTF, 75 kcd - 548 meters
"It's the wood that should fear your hand, not the other way around. No wonder you can't do it, you acquiesce to defeat before you even begin." So many life lessons from Kill Bill (lol)
I was using the original 7 LEDs
awesome job Tom !! 
6,691 lumens OTF, 75 kcd - 548 meters
WOW! :bigsmile: Congratulations on your mod.
So... ~7800 after you get the new driver and add the 7th one back in? :O
Sure - 7,800 - why not? Do you doubt me? "Is it your wish to possess this kind of power?"
Don't u just love Pai Mei?
I haven't even started drinking yet, and it's Friday night! Thanx All! Kenny - FP - comfy, and the Mrs of course... :beer:
I'm thinking I'll get 10-20 minutes of floody glory before something blows and goes poof...
Very impressive Tom. I always enjoy watching your builds.
I don't think it will go poof, just about willing to bet these 5/7/9x boost drivers reeeally don't like being run at their absolute max output voltage for any length of time. Give it some headroom (7x driver with 6, or 9x driver with 7) and it should be OK.
That's actually good news - hope you are right - does make some sense. I got the stock J18, so I'll probably go with the 9X driver and 7 more XM-L2's in it. Leaving this one as is - would make quite an awesome pair I'd say. These KP 26650's seem to be doing ok - I really thought they had higher resistance than expected when I tested them in my high amp HD 2010, but they beat the pants off the TF 5000's in this light.
Really a better 7X setup would be an X100 with a TaskLED driver - 1 more cell, powerful driver, better heat sinking...
???
:bigsmile: