I know Mfg’s and a few of us focus on max lumens somtimes ignoring the duration.
I have a hard time identifying flashligts that can run at (or above 3k Lumens) for a full (30 min) / (60 min)
With all the advances I would like to think that actualy bright tools have also become possible/more common.
please provide any known 3k Lumen 30/60 min plus that are varified (not Chinese lumens)
thank you for the help and also hopfully manufacturers will do the hard engineering to get us there.
The Convoy L6 holds above 3k lumens for the first 45-50minutes. By 70 minutes it’s down to ~2300. Rapidly falling until 80min when LVP kicks in.
It gets pretty hot though after around 5 minutes!
If you stay moving its not to bad, and in cool weather. I’ve never had mine get so hot I can’t hold it. By the head will get hot but the battery tube doesn’t get burning hot. Same with the s70
I had forgotten about the L6.
simon’s store says 3,800 Lumens, it is at least close, maybe we loose 800 lumens with voltage sag and heat soak, or may be not.
Good call, I guess i was thinking about a light that was not in the obvious “monster” class. I was not thinking of EDC, but how convenient could a “bright” usable light be?
Not necessarily smallest, but somthing other than a toilet plunger sized tool.
Still intrested in options.
Heat is the problem. It takes something L6 sized to handle that much heat for that long
Trustfire j20
3k lumen flashlight is very hot when it open. how to solve this problem ?
Admittedly, I usually use my L6 clamped on a tripod (thus no ‘external’ heat sinking), in high temperatures (20C+).
If money is not a problem: X65 Rechargeable Flashlight|AceBeam® Official Store | Flashlights, Tactical Lights
3000 lumens with 100lm/W=30W.
30W*20sq.cm/W=600sq.cm
SRK is about 300sq.cm.
Somebody (hank?) mentioned new 8*18650 light, it should carry such power as long as batteries are not empty (more than 3 hours).
What are conditions for that number? 20 sq.cm/W. Thanks a lot
This is very rough number, it is often used for first calculations in high-power electronics, heat pumps, industrial lightening and etc. just to estimate external dimentions of heatsink/case. Of course different surface finish, anodizing presence/color, vertical or horisontal surface area, environment temperature and humidity, wind presence and speed may influence at this number several times, but what can I say - it works in flashlights. Convoy S series flashlight will not burn with any number of 7135s, but maximum number of them to hold it in any conditions and in any situation without discomfort is 4.
Surface area: 2.4*3.14*12=90sq.cm
4x7135 power: 4*0.35*3.6=5W
90/5=18sq.cm./W which are very close to rough number 20.
:+1: i’ll look at runtimes charts with a new critical eye!
P.S. maybe there is something like this to evaluate how mass modifies the temperature increase during time :smiling_imp:
yes absolutely for long run times the mass of the heatsink needs to be considered.
and the balance of air cooled vs hand cooled needs to be considered. I am not looking for some mega monster, but I was wanting it to be a useful bright light which has more value to me then 30sec max bright numbers light.
.02 worth
A generic 85 watt eBay hid flashlight will do far more than (over double) 3k lumen for well over an hour. I suggest the 4300k version it is very pleasing light and quite a fun toy.
Klarus G30 will do over 90 mins at 2450 lumens. It's not quite as powerful as you request but it's pretty bright !
It also produces good colour (Cree MT-G2), great beam/spill all purpose profile and is pocketable. It's a lot smaller than you might imagine but rather heavy. (3 x 18650)
Wrong. It has very good thermal management with almost unvisible power decrease, but it present. There is wonderfull review on german forum with output graphic.
Yes, and they are much more simple.
Each material object has heat capacity which can be counted easily.
Alumunium parts: (0.9J/gr×K)×weight in gramms×temperature difference=1W×sec
Copper parts: (0.38J/gr×K)×weight in gramms×temperature difference=1W×sec
Delta T=P(watts)×t(sec)/m(gramms)×c(J/gr×K)
For 50gr aluminium host, with 25W heat power (30W led power) (S2+ triple):
10sec: +5.5deg.
20sec: +11deg.
30sec: +16.5deg.
Heat spreading depends on temperature difference so if you have too big result temperature (twice more than ambient or more) you need to consider both material heating and area heatsinking. Please dont forget that there is some non-zero difference between different areas of your host.
For 300gr copper host with 50W heat power (60W led power) (X5 quad):
10sec: +4.4deg.
20sec: +8.8deg.
30sec: +13.2deg.
My calculation may be not very accurate but they can provide main idea - even big and heavy piece of copper wont give you lots of time. If 15-20sq.cm. can provide one extra watt for any long time, you need extra 10gr. if aluminium to have same temperature with same extra 1W only until 30sec. (after this extra heatsink area will beat this extra 10gr.)
The G30 has genuine stepless temperature regulation which depends entirely on ambient temperature (and breeze if present); ie the cooling rate. It does not come into operation in a reasonably cool environment and maintains full brightness. It only throttles down when absolutely necessary and will automatically throttle back up when possible - if cooling rate improves. I prefer this approach to a torch that gets too hot to hold and who's temperature continues to increase to the point of damage.