Is it possible? R-18650 + SSC-P7 = 900 Lumens?

EngrPaul

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There is a number of flashlights that claim upwards of 900 lumens from a Seoul P7 flashlight, using a single R-18650.

Please don't cite examples, we all know they exist.

I'd like to get such a light. However, I have doubts as to whether one R-18650 can provide the oomph necessary to produce that sort of output. And if it could, would the switch and steel spring wires be able to handle it?

I'm just looking for a reality check here. I know the P7 can be wired different ways, and have different drivers. But I seem to remember from my school days that the watts to the emitter cannot be greater than the watts from the power source.

Let's say a P7 light is fed with one R-18650. What is the maximum lumen output possible?

What if 2 RCR-123's were used instead? Any closer to 900 lumens?

TIA :popcorn:
 
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phantom23

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18650 can deliver 3,5-4amps so over 900lm is possible (theoretically).
RCR123? No driver, too small current. 2C is 1,2A, 2x1,2 is still less than 18650.
 

traumerei

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2C seems to be the highest recommended discharge rate which might with some of the newer chemistries can easily be 5A. Let's say 3.5V and that gives 17.5W which is well above the roughly 10W figure that datasheets suggests is needed for 700 lumens. From browsing these threads I know it can get really complicated so hopefully someone more knowledgeable can weigh in.

So I think the answer is yes. The DX/KD specials seem to suffer from inefficient drivers.
 

Dead_Nuts

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ElektroLumens is making a 18650, P7 light that he claims 700+ lumens for. This is probably more realistic. BTW, I am still waiting for mine.
 

PhantomPhoton

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A cream of the crop or hand picked D bin SSC P7 should be able to make 900 emitter lumens on an 18650. With the new AW IMR cells a CR123 can do taht as well... for several minutes at least. :naughty:

The SSC P7 is hardwired in parallel. The Cree MC-E is the one in which you can wire each emitter individually so you can do 4S, 2S2P, 4P depending on your driver and power source.

The Elektrolumens EDC P7 should be able to deliver 600-700 lumens and with the way Wayne makes his stuff there's no question that the switch nac handle it. Compared to some of my incan lights the ~3A is nothing. Even my little 1xAA led lights running full power on an eneloop push almost 3 amps if my mental math is correct.
 

270winchester

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to get 900 out of a P7 you either need to match voltage of the LED and the battery so you don't burn the LED out, or you have to use a driver which is a whole other set of issues.

That being said I have a cut-down Mag 1C with one C Li-Ion driving a P7 and I say 900 is possible with a high binned and low Vf P7.
 

LEDninja

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The 900 lumen claim came from an out of date SSC spec - C bin 740-900 lumens at 2.8A.
I measured 2.1A on my MTE 1*18650 P7 (others have measured 2.2A). THat works out to 555-707 LED lumens.
Now those early lights have been described as a $30 emitter in a $15 light. Which means the reflector/lens is not top quality - maybe 65% transmission. So out the front lumens is now 360-460 lumens. It is still over twice as bright as an XRE at 150-180 actual lumens.

The D bin emitters are now out. To differentiate a D bin light from a C bin light , the D bins use the next higher round number - 1000 lumens. Nothing to do with actual output.
This is similar to
1 watt light = 1 watt driver + Lux 1. ~24 lumens.
3 watt light = 1 watt driver + Lux III. ~28 lumens. Note only 4 extra lumens not 3X brighter.
So what is a maker of a 3 watt driver + Lux III to do. ~75 lumens or really 3X brighter. Can't call it a 3 watt as people expect only 28 lumens and won't pay the extra cost to build the light. Call it a 7 watt of course.

The Chinese flashlight numbers have nothing to do with reality. But it is possible to make an educated guess at what is inside.
Recently I came across 2 threads. Light in thread #1 was measured at 2.8A. Light in thread #2 was measured at 1.4A. So one light is roughly twice as bright as the other. When I checked the pictures at DX both have 900 lumen on the side. My guess is both are still using C bin emitters.

The 18650s range from 1400 to 2200 mA. So you can only get 30-45 minutes runtime.
I have read of switch failures, driver failures, plastic bits in the end cap melted.
You missed the light gets too hot to hold. Bessiebenny aborted the runtime test of his P7 light because it got too hot.
However, I have doubts as to whether one R-18650 can provide the oomph necessary to produce that sort of output. And if it could, would the switch and steel spring wires be able to handle it?
 
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Wiggle

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Now those early lights have been described as a $30 emitter in a $15 light. Which means the reflector/lens is not top quality - maybe 65% transmission. So out the front lumens is now 360-460 lumens. It is still over twice as bright as an XRE at 150-180 actual lumens.
.....
You missed the light gets too hot to hold. Bessiebenny aborted the runtime test of his P7 light because it got too hot.

65% seems awfully pessimistic or are budget reflectors really that bad?

My MTE P7s get warm but then they stop at hand warming temperature and don't get truly hot.

L2D turbo vs MTE P7 high
3_l2d_turbo.jpg


4__mte_high.jpg


DSCF2455.jpg


DSCF2457i.jpg


Looks like about 600 lumens to me, far from the 900 though.
 
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Superdave

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I measured 3.2A draw from my P7 on 1 18650 direct driven. Now that i'm using a 5 mode KD driver it's a tad less on high.

here is my Q5 dropin using 1 18650(R)

Q5-18650.jpg


and the P7

P7-18650.jpg


both are using the same OP reflector.
 

LEDninja

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From this thread:
Actual Lumens readings in 6" dia. Lab Sphere IS with SC 5500 control
https://www.candlepowerforums.com/threads/211402
Mag-LED 4D_____________50
Mag-LED 4D_____________80 no reflector
50/80=62%.
I was expecting higher as the old incan tests average 65% and LEDs do not throw light backwards.
Fenix with AR coating on both sides of a glass lens consistently tested out at ~80%.
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If you are using LED lumens my MTE is somewhere between 555 and 707 compared to 225 to 275 for an XRE Q5/P2. So estimates of 600+ lumens is OK by me as long as you realize you are using LED and not out the front numbers.
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My MTE is 2.1A with a fresh battery. Superdave's (custom?) is 3.2A. So a P7 pushed to the limit produces more heat.
65% seems awfully pessimistic or are budget reflectors really that bad?

My MTE P7s get warm but then they stop at hand warming temperature and don't get truly hot.
Here is a beamshot of Mag P7 DX reflector left MTE 5 mode P7 right.
MagP7DXreflector_MTE5modeP7.jpg

As can be seen from the spillbeam the Mag is quite a bit higher in lumen output and the bigger reflector tightens the hotspot to give more throw.
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With a D bin emitter and 3.2A as measured by superdave 900 LED lumens is possible. So 600-720 actual out front depending on the optics.
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For reference:
WE only claims 680 lumens for the Spider P7.
Surefire only claims 400 lumens for the UB2 Invictus.
I trust those numbers more than what is printed on the sides of the DX lights.
 

Superdave

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I can't wait to see how the P7 looks when in my Magcharger.. the tiny reflector of the P60 dropin just dosen't do it justice.

I don't know that it'll stay in the magcharger, i have a 2D mag setup for 2 18650's that might run it better.. we'll see.
 

Superdave

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Just an update, i can 2nd the larger Mag reflector to be far superior to the tiny P60 one. Same emitter on a regulated driver is pumping an easy 700 out the front with excellent throw and light spill. :thumbsup:
 

yellow

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I know the P7 can be wired different ways, and have different drivers.
What?
:thinking:
it is wired in parallel and cant be wired differently (where step up drivers were available)

different drivers?
:thinking:
Which?
There simply are none, most lights just do direct drive (thats while output is not even near datasheet values)
... and if there were drivers, they had to be built ugly large.


at the end: in theory the 900 lm are possible, imho.
One would have to pump enough current through each die (hoping that the Vf is totally the same!), so that they produce 225 lm each.
Should be about 1000 mA (?) per die.
Given the brutally amount of heat produced by doing so, a light offering suitable heatsinking were unhandy at best.
 

Superdave

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I don't like this driver. Heats up so quickly that overheating protection reduces the power (flashlight goes to low mode) after less than one minute! It's useless!


I don't have that problem... it takes 5 minutes or so on high for it to do that. I don't run it on high for that long anyways, medium or low is plenty for most tasks.
 

jirik_cz

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I'm probably lucky with KD Super blah blah driver. It runs at full power till the batteries are drained (around 75 minutes). No dimming at all.
 
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