Switching to 26650 and XM-L U2 (or T6?), advice needed what to buy (in search for a new portable lighthouse)

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Eduard
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Switching to 26650 and XM-L U2 (or T6?), advice needed what to buy (in search for a new portable lighthouse)

Hi all,

I am new to BLF in regarding to posting, the forum has provided me for years already in sound advice about the different flashlights I own. but now I am tempted to switch to 26650 for powersupply and a multi XM-L emitter (preferably U2 bin) flashlight. At first, after reading about multi XM-L emitter flashlights here on BLF, I was drawn awards the Trustfire TR-J12. As I was browsing the various sites of flashlight sellers my eyes were drawn on the relatively new multi XM-L U2 bin lights. I wonder if anyone could gine some advice of any of these Uniquefire lights I came across are any good, or that I should rather go for the Trustfire TR-J12. The lights I am interested in are these ones:

UniqueFire UF-F5 4xCree XM-L 4*U2

UniqueFire UF-F6 6xCree XM-L 6*U2

Any input on this would be appreciated.

edit: Also found this one:

UniqueFire UF-S7 Cree XM-L U2 7-LED 5-Mode Flashlight

The advertisement text only mentions 18650 as a power source. This is incorrect i think. Should be 26650, shouldn’t it?

Edited by: Eduard on 06/06/2012 - 08:41
Pok
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Welcome Eduard,

IMO, no way for your list are multi LED with U2 Bin.

How about TrustFire X100?

Eduard
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The Trustfire x100 looks impressive (thank you for pointing me to it). But reading this topic I don’t know if it’s a real good buy.

Why do you think my list are no way U2 bin multi LED?

Pok
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In Thai forum, Trustfire X100 tested

3 cells tail cap draw about 4A
4 cells —- 2.3 – 2.4A

Eduard
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that seems grossly underdriven to me

kramer5150
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Eduard wrote:
that seems grossly underdriven to me

It should do around 1.69A to each LED. With 7 LEDs that will generate a lot of heat in smaller hosts like the TR-J12/J18. I think the designers knew this, and thats why the J18 does not emit more lumens than the J12. This 100X however looks like it has a MUCH bigger heatsink, so it all depends on the thermal performance of the host. It definitely looks big/massive enough to handle the extra current.

Eduard
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kramer5150 wrote:
Eduard wrote:
that seems grossly underdriven to me

It should do around 1.69A to each LED.

Can you tell me how that is calculated?

kramer5150
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Eduard wrote:
kramer5150 wrote:
Eduard wrote:
that seems grossly underdriven to me

It should do around 1.69A to each LED.

Can you tell me how that is calculated?

Pok in another thread pointed out my calculations were off, because I was assuming Vbatt = 4.2V x 3 = 12.6. Which is incorrect.

4A x 12.6V = 50.4 W pulled from cells
50.4W x .80efficiency(typ) = 40.32W into LED array
40.32W / 7LED = 5.76W/LED
5.76W / 3.4Vf = 1.69A per XML (assuming 3.4Vf)

In reality Vbatt sags under load to about 3.5V to give…

4A x 10.5V = 42W pulled from cells
42W x .80efficiency(typ) = 33.6W into LED array
33.6W / 7LED = 4.8W/LED
4.8W / 3.4Vf = 1.41A per XML (assuming 3.4Vf)

So on paper it should still emit more lumens than the TR-J12. Since the J12 and J18 are both ~30 watt designs I would expect the X100 to be brighter than the J18 too. Note also this is just a ball park estimation. It does not account for cumulative resistance of the springs, switch, and host body. It does not factor in for variations in XML Vf or cell performance. Driver efficiency of .80 is not a “given” either.

Eduard
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Thank you very much, kramer5150, for your eleborate answer.

I hope someone can tell me more about the UniqueFire models I posted. For now my choice would be the x100, but I will wait with buying until I get some info on the UniqueFire flashlights.

kramer5150
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Eduard wrote:
Thank you very much, kramer5150, for your eleborate answer.

I hope someone can tell me more about the UniqueFire models I posted. For now my choice would be the x100, but I will wait with buying until I get some info on the UniqueFire flashlights.

Sure… someone double check me on XML Vf too… Another forum member pointed out that Vf is lower than my 3.4V estimation in the very last calculation. If that is true then I am under-estimating the current to each LED.

fishinfool
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Aloha and welcome to BLF Eduard!

Don wrote:

"But as I said long ago, you are more likely to be killed by a dead fish dropped by a seagull in the Sahara Desert than by a lithium ion

2100
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I support Pok’s idea.

http://www.aliexpress.com/fm-store/506767/211413955-573337009/1-Set-Trus...CREE-XM-L-T6-LED-8000Lm-High-Power-Flashlight-4x.html

Protected cells. ok.

Estimated 3200 lumens out-the-front.

2100
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Eduard
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2100 wrote:

http://www.hkequipment.net/index.php?sp=&p=6&cat2=178&cat1=66&cat0=1&id=...

!http://www.hkequipment.net/files/mid/1383_0.jpg!

Looks like a very nice/impressive light, but no 26650 and, more important, if I bought that one I’m sure my wife would have me legally declared insane and have me put away, spending that much on one flashlight.

raccoon city
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Welcome to the madness, Eduard!

Best0270

Couldn't find any Eduard jokes.  Here's some pop culture Edward jokes.

Edward1

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Eduard
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thanks, just placed an order for the Trustfire x100. Couldn’t resist temptation anymore 0:)

jaynick
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2100 wrote:
http://www.hkequipment.net/index.php?sp=&p=6&cat2=178&cat1=66&cat0=1&id=...

!http://www.hkequipment.net/files/mid/1383_0.jpg!

holy crap that is interesting. its like an automotive led inside a reflectored head. cant wait to see someone pick one up and put up comparison beamshots