“World’s Brightest” Flashlight

With the crazy extremes of light flux density that are possible these days, we’re putting quotation marks around “world’s brightest”, but it’s abundantly clear that this flashlight build is very much too bright. No, really. Why would you want a flashlight so bright that you have to wear sunglasses to look at anything that’s within a twenty foot radius?

Because you can. [Mads Nielsen] combined 18, one hundred Watt LED units with some giant machined heatsinks, fans to cool those heatsinks, lenses, and other hardware to make a device that turns electrons into photons at an alarming rate. Each chip-on-board LED package requires 32 Volts, and they’re pairwise in series so it’s a 64 V system. A boot converter pushes up the twelve LiPo battery packs up to the required voltage.

Even with the relatively high voltage, this thing sucks in 27 A, so the power supply is distributed among four of these boost converters. All of this means thick cables and a rather hefty power switch. When you’re designing something ridiculous, all of these little details come out of the woodwork. We’ve included part one of the four-part build video here, because they’re full of great detail. [Mads] has a lot more interesting LED-related info on his YouTube channel. You can watch the showing-off video on your own time.


We’ve covered really bright, 100W flashlights before. Not once, but twice. This is eighteen of those.

46 thoughts on ““World’s Brightest” Flashlight

      1. Yeah perhaps it’s time to nail down some basic requirements for these monster flashlight build competitions, like being able to fit it in your pocket or within some certain dimensions (lunchbox size?), not require a backpack or wheelbarrow to make it portable.

        Oh and have it able to run for a minimum of x minutes, say 30, at maximum output.

  1. There’s a whole corner of the defense/law-enforcement aviation and marine industries that get really excited over this kind of thing, particularly if there is a service life/durability advantage over conventional HID and swirl-tube Vortek lights.

  2. I have those boost converters. There some detrimental part flaws. #1 is the fuse wrong size. Do the math E*I=P. The fuse that came with my units was under rated. Got hot as well as contributed to I*R losses. Needs a 20Amp fuse. #2 on the bad parts list is. Input filter cap Chenxing 1000uf @63v. Bad Cap MFG as well as got hot under varying input voltages. Needs (3) 470uf @63v suggest Nichicon in parallel. Mount caps on perf board above holes. Spreading input ripple across three cap is better all around. #3 the output caps were also Chenxing. Replaced with same value Nichicon.

    Ok while you have the unit separated from the heat sink. Boost up the PCB lands for ground and positive input and output. Use solder of course. Better current carrying capacity and less I*R loss as well. I noticed the lands looked pathetically undersized for 20A.

    Now everything works better and nothing gets hot except the coil and heat sink. But then those are suppose to get hot. One last note do not ever run the converter under 9.5Volts. There is an regulator running off the input that supplies all boost circuit power. Bad things can happen. Re: blow out the converter!!

    1. If you want to spend so much time and money (I’d imagine those Nichicon caps are anything but cheap) with them, you’d be better off designing and building a proper LED current-mode controller and sizing all the components like you should…
      A good start would be a junked welding inverter (has big transformer core and a PWM controller), otherwise you’d probably have to a multi-phase setup to make it small enough to be portable.

    1. The whole project is a shitshow. I know very little about machining but I still knew this guy is a complete moron when it comes to how to use his machining tools.

      Dude, you didn’t break your drill bit because it was “cheap”. You broke it because you were holding the workpiece down with your hand instead of clamping it, moved it, and it snapped the bit.

      I nearly cried when he was trimming the edges of the heatsink…

  3. The heat sinks are designed to work as an air duct in conjunction with high power axial or radial fans (see Fischer LA 9 series). If only a low power axial fan is mounted onto the bottom face better cooling could be achieved with a way less fancy heat sink.

  4. There is never enough overkill. These cheap and owerpowered LEDs are humanity’s biggest breakthrough in last decade. I have built 50W TL494-driven custom boostconverter that can be regulated from 1W with a pot and switch. I am taking it in caves, forest, or just for a walk where i can possibly go home after sunset. I use small power up to 5W most of the time and when needed just blast the area with full power. I will build 100W version with backlight and i will not fear the dark anymore. Just kill it with light.

    1. Seriously. What a disaster. “Don’t buy cheap chinese bits.”

      No, learn how to use your tools properly, like securing your workpieces. What would he have done if the drill bit had caught on the workpiece? It would’ve chewed up his arm if he was lucky. If he was unlucky, caught on his clothes and pulled him into the machine.

    1. Because it requires a single, very big current mode power supply and a high-voltage start. Also, a really high voltage starter to make it capable of hot-starting, otherwise you’d have to wait several minutes before you can re-ignite the arc. Also, at this light output, there’s going to be some serious heat dissipation, so a melt/burn-proof enclosure.

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