I’ve noticed that the XM-L can handle 3-4 amps, but has been seen to handle as much as 6A when mounted on a copper star with appropriate heat sinking.
The XP-G2 looks to be able to handle 1.4-1.7A. Do you think if it was mounted on a copper star it could be pushed to say 2-2.5A? If this would be possible, the XP-G2 would make a seriously potent package for lumens and throw ability :bigsmile:
What’s the point of doing something like that?
All over 3A (for XM-L) adds more to the heat than to lumens and shortens the LED’s life span…
You won’t get 2000 lumens from XM-L T6 even U2 if you crank it up to the 6A but you gonna shorten its life significantly, no matter which base is it…
Mounting on a copper star takes the heat away from the Led far better than the normal circuit board, so should in theory increase reliability of the Led at the same current input.
As you say, increasing the current beyond a certain point will just introduce heat and reduce the Led lifespan, but when mounted on copper, you should be able to increase the current by a certain margin to gain more output, without risking any damage to the Led as the heat is pulled away from the Led far more efficiently.
It’s all about that margin and how much you want to push the LED’s. Copper is better but certainly not 100% beter, maybe 20–30?
And, you will need to find drivers of good quality also, I doubt that tipicall drivers from DX or KM will work without issues with 2 or 3 voltage regulators added by soldering (for 3,5A or 3.85A)!!!
Hopefully when the XP-G2 has been out a bit longer, there will be some testing done on copper.
There is a member on cpf who sells XM-L drop-ins with the Led mounted on copper and the pill filled with solder to aid heat transfer.
For what it’s worth, my Uniquefire G10 runs the stock XP-G R5 over two amps at the tail cap without issue so far. It gets warm, but never too hot to hold. And yah, it’s pretty darn bright!
2A at the tailcap but from 1,5V AA battery. That means about 0,5A to the emitter.
About XP-G2. On classic MCPCB:
“http://www.candlepowerforums.com/vb/showthread.php?340892-New-2nd-Generation-Cree-XP-G2-LED![](&p=3982696&viewfull=1#post3982696":http://www.candlepowerforums.com/vb/showthread.php?340892-New-2nd-Generation-Cree-XP-G2-LED)&p=3982696&viewfull=1#post3982696
On copper (copper block, not thin MCPCB/star):
“http://www.candlepowerforums.com/vb/showthread.php?340892-New-2nd-Generation-Cree-XP-G2-LED![](&p=3984771&viewfull=1#post3984771":http://www.candlepowerforums.com/vb/showthread.php?340892-New-2nd-Generation-Cree-XP-G2-LED)&p=3984771&viewfull=1#post3984771
xp-g2 emitter is worth being put in a copper star. Even@1,5amp you will see great results and i am pretty sure, due to its good design, i can handle easily currents of 2amp. It is a step ahead of xp-g and other leds.
Very impressive results from the XP-G2 in those links.
So it looks very possible that running an XP-G2 on a copper star at 2A would provide serious output, yet should still be completely reliable.
Hey Phantom,
That was over two amps on a fully charged 14500. EDIT: I figure 2.2 amps times 3.7 battery volts under load divided by 3.5 front voltage times .75 driver efficiency should be about 1.7 amps to the led. My best guess anyway.
I will give another interesting measurement:
Jetbeam BC10 xp-g2 modded,
tested with 2600mah sanyo cell for direct drive, @2amp, i get 460 OTF. I guess it is a nice number right?
Beautiful! And the beam pattern suits a AA size light perfectly.
Any guess when they will be widely available?
Sounds nice 