XM-L2 upgrade = don't bother (now with pictures)

Something changed that shouldn't have during the swap, those hotspots are very different size. If they were the same size I bet the L2 would be noticeably brighter.

Can you swap *just* the reflectors between the two lights, and see if the difference is down to the reflector or the emitter (or something else)?

Wow, living that far away from anything you really dont like people, do you? :D

Wow. Gorgeous area. Nice clean air and you can see out as far as the eye can see. You have a real reason to have powerful flashlights. I would think you would want light with a high CRI so spot critters like rattlesnakes and scorpions. Do you have scorpions out there?

Not many open areas out my way. Vegetation and trees are quite aggressive here.

Don’t have any input on you beams. The xml2 does seem not as bright. Something must be off. Are your tail current readings on low normal? If they current is high on low, you may have a short.

EDIT: You may want to check for shorts between the emitter pcb and pill even if the low reading are normal. You could have a short that is kept in check by the driver’s current regulation.

This picture explains a lot…

1. The XM-L2 hot spot looks way bigger. That always makes perceived brightness go down. If there is no differenecs in reflector, I guess it sits too low (not enough into the reflector) Change around on the reflectors/centering rings. Make both lights have the same beams. Or swap completely around just to see the difference.
2.Your XM-L2 is less cool. Perceived brightness is lower. (Is it CW vs CW btw?)
3. For comparison to be accurate, you should check the the emitter gets similar current. Tailcap reading is not good enough since driver efficiency can be different and invalidate the whole comparison.

Wow, what a breathtaking landscape. Must swallow up any light you can throw out there.

As for the Tale of Two SmallSuns, I suspect there’s more at play than meets the eye. Thanks for the beamshots, hopefully we can get to the bottom of this.

The T08 with XM-L2/SinkPAD running at 4.2A or 4.5A with a Nanjg driver is my favorite mod of them all so far! Here's the results from the T08 review thread here - https://budgetlightforum.com/t/-/16808#comment-351934:

New #'s on my mod'ed T08. My mod'ed ZY-T08 w/XM-L2 U2 SinkPAD, Nanjg @4.2A lost a 7135 somehow - maybe it never worked day one I'm think'n. Anyway, added another 7135, with the 2 Pana PD batts, measured 4.27A now, and measured output:

lumens - 1,395 @start, 1,366 @30 secs

throw: 100 kcd (broke the 100k barrier)

Not bad with Pana PD's, but probably even better with Samsung 20R's. This is amazing, plus I did another even better at 4.5A, de-domed XM-L2 that got over 200 kcd! I really like the parallel battery setup on this light for mod'ing to XM-L2/SinkPAD's. Just got another T08 in today, probably will do a 4.5A straight XM-L2 U2 1C.

It looks like you have a T6 3C there - comparing a XML T6 1A with a XM-L2 T6 3C, it's apples and oranges... I like the 3C tints, but not when I'm looking for pure power, or comparing brightness to the cool whites because they will dissapoint. In a BLF A8 and an EDC XIAOZHO I got XM-L2 T6 3C's and they are down 150-250 lumens from the T6 1A or XML U3's. Unfortunately, it's hard to find a "true" (no lies) XM-L2 U2 1A, because th U2 1C's are a bit too neutral for many people's taste, I've been finding out the hard way...

>>>>>>those hotspots are very different size.

As I said way back in the beginning of the thread, because of differences between the stock star and replacement star, the XM-L2 star is recessed maybe .5mm-.25mm (1/2-1/4mm) lower than the stock star, hence the slightly different sized spots. The solder connections on a 21-mm star need a super thin spacer to prevent shorting against the reflector.

Yes the L2 could be reflowed onto a properly size GIANT star to make the comparisons exacty the same, but I will leave that to others. The spot sizes are less different the farther away they are, i.e., the outside spots are not that different in size. And spots-size doesn’t matter in tailstanding tests.

Tailstanding shows the L2 maybe an almost undetectable hair brighter than the stock T6.

Yes, the test is slightly imperfect, but please don’t forget that I upgraded TWO lights. The XM-L2 in the aurabuy C8 fits exactly the same as the original stock T6. I am waiting for more exact-same aurabuy C8s to compare with the L2 modded C8. BUT, the point is, in the C8 with the L2, I also can see very VERY plainly that the XM-L2 in the C8 is LESS bright than similar C8s with U2s/U3s and not that much brighter than a stock aurabuy C8.

I mentioned that I have two MORE lights intended for this L2-comparison project, two exact-same A0 clones. I have decided not to change one to an xm-l2 but will use a U3 instead. Why? Because I tried both the modded Small sun and modded C8 last night, and the L2 tint is just horrible for this landscape.

And there is NO DOUBT in my mind that the U3 — for me anyway — is the preferred upgrade with noticebly more light, minus the yellowy orange tint of the L2s that I have. So I won’t be doing a third light. Perhaps others will find better-performing L2s from different vendors. But stick a fork in me, I’m done with this project.

ESPECIALLY since last night I noticed that the bottom fell out of whatever brightness the L2 offered when it hit about 3.95 volts. Both L2s became noticeably dimmer. Could this be the more aggressive power demands of the L2 that others have mentioned? I don’t know. Yes, it could be the drivers I am using I suppose, but this sudden dimness did NOT happen with the stock emitters.

This is yet another reason, i will be passing on the L2 for now.

Perhaps with dedicated drivers in lights designed for this new emitter, the promised increased brightness will shine through, but as a drop-in upgrade in existing T6 lights, I am just not seeing ANY benefit to the L2 over the U3 or even a heavily driven T6 in some cases.

I really really wish that others with L2s would post some comparative beam shots. And I hope if others decide to do the L2 upgrade that they will post the results on BLF so we all can get a better handle on what this new emitter offers or doesn’t offer.

Finally, not meaning to sound like a broken record, as one BLFer said in this thread, technical specs are one thing but real-life testing is quite another. I can see NO 20-27% increase in brightness with the L2 over a T6 and certainly NOT over a U3 or even a U2. I WANT to see that increase. I didn’t set out to trash or dis the L2. I wanted a brighter emitter.

I hope others will pick up the testing gauntlet and prove me wrong. Do some more tests; post them here on BLF showing what a super-bright emitter the L2 is.

The second I can see how to make this emitter work, i will be back in line to buy more and use them in the way that does make them brighter. But, until that time, my L2 testing is done. I’m sticking with U3s and heavily driven T6s.

Thanks to everyone for their comments and their help.

what do you mean the hard way Tom? :wink:

I updated several light already mod'ed to U3 1C and upgraded them to XM-L2 U2 1C's and every time it's a bump and identcial tint, nothing perceived different in the beam pattern...

Not sure I picked it up here, did you post the bin and tint of the XM-L2's you used? This is very confusing....

How about a light sent literally half way around the world, only to get it returned because of the tint? Not a monetary loss, and it was handled very well considering, but it was more an emotional stress that maybe I did something wrong here, not explaining it or not asking the right questions on tint. I was thinking the 1C tints would be preferred by most over the 1A or even 0D but I'm wrong about that assumption for sure.

That’s really THE key - go with the LED you like for the conditions you are using it.

I tend to prefer a little more cool light where there is no reflective bounce back, like I get from glossy or thick leaves and some tall grasses or water.

I’ve found that when I have two lights like you’re showing, the warmer tint is better for looking at things hiding in foliage, where the cool is better for open, non-reflective terrain. In the desert, it would be no contest for me, either.

Still, even where I prefer the warmer light the cools tend to look like more light to my eyes (and reflections may be helping with that). I prefer it for most outdoor conditions, except when looking in and being under the trees. In the woods, I prefer the warmer LED.

PS - on the reflector focus issue, I’ll have to say in my 2 DSTs the warmer L2 hot spot is very close to the T6 size and if yours starts less focused, then it is probably loosing some throw and lumens OTF so that probably is part of the difference (knowing that you can’t really adjust for it in your setup).

Tint IS the main factor.

I upgraded a few lights with the XM-L2 and found them to be slightly brighter than the cool tints of the t6’s I swapped.
I swapped my zy-t08 and my Coast Hp50 and both were noticeable. My t08 gained a good bit of throw with a dedomed xm-l2 versus the dedomed t6 and my coast has a much brighter pleasing flood to it. Though zoomed in it doesnt do much justice toward the swap, it really isn’t noticeably brighter or throwier.

I do however love the warmer tint and my dedome is VERY warm and pleasing to my eye. I DO NOT like cool lights, neutral is the coolest I want.

The forward voltage of XML2 is higher than XML so you’ll need a higher cell voltage if you want to drive your led at 3000 mA. If you just replace the LEDs you may be getting a lower current on XML2 and getting the same power as the original LED. You’ll need your cells topped up, current strictly controlled and/or use a 2 cell light to be able to make a proper comparison. A direct drive light would not be suitable for such test.

There seems to be some confusion about my purpose in this thread.

This thread is the tantalizing and thrilling story of an old guy replacing EXISTING T6 emitters (Whatever they may be — Tint CB76 lawnmower carp 78B) with XM-L2s from lck-led. This experiment is what it is. I hope some find it helpful. If not, then they can skip the thread and read one more to their liking.

At the end of the day with the two lights I used — the aforemetioned Small Sun and a Aurabuy C8 — the emitter changeout was not worth it TO ME, for the reasons I have already stated throughout this thread. Little gain in PERCEIVED light output and a tint to me that renders everything in the desert an unappealing yellowish orange.

Rather than do this emitter swap in a closed room and closely guarding the results, I decided to share the results on BLF.

YES, comparing the existing T6 in the Small Sun with the orangey tint of the L2 is DEFINITELY comparing apples and oranges. It was done intentionally. ;) ;) Because I thought — like me — quite a few modders here are contemplating changing out existing T6s for L2s. By using one of the most popular lights here on BLF (the Small Sun T08) and one of the cheapest (aurabuy C8), I hoped to provide a hint of what modders can expect with the L2, imperfectly fitting 21-mm star in the T08 and all.

I could change out the existing driver in these lights for a P78yh65 Cow Head Nanjiboom Exploding Smiling Gopher Bat and get more power, but that was not the point of my failed experiment. It was to see if simply switching an existing (whatever tint it may be) T6 for the new sooper-dooper L2 would light up the 38 miles from my house to the nearest gast station. It didn’t. :–0

If anyone has success with an L2 in any stock light, I hope that they will post the results here on BLF!

And once again. I appreciate all the suggestions from everyone and all their keen observations. Hopefully they will aid others in maximizing the L2 i whatever light they choose!

I have never bought from LCK-LED, but even the best make mistakes. There's no way to know what a bare emitter is once it's snipped off the reel, and you might not get what you ordered either because of honest mistakes or lazy and/or unscrupulous resellers. Your findings do not match what others have done with what are supposedly the same parts. You need to dig into this a little more instead of just getting bad results and then condemning all XM-L2s as worthless. :)

>>>>>>Wow, what a breathtaking landscape. Must swallow up any light you can throw out there.

Yes, it does. Lights that seem like the brightest on the planet in the city seem ineffectual out here.

>>>>>Nice clean air and you can see out as far as the eye can see.

Yes, the air is USUALLY very good. But lately we have been getting some air pollution from China (especially sand storms from Mongolia) that really hazes everything up. They even announce it on the radio here when it happens. This Chinese haze was nonexistent 10-15 years ago.

>>>>>Do you have scorpions out there?

We’re at 5000 feet in the mountains above Death valley proper so it has just started to warm up …. And I have been finding scorpions for the first time with my BLF-member-suggested UV light. BOY does it make them show up!!! Fluorescent glow-in-the-dark green. Pictures don’t do justice to how bright the UV lights makes them.

With the Uv light, it has given us a chance to really check ’em out. They seem incredibly docile and eager to avoid humans at all costs. Which explains why I have only been stung once in 25 years. You really have to beat on them to make them show any aggression at all.

>>>>>Wow, living that far away from anything you really dont like people, do you?

There are plenty of people here. Death Valley has over a million visitors a year …. And MANY of those visitors are German! I have been in area restaurants where Germans outnumber the locals two to one. French too. And the Germans almost always come in the summer.


I think this is a good thread. It’s good for people thinking about upgrading to see the good and bad. Gives a better feel for the potential outcomes they may experience themselves. It also shows that if you don’t need NW, you may be able to get more bang for the buck with XML U3’s.

I have only upgraded 2 lights and built one with the XML2 (T8 3C). I’m very happy with them, but I don’t feel compelled to upgrade the remainder. At least not until prices drop significantly.

:slight_smile: I hear ya :slight_smile:

I think you should try a cool white XP-G2 at 3.5-3.8A. They're nice. :)