Fenix L2D CE on Turbo with Cree Q4 - almost 1000mA

wintermute

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OK, so my new L2D CE w/OP reflector was bright...really bright. But I put a WC tint Q4 in it. Wow, is this thing bright. So I just decided to test this out a bit.

2 x Sanyo Eneloop batteries - 2.5V under load --- Pulling 1.6A from the batteries = 4.0W to the driver.

Assuming a 90% driver efficiency, that's 3.6W to the LED. Voltage at the LED is 3.7V...that means ~970mA to the emitter.
Edit (add): (Assuming a 85% efficiency, that's 3.4W to the LED which means ~920mA to the emitter)

Has anyone else tested the Fenix lights to see what they're drawing from the batteries and such?? Doesn't that seem quite a bit for a Fenix L2D CE?? I am going to compare it to a SSC P4 w/ VIP-750 and post beamshots in a couple of days. There's a good chance that the efficiency is less, but still - quite a bit to the emitter, right?
 
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WildChild

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There are variations in the circuit and LED efficiency. Mine pulls 1.15A on turbo and chevrofreak tested one that pulled 1.45A on turbo from the batteries. Usually, I base my calculation on a 85% efficiency. But I wouldn't be surprised if the circuit gives around 800-900 mA to the LED on turbo. ;)
 

wintermute

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Another question - on Flashlight Reviews it says:
"Accessories: Several accessories are included with the light. Inside the package you will find spare O-rings, a spare rubber switch boot, a wrist lanyard, and a belt sheath."

The only thing I got with my Fenix was the holster - have they just stopped including stuff, or was my box shorted by mistake.
 

d123

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Another question - on Flashlight Reviews it says:
"Accessories: Several accessories are included with the light. Inside the package you will find spare O-rings, a spare rubber switch boot, a wrist lanyard, and a belt sheath."

The only thing I got with my Fenix was the holster - have they just stopped including stuff, or was my box shorted by mistake.

I got all those bits with both a P2D CE and a P3D CE I have bought separately in the last month. Both were bought from fenix-store.com.
 

wintermute

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Based on a quick comparison of my L2D vs. a light which has a VIP-750 and SSC USX0H, the Fenix kills it. Crazy. The tint is noticeably different though...have to re-check this further when it's dark and I can try to get beamshots. Anyone who says Fenix lights aren't an amazing deal is nuts. Can't wait to get this other Q4 into a P3D. Big Beam, check with qip - he had an extra WC Q4 for sale.
 
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f22shift

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Another question - on Flashlight Reviews it says:
"Accessories: Several accessories are included with the light. Inside the package you will find spare O-rings, a spare rubber switch boot, a wrist lanyard, and a belt sheath."

The only thing I got with my Fenix was the holster - have they just stopped including stuff, or was my box shorted by mistake.

those should be included
 

rizky_p

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where can we get Q4 pin emitter? and how is it done. Step by step would be perfect.
 

joerky

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3 Volt - 1000 mA
2,4 Volt - 1500 mA

From 3 Volt down to 2,4 Volt the current is going up - and the brightness is the same.

Going lower than 2,4 Volt, the current does not rise more - and the brightness is getting lower.

From 2,4 Volt down to 1,5 Volt the current is stable at 1500 mA.
Going lower than 1,5 Volt the current is also going down.

1,3 Volt - 1150 mA
1,1 Volt - 900 mA
1,0 Volt - 600mA

On 1,0 Volt the brightness from turbo mode is equal to 9 lumen mode. Interesting is, that the real 9 lumen mode needs much less current at 1,0 Volt than the turbo mode which is running at the same brightness now.

Lower than 1,0 Volt i cant switch on.

On 1,2 Volt i can still switch to 80 lumen mode and can see that 80 lumen mode is brighter than 40 lumen mode - so if my L2D-CD runs on eneloop it would be difficult to recognize that my cells are lower than 0,6 Volt each.

At 1,5 Volt:
9 Lumen - 0,07 Ampere
40 Lumen - 0,39 Ampere
80 Lumen - 1,05 Ampere

At 1,2 Volt:
9 Lumen - 0,08 Ampere
40 Lumen - 0,69 Ampere
80 Lumen - 0,9 Ampere
 

wintermute

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My L2D-CE draws 1.34amp on turbo from battery.
I posted a link in your other thread to step-by-step directions for the most part.


Also, bonus news - I am getting a spare LxD head circuit to do testing on...so I'll be able to tell what this little thing really does.
 

x2x3x2

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Could u post some beamshots? And pics of the mod?

[edit]

Nevermind, found them oh the other thread. Very nice.
 
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jc28841

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Another question - on Flashlight Reviews it says:
"Accessories: Several accessories are included with the light. Inside the package you will find spare O-rings, a spare rubber switch boot, a wrist lanyard, and a belt sheath."

The only thing I got with my Fenix was the holster - have they just stopped including stuff, or was my box shorted by mistake.

Got all that stuff on all five of the Fenix lights I purchased from Fenix-store
 

wintermute

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Got all that stuff on all five of the Fenix lights I purchased from Fenix-store

Fenix-store has already taken care of it. As soon as I asked them about it, they replied that they would send out the accessories ASAP. 4sevens even included a free L2D holster :party: (I got the L1D holster with my light). Received a shipping notice from Fenix-store within 30 minutes of initial reply to my email. Excellent customer service!!! The best! :thumbsup:
 

wintermute

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so what would be the theoretical output of your q4 l2dce ?

Theoretical output at the emitter of a Q4 @1000mA is approximately 220 lumens. Take the losses of the reflector, lens, depression of luminous flux due to heat, etc (depletes it by 25%, maybe more) = possibly 165 lumens. Which really wouldn't surprise me because Chevrofreak estimated his Fenix P1D CE - Q2 SE on High at 136 lumens. Estimating lumens is very difficult, I am only going from theoretical emitter lumens - acceptable loss numbers.

My searching skills seems to be lacking. Link to other thread please?

Thanks.

Here.
 

RV7

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Also, bonus news - I am getting a spare LxD head circuit to do testing on...so I'll be able to tell what this little thing really does.

I look forward to your test results!

A little note about the testing - my apologies if you know it already: When measuring battery current draw, multimeter internal resistance plays a very big role due to low voltage and high current. If it's not a high end multimeter, you may get a reading of 1.2A while the actual working current is 2A. A good workaround is inserting a 10 milliohm resistor to complete the loop and measure the voltage over the resistor to get a better idea of the actual current.
 
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