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

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 ]

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.

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.

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.

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.

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.

I was just wondering that myself. Gimee 10 minutes.

boredFoy

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 .??

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.

Foy

Wow Match, thanks for your effort these results are really interesting!

Great job! I really appreciate your work!

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

[quote= Flashlight Foy]

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

[/quote]

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).

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.

[quote=oldbobk]

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

[/quote]


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 explode ).

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.

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)

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.

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 . . .

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