Lighting-Gallery.net
General => General Videos => Topic started by: wattMaster on June 02, 2016, 11:05:53 AM
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https://www.ispot.tv/ad/AT30/bell-howell-taclight-brighter
The commercial boasts that you can put it in boiling water!
Too bad the LED won't last long in that.
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Well, actually in the boiling water, the LED will by far outlast the rest, as it won't be powered for any long time. The first to fail there will be definitely the battery, chemically destroying all around...
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Well, actually in the boiling water, the LED will by far outlast the rest, as it won't be powered for any long time. The first to fail there will be definitely the battery, chemically destroying all around...
Oops, I didn't consider that.
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Actually the battery thermal problems are the main issue for such format flash lights using high power LED's.
Traditionally, the maximum lamp power was limited by the maximum battery power, what is usually around 10W or so.
With a halogen, or later MH, the vast majority of that power leaves the flashlight in a form or radiation (some visible, but most in the IR), so barely 2W remains within the torch body. That is low enough to ensure, the whole thermal mass does not get heated above the limit before the batteries discharge.
But with the LED's, the designers again try to get as much light output as possible, so many still go to the battery limit, so the 10W or so (of course, it gives off way more light than the halogen and even the HID of the same power). But with the LED, all the power not radiated as the light (so about 8W), ends up heating the flashlight body, That means 4x more heat than with the halogen and/or HID and that is able to overheat the battery way before it drains it. And mainly with now quite popular LiIon's (the 18650 size is extremely cheap and easy to get, yet powerful), which both store a lot of energy, as well as have really low max temperature limit (just around 40degC ambient when any load is expected from them) and tend to really unpleasantly fail when overheated.
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What makes it worse it that they likely use cheap cells.
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I had to research this myself, they are trying to resell a different light that was already super cheap!
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they talk about the 200 lumens like its sooooooooooo bright. ive got a 500 lumen Duracell and a even larger 650 lumen defiant brand. both have cree Leds. granted they're large. the Duracell takes 3 C's and the Defiant 3 D's so they aren't small like that but they act as if its the most powerful flashlight consumers can buy. I know you can get some that size that put out 350-500 lumens and use a 18650 cell. the charge wouldn't last as long as that flashlight but its gonna be brighter.
they also act like that's the only one you can find around with the strobe feature. the Duracell one I got has 2 strobe modes. misleading advertizing
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they talk about the 200 lumens like its sooooooooooo bright. ive got a 500 lumen Duracell and a even larger 650 lumen defiant brand. both have cree Leds. granted they're large. the Duracell takes 3 C's and the Defiant 3 D's so they aren't small like that but they act as if its the most powerful flashlight consumers can buy. I know you can get some that size that put out 350-500 lumens and use a 18650 cell. the charge wouldn't last as long as that flashlight but its gonna be brighter.
they also act like that's the only one you can find around with the strobe feature. the Duracell one I got has 2 strobe modes. misleading advertizing
What's more misleading is the "X800" flashlight.
You likely saw those ads on the internet, "Bright enough to blind a bear" "Military technology" "Controversial new flashlight"