I'm only achieving 2.25A from a 3.04A driver

I should have elaborated more. I’m speculating that an errant conductive source may have caused an inadvertent and unnoticed short on some of the driver contact points in the process. Proabably worth checking before throwing a possibly good emitter out.

Driver is still working great
I just soldered it up to a pt54 red LED
I know it can handle whatever you throw at it
So I tested it in DD and I got a reading of 11.47A ( I’m suprised it didn’t blow the fuse in the dmm)
And 2.74A through the driver so I’m sure it’s my dmm that’s to blame
I love the pt54 it’s built like a tank and it comes with a pretty massive heatsink

Sounds like you tested the PD cell, and that's why the emitter blew, can't handle over 11A even with a good copper heat sink.

When you were first asking, the cell you were using is...I think...rated at just over 4A. That one should'nt have hurt the Cree emitter. The PD is a different story.

That test was with the Sanyo red cell
They seem to be great battery pack pulls

Yes they are, I am using them myself. I had my MT-G2 in the Solarforce M8 running direct drive. With 2 18650's the Sanyo FJ cell allowed 7.51A, Samsung 20R allowed 12.18A. I could run the M8 with a McClicky switch using the Sanyo's, was scared to attempt it with the 20R cells. lol Now it has a driver in it and is pulling 3.74A through the Sanyo's with 2 extra chips on a Qlite.

Hope you find the problem! I use Qlite's all the time, probably put in over 30 of em. Have 10 sitting here waiting their turn. ;)

I tend to approach it like this… a fully charged 18650 DD to an XML = potentially unsafe current levels.
How unsafe is arguable and there’s too many variables involved to really work out exactly what the max current will be and for how long before the cells sag or at what current that particular emitter will go pop.

So in general I think it’s best to just be cautious with any DD test especially if you want/need the LED to still be functioning afterwards.

If testing direct drive to ensure operability, I typically use a 14500 or 18350 cell.

Lesson well learned
I’m gonna have to send some business to RMM here soon

Yes those would certainly be safer, or use a partially depleted 18650 at around or below 3.7v resting voltage.
Then you can be sure there’s less chance of a dangerous peak current.

Well I fried an emitter tonight too :) I have (or had...well I guess I do still technically "have" it :) ) a cheap XM-L2 on a 16mm aluminum star that I've been using to test drivers, etc. for functionality after I make changes before I either send them off or put them into one of my own lights. I got everything setup like I always do, with the multimeter measuring LED current instead of input current. This particular driver had 6 extra 7135s stacked on it, which should give a bit over 5 amps if everything is working correctly. I hooked up the driver with a freshly charged 20R.... I went through the modes, low...medium...high...looked over and saw over 5 amps on the meter! Looked back and the LED was smoking something fierce. Good news is that the driver is fine! Still puts out around 5.10 amps to the emitter. This time I went with a copper star instead lol. I wasn't thinking about that... I had only ever run this LED/star combo up to around 3.7 amps before.

Life's still good and I was able to have a good chuckle about it. I've done much worse before. :)

Hehe yep I’ve had a few smoking test emitters myself. Though usually looks worse than it is. I bet it’s like the gunk and oil on the dome that vaporizes rather than anything truly bad actually happening. Never left the emitter on long enough to find out though :stuck_out_tongue:

So I always assumed that my stock dmm leads were off a bit, but they’re thick so I assumed they weren’t too bad. Looking a bit closer they’re 22 awg! I’m guessing they just have thick insulation on the wires, because the 22 awg I received from IOS is a fraction of the thickness.

Where would I go to find some decent, flexible wire for measuring current with a DMM?

12AWG silicone wire and some 4mm banana plugs.

I got some Tenergy Silicon Insulated 12Ga that is amazingly flexible, like a rope. I got gold plated banana plugs for each end to go in the DMM, works like a charm.

Can’t remember where I got em though, and can’t find the emails on em.

I usually buy mine at Buddyrc, but they were out of 12AWG silicone wire. So I purchased from this seller on ebay, he offers a few different lengths. Super fast shipping and good quality wire. I’am on the east coast and he’s on the west coast. Ordered late on a Friday, showed up at my door on Monday.

Turnigy 12Ga Silicon Insulated wire at Hobby King . Super flexible, almost unbelievably so. I’ve found silicone coated wire is not all the same. Turnigy is very good stuff!

I got these: buddyrc.com red-14awg, buddyrc.com black-14awg, soldered into banana plugs, then soldered up the ends to test with, just enough to keep the wire strands together, stripped back a 1/4 inch or so. Very reliable, very flexible, about 18" each...

PS: I always test my drivers first with a rigged up XML T6 on a simple aluminum star mounted to a big metal piece (scrap bracket I had laying around), 22 gauge leads on the T6. The lower Vf of the XML's is easier to bench test high amp drivers.

This meter works great for high amp measurements: Uni T ut33b. For $13, it's the cheapest I'd go for in a meter, no frills.

I’ve gone and confused myself by reading just about everything I could about upgrading leads… Some posts were saying it’s a great thing to do, but others said it didn’t affect anything or negatively affected readings. :~

My 2800mA C8 from FT is showing 2.7 amps at the tailcap from a few day old full charge protected nitecore 18650 (~2 year old battery) at 4.17v. This seems reasonable to me?

Your readings seem ok for that light, but how does it do at 4+A? I can't recall any posts about upgrading leads being a negative, but it has been confirmed many times over that 12-14 gauge leads vastly improves amp readings over stock leads, but I'm thinking if you are using 22 gauge, I think 22 gauge is thicker than most stock DMM leads. Also it will depend on the quality of the DMM. The UNI-T meters, even the $13 one, I know is good - a very seasoned tech I work with (I call him a super tech) owns several of these and swears by them for this type of usage.