ENEDED

Mitko - I tried two more XP-G2 S2 2B's from FastTech on copper MCPCB's last night, and again, can only get about 4.2A max on a direct wired, no driver, soldered up bench setup using a LG HE2 @4.22v. Did not even dedome them yet. Now I looked up when I ordered these, and it was back in Aug and Sep 2014 - 1 1/2 years ago. Wonder if the newer batch's performed better? I got slightly lower amps on a Samsung 30Q @4.22v, so figure the HE2 cells do good. My old SONY VTC5's always do worse than the HE2's and 30Q's, think I spot checked one and performed lower.

I ordered qty 3 more of the FT XP-G2 S2 2B's over the weekend, just to see if latest batch FT has is any better. How are you reflowing yours? I've been using a butane torch as of late - quick method. I used to use a frying pan and bring up the heat slowly, similar to what CREE recommends. No idea if one method is really any better than the other...

I hear you bout the small XP-G2 hot spot. I recall guys complaining about the tight hot spot of the early OSTS version of the TN31 using a XP-G2. I kind of like the results I got with the XP-L, and now that's it's solid over a mile, I'm pretty happy with the results.

could someone post a photo comparing hotspots of both xp-g2 and xm-l2 in the same reflector?

Tom, based on Mitko’s results I went ahead and ordered 8 S2-B2’s from FT. Also ordered 4 from Mtn. After I received them I hot de-domed 1 from each supplier. I, like you, was only able to achieve around 4.2-4.3a. Not sure what to make of all of this, but would like to figure it out.

Oh boy, think you mentioned this before - totally forgot. I trust Mitko but I would certainly like to understand what's goin in.

Fenix TK 61, with XP-G2 de-domed vs. XP-L de-domed

XP-G2

XP-L

I worked hard on this particular light, had issues with current spikes frying emitters, tossed 8 XM-L2’s in the trash. Traded it off to Richard with a 32mm Noctigon sporting the de-domed XP-L emitter doing up close to 600Kcd. Hate plastic reflectors.

Yeah I never had any crazy results from those S2-2B’s either. I’ve never had any XP-G2 go over 5amps. Recently I started ordering their S2-1D’s because I like the tint better.

is there a driver that will drive them ( the xp-g2s) over 5 amps AND is small enough to be used in the boss1?

Well, think I posted earlier - there is some vertical room, so it's not all that bad. Problem is you need a high amp boost, or high amp buck driver and somehow manage cells in series, like a big battery mod done by CWK above, or using 4-5 pair of 18350's (might fit 5 pair, but 4 definite).

I think if we used a zener mod FET driver with a 2S setup, there would be too much voltage to burn off - not sure, others may know better.

Yeah you can’t use a zener FET 2S on a 3v emitter, it would fry instantly. The emitter would get the full 8.4v.

If somehow this driver: https://budgetlightforum.com/t/-/37354 could be cranked up to 5A or so to the LED and output voltage reduced, it would be a great match for this light. You could make the driver diameter much much bigger for the BOSS1 - width is no problem at all .

Dale - that's a great example. I don't have two de-domed matching lights, least I know of off hand. I thought though there would be examples around, maybe going way back: rdrfronty, relic38, ILIKEFLASHLIGHTS, RaceR86 etc., plus a few others that posted some real classic stuff. One guy who did mostly de-domed throwers had some great beamshot posts, think from Eastern Europe -- he was pioneering de-domed LED's at the time I thought, and had some great comparison shots.

Edit: Found it!! It's viffer750, shots here: https://budgetlightforum.com/t/-/12247.

But this is one of rdrfronty's classic, lists a XP-G2 and XM-L2 TM31, both dedomed: https://budgetlightforum.com/t/-/25465 (I did the XM-L2 dedome ).

Yes, XM / XP-L is much more practical, as Dale's photos above illustrate.

The XP-G2 S4's seem to do well. With the testing I've been doing recently on the KD86mm reflector, I have one running at a solid 5.4A (slightly higher on start-up), & that's measured through the DMM, so likely to be higher (roll out the clamp meters...).

I tried a little over 6A, but popped one straight away. I'm betting it's the spike at turn-on which pushes it over the edge.

Got some replacements coming in from IOS :)

Yeah, great photoes Dale, actualy TK61 is my main hunting searchlight atm- it has ultimate range and aint that heavy to carry: you can clearly see everything in a 2km range with a 20x scope

Yet, for C8 XPG2 is the better option, it like you have M2x but smaller, lighter ad way more pocketable- they gone crazy here about XPG2 C8s you know, to a level at whitch i dont have more place to store the hosts:

And here comes S2 2b- i dont know what are you guys doing but i got above 5amps every time, measured with the same DMM i have never measured above 5amps using U4 1C: and i dont do a spring bypass anymore, above 5.5amps is “scary” on a long term base - yet this sucker is tought, i dont have a dead one so far( from many builded)

Curretnly using in mass He2 as 25r price rose alot here, yet He2 one is under 3 euros whitch is strange as long as its the same or even better option

Hehe, the story of my life, i killed 4 XPLs too but thats the sweet part of being a BLFer , right Dale? :slight_smile:
That actualy was one of the hardest mode i ever done, i took like 20 hours or more to complete it like it should look but at the end i have line 8 ppl constantly tormenting me to make something like this

What exactly is the setup for the 5.4A you are getting? Is it a FET DD driver? big wires? Parallel cells providing voltage input?

I have no clue how to get or see over 5A on any XP-G2 so far without going to a buck driver, that's why I'm trying to figure this out. I'm not alone on this. Maybe it's how the reflow is being done?

Typical max amps I get on DD FET setups:

XP-G2: 3.8A - 4.2A

XM-L2 new gen: 5.2A-5.35A

XP-L: maybe little higher than XM-L2 new gen, 6.35A in this BOSS1 is the highest, but no driver

XM-L2 old gen: ~6.5A (XM-L2 T6 4C's seem to get this - could be an old batch)

The best i did with a IOS S4 2b and a FED DD driver was 4.8 amps:a fresh Efest 4200, 18 awg wires and a spring bypass ofc: yet i dont have much exp with this emitter, used only like half a dozen, still got 3-4 pcs in the cache though

Tom, it seems that IOS V6 1A is good too, unfortunately its price isnt, i still dont have KD V6 1A to compare with but the IOS tint is better than U2 1A and 6amps are reachable

Ios V6 1D were great indeed, wonder when shall we have them again

Tom, those numbers are close to what I usually see. Actually yours are a little higher than what I get with the XM-sized dies. I’m really hoping I’ll get this clamp meter and suddenly all my readings will be way higher than I thought this whole time.

I can’t get anything over 4.2amp (3.8-4.0 avg.) either on the S2 2B (5) of them from FT, and (6) that I had laying around and can’t remember what they are any more, running 2’’ 18awg directly to any battery… Imren 26700’s P-Efest 3500 P-Efest 4200 VTC5’s 30Q’s 25R’s Using a Fluke 36 clamp on, Klein clamp on, Klein DMM 10awg Leads? Highest reads are all way’s from the Fluke 36, but Big deal .2? I’m just happy as HELL it’s not only ME!!! :bigsmile:

I have found this vid by Djozz https://www.youtube.com/watch?v=I3oMm-jFSy8 . It shows how the Vf increases with the current. Could it be that xp-g2s at higher amps have too high Vf, thus making it almost impossible to drive them at 5a from 1s? It needs around 4V to run on 5A, which is quite high voltage even for 4p cells (maybe my stupid suggestion again, but what difference would 5p 18650 4,35v cells make???)
could someone measure not only the current, but also the voltage when testing an xp-g2? That should give us some answers

We all know about the higher Vf of XP-G2's, and the 4.35v cells don't do any better - I don't fully understand why, and can't explain it, but in real world tests, they perform relatively miserably compared to high performance 4.20v cells like the 25R, HE2, 30Q, etc., but this is all in one cell applications, never tried in multiple cell parallel setups. I don't think I have that many 4.35v cells to test - maybe I could test with what I have?

Mitko, and maybe couple others, see over 5A on a XP-G2, so the question is what am I doing wrong, or Mitko doing right? From 4.0A to 5.25A or 5.5A is a hugh difference probably due to a big difference in Vf. I'm not set up to measure volts while I measure amps, least not at this time.

Can we solder a simple voltmeter to the emitter wires at mcpcb while measuring current at the tail? Would that voltmeter affect the readings at all?

I was seeing this when I started measuring other peoples builds using the XP-G2’s. Case in point was member D36ME’s TK61 XP-G2 build and quite a few Courui’s built with the XP-G2’s, ( a few Direct drive) I was testing them for LUX on my light meter. Then I started measuring amps, trying to figure out why they were not smoking de-domed XM-L2’s and XP-L’s? So it’s not just my builds but other peoples builds too? :~