Serious problem with XML2 current. Is this happening to you???

Sure, I've replaced then before - pretty simple. Think you should first try out the drivers though to see if it has the mode switching problems. My two BLF A6's I believe switch modes fwd/back pretty good - didn't have problems like many described. Lot of reports they worked fine as well.

Back in the XR-E days, flat regulation was something people looked for, there were drivers which would initially regulate and then go into boost mode. The driver I put into my SmartFire V-68C pulls 2A out of the battery whether it’s at 3.0v or 4.2v, I’ve got no idea what it’s efficiency is like but I’d expect 2A to kill an XR-E so I don’t think it will be wonderful.

Question: I cooked a BLF 17 DD FET driver (original double sided version) by soldering the zener on backwards (also used an R100 resistor instead of R200) and running it at 8V. Can this be rehabilitated? Is it the MCU that got cooked, and could I swap a new one in from a q-lite?

Today killed a dedomed XP-G2 S4 2B from IntO, a dedomed XM-L2 U3 0R from Kaidomain and previously a U4 1C. Next tried XP-L V6 1D from IntO dome intact survived the HX –1175B1 running on 4 Tenergy D cell NiMH hot of the charger. Tail cap reading was close to 6A. This is in a Maglite 4D voltage @ cells 4.8V+ with my machined custom head with a SR90 reflector and UCLp lens. Would really like to run a dedomed emitter but as-is handily spanks my Y3 U4 1C dedomed resistor modded light and Sniper M24 BLF edition.

I'm not sure I understand the Maglite/SR90 custom light setup (never modded a Maglite myself), but if the 6A tail means about 6A to the LED, and you measured on a DMM and not a clamp meter, then it makes sense you killed/popped those other LED's. 6A on a DMM could mean 6.5A actual (clamp meter), and that's way too high to expect a U3, U4 or XP-G2 S4 to survive at.

Hi, i just buy this springs for change the stocks springs in my moded m1.

You think that this springs are better than the original a6 driver spring?
and for the original tail convoy m1 spring?

Thanks.

Alberto.

For sure the Fasttech 'carobronze' spring has lower electrical resistance than the stock Convoy steel springs. They are not better than the spring on the Banggood A6 driver that I tested. Not sure how either compares mechanically.

Both will not heat up below 7-8 A, but a wire bypass is still a good improvement on both if you are chasing amps.

I did some measurements at 5 A over the weekend. My numbers are slightly higher than djozz, but I did not solder to the springs and I measured spring tip-to-tip. The M1 should come with the same springs as the S2/S2+:

Hi, thanks for the info and the image. Very valuable info.

So, i only change the tail spring for the fasttech carobronce spring. BTW great spring have the BLF A6 of bangood.

Thanks. :slight_smile:

Alberto

Edited:

Anyone have a picture for compare tint Xm-l2 u3 1a and Xm-l2 u4 1c ?
Time ago i have an Xm-l2 u2 1c and the tint was green so i decided to not buy u4 1c but i don´t know if this cahnge. Anyone can help me?

Thanks to all.

This thread needs reviving…

Why? If Cree changed production process for XP-G2 emitters they could also change it for XM-L2 emitters.

So if anyone has lower or he is unsatisfied with performance of lets say XML2 U4 bin emitters thing could be that Cree changed production process for them.

Applied DC 3.6V-6V 400KV Boost Step-up Power Module High-voltage Generator 1pc

Problem solved!

Cheers ^:)

I recently got a XM-L2 U4 1C from IOS and all I could get was 3.6A at the tail with a 30Q. The previous XM-L2 U4 1C I got from IOS and RMM when they first came out did 4.4 - 4.6A.

The new XPG3s are no better for VF. About all I get for output is basically what XPG2s from a year ago gave. Still again though I suppose since I get about the same output per emitter, but at a lower drive current.

They certainly can be driven hard on the SC5 platform though. I will be posting results for that in my next youtube vid. Internet lumens VS actual lumens.

Wut? From Dale's results here: https://budgetlightforum.com/t/-/39600, I understood the XP-G3's have a lower Vf than XP-G2's, so you can get higher amps out of them on a DD setup, and every mod he built up with them did notably better. Wut's goin on then?

I’m also confused, remember that was Dale’s comments…

I don’t have any newer version XP-G2 S4s or XM-L2 U4s to test, still waiting on stock. It’s upsetting all this controversy & what CREE is busy doing at the moment. The funny thing related to the XP-G2 S4s is that Richard did not find any substantial difference in Vf between the old and new S4s? Lots of other findings show different - they’re struggling to push amps? What we do know though is that the newer batch XP-G2 die size has been enlarged, which totally messes up throw figures, which indeed sunk the XP-G2 boat for me. And, worst of all, there’s no substitute available.

Sigh! Sigh! Sigh!

They changed production process (bigger emitter dice, the number of dots on the die have increased, the phosfor is rougher (not clear on the picture, very apparent in real life), the tint of the phosfor is a bit more orange with small red bits in it which are absent in the old die, all that results in low current draw, low lux performance, and bad tint if lacquer is not used)
Old G2 S4 2B

New G2 S4 2B

Under UV light: (left old, right new)

(pictures by Djozz)

So same could happen to XM-L2?

Thanks for all your work and reporting on the impacts for the apparent production process changes Li.

Can you tell us what lacquer you are using or recommend using?

I don’t know anything about lacquer, but I imagine the recipes from different manufactures/product types might potentally behave differently optically and thermally.

I did try that but am not using them…

There was no need for that imho with old xp-g2 s4 2b cause it had perfect tint and I refuse to use this method on new G2 S4 2B simply because it has crappy performance so tint shift to cooler one can’t change the fact it will still throw like crab.

If you want to experiment led seal(RMM) or judikins diamond glaze(Vinz) should work. If you’ll do that “the less is more rule should be applied” and watch out that dd emitter surface is ass clean and dry ass possible.

Or you can buy from RMM

I haven’t purchased any Cree emitters in a long time. I have some old “T6” emitters that I dedomed a ways back that turned awful green. Wouldn’t mind trying to rehab them if it isn’t expensive. Thanks for the fast response Li. :slight_smile:

Any more real life test from members on XM-L2 U4 and others? Are you happy with latest orders from your favorite stores?

I’m still getting about the same. I pretty much resigned to the fact that this is how its going to be. Thus the rating of my triple XML2 bulbs being 2,000 lumen. If we were still getting the low vf emitters from the good ol’ days I can’t help but think that number would be 3K. On the “bright side” run times and efficiency are up. If XPG3 is any indication of what XML3 will be we might get lucky and have super low VFs again some day…