How do I explain that powerful flashlight gets hot easily at highest level is normal?

I like lights to have temperature controlled turbo, with the default set to something very reasonable (50°C or so). If you know enough to go changing the configuration, you hopefully know that doing so might make things toasty.

You can’t so you some nifty marketing.
Instead of calling it stepdown for example call it SSF Sofrin safety features which keep the LED at optimal temperature for long a longer life span and give you better run times.
Best way i think use marketing wank lol. Every company has there own name for stepdown whether it be timed or thermal.

Say the all new SP70 has SS Sofirn safety built in. The SS thermal management system helps keep the light at optimal output levels at all times?
I know i know its a bit wanky but its layed out for every day people.

If this is to be printed in the manual or something, how about adding a drawing of a table lamp with a light bulb, and this sentence: “Heat is a normal byproduct of lights.” I think everyone over the age of 5 knows intuitively that if you touch a light bulb it will be hot. Just a simple line drawing of the lamp and bulb, with wavy lines above the bulb to indicate heat rising, would be good; it doesn’t need to be a Picasso.

Of course, there’s also the standard yellow triangle symbol…

In it’s simplest form light is just another form of heat/radiation. Whether it’s led, halogen, fluro, hid or whatever, they all produce heat. The more light the more heat.

I like Relampago’s analogy (nitrous). Turbo is for short bursts only.

Some manufacturers like to claim highest lumens possible but, of course, it’s not practical for the average muggle.

Barry, I think I have a simple yet sophisticated solution for customers who do not like hot flashlights without driving away your loyal fans and enthusiasts who prefer maximum power and output at all costs. This hint is meant for any „non-Andúril“ or „non-NarsilM“ flashlight with a simplified UI by Sofirn:

Just have a look onto my suggestions I posted here:

https://budgetlightforum.com/t/-/54158/1011

  • Please remove timer-triggered stepdowns from future drivers/flashlights. I do not see any reason to have both thermal and timed stepdowns at the same time.
  • Please allow a user defined choice of ATR thresholds (e.g. 45°C, 55°C, 65°C) just like HaikeLite did with their SC26

Thermal protection setting can be accessed by 10xclicks:

The light flashes once => turn it off to select 45 degree step-down temperature

The light flashes twice => turn it off to select 55 degree step-down temperature

The light flashed 3 times => turn it off to select 65 degree step-down temperature

Eventually, Sofirn could use 45°C as the default setting that will allow a safe and comfortable usage while flashoholics, experts, evangelists and enthusiasts can raise the threshold to a higher value they deem more reasonable, maxing out the full potential of Sofirn's powerhouse flashlights like SP70, Q8 and SP36. There will not be any trade off for customers who prefer a simpler UI than Andúril or NarsilM as they still get the chance to push their flashlights (and skin ) to their very limits.

About the warning sign...

Very good idea! I could help Sofirn to integrate this in future manuals (English and German). However, there already is a part („Caution....“) included that warns customers about excessive heat when using the light on high level modes.

You can throw some numbers as them. Numbers below are fictional, might even be wrong, but give an idea.

A flashlight on turbo is not verry efficient. Maybe 50% turns is light and 50% in heat.

3,7v * 5amps = 18 watt

0,5 * 18 = 9 watt Heat.

60 sec turbo gives 9*60=540J heat.

Q=c*m*∆T
c=0,88J/g°C for alu
The cooling mass is +–20 grams.

540=0,88*20*∆T gives a raise of 30,6 degrees so at room temperature you and up with a 50°C light.

I like to think aluminum & copper metal flashlight acting like headsink for led emitter. High thermal conductivity of Aluminum ‘237 W/(m·K)’ & Copper ‘401 W/(m·K)’ allow it to distribute heat really fast compare to lower thermal conductivity materials such as cast iron ‘52 W/(m·K)’, titanium ‘21.9 W/(m·K)’, stainless steel ‘14.3 W/(m·K)’ & PVC Plastic ‘0.19 W/(m·K)’. It reason why both aluminum & Copper used in cookware base of pans, heatsink & heat pipe, etc.

It’s not normal. It’s only ‘normal’ in the small enthusiast segment.

Most non-enthusiast buyers get worried when a flashlight gets very hot.

Think of it like a car, just because it can drive at 200km/h doesn’t mean you should do that, but it can

yes the problem is like 60% or more of emitters is produced heat, rest is lumens…. if the emitter didnt produce any heat it would be wonders…. many think its a flaw when a light gets very hot quick but that is the price we have to pay sadly…

How hot is hot? Some Acebeam and Armytek lights get over 60°C, which is nuts to me.

That’s just it:

Hot to the point of burning skin is not normal.

Warm to the touch is normal.

If it gets hot QUICKLY, that’s actually better. It means the thermal path is good and it’s pulling heat away from the LED.

If they don’t understand it the first time you explain it, tell them to turn on a (incandescent) 100 watt light bulb, and then lick it after a few minutes.

At the very least, they won’t be able to verbally complain to you anymore.

…about sums it up.

Along the same lines, people want the hottest new light but they’re surprised when it turns out to be literal.

Yeh. They want controlled fusion in a lipstick-sized tube, then return it because “it gets too hot”.

FW3A step 4 draws 561 mA and generates 177 lm pluss heat. Turbo draws 12A. If the Leds were as effective as in step 4 the flashlight would generate 3800 lm, pluss propositional amount of heat as in step 4. For turbo you can then add 1000 lm extra light energy lost as heat energy.

How about:

“This flashlight has the same power as a household lightbulb. Please remember that it will get very hot at high power, just like the lightbulb. For your safety, we have designed this flashlight to reduce power after 3 minutes at high power.”

(You can write “on turbo” instead of “at high power” if you prefer.)

Don’t ask me how to make people actually read the warning, though :slight_smile:

No offense, but I don’t like the idea of giving Sofirn suggestions about more flashlights with timed stepdowns. A timed stepdown is the worst solution both for muggles and enthusiasts. Repetitive activation of turbo will still heat up the flashlight beyond its designated threshold unless a thermal controller is in place, too. But once you have a thermal controller (like „ATR“ called by Sofirn) in place you don’t need to have both timed and thermal stepdowns. That’s why I suggested to Barry to implement 3-4 user-selectable thermal thresholds for stepdown. Sofirn could sell their lights with a factory default of 45-50°C and put a big warning sign as well as some instructions into their manuals how to raise the threshold by hidden settings in the UI.