Hello, looking for help identifying emitter in a bike headlight (pedal bike) It was connected to a lithium ion battery pack says 7.2v.
I wish to swap for more lumens and efficiency, possibly sst20. But I’m really not sure what emitter these are exactly and what emitters I should be looking for.
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Looks like an XM-L based on the images in this thread
You’ll get more lumens from the efficacy gain but to get significantly more lumens you’ll need to modify the driver for more output, which might result in overheating if you overdo it.
Tests from here suggests XM-L will do roughly 600lm at 2A. SFT-40 test on the same link suggests it’ll do c.800 at the same current.
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Dc38
(The Glutton)
3
They look like XM-L, on a 5mm×5mm footprint.
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SST20 isn’t going to give you more lumens or efficiency.
That said, these look like fake CREE XML LEDs and they look like they are on 16mm MCPCBs.
So you could swap them with any 3v LED on a 16mm MCPCB.
The gaskets (white plastic around the emitters) look like they are for 9mm reflector holes so if you go with a smaller emitter you’ll need new gaskets.
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koef3
(LED tester)
5
The LED looks like a fake. Or rather, I would say that it is a fake XM-L. Why? Because despite the rather convincing design, the vast majority of “XM-L” in cheap lamps or generally white label or no-name products are fake.
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SST-20 probably would not give a big lumen jump, but it definitely gives more throw, which make it appears brighter.
XM-L.
No recommendations without knowing how much quality-vs-quantity you need/want.
Lumen-chasers will go for arctic-cold and not caring if the beam’s hideous green, whereas lower-CT high-CRI folx will give up output for a nice beam.
Oh yeh, keep in mind that twice the lemons will only visually look maybe 30% brighter.
So going from, say, 600lm to 800lm might be 33% brighter, but afterwards you’ll probably go, “That’s it?? I can’t tell any difference”. And you’d be right.
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Firelight2
(Firelight2)
8
As others have mentioned, that looks like an old XML emitter. They were almost standard for quite a number of years. However, by today’s standards XML are dim, have bad color rendering (CRI), and most are ugly greenish cool white. Modern LEDs are much better.
I wouldn’t recommend swapping to SST20 as that probably won’t give you much, if any increase in output. SST-20 is also somewhat old. It would probably give more throw and a tighter beam though.
If you want a significantly brighter beam, I suggest SST-40 or SFT-40. Both should give a lot more lumens and throw even with the stock driver. Color rendering is not very good though.
If you want the best beam possible with both more output, better tint, and much better color rendering, perhaps replace it with an NTG-50 from International Outdoors.
Define “a lot more” though, @Lightbringer is correct:
See above my comment, at 2A the old XM-L did c.600 lm and SFT-40 does c.800 lumens. It’s absolutely more output, but unless you compare side-by-side, the increase is far less noticeable than one would first imagine and OP might be disappointed.
That said, I’d absolutely recommend an LED swap, these look fairly straightforward and would allow OP to choose the “ideal” LED for their use, SFT-40 would be more throwy, 519a for high CRI with nice (subjectively) tint etcetc
LMP LHP531 for higher brightness and efficiency. That fake xml probably has a very high Vf and it probably has a FET driver. LHP531 is a low Vf LED so expect higher brightness. Seems to be 16mm mcpcb.
Seriously? I saw the 600, but just pulled 800 outta my ass as an example.
Damn, I’m good…
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Dc38
(The Glutton)
12
That logarithmic dimming is one reason as to why Anduril 2 is so great.
Brightnesses should be relative to intensity values, with a peak (max lumen) output setting the ceiling cd, then cutting that down by half the intensity rather than half the lumens.
Mfg’s should put the lumen AND candela rating of their lights, it’s one of the redeeming qualities of Weltool besides their lackluster CS.
sst20 are 3535 LEDs, so would require a different mcpcb and centering ring. It is easier to just use a 5050 LED
but if you are OK w Cool white with green tint, Low CRI, and negative R9 (poor Red rendering), you could probably get more raw lumens and throw from an SFT40 6500K.
note: The hotspot will be smaller than from your present LEDs. And people on the road will hate you for running “blue” LEDs
I dont think a narrow hotspot is appropriate for vehicle use and would go with NTG50, because I hate Low CRI
This is the way!
Gotta love a post that tells you what to use instead and why.
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NeutralFan
(NeutralFan)
14
My experience with these LED swaps is that the lumens will be less. I’ve done a couple bike lights and they became noticeably less bright. It seems the manufacturers want to maximize the lumens, so they will sacrifice CCT, CRI, and tint to do so.
As others have mentioned, you would probably need a new driver to get the significantly more lumens and may need to beef up the thermals to dissipate the extra heat. Although a bike light has plenty of wind to help with that.
BUT for my mods, they were worth it since I wanted a lower CCT. I swapped out the LEDs to 2700K SST-20s. I don’t think high CRI is needed for a bike light, but I really like the lower CCT since it’s much less annoying to others on the bike path.
And they still produce plenty of light for my needs.
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Kraids
15
I had good luck replacing the emitters in my bike light, they use a standard 5050 footprint along with the TIR being the perfect size to drop in some from Convoy. Upgraded from basic SST-40’s to W5050SQ3’s, but now I’m curious to see how LHP531 would look in 4000k
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Forgive my ignorance, I thought these was only 6V LEDs? are these available in 3V now?
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youre right! good catch ;-)..
