Ok, thats solder 
yeah thats how i make them also, a big dab of solder on top of the wire bypass on the spring sanded flat 
But yours where so tidy & round i didn’t recognize it for what it was.
The Efest purple 26650 battery should easily supply what ever the driver is letting through, the only “hotter” battery i know of is the green Efest 26650, but that is only 0.3A more capable.
cajampa
There are Purple 4200ma now- quite new ones, which are on thier way to me: i believe they would be better
Its true: for some wierd reason 4200 Green ones are better at 4-5-6 amps on both LD1 and A17DD drivers- i tested them alot
Maybe for high amps 3500 Purple ones would be a better option(havent tested it realy), but we dont see that often 10+ amps from a single battery in flashlights
Anyone able to post some beam shots of their setups yet?
Really keen to see what the de-domed XP-G2 will look like, as I need to order an emitter for my host.
If anyone could post a side by side shot next to maybe a stock Zeusray that would be handy. My worry going XP-G2 is the beam will just be too darn narrow.
I have a domed XP-G2 in an Aleto 26605 (giant SK68 look alike) @ 3 amps. But I find it quite useless for distance as the beam is so tiny. My de-domed XM-L2 Zeusray easily throws as well, but with a far more useful beam.
So I’d kind of like to know what the XP-G2 de-domed is like in the 1504, as I might go XP-L de-domed instead.
High lux is great, but not if it’s actually useless. I can always use a laser pointer for that kind of work.
I’d recommend you go with the XP-L based on what I’m seeing right now. If the Vf is going to be the limiting factor with the XP-G2’s then the extra 60kcd won’t make that big of a difference in ultimate throw distance.
Not the final word though, I’ll know more tomorrow.
Interesting i did not know Efest had a purple IMR4200.
I checked out there web side, and the purple IMR4200 is only a 40A, so i would guess that the 50A green one would still be stronger at under 7A.
And yes you are right at higher amp over 6A the 64A purple Efest looks to be the stronger battery.
It is really unfortunate that HKJ haven’t done a test on the green one yet.
When i checked Efest webside i saw this a IMR 35A 2800mAh 18650 purple thats looks interesting, a very unusual capacity at 2800mha i really wonder what it is based on.
And i hope HKJ soon test it because if it really are as strong as the old 2500mha purple 35A the added capacity should make it easily one of the strongest battery on the market. But we know they fudge the amp rating a bit so i wait for HKJ’s test on it, Efest is usually good at sending battery’s to him.
Guys i don’t know if you saw that in RMM’s thread he announced that he had ordered a reel of XM-L2 U4 1C’s, those could also be a candidate for the bigger die max throw.
They are reasonably CW & should be very efficient, i can’t wait to see what they can do
They XP-L V6 1A that LEDDNA sells are suspected to only be V5’s, and if they are the XM-L2 U4 should be 2 flux bins over that
Personally, I ordered a 1405 to use with one of RMM’s new buck drivers. I was planning on going with an XP-L, but I may still opt for an XP-G2. We’ll see.
Well I put together a dedomed XP-L V6 3C and a BLF17DD driver. I’m getting 4.5 amps at the tail and about 225kcd.I think the high Vf of these new emitters is going to be the bane of single cell lights.
KKW, I was pulling either 5.6 or 5.8 at the tail (no switch) with the dog dedomed XP-L V6 3C with 17DD-S08 driver and a 25R so something else has to be going on with your light.
I have yet to personally see 5amps+ on a single XP-L, you maybe have just gotten a great one.
You may be right, just reporting my results. I did scrape the wire on the diode to the right of the die, there are reports that this may raise the Vf. In preparation for this I tested it before the dedome. 4.5 amps at the tail (no switch).
Maybe I’m just unlucky and the fact that I’m not cherry picking LED’s is making a difference too.
Soldering looks good and thick but yet you never know... maybe you overheated something? Person need to be expert for drivers to reveal truth.
If I don't have good results I just toss driver in a trash(plenty of guys there :) ) and get another one. Why bother for few$?
But however I would change main spring with carobronze one.
Before you give up on that possible damaged XP-L, test direct driving it with an omten switch & 18awg wires. If you don’t get a much higher Amp then you know it is a bad one.
You say scrape the wire, if you are talking about the delicate bond wires, then yes if you have disturbed them in any way you have most likely damaged the emitter 
I don’t think my XP-L was damaged. I think you may have missed the part where my tail reading was the same before and after the dedome. I didn’t make it the clearest as it was across 2 posts.
Hehe, yes when i read them again i got that now.
I would still test a DD set up before you give up on it though.
4.5A is just so low for an XP-L on a FET or DD i think it is about the lowest i have read about here & because this is the BLF i don’t think many of us ever cherry pick the emitter.
I remember djozz did when he bought cheap XP-E2’s from Mitko to do a write up & test on it but right now thats the only instance i can remember.
Well, i usualy get 4.5-5.1amps from either U2-u3 or V6 bins with a BLF17DD driver so your result is quite okay: consider that the battery will drop very quickly from 4.2v, no there is no point the chase more - with a 4.25v battery youll prolly get above 6 amps at startup but yet, it would drop even faster
I wonder how purple 4200 will perform vs green 4200, cant wait
I ordered it some time ago, its 100% as V5 1A that Simon from Convoy offers for 3$ or something- absolutely the same emitter- 300 or so lumens at 700ma
Yes. It is nice to experiment and stacking chips but we need to think about runtime. Single cell light should not go over 3,5a(15 or less minutes of full power). I am afraid what would be runtime with 12-15 chips 
Edit:
Any chance they will be offering smaller single cell brothers? I think that would be a lot interest for them also.
It seems the UF1405 coupon has expired :( Any chance of extending it?
Hi Lothar, UF-1405 $25.99 Code: UF-1405, thanks for your liking this deal from GearBest.
You also can see more deal in OP OFFICIAL Group Buy UF-1504, UF-1504 host, UF-1405, tail switch, 26650 batteries DISCOUNT CODES EXPIRED!!!!!!!!
Thank you :) I could not resist pulling the trigger on the UF-1405