Results: Testing XM-L, MC-E, SST-50, and XP-G emitters **Updated**

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Results: Testing XM-L, MC-E, SST-50, and XP-G emitters **Updated**

**Update Jan27, 2012**

(Cleaned up the post a bit and added xp-g data)

 

Gentlemen,

  Here are my results from testing the Cree XM-L emitter(s) up to 5 amps.

**Update Jan27, 2012**

(Cleaned up the post a bit and added xp-g data)

 

Gentlemen,

  Here are my results from testing the Cree XM-L emitter(Drunk up to 5 amps.  This is something I've wanted to do for awhile now, mostly because I haven't been able to find this info on the interwebs, and partly because of some debate and speculation going on in a few recent threads. This test took a heck of a lot longer to do than I first thought, so without further ado here are the results:

Test Set-Up:

 

* Emitter tested: Cree XM-L 1C mounted on a 20mm star

* Sample Size: 8 chosen randomly out of 80 (all I had the patience/time for)

* Test rig: Stars mounted on 1lb 25mm pure copper barstock set into a ~10lb block of pure aluminum.  Arctic Silver 5 used on star.

* Temperature just under star monitored entire time. Maintained +/- 1 Degree throughout testing.

* Results taken 10sec after power on for any given level

* I know it's obvious, but lumen results are emitter lumens (bhp, not rwhp for you motorheads)

Here's a few pictures of the heatsink and test set-up:

 

 

And now for the big table and graph.  The following represents the average results of the 8 different emitters for each data point (All emitters were within <1.1% of each other...another reason I stopped after Cool:

Current (ma)  Lumens  
10040.31
250104.3
350147
500207.1
750303.5
1000392.1
1400520.9
2000686.2
2400773.1
2800852.2
3000881.4
3200905.9
3400937.5
3600956.5
3800977.1
4000988.9
4200996.0
4400996.8
4600996.0
4800988.1
5000973.2


 

   

 

 

6-24-2011 Cree MC-E test added:

 Mr. Oldbobk was kind enough to send me both an MC-E and an SST-50 to test.  Test performed is exactly like the xm-l above, except only one emitter was tested.  I will update again with sst-50 data once that test is complete.

 

Current in maLumens
200ma73.5
400ma142.3
600ma207.1
800ma267.2
1000ma323.3
1200ma376.2
1400ma424.5
1600ma470.4
1800ma513
2000ma553
2200ma596.8
2400ma630.8
2600ma661.7
2800ma693.3
3000ma718.6
3200ma746.2
3400ma768.4
3600ma788.1
3800ma808.7
4000ma826.1
4200ma837.9
4400ma849.8
4600ma861.7
4800ma868
5000ma874.3
5200ma869.6

 

 

 

 

 

 

 

6-30-2011 SST-50 Test added:

 

 

Again, same test set-up as for the xm-l.  Here are my results up to 6.4 amps, which is as high as my bench power supply would go.

200ma61.3L
400ma122.8L
600ma181.8L
800ma239.5L
1000ma

294.2L

1200ma348.6L
1400ma400L
1600ma449L
1800ma497.2L
2000ma543.1L
2200ma587.4L
2400ma630L
2600ma670L
2800ma708.3L
3000ma746.2L
3200ma790.5L
3400ma825.3L
3600ma857.7L
3800ma889.3L
4000ma921L
4200ma948.6L
4400ma975.5L
4600ma1001.6L
4800ma1026.9L
5000ma1047.4L
5200ma1056.4L
5400ma1067.2L
5600ma1087L
5800ma1110.7L
6000ma1126.5L
6200ma1146.2L
6400ma1160L

 

 

  And there are the results. I didn't notice the drop around 5200ma until just now, but can attribute that to being distracted at the time and may have gone past my 10sec lumen snapshot.  My data is rather more conservative than what is stated by the official datasheet, and that could be contributed to any number of variables.  For example, even though my test heatsink is monstrous I feel that the 20mm star itself is the bottleneck for heat transfer.  It is interesting to note that where the XM-L falls on its face at any current past 4.2amps, the good old SST-50 keeps chugging along.  In certain high draw applications this would definitely be beneficial, not to mention the bond wires are much thicker and more numerous vs. the xm-l.   

  That's it for now...Considering all emitters were tested under the same conditions and with the same equipment, this should hopefully provide a good comparison between them.  I hope some find this info useful.

Thanks for your time,

 - Match

 

*Added Jan27, 2012*

 Cree XP-G R5

200ma80.9L
400ma154.2L
600ma218.2L
800ma274.3L
1000ma

322.5L

1200ma365.2L
1400ma398.4L
1600ma423.7L
1800ma442.7L
2000ma453L
2200ma454.5L
2400ma446.6L
2600ma430.8L
2800ma403.2L
3000ma364.4L
  

 

For your viewing pleasure, the Cree XP-G. Test set-up was the same as the xm-l above (except only one emitter tested). 

  Special note for the morbidly curious:  After the testing, I decided to sacrifice an xp-g by seeing at what particular amp level it would let out the magic smoke.  I kept increasing current at 200ma increments past 3 amps (roughly 3 seconds between steps) until *poof*. The answer is 4.2 amps.  I don't know about you, but I was rather surprised! 

Enjoy,

-Match

 

Update April 28, 2012

 Many of you have requested that a test be run on the Cree XR-E R2.  Thanks to Dthrckt who was kind enough to send me one, those results are now in.  Again, testing procedure was performed like the others above.

  Seeing as how the xr-e's are primarily used for throw, the above graph shows why such great sucess in this endevour is seen at greater than stock current draw.  What my testing only indirectly shows is the increase in surface brightness that's critical for extreme throw. 

  Also note that this emitter was tested as shipped mounted on a 14mm(?) star.  Life's been rather hectic as of late, but I plan in the near future to test this, along with the xm-l, directly mounted to copper.  I believe it will be possible to get over 400lm out of the xr-e, along with a substantial increase in throw, in this configuration.

As always, thanks for reading.

-Match

Edited by: sb56637 on 08/26/2014 - 18:23
trooplewis
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Nice data, I appreciate the effort. Looks to me like all you need is a real 2.8 to 3.0A, after that the law of diminishing returns kicks in.

My big question is, does the draw that I measure at the tailcap actually equate to draw you get in these measurements?

Rats, finally sold my 2010 509hp Mustang...now I can buy more lights!

Sold the red one too! Now guess what I drive, doing my penance for 500 hp commuters...

http://dreammustang.com/

http://i884.photobucket.com/albums/ac47/Ha

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Great work! 

Piers said " ....but who wants enough light, when you have the option for far too much "

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Okay Match, I for one am satisfied.  My 980L is not over 1,000 lumens.  (I'll be updating my review)

The only other question I had was the "overdriven" issue.  Based on this it would seem 4.50 amps (which is what my 980L draws every single time I test it on high) is a waste.  I would be perfectly happy with 3.5 amps and >900 lumens.  Less heat and all that . . .

You are a real asset to this board Match and I applaud you.

Foy

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Match
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trooplewis wrote:

Nice data, I appreciate the effort. Looks to me like all you need is a real 2.8 to 3.0A, after that the law of diminishing returns kicks in.

That's my feeling as well.

trooplewis wrote:

My big question is, does the draw that I measure at the tailcap actually equate to draw you get in these measurements?

Not unless your cell is directly connected to the emitter (DD).  My test bench power supply was connected directly to the emitter, so the amps it put out was what I read and what the emitter truely saw.  Anytime the power has to go through a driver there will be a loss.

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So can you put a number on that loss Match? I have heard 20% thrown around, so at the tailcap we would need to see a number of roughly 3.5 or 3.6A to know that there is really 3.0A getting to the emitter?

Rats, finally sold my 2010 509hp Mustang...now I can buy more lights!

Sold the red one too! Now guess what I drive, doing my penance for 500 hp commuters...

http://dreammustang.com/

http://i884.photobucket.com/albums/ac47/Ha

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Very nice Match ..

The only thing I would like to see is vF  results ...

Can you vary voltage ?    To the emitter ?   say starting at 3.2v and maybe to 3.6v or 3.7v  ?  [ That would be interesting ]  

 Always remember , the easiest thing in the world to do , is to expel hot air from your lungs and through some vocal chords ..
The resulting sound may , or may not be worth listening too ….

 

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Thank you sir for taking the time, effort and expense for conducting this experiment for the benefit of fellow enthusiasts around the world. Great job, you are the man.

I am already visualizing the duct tape over your mouth.

Match
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Flashlight Foy wrote:

Okay Match, I for one am satisfied.  My 980L is not over 1,000 lumens.  (I'll be updating my review)

The only other question I had was the "overdriven" issue.  Based on this it would seem 4.50 amps (which is what my 980L draws every single time I test it on high) is a waste.  I would be perfectly happy with 3.5 amps and >900 lumens.  Less heat and all that . . .

You are a real asset to this board Match and I applaud you.

Foy

It would be neat to test the 980L in the I.S.  I'm guessing it would do ~850 OTF lumens.  The real strength of the 980L lies not in the tailcap amps, but in the very well designed reflector (and the fact that it's a damn good looking light).  I'd be willing to bet that it would very hard to tell the difference between a 980L with 2.8a SB driver and a stock one without having one in each hand and flashing them back and forth. So yea, less heat and better battery life.  

Thanks for the nice comments guys.  I'm glad to see folks find this info useful.

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old4570 wrote:

Very nice Match ..

The only thing I would like to see is vF  results ...

Can you vary voltage ?    To the emitter ?   say starting at 3.2v and maybe to 3.6v or 3.7v  ?  [ That would be interesting ]  

I had a extra fluke, but neglected to record vf as I didn't feel it was necessary at the time.  The test bench power supply I used is either in CC or CV, depending on the setting, so no way of varying that.  Previously (about a month ago) when I was playing around I set the current at 6a just so it wouldn't be a limiting factor, then proceded to vary the voltage starting at 2v and going up.  Unfortunately I didn't write it down, was just messing around, but I do rememeber current rising quite rapidly due to small variances in voltage.

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Another thing I just thought of is, it would seem the 3-mode UF XM-L is driven a little high too.  Most of the time I get 3.5 to 4 amps in an L2P.  Tonight, I just tested one of mine in a Solarforce L2. (Mr. Silver)

with protected Solarforce 2400:

high -       4.30 amps

medium - 1.18

low -         .19

with protected AW IC 2900:

high -       4.36

medium - 1.17

low -         .19

Here it is with the first black L2P I bought.  Same exact drop-in, same exact batteries with the addition of the Trustflame.

with protected Solarforce 2400:

high - 4.20

medium - 1.14

low - .18

with protected Trust Fire flame 2400:

high - 4.00

medium - 1.17

low - .19

with protected AW IC 2900:

high - 4.10

medium - 1.15

low - .19

I'm just a little bored tonight so, sorry if this is irrelevant.

whatissocoolaboutAWFoy

p.s. Match, if this is a thread hi-jack I will quietly delete.

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Flashlight Foy wrote:

Another thing I just thought of is, it would seem the 3-mode UF XM-L is driven a little high too.  Most of the time I get 3.5 to 4 amps in an L2P.  Tonight, I just tested one of mine in a Solarforce L2. (Mr. Silver)

with protected Solarforce 2400:

high -       4.30 amps

medium - 1.18

low -         .19

with protected AW IC 2900:

high -       4.36

medium - 1.17

low -         .19

I'm just a little bored tonight so, sorry if this is irrelevant.

whatissocoolaboutAWFoy

I'll have to bust out my AW 2900 vs Trustfire Flames graph when I get a chance. They're pretty evenly matched.  Actually, the AW 2600 is better at holding its voltage (resulting in higher amps) than either.

 

Now...the question is why the difference in amps between the L2P and L2?

 

EDIT: Yup... I just moved into a new place in Hijacksville. I'm such a hypocrite.

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I was just wondering that myself.  Gimee 10 minutes.Smile

 

boredFoy

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Sort of like putting an 850 holley double pumper on your honda civic ..

Foy if your flashlight is drawing that many amps instead of thinking of changing drivers to bring your amperage down why not just add two more xml's .??

καὶ τὸ φῶς ἐν τῇ σκοτίᾳ φαίνει καὶ ἡ σκοτία αὐτὸ οὐ κατέλαβεν

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I just updated my earlier post with the additional readings.

Well Boaz, in an attempt to at least somewhat stay on topic I guess my point is that all these XM-L drop-ins may be needlessly driven too high.  Seems like I'm getting 10 or 20 more lumens at the expense of more heat and less run time.

2 more XM-Ls?  Yeah, that's what I need; two more XM-Ls.Laughing

 

Foy

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Wow Match, thanks for your effort these results are really interesting!
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Great job! I really appreciate your work!

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Really a great work Match. Would be really useful for everyone that approach a DIY wit an XML.

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Match
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Flashlight Foy wrote:

p.s. Match, if this is a thread hi-jack I will quietly delete.

 No, not off-topic at all.  In fact, this brings up a good point.  After testing I took out my MF UF 3 mode drop-in and measured the current it was drawing off the battery ( measured without host.  Used ampmeter leads to make negative contact).  I measured @4.2a on high with a fresh battery.  Then I hooked the same battery directly to an xm-l (DD) and took another reading.  Guess what it read? @4.2a!  

From what I've observed, with these new "xm-l drivers" is that they are DD in high mode and there is no current regulation happening at all.  

I feel any current difference at high end is largely due to the individual cell.  With that in mind, I would highly advice against running a low  internal resistance cell like an IMR due to the high potential for excessive current. (If anyone has an 18650 IMR and is willing to test this, I'd be very interested to hear the results).

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Great  work Match , the results are what is expected given the manufacturer's data.

 

Trooplewis, the loss near or beyond 150 Celsius which is the temperature surely reached for those 'monsters' is around 30% therefore at this numbers a big chunk must be corrected , so I doubt you can get more than 700 L at 5A.

Also, roughly the tailcap current  is the emitter current , what the driver burnt is the excess voltage Vin -Vf...

Foy; you are not getting 20 or so more Lumen  . Temp corrected probably are getting as say above 700L ...that is what I mean in the other thread , dim , weak, less bright  ...

The trick here is find the most you can push an emitter in a given body to get the most. Don't even dream you can put 4A successfully in a flashlight , not enough mass and a lot of thermal resistance.

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oldbobk wrote:

Match,

      Thank you for a very scientific test! However, (there's always one of those) what about testing other emitters with the same methodology you used for the XM-L? I'm thinking specifically of the SST-50. As previously noted, 2.8 A. at the emitter is a sweet spot for the XM-L. Where does it start to nose over with the '50? Or the MC-E? People have opined that these two emitters are somehow obsolete, with the coming of the XM-L. I wonder if that is true. I could order some from Digikey (who ship very quickly), and have them shipped to you. You up for it?

                                                                                                                                                           Bob K


Since this is a rather recent hobby of mine, I have no experience with the SST-50 or MC-E.  Has a test like this been performed yet for either of those two?  I haven't looked. The main reason I wanted to do this test was because of all the heresay about the XM-L at >3a (including my own).  

Thank you for the offer Bob. I'd be willing to test them though and can return them to you afterwards (pending they don't explodeSurprised ).

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Match wrote:

Flashlight Foy wrote:

p.s. Match, if this is a thread hi-jack I will quietly delete.

 No, not off-topic at all.  In fact, this brings up a good point.  After testing I took out my MF UF 3 mode drop-in and measured the current it was drawing off the battery ( measured without host.  Used ampmeter leads to make negative contact).  I measured @4.2a on high with a fresh battery.  Then I hooked the same battery directly to an xm-l (DD) and took another reading.  Guess what it read? @4.2a!  

From what I've observed, with these new "xm-l drivers" is that they are DD in high mode and there is no current regulation happening at all.  

I feel any current difference at high end is largely due to the individual cell.  With that in mind, I would highly advice against running a low  internal resistance cell like an IMR due to the high potential for excessive current. (If anyone has an 18650 IMR and is willing to test this, I'd be very interested to hear the results).

 

The manufacturers are using the limitations of the battery technology to limit the current to there emitters instead of building high amperage drivers, a very cheap solution to an expensive problem. As battery technology increases I have three direct drive lights now that may burn out. The Ultrafire UF980L, The Manafont Drop-in and the KD C-8.

I am already visualizing the duct tape over your mouth.

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Excellent effort, Match, and it is much appreciated! I am sure this will be used as a reference for a long while both here at BLF and elsewhere. Keep up the great work. You are truly an asset to the group. 8)

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Thanks for doing this test Match! I just got a Trustfire X8 and the most im seeing out of it is 2.56amps at the tail but it is quite bright and throwy with the deep reflector so im really happy with it. im wanting more deep reflectored lights but there does'nt seem to be too many around.

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Okay, that non-linear part was bugging me, so I put the data on a regular graph and now I am much happier. This is a great test, Match. Now if I can only find a big block of aluminum with a lanyard . . .

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oldbobk wrote:

 

 

. Run in series, you have to have a resistor that will run the wattage of the light. In parallel, the resistor can be much smaller. Lets make the math easy. Say we've got a setup where the XM-L is running 3.5 V., and 3.5 A. Ohm's law gives us an answer that this emitter is acting like a 1.0 ohm resistance under load. OK, let's throw a 3.0 ohm resistor in parallel with the emitter. This means that the emitter will see 75% of the current, or a little under 2.7 A. The resistor will see about 0.8 A, times 3.5 V., for a power consumption of 2.8 Watts. Physically a much smaller resistor

 

It's not that way .The wattage the resistor must cope is E.I being E the voltage drop across the resistor and I the current.

An XM-L fed with one li-ion at 3A need 1W resistor...Vin 3.7V  Vf at 3A =3.35V  so 3.7-3.35= 0.35V drop X 3A = 1.05W the resistor being .35/3=0.11666  Ohm

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Amazing work, match and foy Wink Looks like 3,4A-3,6A is the best for XML.

BTW, here you have a very good cell comparison: http://lygte-info.dk/info/Batteries18650-2011%20UK.html 

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Flashlight Foy wrote:

Another thing I just thought of is, it would seem the 3-mode UF XM-L is driven a little high too.  Most of the time I get 3.5 to 4 amps in an L2P.  Tonight, I just tested one of mine in a Solarforce L2. (Mr. Silver)

with protected Solarforce 2400:

high -       4.30 amps

medium - 1.18

low -         .19

with protected AW IC 2900:

high -       4.36

medium - 1.17

low -         .19

Here it is with the first black L2P I bought.  Same exact drop-in, same exact batteries with the addition of the Trustflame.

with protected Solarforce 2400:

high - 4.20

medium - 1.14

low - .18

with protected Trust Fire flame 2400:

high - 4.00

medium - 1.17

low - .19

with protected AW IC 2900:

high - 4.10

medium - 1.15

low - .19

I'm just a little bored tonight so, sorry if this is irrelevant.

whatissocoolaboutAWFoy

p.s. Match, if this is a thread hi-jack I will quietly delete.

 

The two MF Ultrafire XM-Ls I bought recently (the ones this group suggested) both measured roughly 2.8 at the tailcap using Panasonic 2400s for me.   I wonder if you just got a flaky one or if maybe they changed drivers at some point.

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What I've noticed is that the amps drawn seems to vary more with the battery I use than between the different XM-L drop-ins I test and remember; we're usually talking about max amps which is often direct drive.  My XM-Ls have been fairly consistent and what Match said about DD in high mode is important.  Every time I test for amps with these UF drop-ins, medium and low hardly vary at all while high is all over the place.  Your Panasonic battery with your XM-L drop-in on medium or low might not be much different because those modes are regulated.

Foy

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Great setup and great measurments, Match Smile

I compared it to the Cree datasheet specs, and it matches quite well up to 2.5A, then your values are a bit below theirs (3% at 3A). I guess that's due to their measurement method: If I remember correctly, they only power the LED for a small fraction of a second to avoid increasing the junction temperature. (Unfortunately I can't recall where I read that.)

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Oldbobk,

 

"Run in series, you have to have a resistor that will run the wattage of the light"

I understand perfectly what you say but just because the above sentence is incorrect what you get is the opposite. In parallel with the emitter the resistor must be much more powerful than one in  series.

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