Is there a perfect two 18650 Light under 60 Grams with these specs?

[degarb]

[h=3]Just wondering if such a 2x18650 flashlight exists:

Specs:[/h]1. 4000 candelas
2. As close to 300 lumens, lasting >8 hours with no dimming due to cell drain (This spec means a max of350 ma per 18650 or three AA, limiting me to 300 lumens with two18650s. Over years, I learnedthat higher current settings too often translate to accidental deadwork light before work day done. Great excuse for smoke breaks andgoing home early.)
3. Neutral bin 4500 kelvin best (sinceI have no control over headlamp color)
4. Light weight aspossible. 50 grams or less 150 total withbatteries (60 grams intl-outdoor single 18650 light)
5. Infinitely dimmable, for super longrun times.
6. Glass lens.
7. Splash resistant. Waterproof not essential

 

[Poppy]

I can't check of all of your boxes, but I can get pretty close, if you will accept a single 18650 light and change out the battery at lunch time, OR get two of the same light, if for some reason you are in an environment that you can't open the light up to swap out the battery.

Convoy S5 Cree XM-L T6-4C 420-Lumen 4300-4500K 2-Group 3/5-Mode LED Flashlight 1*18650 / AMC7135*3 / carrying strap

driven at 1000ma, I *think* you'll get 3.5 hours on max ... I'm sure that the 420 lumen is LED lumens, not out the front. You'll probably get a little over the 300 you were looking for out the front.

$19.73 each at fasttech and they offer a "CPF" discount code.
This light weighs in at 60 grams. I don't think it is possible to get a two cell light that would be dependable weighing in at 50 grams or less.
This light also has a 5% low, about 25-30 lumens, I'm guessing 60 hours.
Oh... I estimate that it would be right at about the 4,000 cd you are looking for, maybe a little less, but not less than 3500 cd.

 

[Poppy]

Here is a beam shot of the 4C tint.
Courtesy of our friend ven


http://www.candlepowerforums.com/vb...ther-new-EDC&p=4396215&viewfull=1#post4396215

 

[CarpentryHero]

The TK35 is the only side by side 18650 light I have (I have it's clone too, green anodized)

the TK35 specs
• Output mode / Runtime:
Turbo 900 lumens
1h 45min
High 375 lumens
5h 30min
Mid 125 lumens
18h

Low
15 lumens
140h

Strobe
900 lumens


SOS
125 lumens


• Dimensions and Weight:
Length
6.49"
165mm

Diameter
1.73"
44mm

Head Diameter
2.03"
52mm

Weight
9.6oz
273gm
(excluding batteries)

 

[degarb]

I also do have the 4c t6 xml2, and love that tint 4500k-best xml colorwise I own, imho. A bit preferred by me over the 4000k xml2 that ledsupply sells.

 

[Poppy]

I also do have the 4c t6 xml2, and love that tint 4500k-best xml colorwise I own, imho. A bit preferred by me over the 4000k xml2 that ledsupply sells.

I have the tk35, love the runtime and output. Now, lets get that in about 50 to 100 grams. It is just too heavy for what I need.

The convoy looks exactly like my int-outdoor.com light. I chose the xpg2 since it had longer runtime, lower driven, and more throw than the xml. It has a 20 mm reflector. I do like the 360 lumen output at 4k candela. But reality is that it kills a panasonic 3400 in only 1 h 45 minutes. I cannot see driving it any lower, since throw is so bad in a 20 mm reflector with an xml.


I also do have the 4c t6 xml2, and love that tint 4500k-best xml colorwise I own, imho. A bit preferred by me over the 4000k xml2 that ledsupply sells.

Back to convoy, fasttech

Link removed as per the banner at the top of the page
Why has my link been removed? - Norm

.

You should be able to get pretty close to run-times by dividing the battery mah by how hard the emitter is driven. For example the light I recommended is driven at 1000 ma. Therefore 3400mah/1000ma=3.4 hours

 

[degarb]

You should be able to get pretty close to run-times by dividing the battery mah by how hard the emitter is driven. For example the light I recommended is driven at 1000 ma. Therefore 3400mah/1000ma=3.4 hours

I don't see or missed your posted link to the light. Most these lights say 1400ma. The intl-outdoor one I own, I am measuring something like 1.2 amp, but it cuts off at 1h45 minutes. nanji, something driver. Not really flat output, like my fenix lights.

Have you tested this runtime? My kaidomain panasonics cut off at 3v, for closer to 3200 mah in real world.

 

[Poppy]

I haven't actually tested my runtime, but I did check the ma draw at the tail switch, and it was pretty accurate at about 1400ma. You have over 1000 posts, you know we aren't allowed to post links to sales sites.

you can google the light with specs I mentioned, OR go to fasttech dot com and search convoy. They have a drop down list that allows you to select model, driver ma, and the tint.
I believe that @ 1000 ma you'll get a little over three hours, (almost time for lunch).

 

[degarb]

It is pretty easy to see spammers a mile away. You mention fasttech, which is essentially the same as posting url. THIS GOOD. Without concrete information, NOONE -nooobody- would ever visit CPF! CPF is, was, and should remain a place for useful, practical info.

I don't see any difference in listed specs between the s4 and s5 convoy. both 4 amc7135 both with %40, both with xml t6 4c. I am probably missing something.

So, at %40, you would get a 560 ma. At 1100 candela (20mm op) per watt this is 1760 candela, and something like 224 lumens--probably less due to pwm. I suppose I could hacksaw off the head and try to modify with a deeper smo. A 26 mm p60 smo should get about 3200 candela, which should last 5.7 hours. If my math and assumptions are correct....not bad for size/weight...

 

[degarb]

I don't see any difference in listed specs between the s4 and s5 convoy. both 4 amc7135 both with %40, both with xml t6 4c. I am probably missing something.

Ah, hah, I see difference in size! Couldn't see forest for trees.

Yes, s4 is my interest due to s5 heavy weight. So, lux/lumen guess still applies.

 

[degarb]

Ideally, I guess, rather than listing 100 lights, you could enter specs from pulldown menu and the site could recommend the light to you. Silly thought.

 

[Poppy]

Ah, hah, I see difference in size! Couldn't see forest for trees.

Yes, s4 is my interest due to s5 heavy weight. So, lux/lumen guess still applies.

Nope... you can't get an S4 driven at 1000ma.

 

[CarpentryHero]

So 60 grams not including batteries ? There would be so little metal that you won't be able to get over a 200 lumens without over heating
Even a Ruinovo is 99grams and theirs not much to one of those, maybe 80-100 lumens, it ramps and you can recharge your phone


Ruinovo 102 1A 2*18650 Single USB Output Mobile Power Pack Battery Charger w/ 2-LED Illumination


DEPTH 22.5 mm
HEIGHT 104 mm
WIDTH 45 mm
PRODUCT WEIGHT 99 g




goodluck on your search

 

[Poppy]

I don't see or missed your posted link to the light. Most these lights say 1400ma. The intl-outdoor one I own, I am measuring something like 1.2 amp, but it cuts off at 1h45 minutes. nanji, something driver. Not really flat output, like my fenix lights.

Have you tested this runtime? My kaidomain panasonics cut off at 3v, for closer to 3200 mah in real world.

My S2 with an XMl is driven at 1400ma, and I just ran it for about 2.5 hours on a EagleTac 3400 on high. at that point it was probably at 50% 0f high output, and the battery was at 3.18 volts. I started the test at 4.01 volts. So again, I believe that an XML driven at 1000ma should get nearly 3 hours at high, and an additional 30-45 minutes of useable output on a 3400mah battery.

 

[degarb]

So 60 grams not including batteries ? There would be so little metal that you won't be able to get over a 200 lumens without over heating

I have been weighing, with gram scale, just yesterday, a spiky aluminum graphic card heat sink: 25 grams at 15-18° C/W. In home builds, I haven't tried it alone with star at 2 watts, but have used this heat sink, thermal-epoxied mated a star to it, plus aluminum reflector and plastic battery holder. So, the 2 watts of xml2 heat is released into air, via heatsink+reflector+glass lens+battery holder. In total, I am wondering if this was over kill.

It seems obvious, you want a chimney effect, to increase airflow across aluminum. Attention must be paid to shape and thickness. There is tank thickness, soda can thickness, and all in between. I think the pull is toward heavy duty lights, since that is first jugular a reviewer goes for. The reviewers step on the lights, run them over with the car, freeze them. Nary a one will post a junction temperature, gram weight reading (to verify stated weight), tailcap current reading, lux drop graph. So, if you want a good review, you have to make a flashlight heavy. For me, I don't hold my lights in my hand, so weight matter. I want a light that crushes when you run over it.

 

[degarb]

My S2 with an XMl is driven at 1400ma, and I just ran it for about 2.5 hours on a EagleTac 3400 on high. at that point it was probably at 50% 0f high output, and the battery was at 3.18 volts. I started the test at 4.01 volts. So again, I believe that an XML driven at 1000ma should get nearly 3 hours at high, and an additional 30-45 minutes of useable output on a 3400mah battery.

Thanks. You could do a half hour measurement of lux from beginning of test and post results. What was the lux at beginning and every hour at least. But your time, already, is appreciated.

Even though I am skeptical, I must say, I am attracted to many specs of this light (price, battery format, cc driver, xml2, 4c tint, weight). I will probably order one later this summer for kicks and to support my addiction. I probably will modify it out the gate with a hacksaw, fasttech 26mm reflector, and one of their non AR glass lenses.


I know that my int outdoor 20 mm reflector light can easily modded for 20mm TIR. Unscrew, drop in, shim glass lens. I measured 25-27% drop in lumen output, and %37 increase in lux. I need to study more (lead clearance, led centering, and throw) and own more reflectors of various sizes before I go all out modding lights that kinda work.

 

[CarpentryHero]

I have been weighing, with gram scale, just yesterday, a spiky aluminum graphic card heat sink: 25 grams at 15-18° C/W. In home builds, I haven't tried it alone with star at 2 watts, but have used this heat sink, thermal-epoxied mated a star to it, plus aluminum reflector and plastic battery holder. So, the 2 watts of xml2 heat is released into air, via heatsink+reflector+glass lens+battery holder. In total, I am wondering if this was over kill.

It seems obvious, you want a chimney effect, to increase airflow across aluminum. Attention must be paid to shape and thickness. There is tank thickness, soda can thickness, and all in between. I think the pull is toward heavy duty lights, since that is first jugular a reviewer goes for. The reviewers step on the lights, run them over with the car, freeze them. Nary a one will post a junction temperature, gram weight reading (to verify stated weight), tailcap current reading, lux drop graph. So, if you want a good review, you have to make a flashlight heavy. For me, I don't hold my lights in my hand, so weight matter. I want a light that crushes when you run over it.

yes if you put bare parts on a scale you can get a light weight, your basically looking for a plastic light with a heat sinc just large enough to handle the heat. Or a pop can thin light, which most manufacturers won't make a brittle product like that. It's impractical to make a flashlight you can crush in your hands.

You want something light you may want to look into the plastic lights made by Streamlight, Pelican, and dive light manufacturers. They'll be lighter, still have heatsincs, but few are made with 18650's it'll more likely be a 4 aa light

 

[Poppy]

Thanks. You could do a half hour measurement of lux from beginning of test and post results. What was the lux at beginning and every hour at least. But your time, already, is appreciated.

If you want to send me a lux-o-meter, I'd be happy to post three hours of run-time.


BTW... where did you get your formula to convert ma to cd? and what is the formula?

 

[degarb]

yes if you put bare parts on a scale you can get a light weight, your basically looking for a plastic light with a heat sinc just large enough to handle the heat. Or a pop can thin light, which most manufacturers won't make a brittle product like that. It's impractical to make a flashlight you can crush in your hands.

You want something light you may want to look into the plastic lights made by Streamlight, Pelican, and dive light manufacturers. They'll be lighter, still have heatsincs, but few are made with 18650's it'll more likely be a 4 aa light

http://en.wikipedia.org/wiki/Specific_strength

If my 2 minute read of the above link is correct, looks like ideal (practical) light would be just enough aluminum, and the rest carbon epoxy. Unless carbon nanotubes are lying around your workshop.

Still, (reading wiki above) an aluminum light, with balanced thickness, should be lighter than a plastic light. It is all about the engineering choices.

I just found a $4 aluminum Walmart 9 led light in my junk drawer. This thing is super light and quite crush resistant.


I have been playing with some 20 and 26 mm TIR's over last few days, trying to get my 20 mm xml OP to throw more. This is where I am getting this number; based on the specific brand in my setup. Brand, bin, etc., so just a guess.

 

[Poppy]

Just wondering if such a 2x18650 flashlight exists:

Specs:

1. 4000 candelas
2. As close to 300 lumens, lasting >8 hours with no dimming due to cell drain (This spec means a max of350 ma per 18650 or three AA, limiting me to 300 lumens with two18650s. Over years, I learnedthat higher current settings too often translate to accidental deadwork light before work day done. Great excuse for smoke breaks andgoing home early.)
3. Neutral bin 4500 kelvin best (sinceI have no control over headlamp color)
4. Light weight aspossible. 50 grams or less 150 total withbatteries (60 grams intl-outdoor single 18650 light)
5. Infinitely dimmable, for super longrun times.
6. Glass lens.
7. Splash resistant. Waterproof not essential

I just took another look at your specs, and they are unobtainable with today's technology.

An XM-L2 in the 4500 kelvin range can get nearly 300 lumen @ 700ma
A XP-G2 R3 in the 4500 kelvin range can get up to 138 lm @ 350ma or 276 lm @ 700ma.

In either case, it will take twice the power to get what you are asking for, regardless of the form factor.