New 2nd Generation Cree XP-G2 LED!

[saabluster]

I don't have a lot of time right now so don't expect the fancy graphs. Just a quick test of it mounted to an MCPCB which in turn is mounted to a block of copper.

This is an R5 flux bin.

A-------Lumens

.1------95
.2------129
.3------167
.4------197
.5------232
.6------264
.7------289
.8------319
.9------340
1.0-----367
1.1-----393
1.2-----411
1.3-----432
1.4-----448
1.5-----466
1.6-----484
1.7-----496
1.8-----510
1.9-----519
2.0-----527
2.1-----536
2.2-----541
2.3-----546
2.4-----548
2.5-----549
2.6-----548

Keep in mind this test is room temp not the 85C test which would be more real world but considering we all still have in mind the specs of old LEDs tested at room temp I figured it would make the comparison easier.

My recommendation is no more than 2A if you want to push it harder than spec and are using an MCPCB. I will also be testing one mounted direct to copper soon.

And no I did not capture the Vf. Sorry.

 

[ergotelis]

May i guess that you did a mistake in the 0,1amp reading? 95 lumens??!!I think it is 65, you pressed wrong button?

edit1:
Anyway, we can see here that with 0,5 amper we get the same performance as with a xr-e Q5 bin @1 amper.And less vF,that means same lumens with less than half consumption. Nice!

edit2:
Do you see here any new record in the category lm/watt in a consumer product? What is the top efficiency? Is it more than 180lm/watt @ 0,1-0,3amp???Am i estimating well its performance?

edit3:
The lumen increase from 0,7 to 1,3 amp is not declining always. Am i missing something or is it just a power supply inaccuracy?

 

[BigRiz]

Will there be an XM-L2?

One can only hope.. an XM-L with a 15% (or whatever) improvement in efficacy would be most welcome!

 

[djozz]

Saablusters data in a simple graph, just because I wanted to see it:


XPG-2currentlumens by djozz1, on Flickr

Looks like the lumens/watt ratio drops quite rapidly when current goes up.
djozz

 

[mds82]

Will there be an XM-L2?

From what i hear Yes. There will be an XM-L2 and also a XP-E2

 

[RoGuE_StreaK]

Looks like the lumens/watt ratio drops quite rapidly when current goes up.

Yeah, wonder if they just rate them to 1.5Amps 'cause there's not much point after that? Seems that after say 1.7 - 2Amp the increases aren't worth the effort.
Thanks for the graph, and thanks Saabluster for taking the effort.

 

[wquiles]

Thanks for the graph, and thanks Saabluster for taking the effort.

+1

 

[jasonck08]

Which is 83% of XM-L T6 and 78% of U2, both unadjusted to higher binning temperatures. It looks like CW XP-G2 is more or less equal to XM-L T6 at max power, but can't go as far as the latter.

According to the cree tool:
-------------------------------
1.5A @ 85C
-------------------------------

XP-G R5 = 400 Lumens
XP-G2 R5 = 458 Lumens
XM-L-T6 = 478 Lumens
XM-L-U2 = 512 Lumens

-------------------------------
1A @ 85C
-------------------------------

XP-G R5 = 301 Lumens
XP-G2 R5 = 338 Lumens
XM-L-T6 = 337 Lumens
XM-L-U2 = 361 Lumens

-------------------------------
0.7A @ 85C
-------------------------------

XP-G R5 = 224 Lumens
XP-G2 R5 = 254 Lumens
XM-L-T6 = 243 Lumens
XM-L-U2 = 260 Lumens

So it looks like the XP-G2 is a better option over the XM-L T6 when it comes to currents <1A. And also approximate lumens for the XP-G2 @ 25C @ 1.5A is 528.

 

[Th232]

Interesting, although note that Michael's said that the XP-G2 was mounted to a MCPCB and that he'll test one mounted directly onto copper later. I'm more interested in that test, since if you're really wanting to push it that far past the recommended ratings, a MCPCB is out of the question IMHO.

 

[saabluster]

May i guess that you did a mistake in the 0,1amp reading? 95 lumens??!!I think it is 65, you pressed wrong button? edit1: Anyway, we can see here that with 0,5 amper we get the same performance as with a xr-e Q5 bin @1 amper.And less vF,that means same lumens with less than half consumption. Nice! edit2: Do you see here any new record in the category lm/watt in a consumer product? What is the top efficiency? Is it more than 180lm/watt @ 0,1-0,3amp???Am i estimating well its performance? edit3: The lumen increase from 0,7 to 1,3 amp is not declining always. Am i missing something or is it just a power supply inaccuracy?

I would disregard the last numbers I posted. It was a quick test like I said. I just bought a new power supply and I trusted too much what the readout was telling me. Not liking this new PS very much. grr. So I used a meter to see exactly how much current the LED was seeing and reran the test. This time with it attached straight to copper. These numbers are much more accurate.

I want to emphasize that the higher numbers are not achievable in a flashlight unless active cooling is used to keep the junction temps down. The lower you go in current the more representative these figures are going to be to real world flashlight usage. Still it is amazing to see this relatively tiny LED putting out over 1000 lumens. 1033 at it's peak. I chilled the LED to about 45F and got a reading of 1100 lumens even @4.91A.

.02 9
.08 36
.17 74
.2 87
.28 122
.38 163
.46 194
.57 233
.67 268
.75 294
.85 327
.93 353
1.03 383
1.13 412
1.21 436
1.32 465
1.4 487
1.5 513
1.6 537
1.68 557
1.76 575
1.87 600
1.97 624
2.07 646
2.15 664
2.2 673
2.33 699
2.43 718
2.53 738
2.62 755
2.72 773
2.8 786
2.9 800
3.0 816
3.09 829
3.15 839
3.2 847
3.27 858
3.38 876
3.48 890
3.57 903
3.66 914
3.75 925
3.85 937
3.95 949
4.03 960
4.13 970
4.22 979
4.32 988
4.43 999
4.5 1006
4.61 1016
4.69 1021
4.8 1028
4.91 1033
4.99 1032

 

[ergotelis]

I think that you results now seem more logical and amazing at higher amperage.We see that this led is another leap in small form factor leds. If you properly cool the led, it has similar performance to a xm-l for currents up to 1,5amp and maybe more.
Still waiting for mine to come from cutter.

THanks for the effort for both tests!!!

edit: Quick question, did you manage to keep the led cool all over the test @78F? Directly attached to copper means excellent cooling, but i think that the led will still heat up a lot more than than 78 F.

 

[monkeyboy]

Quick question, did you manage to keep the led cool all over the test @78F? Directly attached to copper means excellent cooling, but i think that the led will still heat up a lot more than than 78 F.

78F was the ambient temperature (temp of the surroundings) not the die temp!


@saabluster, Thanks for doing these tests. These are interesting results. How was the emitter attached to the copper heatsink? Was it soldered on? Did you file down the emitter at all?

 

[ergotelis]

78F was the ambient temperature (temp of the surroundings) not the die temp!


@saabluster, Thanks for doing these tests. These are interesting results. How was the emitter attached to the copper heatsink? Was it soldered on? Did you file down the emitter at all?

Well i wasn't sure because he mentioned that he did some extreme cooling too later! So, all we need is a good copper pcb, like the one in xm-l, to manage to transfer the heat right!

 

[IMSabbel]

Damn.
If you drive it at 2.5 or 3A, it would make a hell of a thrower, especially with an aspheric.

 

[saabluster]

I think that you results now seem more logical and amazing at higher amperage.We see that this led is another leap in small form factor leds. If you properly cool the led, it has similar performance to a xm-l for currents up to 1,5amp and maybe more.
Still waiting for mine to come from cutter.

THanks for the effort for both tests!!!

edit: Quick question, did you manage to keep the led cool all over the test @78F? Directly attached to copper means excellent cooling, but i think that the led will still heat up a lot more than than 78 F.

The readings were taken with the LED at 78F. In order to keep the readings consistent I allowed time in between each reading for the heatsink temp to fall back to ambient. I then turned on the PS and took the peak reading before the die could warm up appreciably. For this reason even having the LED mounted to an mcpcb would not have changed the numbers. So don't take the massive current levels reached here as meaning it is possible due to the copper.

78F was the ambient temperature (temp of the surroundings) not the die temp!


@saabluster, Thanks for doing these tests. These are interesting results. How was the emitter attached to the copper heatsink? Was it soldered on? Did you file down the emitter at all?

The emitter was direct soldered to the copper. No modifications were done to the LED.

Well i wasn't sure because he mentioned that he did some extreme cooling too later! So, all we need is a good copper pcb, like the one in xm-l, to manage to transfer the heat right!

No I didn't say I did any extreme cooling. Only that if you expect to see these results in practice in a light it will take active cooling to keep the junction temps down where they were for this test.

 

[RoGuE_StreaK]

Am I reading the Cutter site right, that the XP-G2 is actually cheaper than the XP-G, right off the bat? You'd think they'd be getting rid of their old stock first?

saabluster, you didn't happen to take Vf readings as well did you? Not that the data isn't brilliant as it is...

 

[saabluster]

Am I reading the Cutter site right, that the XP-G2 is actually cheaper than the XP-G, right off the bat? You'd think they'd be getting rid of their old stock first?

saabluster, you didn't happen to take Vf readings as well did you? Not that the data isn't brilliant as it is...

No I did not capture those.

 

[SemiMan]

XP-E2 = XTE I believe.

 

[SemiMan]

Was this using CRee PCT?

I am not seeing the XP-G2 as an option when I log in ... or MT-G2 for that matter.

Semiman

According to the cree tool:
-------------------------------
1.5A @ 85C
-------------------------------

XP-G R5 = 400 Lumens
XP-G2 R5 = 458 Lumens
XM-L-T6 = 478 Lumens
XM-L-U2 = 512 Lumens

-------------------------------
1A @ 85C
-------------------------------

XP-G R5 = 301 Lumens
XP-G2 R5 = 338 Lumens
XM-L-T6 = 337 Lumens
XM-L-U2 = 361 Lumens

-------------------------------
0.7A @ 85C
-------------------------------

XP-G R5 = 224 Lumens
XP-G2 R5 = 254 Lumens
XM-L-T6 = 243 Lumens
XM-L-U2 = 260 Lumens

So it looks like the XP-G2 is a better option over the XM-L T6 when it comes to currents <1A. And also approximate lumens for the XP-G2 @ 25C @ 1.5A is 528.

 

[saabluster]

Was this using CRee PCT?

I am not seeing the XP-G2 as an option when I log in ... or MT-G2 for that matter.

Semiman

That is from page two of the data sheet.