Are there any flashlights that can sustain 9-12k lumens output for 5 minutes?

mattheww1950 · 2018-10-19T01:45:29.000Z

The problem is neither the battery or the emitter. If you could adequately cool the emitter, what you want is easily done. Unfortunately what you want is very hard to do with any light that does not have active cooling. Nobody wants to lug around a light with enough mass to take up the heat output from a 10K lumens emitter for 10 minutes. 10K lumens you are going to have to dissipate close to 100 watts, and absent some form of active cooling, that is going to require a very large heat sink. Once you opt for active cooling such as forced air, the problem is solved with relative ease. The trouble is that moving parts are almost by definition potential single point failures, so while the LED may have a 50k hour life expectancy, there are no motors or bearings that are likely to last anywhere near that long.

clemence · 2018-10-19T03:24:00.000Z

There’s a way although impractical. Most Cree high power can outputs 200+lm/watt at low (or very low) current. 12.000lm/200=60 LEDs. With all the inefficiencies and losses you can expect 70-80 watt input.
But driver and input power source are another challenge to overcome.

- Clemence

2100 · 2018-10-19T03:21:39.000Z

mattheww1950:

The problem is neither the battery or the emitter. If you could adequately cool the emitter, what you want is easily done. Unfortunately what you want is very hard to do with any light that does not have active cooling. Nobody wants to lug around a light with enough mass to take up the heat output from a 10K lumens emitter for 10 minutes. 10K lumens you are going to have to dissipate close to 100 watts, and absent some form of active cooling, that is going to require a very large heat sink. Once you opt for active cooling such as forced air, the problem is solved with relative ease. The trouble is that moving parts are almost by definition potential single point failures, so while the LED may have a 50k hour life expectancy, there are no motors or bearings that are likely to last anywhere near that long.

clemence:

There’s a way although impractical. Most Cree high power have 200+lm/watt at low current. 12.000lm/200=60 LEDs. With all the iefficiencies and losses you can expect 70-80 watt input.
But driver and input power source are another challenge.

- Clemence

Yes i agree, hence the question that i have put up probably has 2 answers.

(1) definitely doable, Imalent and Acebeam has done it. 5 mins is relatively easy with huge amounts of 70.2 and sufficient heatsink mass in addition to passive convection cooling (relatively inefficient), so we’d need a pretty huge light.

however

(2) Is it practical, effective, efficient? Perhaps not so much, though it would work relatively “ok”. I put OK in quotes simply because different people have different expectations.
Also if we extend this further than 5 mins, we’d need active cooling. Some folks might need longer than 5 mins, some don’t.

And point (3a), the Imalents and Acebeams are $$$ lights. Since this is BLF as in Budgetlight forum, i am wondering what form factor can we wire this up as and DIY from current hosts.

2100 · 2018-10-19T03:37:11.000Z

Ok, some more background. My Father in law and his workers are using some portable XM-Ls, 1S or 2S lights, typical 200g lights. They work ok in the plantations and his bird nest man-made caverns. For inspection purposes. Workers have their own headlights.

If they need more light, they’d bring those Ebay/Aliexpress/Taobao 65W HIDs with 3S3P, these are semi-portable and believe it or not they are able to sustain about 4000-ish lumens (using the lower level of the 2 output levels) for 30 mins easily without burning out (gonna be very hot though!). These hosts are 1400g heavy, 90mm head diameter and 40cm long.

Yeah the hotspot is pretty crappy, but hey it does sustain a fair bit of lumens, it does come with a sling and they are not expensive. They have been using it like that since 2010 /8 years ago and if they need more juice they’d always have a couple of spare lights/packs in the vehicle. The only issue is that they cannot sustain any 1.5m drops, 50-100cm drop is ok though so they still can take a pretty ok beating.

That is why i am wondering if the current technology allows for more output and efficiency, hence able to bring the hosts weight down.

2009 technology

2100 · 2018-10-19T03:48:45.000Z

There are 85W and 100W versions of course, but sort of unwilling to go buy these ballasts due to the heat issue, and also unwilling to load the battery packs so heavily. Replacement lights and battery packs are relatively cheap via Taobao. But yeah crappy hotspot, they can be unfocused to give a pretty big hotspot though, so its usefulness is not as bad as it’s reported by flashaholics (coz we always go perfecting things like lux, beam quality, runtimes, etc)

blueb8llz · 2018-10-19T06:25:54.000Z

Btu shocker, j20, my tn36ut will come close. I need to test my x45

Enderman · 2018-10-19T06:42:32.000Z

2100:

twisted raven:

Pretty sure the Imalent MS12 does, with its 9x XHP70s and active fan cooling.

Ah…i plainly forgot about those big dogs.

!

15k lumens for an hour and a half??
That’s pretty insane.

2100 · 2018-10-19T07:27:02.000Z

Enderman:

2100:

twisted raven:

Pretty sure the Imalent MS12 does, with its 9x XHP70s and active fan cooling.

Ah…i plainly forgot about those big dogs.

!

15k lumens for an hour and a half??
That’s pretty insane.

Yep, i didn’t really go into the detailed specs of the MS12 and X70, apparently it should be doable with the sling and/or plastic handle, with good electronics handling the heat. The LEDs should be able to survive it.

I think even an aluminum handle would not work, it’d be too hot to have any prolonged duration of hand holding.

I’m not kidding, just 15 mins ago, i just tried 43-44 deg C ~ 2 mins holding of the Q8 with my left hand, and up to 48 deg C holding of the Q8 with my right hand (max 20 seconds, decent pressure applied, i tried to endure). Now my hands are a bit heat injured, gotta use some ice packs.

Don’t try for 50 deg C (eg the head portion of a Q8 in Turbo after 3 mins) by pressing your hands firmly onto the head trying to endure it for 1 minute. There is a high chance of injury once past a few seconds.

Aleister · 2018-10-19T07:28:41.000Z

mattheww1950:

The trouble is that moving parts are almost by definition potential single point failures, so while the LED may have a 50k hour life expectancy, there are no motors or bearings that are likely to last anywhere near that long.

I disagree. I have a Sunon 220V fan for ~30 years which counts many more than 50k working hours and it still works fine. For its first ~10 years it was working non stop for 6 months each year cooling my Amiga or me (no AC back then) or other electronics and it’s still on my desk, today, in front of my monitor and I still use it to cool me when temperature is a bit high but not enough to turn on the AC. So, I see no problem for a - well made - fan to last for more than 50k hours.

2100 · 2018-10-19T07:36:16.000Z

Interesting………

It’s good to know. Don’t push it with regards to hand holding your powerful flashlights.

This is muscle tissue damage, not burns.

PubMed Central (PMC)

THERMAL DOSE REQUIREMENT FOR TISSUE EFFECT: EXPERIMENTAL AND CLINICAL FINDINGS

In this review we have summarized the basic principles that govern the relationships between thermal exposure (Temperature and time of exposure) and thermal damage, with an emphasis on normal tissue effects. We have also attempted to identify...

Predicted times to reach muscle necrosis over the temperature range from 37–50°C, based on data by Meshorer indicating that 30 min at 43°C is sufficient to cause damage to muscle
At 41°C, the predicted heating time is down to 1800 minutes, or 1.23 days and at 42°C the predicted time of heating to approach the threshold for damage in muscle has dropped to 230 min.

kiriba-ru · 2018-10-19T07:37:23.000Z

Aleister:

mattheww1950:

The trouble is that moving parts are almost by definition potential single point failures, so while the LED may have a 50k hour life expectancy, there are no motors or bearings that are likely to last anywhere near that long.

I disagree. I have a Sunon 220V fan for ~30 years which counts many more than 50k working hours and it still works fine.

Asynchronous motor have much more reliability than any dc motor. Regular bearing PC fan lifetime is not longer than 10k hours (without vibration, moisure etc.). Laptop small fans can get too noisy after 1000 hours.

2100 · 2018-10-19T07:49:58.000Z

My guess is that you’d have changed the battery packs many times already before you’d need to change the fan due to dirt chockage or something like that……in a professional setting requiring higher levels of output for long periods of times (not necessarily even at 60k lumens or even half of that lol ) . eg my father in law’s application for inspection in the plantation and birds nest caverns (delicacy in South east asia and Hong kong etc), where the surfaces are especially dark and non-reflective + somewhat larger spaces, and a decently large hotspot certainly helps.

Maybe inspection of large underground tunnels as well? You could use throwers, but the FOV would be narrow.

2100 · 2018-10-19T10:18:42.000Z

blueb8llz:

Btu shocker, j20, my tn36ut will come close. I need to test my x45

Wow…BTU shocker (Fenix TK70 chinese clone), one classic big budgetlight. Replaced with 70.2?

Enderman · 2018-10-19T18:32:09.000Z

2100:

Yep, i didn’t really go into the detailed specs of the MS12 and X70, apparently it should be doable with the sling and/or plastic handle, with good electronics handling the heat. The LEDs should be able to survive it.

I think even an aluminum handle would not work, it’d be too hot to have any prolonged duration of hand holding.

I’m not kidding, just 15 mins ago, i just tried 43-44 deg C ~ 2 mins holding of the Q8 with my left hand, and up to 48 deg C holding of the Q8 with my right hand (max 20 seconds, decent pressure applied, i tried to endure). Now my hands are a bit heat injured, gotta use some ice packs.

Don’t try for 50 deg C (eg the head portion of a Q8 in Turbo after 3 mins) by pressing your hands firmly onto the head trying to endure it for 1 minute. There is a high chance of injury once past a few seconds.

The more LEDs you use the higher your efficiency will be for X amount of lumens.
If you build something with like 20 XHP70.2s you can probably get very long runtime at huge lumen outputs.
Only problem is that you’re spending hundreds of dollars on LEDs

SKV89 · 2018-10-20T05:01:42.000Z

2100:

blueb8llz:

Btu shocker, j20, my tn36ut will come close. I need to test my x45

Wow…BTU shocker (Fenix TK70 chinese clone), one classic big budgetlight. Replaced with 70.2?

The BTU shocker is not that big and massive compared to the TR-J20

2100 · 2018-10-20T05:44:45.000Z

For sure the TR-J20 is bad ass.
The shocker is wider by about 20mm.

The BTU shocker host can still be found in China….i think about 300rmb+ or something. I saw a 3 x xhp 35 HI Shocker light at 439rmb, or 63usd, before discount.

charles_lin · 2018-10-20T06:36:34.000Z

twisted raven:

Pretty sure the Imalent MS12 does, with its 9x XHP70s and active fan cooling.

MS12 ’s internal active cooling fan is so inefficient & without any cooling fins on outside of the body Which make MS12 a very bad heat dissipation light.
3 minutes internal temperature reach over 100˚C & the handle is way too hot to hold!

Enderman · 2018-10-20T06:43:51.000Z

That’s not good, the LEDs are probably at 150C+

mortuus · 2018-10-21T21:49:48.000Z

Thats crazy, its just a matter of time before the leds cook themself and die from extreme heat…

clearly imalent just rushed that thing and didnt thinkg about the problems in the long run… there is areason olight and acebeam ditched internal fans.

clemence · 2018-10-24T03:28:46.000Z

Internal fan is a good move for hot-rod torches, if designed with few consideration at early design stage:

- Thermal shutdown sensor in the driver with or without the fan working.

- IP68 fan with thermal trigger and overload switch. If the fan keeps spinning when suddenly immersed in the water it will robs more power while do nothing to cool the assembly.

- adequate fan with optimal airflow debit

reasonable airflow, not just stirring the air inside or near the fins with nowhere to go. The air inlet/outlet must be placed in optimal position. Most IP68 micro fan designed to last with no more than 60°C air input temperature. Best to blow cold air than to suck hot air.

In above case I guess the fan was included in the system after the head designed finished.

- Clemence