L2

astrogrub

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Picked up an L2 today. Its nice but quite long. The beam on this one has a very slight donut but at least the beam quality on high is better and slightly brighter(?) than that on my early L4. I think I still prefer the A2 but have to wait 'till dark to really see...........
 

The_LED_Museum

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I received an evaluation unit of the SureFire L2 this morning. My page is right here if you're interested.
My L2 does have a very slight doughnut configuration to its beam too, but this is perfectly normal with a 5 watt LS LED and reflector, and does not indicate any problem whatsoever with the flashlight.

The beam of my L2 on high is very slightly brighter than the beam of my KL4/L4.
745,000mcd on the L2 vs. 700,000mcd on the KL4/L4.
 

IlluminatingBikr

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[ QUOTE ]
To change the batteries in your L2, unscrew the tailcap, throw it in the {vulgar term for feces}bowl, and flush it away...O WAIT, YOU'LL NEED THAT!!! So just set it aside instead. ;-)

[/ QUOTE ]

LOL! Great review Craig. /ubbthreads/images/graemlins/thumbsup.gif I think the L4 is the perfect EDC for me, but idk, this looks awfully tempting. The pila's not being able to fit is a turn-off for me though.
 

luxlover

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May I assume that you have or will conduct runtime measurements? About a month ago, a SureFire rep told me that the high beam will run for 58 minutes, before regulation ceases. We all patiently await your input.
 

JanCPF

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.357,

The 5 Watt luxeon is actually made up of 4x1.25 watt emitters in a square configuration, so there is a small void (is that the word?) in the middle of the chip where no light is produced. This is somewhat blended out by the reflector, so you really don't notice it in the beam, unless pointed at a white wall.

Jan
 

Aten_Imago

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Nice review. This functionality especially is encouraging...
" For momentary, low level light any time, press lightly on the tailcap button and hold it that way for as long as you need light. Release the tailcap button to turn your L2 back off. For momentary, high level light, press in more firmly on the tailcap, and hold it that way for as long as you need light. Release to turn your L2 back off. For continuous mode, twist the tailcap clockwise (as if tightening it) to turn the LED on in low mode. Twist it clockwise some more to get high mode. To turn the L2 off, twist the tailcap counterclockwise (as if loosening it) until the LED in its business-end extinguishes".
the 2 levels are a substantial improvement over the already excellent L4.
Thanks! /ubbthreads/images/graemlins/thumbsup.gif
 

357

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[ QUOTE ]
JanCPF said:
.357,

The 5 Watt luxeon is actually made up of 4x1.25 watt emitters in a square configuration, so there is a small void (is that the word?) in the middle of the chip where no light is produced. This is somewhat blended out by the reflector, so you really don't notice it in the beam, unless pointed at a white wall.

Jan

[/ QUOTE ]

Okay, thanks for the explanation. Why is the 5-watt configured that way?

Are 3-watters also configured with multiple small emitters?
 

The_LED_Museum

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[ QUOTE ]
357 said:
Are 3-watters also configured with multiple small emitters?

[/ QUOTE ]
As far as I am aware, the 3-watt Luxeons consist of a single die (light emitter) like the 1-watt (actually, 1.25 watt) Luxeons.

The primary difference between the 3W and 1W Luxeons is that the 3W unit has better thermal management, so that more current can be pumped into the die without the die getting too hot and then popping.
 

The_LED_Museum

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[ QUOTE ]
luxlover said:
May I assume that you have or will conduct runtime measurements? About a month ago, a SureFire rep told me that the high beam will run for 58 minutes, before regulation ceases. We all patiently await your input.

[/ QUOTE ]
I'll do a battery discharge analysis on the L2 as time permits, then we'll all know how long it runs in regulation.
Might as well get started on that now...turning lab computer monitor on...rebooting in DOS mode...changing directory to where meter program is...running RS.EXE...creating meter file "L2.ME1"...scaling to 600 seconds...positioning L2 and PV cell...starting test...OK, the test is officially underway. Assuming I don't ***** the test by bumping something I shouldn't bump, the machine should poop out a chart later today. /ubbthreads/images/graemlins/smile.gif
 

sideshowandy

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as usual an interesting & entertaining review /ubbthreads/images/graemlins/thumbsup.gif
 

The_LED_Museum

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[ QUOTE ]
Size15s said:
How many battery sets will you put through it?

[/ QUOTE ]
At very minimum, two sets of SF123A cells (the red ones, from SureFire).
The first chart looks an awful lot like an alkaline discharge curve (rather than that of a regulated flashlight), so I'll be running a second set of SF123As through it, still on the machine of course. Just to be safe, ya know. /ubbthreads/images/graemlins/smile.gif

Right now, the L2 is at about 3% or 4% of its starting value, so it won't be long now that I'll replace the cells in it and start a new chart.

(Edit, a moment later)
As of 10:47am PDT, the second battery test is underway.

(Edit, about 50 minutes later)
The L2 started flickering at 11:36am PDT, indicating it's falling out of regulation.
Temperatures were also measured two or three minutes ago; the bezel measures 173°F (78.3°C) and the barrel measures 157°F (69.4°C). These temperatures are somewhat hot, and are above what would be comfortable to the bare hand.
I almost need a pyrometer to measure these temperatures, not a non-contact IR thermometer. /ubbthreads/images/graemlins/icon15.gif
 

The_LED_Museum

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Ok, here's the chart I made using a second set of cells:

l2-2.gif

It runs for 40-50 minutes in regulation, then rather rapidly decreases in brightness over the next 30 minutes.

Total runtime was 4 hours 40 minutes, using high mode.
I used SureFire brand CR123A cells (SF123A cells in the predominantly red covering).
 

luxlover

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I am very confused. Which dealers have the L2 in stock? I don't mean which say that they "will be getting them any day now" and that we can pre-order them. I mean who already has them? So far, I know that Craig of The LED Museum has one, and reviewed it for us the same day he got it. That is devotion. Thank you Craig.

Is there any CPF member who has acquired an L2?
 

Kiessling

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well, that graph does not look too impressive !?!?!
I hope that Craig's equipment is somewhat messed up (sorry Craig /ubbthreads/images/graemlins/grin.gif ) ... this looks much less perfectly regulated than what we are used to ... any comment sof those who also have one?
bernhard
 

357

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Both high and low beam are regulated, IIRC. I would hope that the low beam gets much better runtime. I agree, the graph above is not good runtime.
 

The_LED_Museum

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[ QUOTE ]
Kiessling said:
well, that graph does not look too impressive !?!?!
I hope that Craig's equipment is somewhat messed up (sorry Craig /ubbthreads/images/graemlins/grin.gif ) ...

[/ QUOTE ]
The first set of batteries I ran through it were even worse. Let's see if I can dig up a chart here...BRB...

l2.gif

Here's the first set of batteries.
Runs for about 40 minutes to the half-intensity point.

l2-2.gif

And for reference sakes, here's the second set of batteries.
Runs for about 50 minutes to the half-intensity point, then continues to drop like it got its head slammed in the toliet seat. /ubbthreads/images/graemlins/jpshakehead.gif
 

thesurefire

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This is dissapointing. What was surefire thinking /ubbthreads/images/graemlins/icon3.gif
 
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