Lumileds Luxeon V, test of a 4000K 70CRI emitter

But from my experience, the failing Luxeon V’s is not a one-to-one result from overcurrent. The failing Luxeon V in my C8S was already the third one failing, after three reflows (on the challenging triple 3535 board :person_facepalming: ) and again a failing led I called it a day. And from the output (a bit over 4000 lumen when all 3 leds still worked) it is drawing under 15A (I could measure actual current again) so not really extreme for the V. On the other hand I have one Luxeon V in a VG10 with BLF-A6 driver and all bypasses doing over 2000 lumen, and still going strong!

I have wondered if, for super low Vf LEDS, high cell voltages may induce damage even if the continuously delivered current is not excessive. Also, LEDs are sensitive to reflow temps and duration, maybe some more than others, and possibly even moisture content as per the datasheets.

My little OTR M3, though modded to FET+1+bank, is running on a 16340 so can't achieve high amps, still damaged the LED. There may be something else goin on.

At least I do pay a bit of attention to my reflows, not in a frying pan on the stove but on a “regulated” heatblock that does not exceed 240 degreesC and with the board sitting on a separate small piece of aluminium placed together on the heat block so that the heating up and cooling down is not as instant as with the bare board on the heat block. Of course this still does not follow the reflow-instructions.

Based on failure reports, I noticed that all problematic LED were from earliest batch, which is possibly some kind of pre-production batch, and they could suffer from "child diseases", maybe Philips was in rush and wanted to release several sample reels ASAP, so it could be some kind of manufacturing defect. I never seen that failure on new batches.

Very interesting! Who wants to try to fry one, for science?

I bought mine so long ago, can't recall from where - I know I bought some MCPCB's from L4P, but not sure bout the LED's -- need to track back.

That’s exactly what happened to my direct driven Luxeon V’s.

Thanks, this makes sense now. My observations were “4 dies” when looking very carefully at the edges of the phosphorus around the edge of the LED.

Do anyone know if there are plan to make different colour temp for luxeon v? I hope that it will be similar to luxeon v2 but it seem like luxeon v is different and only has 4000k temperature?

4000K,5000K,5700K,6500K is what datasheet says, I have 4000K and just recently got 5700K (it should be great combination for tint mixing to get 4800K and even more rosy tint):

https://led4power.com/?s=l1v1&post_type=product

Kaidomain has the 5000K and 6500K

L4P - looks like your V's are a higher flux bin as well? Are both the 4000K and 5700K both bin W?

Also, are you sure these new batches last longer, or can take the higher amps than earlier batches? If I knew they would last at high amps now, I'd buy a few from you.

I could throw one in a FET light to test, but it was purchased April 2018. My D4's quad board was purchased in August. Not sure when the bin transition took place.

...My Thorfire VG10S has a dead driver anyway, and a Luxeon V already under the reflector. Maybe I'll go do that soon, can't remember if I have any spare FET drivers in the right size though. Plenty of Blue springs for it though!

W flux bin is the most common one, actually I've never seen any flux bin other than W, KD are the same regardless the different CCT. Vf bin is also F on all recent reels.

Initial samples were G Vf bin, and reported "1/3" failures were only from that first batch, no one reported problems after that.

It might be worth mentioning that I've seen that exact failure on my own (on that batch), it was not max. current related, but it appeared immediately after reflow.

I realized that after one of the LEDs had that problem after soldering 4pcs on quad L1V1 board. I replaced that one, put new one, and after reflow the LED on the other position failed this time, so it was thermally related issue (my guess is problem with die glue - too little on one side of chip), not current related.

Again, I've never seen even a single failure (and no complaints from customers) after that 1st batch of 4000K LEDs.

Max. "usable" current form Luxeon V is about 9A, so it would be good to stay below that when DD drivers are used.

So it’s safe to say I can use it at 7A high mode om one of your LD-4 drivers?

Yes, it's similar to SST-40 when it comes to max. ratings.

So, has any one tried the newer batch on direct drive yet? If so, what current can be expected of good gold plated springs like the ones from led4power.com?

They are bone heads for naming the new led V !!!

No flashaholic would buy a new flashlight with an led from 2007. And, once educated on how stupid the naming department of luxeon is, it will be impossible to Google a V without being drown by outdated lights.

Flashalcohics are 0.001% of their business, they just like the V for Victory.