Portable 100W led flashlight

A monster flashlight containing a 100W 8500Lm led with big heatsinks and batteries.
With morse function to tell the night goodbye.

Similar projects worth following
This is a very bright portable light with proper cooling and an enclosure built from an old atx psu.
Every high power led should run cool so ot os mounted on a huge heatsink and a 120mm fan blowing the air into the psu case where al the electronics are.
The original fan from the psu still runs in the same place and pulls the air out of the back.
Nothing get hot at all. Even after long use it gets only warm.

All leds need a constant current source, so i mounted a big 600W constant current boost converter in the case supplying 3,2A at >32V.
At the moment it runs on a 5000mAh 5S Zippy Li-Po.

The lens and reflector are bought in a kit and can be mouted almost directly onto the led. I needed to cut an aluminium plate to mount the led and the lens.
It is brighter than car headlights and you can hold it in your hand ;)

The morse function makes this project connected and lets you send quiet messages through the night.

See it in action here in comparison to other flashlights:

And the morse function:

The light can be seen from a very wide area and is great for morsing through the night.

  • 1 × 100w led
  • 1 × Constant current boost converter at least 10A input and 3,5A output
  • 1 × Big heatsink
  • 1 × Battery or power supply capable of supplying over 100w at lbetween 12v and 20v
  • 1 × Arduino For pwm and morsing

View all 10 components

  • Change of boost converter

    Yannick (Gigawipf)06/11/2019 at 15:44 0 comments

    It was about time i revisited this project.

    The boost converter i had initially was a beefy "600W" part that seemed like a good idea back then but only runs good at around 17V+. No chance at 12V to get full output power.

    So i got a new "250W" one that claims to run down to 9V, bolted to an old pentium 3 heatsink and tested it at 12V. It draws about 14A at 12V which is way over the claimed 10A it is capable of but with some added output capacitance and overkill cooling i see no issues. Should be completely fine at higher voltages and even at 12V it achieves maximum output power :)

  • Added a morse function

    Yannick (Gigawipf)08/02/2014 at 18:15 0 comments

    To do something useful with the arduino in this project i added a morse function to tell the night what you think about it ;)

    It will send any text that is received via serial and return to normal brightness afterwards:

    It is possible to put the light and a raspberry pi anywhere and send messages over the internet into the darkness.

  • Power Terminals and Poti finished

    Yannick (Gigawipf)07/13/2014 at 18:23 0 comments

    Got the potentiometer and some high quality banana terminals fixed to the case.

    A lipo can be connected safe and everything works at high power.

    Video will follow soon.

    Next step: Video and maybe a strobe mode and a pushbutton.

  • PWM working

    Yannick (Gigawipf)07/08/2014 at 16:24 1 comment

    Almost all components are now stuffed into the case. Still looks awful but works great. 

    Cooling and PWM control are working fine.

    Next steps: cleaner wiring, making use of the switch and screwing banana plugs for power in and replacing the old power socket with the volt/amp meter.

  • Boost converter arrived

    Yannick (Gigawipf)07/07/2014 at 10:40 0 comments

    Some minutes ago the new 600w constant current boost converter arrived.

    Sadly some capacitors were damaged and broken off the board.  duh. what a mess. Bent in all directons.

    This is how it arrived:

    Managed to solder them back on and they seem to work fine. (not exploded in my face :P)

    Constant current is set to 3,2A and maximum Voltage to around 35v as there is a drop in the wires and the pwm mosfet.

    The booster has only two transistors but three holes in the heatsink so i screwed my mosfet onto the heatsink.

    I can now control the brightness with an arduino and a potentiometer. The arduino will do a fade if the pot is turned fast and i want some kind of exponential curve as the high settings have almost no change and the first values with high brightness changes are very close to each other on the pot.

  • Everything tested

    Yannick (Gigawipf)07/06/2014 at 11:56 0 comments

    Found a good heatsink and got almost all components.

    Still waiting for some boost converters from china.

    The led was first secured by wood.

    Now i am using alu plates and long screws.

    Everything holds together and won't fall apart anymore ;)

    Next step: waiting for the better boost converter to arrive and connect a lipo.

View all 6 project logs

Enjoy this project?



Martin wrote 11/25/2015 at 11:59 point

I wondered about the arduino, because for dimming I would just use a pot and adjust the constant current. It is not that great to PWM the LED current itself. This gives flicker (depending on frequency) and reduces efficiency. The efficiency of LEDs goes down with higher current. Therefore the overall efficiency goes down if you use high current pulses with pauses in between for dimming. It's true, that it is often done this way, but just out of convenience. You have a real switch mode converter, so you can drive it with DC.

  Are you sure? yes | no

Yannick (Gigawipf) wrote 11/26/2015 at 19:12 point

Yes. I would also want to use current based dimming instead of pwm.

The reason i threw the arduino is was that i wanted to make some measurements like temperature, current, voltage and drive a display but i never got the motivation for that.

To reduce the pwm problems i increased the frequency so it won't be as bad on videos. But it is not that easy to regulate the boost converter with the arduino.

The easiest way would be to wire the pot with some resistors directly to the converter. Sure. But i am happy for now.

  Are you sure? yes | no

Chaz wrote 08/08/2014 at 18:04 point
Cool, I actually built one of these. a few years back. but battery powered.
Here's some pictures.(sorry they are from ebay)

  Are you sure? yes | no

Yannick (Gigawipf) wrote 08/08/2014 at 18:49 point
very interesting design.
I am not sure if you find a buyer with this case.
Even if i like the idea. It could need some restauration ;)
Anyways the commercial 100w portable lights are often sold at way higher prices.

  Are you sure? yes | no

Similar Projects

Does this project spark your interest?

Become a member to follow this project and never miss any updates