LEDs Not Drawing Amps of Old

Hrmpf! That just plain sucks! Unless of course they put out as much light at ~5 amps as the old ones did at ~6,5 A.

On the top end it’s hard to say the amount of light output—If you were to have a medium at 5.4 amps and a high at 6.5 amps not sure if there would be much difference
What I have noticed is I buy drivers pre programmed (I’m older and can’t see s….t) the lower modes are always lower than programmed to be—with the patience of RMM I have drivers more to my satisfaction—this is more of an issue to me—lets face it who uses their lights wide open for any period of time

Some of them seem like they are coming pretty close to that. DBCStm has measured some lights with a U3 at around 5A that are doing about what the old ones did at around 6A. Dale, care to chime in? I know that the M6s I build with the U3s all measured 400-500 lumens higher on average than the U2s did. I have built 100+ of these and measured dozens, so I know the usual range, and the average U3 was as good as the best U2s I've ever measured. This surprised me a bit, but I can't argue with those numbers. In some lights, however, the lumens have gone down a little bit but the efficiency has still improved.

It sounds like we’re gonna need a bit of data about this.

Looks like we have a volunteer. I'll come around and watch a pro at work.

Hmm, needs to be someone with access to cells of all types, hosts with DD drivers, well acquainted with high current testing, and the means and time to do so. It would also help if they were handy with a camera. Hmm…

It would also come in handy if he/she had 20 mods-a-day capability, hmm...

Thats at least encouraging RMM. Thanks for the info.

Do you know what the amp #'s are between the U2 and U3 builds? Suspect you are in the 4-5A range?

Ive got some emitter data that might be interesting. Various testing with driver circuit and batteries or powersupply only. Sometimes with a capacitor on the output. I have been thinking about starting a thread on it for some time, but I have not gotten around to it yet.... I have used a camera and recorded video when testing many of the emitters. Some that I have blown... Might be some interesting data despite that its not a super scientific testing.

Time will tell when I get around to post about it. I have not looked that much at the clips I made yet. But im not super surprised to hear what chops728 reported.

Btw MRsDNF.. Im running 6,6A now. Short story, I found the right emitters.

I trust your tests, but also don't want to throw away money on a LED order right now. Is it worth waiting for your posted info? Smile

I think we need another round of emitter crash testing.

Can we get a volunteer? :wink:

well, unvoluntarily I did a crash-test of a U3 2A from intl-outdoor in this thread, post 45:

But to get the whole picture of the new batch of XM-L2's you need to test many of them.

Are the XML-2 T6? So do you think there is an issue with voltage ripple with this driver? I'm glad that its sorted for you by the way.

I'm willing to do testing if someone can tell me what they want done below 5 amps. Anything above 5.5 amps and I can only blow them up. I also do not have any older generation spare XML-2 U2 or U3 leds. I could pull them from lights though if needed.

Really dunno - dunno what's going on. Seems like conflicting info: Richard says his M6 builds get more output (lumens) with the U3's, but djozz's tests indicate high Vf, mediocre output with the U3's he tested. Your tests in post #11 show virtually no difference in Vf from 1A thru 5A. Others have found high Vf with the new LED's as well, but your tests are the only ones I've seen or heard of where the Vf is basically unchanged between a U2 and U3. Obviously we don't have all the info, and no idea whether sourcing and tint variations is partially to blame.

Tom E. Hard to say. Depends on what your are going to use the emitters for and what you expect out of them.

Bdiddle and Djozz. Ive got some crash test data that you guys might find interesting along with various data.

MRsDNF. 6,6A to U2 emitters. No, I don't think there are any voltage ripples issues with the H6Flex.

I hope to post about my emitter testing within few days..

As far as I know (I’m ready for MRsDNF to correct me), the numbers MRsDNF posted just show that fresh U2 and U3 parts have similar Vf. MRsDNF didn’t state that it was an older U2…

Ahhh - could be...

Thanx RacerR86 - I generally order LED's to stock, so hard to say. I'll do lower level amp builds and sometimes max'ed, all depends...

I dont have any older leds to test. Hopefully I can get an older XML-2 of Rod911 and compare voltages with the the later ones and see what current it goes to. I have retested two later leds last night again without a switch in line The voltages are quite a bit less than previously posted but again very similar to each other. When I get the led from Rod I'll post it all up.