I have a Convoy C8, original one, with a de-domed XP-G2 I built maybe 2+ years ago - can't find my notes on it, probably a 7135 stacked driver, at the time, pre-FET period, somewhere after the Jurassic age 
, but can't find my notes on it. THinking it did bout 120 kcd.
FWIW, when taking an amperage measurement at the tail itās important to have proper polarity. One might think the numbers would be the same either way, but I havenāt found that to be the case. The 5.50 thatās showing also has a negative mark to the left, meaning the contacts are reversed. Given proper DMM probe placement that one most likely wonāt be 5.5A. You might check it out and see if thatās true in your set-up as well.
I hot de-dome in the light, at high amps, usually within 30 seconds. We all develop a style that works for us, interesting how many different ways there are to do the same thingā¦
I have already give the link to the spec sheet in my previous post. I am listing it here (Redirect Notice) again. It clearly says maximum current is 1.5A. Please let me know what I have missed.
There is only one XP-G2. I donāt understandā¦ I have no clue where you saw 1.5A - as was said, we never restrict our amps based on CREEās specs. Please try to find your reference - it doesnāt make any sense. Weāve been using XP-G2ās well over 2A since they were released - no problems.
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Ok - you didn't miss anything. We happily ignore, and throw shame on the CREE max amp specs - it's what we do, it's what makes us happy 
. We've been totally ignoring them for so long, guess I just assume that anyone here on BLF knows what we modders do.
Yes, CREE states max amps - of course they do. We, on the other hand, do not take that as gospel, so we test on our own what the little LED diode can really handle. So, we establish our own maximums., and they are all much higher than CREE's maximums. djozz has been the unofficial/official best BLF source of the test data. Does it shorten the LED's expected lifetime and MTBF specs? Sure, of course it does, but by how much? Not really too sure. There's been some testing done by Mitko on that, but not on all LED models. Do we really care? No, not really. If it last for 3 years under common usage for a flashlight - that's great! It would be obsolete in 3 years anyway. ANother contributing factor is we use high quality, expensive copper MCPCB's that have a Direct Thermal Path (DTP) that keeps the LED cool. CREE's max specs are probably based on a poorer mount and housing environment that what we build.
Is CREE correct on their stated maximums? Of course they are - for their own concerns which is mostly for the large commercial use of their products, like in street lights, home lighting systems, etc. Regular failures in the field under stress would be a disaster for them.
Hope this explanation helps....
You (TomE) just reminded mi that I need to order more XP noctigon mcpcbs :bigsmile:
And some of those S2 2b m8 
I stacked nice ammount of thoseā¦.unfortunately FT shipping lately is a nightmare
Oohā¦ a short form of mateā¦ m8 Back in 3dmark forum we used that alot and i got used ot it
Thanks!
Tom:
Thanks. You certainly explained that clearly. I am more inside box guy would never think about doing some thing like that on my own.
Overdriving the LEDs, just like overclocking CPUs, are certainly interesting and can be rewarding. One thing I observed from what reported on the forum is it appears the overdrived XP-2G appears less efficient in the very high current region (~ or >3A). At low and mid regine, e.g., up to 1.5A (top of the spec.) it is very efficient. I tried it on an SK68 that I have, it can produce the same or maybe more lumens than XM-L U2 with 14500.
Do you think my observations are correct?
Yes - definitely, in the high, off-the-scale range of amps, efficiency takes a nose dive across the board, pretty much, on all CREE's. Where CREE quotes lumes/watt #'s, we generally don't care - same is true for over-clocking CPU's in that we really don't care how much power is used, all we care about is performance. If double the amps gives you 1500 lumens vs. 1000 lumens, we'll take it: 50% more output at double the power - not efficient.
It's crazy - something like doubling amps can give you 25-50% more output. The output vs. amps charts we publish pretty much confirm all that. Again, djozz is the man for doing those tests. Then there's heat sag issues, cells dropping charge coincides with the voltage, so, max amps drops steady as the cell discharges -- all sorts of bad side effecs for direct driving, or FET driving LED's. Fortunatley the Vf demand of the CREE LED's is high enough to keep things safe from damages (in general), but the new Nichia 219C's is very different - they have a lower Vf than CREE's, so you can get intot some very high amps.
Hmmā¦. i tested the last night S2 2B with the default M2x UT driver( from the XPL HI revision of the light) equipped with 18awg wires and a spring bypassā¦.with only those modes it gives 4 amps.
Been wanting to try this light/host with a de-domed XP-G2: tmart.com/Trustfire-168A. I got one I've had a long time, back when it was like $25-$30, now at $15 it's a steal. It's an old fashion quality host with a SS bezel, brass pill, deep C8 size reflector, one of the deepest I've seen, not much spill, and it's built like a tank - downside is it's heavy, long, and has the old fashion single hole for the lanyard. I'd say it does slightly better in throw than a C8 reflector - the hot spot looks crisp, but those deep reflectors always seem to disappoint somewhat because the hot spot looks so focused, but measured doesn't do as good as it looks - width is much more important than depth, but what I recall it did slightly better than a typcial C8.
Today i had to build a XPL C8 for another fella, used IOS XPL V6 1D dedomed on Noctigons, same driver as before , 18 AWG , those lovely 42mm AR glass from IOS ( Thanks Daniel, they are realy great) : the battery used is Sony VTC5A
Personaly, i havent seen above 6 amps inā¦.a year or so? That combo V6 1D/VTC5A is great, just look at the candelas and the same distance, i was thinking that results are wrong but they arent, measured them 3 times
Damn, thats 172kcd (829m)!! :~ Not too shabby! Its probably the battery that plays the biggest role here? Doubt if its the LED. I see youāve measured the XP-G2 with 25Rs?
I am charging a brand new 25r atm, will keep you updated
Thanks for the first proper test of the VTC5A in a modded light Mitko
Great to know they are as good as they seem in the fixed amp discharges curve tests.
What is your opinion on the mysterious fasttech XP-L HI V5 1A ?
I think if they are real they should be stronger than a V6 that has been dedomed, because dosenāt a XP-L lose more than 1 flux bin after dedoming.
Tested already with 25r, the max i could get is 5.7 ampsā¦VTC5A is the best battery i have ever tested so far, yes it has a bit lower capacity but who caresā¦.6 amps i have never seen on a XPL V5-V6, even 5 is hard to get, single battery setup
That particular emitter is very very good btw, i bought like 20 pcs of V6 1D but this one is exellent: after aditional measurements it gives 1974 lumens at start and 1795 at 30s even dedomed
About the FT V5 1Aā¦well, i dont like XPL Hi versions, the ones i tested have kinda low lumen output, and a tint i dont like but in this case i think its just an error, for sure its a v2 1A
XLP is so easy to be dedomed though
Anyway, FTs U3 0D, V6 OD, S2 1A, U2 3d, u3 2a, v5 3a are ordered, if there is something interesting i will post it out of course
S2 1D aint that good, both from FT and IOS, hardly reaching 4amps, the last 2 even hot dedomed hardly reached 3.6 :~
I agree about that HI having to low output to be interesting, but that was when they only existed in V2 V3ās as a top flux bin, if they would start showing up in V5ās it would be convenient and easier to get exactly the tint you want. For example i would love a HI V5 3D version if it existed.
How do you like the dedomed tint of the XP-L V6 1D? compared to the non dedomed XP-L 3D (my favorite) and the dedomed XP-G2 S2 2B.
Kinda cooler, S2 2B as you know has a lovely pinky tint after dedoming
You wont like it under IOS AR glass but i do, has an exellent piersing powers even in not so good weather/air conditions
Well, its everybodys favourite m8