Pretty much all my Luxeon V lights have lost amps and output - thought this was known well? I'm gonna convert what remains over to something else.
How dramatic are the losses? Could you talk about how you ran them? Were they DD’d, etc.?
Oh boy, @work now, but again, thought this was common knowledge. Initially in a SD Mini w/FET+1, the V did 8.5A on a GA cell at 4.16V, ~2200 lumens at start, 2000 at 30 secs. Now I think it's down to ~1500 lumens, not sure of amps. Think it's in my notebook somewhere but I don't have a cross ref to find it easy.... No time now to research.
Again, though everyone knew this? Anyone knows of it? Am I crazy?? 
I don’t think driving this LED with FET is a good idea. I lost half of my output (physically two of the 4 four emitting surfaces stopped working) using a LD-A4 driver. I had high mode set to direct drive and it was a huge mistake. Had to replace the LED. Currently, I’m running high mode constant current at 5.25A.
It’s been months of heavy use and lots of turbo runs and it’s still as it was since I tested it after the new LED was installed.
Ahh, ok - that helps somewhat. Soooo, I take it running/testing at 8-10 amps wasn't good? Didn't know there were 4 separate emitting surfaces - need to take a closer look at mine.
I hadn't heard of it. My D4 is using Luxeon V and still doing quite well AFAIK. Of course, that's a bit different than direct driving a single emitter. I should do a test with the bezel open and measure the voltage across the LEDs, since I don't have any good way to measure current (especially current that high).
A single Luxeon V that’s FET driven with proper springs or bypasses is not a good idea. VERY bright, for a VERY short time.
It’s a news to me that this LED has problems with sustained FET use.
It’s also a news to me this LED has 4 dies.
So…thank you both for your reports. 
In a quad, probably 5 amp per LED at best, so sounds like it's still in the safe zone. 20 amps is pretty high for typical compact quads.
So guess for those using the V's on a quad, you reflowed the 4040 V onto 3535 pads? I was only using L4P's 4040 MCPCB's.
I missed this. A bit confused: Is the Luxeon V 4 dies?
Ohhh - that 4040 quad is not listed under his MCPCB's, so guess he doesn't sell them bare :facepalm:
Yep, I'm still confused bout the 4 dies as well.
And since a couple guys chimed in about running these at high amps, djozz is either unaware, or didn't take time time to update his OP, because reading the OP, everything is fine and dandy with the Luxeon V at up to 12 amps or so...
Certainly that L4P quad or triple seems to be the best way to go with these LED's, or, be sure you constrain the amps way down, under 6 I suppose.
MOSLED EXTREME ( mosX ) ceramic insulation 4XV 4040 quad MCPCB (BARE) is here:
https://led4power.com/product/mosled-extreme-mosx-ceramic-insulation-4xv-4040-quad-mcpcb-20mm/
It is on page 2 and easy to miss. Can only find the AL version though.
Lumileds claims that Luxen V has a single die:
https://www.lumileds.com/news/299/50/Lumileds-Transforms-High-Power-Category-with-1-700-Lumen-Single-Die-LED
KevinZA1988 do you have any pictures of the failed LED?
Yes, ideally both lit partially as described, and un-lit.
I think Kevin is talking about Luxeon MZ, which is quad 4x2mm2 die LED. Luxeon V is single 4mm2 die LED.
MosX boards more than good enough for triples, quads etc. because no one run LEDs at absolute max. in those setups - difference between DTP and mosX is marginal when you run LEDs like XPL, Luxeon V at 50-70% of max. current.
MZ explains it - details, details...
What's your definition of max current?
Are all MosX boards aluminum? Guess so... From this listing on a Luxeon V quad, I had no idea a MosX board is alum - would have fooled me for sure...
I'm surprised in triple and quads you are saying alum is no worse than copper - think about it, quads have 4 times as much heat, though amps per LED is lower, but the heat is not reduced.
This PCB w/out LEDs is in the “MCPCBs - ALUMINUM” part of the shop. And there’s no copper mentioned anywhere. And weight is low for copper.
Yep, I know all that for the bare alum board, but for the pre-mounted quad in the listing I linked -- nothing about alum, copper or weight.
It's confusing without reading every post on BLF about this stuff...
1 Thank
Actually weight is available under “Additional Information”.
But I agree, these could have been clearer.
Here is a quick picture of my C8F with Luxeon V’s . You can see that one is only lighted half. I did not know that one-quarter and three-quarter were also possible. You can not see individual dies though, I do not know how the led is built up.
