My 100W LED Flashlight Version.





Introduction: My 100W LED Flashlight Version.

I decided to build 2 100W LED flashlights after seeing this:

Since I do photography as a hobby, I thought they could be quite useful. I also build PC’s for personal use, so had a bunch of heatsink that I could use. Years ago I used peltiers for overclocking and CPU cooling and wanted to give that a try.

I went and bought all the other components and started the assembly process. I could not solve the problems (fast enough) that I had with mounting the LED on the peltier heatsink, so went with a standard heatsink. If I had tools, I might revisit the peltiers for cooling the LED. When I needed to build the frame I decided to try something else. I had an old $4.00 6V lantern flashlight, from Menards (bought a second one), lying around (was going to try and convert it to an LED light), so decided to use that instead.

Step 1: The Completed First Light.

Here is the first one I completed with a battery pack I put together.

Step 2: Starting the Second Light (electronics).

The mounted LED and electronics. The electronics was assembled according to the instructions in the mentioned video.

Step 3: Preparing the Frame/body.

Preparing the frame/body and getting ready to assemble it.

Step 4: Testing.

Testing before assembling the light. Just making sure everything works!

Step 5: The Final Product(s).

Assembled and both lights working!!


· I did not add a lens. If I did, I would need to do more mods, and just the reflector served my needs.

· I modified a USB car charger, so I can use this in and around the car as well.

· On the second light I only added an input voltage meter. The first light shows the output voltage too.

· I still need to shorten the battery pack wires for a cleaner look.

· For the second light I still need to add a battery support.

· For both lights I still need to add mountings so I can use them on a tripod for photography.

· I still need to determine run times on different battery packs.

Thanks for looking.



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    50 Discussions


    1 year ago

    I like the idea of using this as a light for an umbrella rig, or other bounce lighting techniques. Can this led be strobed?

    thats how it appeared in my feed and i wondered for a second. the wire is going where ? :P

    1 reply


    is cheaper and provides more light. Lumens is a measure of perceived light, but an approximate conversion is 100 watt incandescent is equal to about 1000 lumens. I have some 100 watt leds and so far as light I think the 100 watt incandescent is better. I also have a 3 led flashlight like this advertised flashlight. It is supposed to be 3000-6000 lumens. It puts out more light than any 100 watts incandescent.

    This 13000 or so lumen flashlight will undoubtedly be equal or better than a good automobile headlight.

    There are so many things to do in my lifetime and so little time to do them that I don't often build something I can buy that is cheaper and better. Now if building the flashlight was only going to require me to spend $5-10 I might do it.

    7 replies

    Thanks. The purpose was not to build a flashlight with a spot, but rather one with flood, to use for photography. The 2, used together, works well in a small studio setup. I do own a Nitecore TM26 and a TK75 for real flashlight purposes.

    I hate to break it to you now, but that's not a good light for photography because those generic 100W LEDs have terrible CRI and color temperature. You can use a combination of different color temperature LEDs for bettering both aspects, but not using variable binned generics and doing so takes much time and fine tuning with multiple LEDs of different color temperature to arrive at a fuller spectrum.

    I understand what you are saying, but it works for me. It gives me a nice soft light for the setup I used.

    And what is your point. I do realized the ratings are often overstated. That is why I used some comparisons. And also for general information I'll state again that lumens is a measure of perceived light. There is no way to compare the amount of lumens omitted by an led to another led in a different environment. I'm quite sure the lumens of the led flashlights on Ebay is never measured, but an average estimation is stated consistent with the literature of the manufacturer of the led.

    You simply cannot tell me or anyone else what the output in lumens of their flashlight is, unless you operate it in the same environment. Also lumens cannot be directly measured. A indirect approach much be used.

    The flashlight may or may not be 13000 lumens, it certainly is more light that several 100 watt light bulbs. Maybe if you stop LOL you can comment on the post in context.

    1* XM-L T6/ 3000mA =
    910lm x 8= 7280lm x 0,75 (losses in the spotlight) = 5460 x 0,93
    (loss on glass)= 5077lm . Additional losses will be warming.4x 18650
    is low for 8 LED XM-L. LED they are malnourished, so they will shine
    even less.

    This is not a math equation 1*XML T6/3000 ma = 910lm x 8. It doesn't make any sense at all. The best I can tell it is just gibberish. One certainly can't divide 1*XML T6 by 3000 ma and get anything.

    Cree is an industry leader in the led light business. Their specifications have to be accurate to be quoted on engineering studies. They state that 1 xml T6 led bulb will output 1000 lumens with 10 watts of power. With a rated output of 100 lumens per watt.

    These specs are not made up by a manufacturer of a flashlight. They are correct and have been used to build light system for US highways, for industry and for the US government.

    So an 8 cell led flashlight is capable of delivering 8000 lumens. If it doesn't it is because the electronics doesn't allow the leds to draw enough power. No fault of the led.

    The FTC (US Federal Trade Commision) states that a 100 watt incandescent outputs approximately 1600 lumens. So provided the electronics is designed correctly the 8 xml T6 flashing should provide the approximate light of 8000/1600 incandescents. Or 5 100 watt incandescent bulbs.

    And as an added note this is plenty of light for a photo floodlight, even when using filters to alter the color. That link I sent is for a flood flashlight, and I can attest to this. The light is about as broad as the distance to the lighted subject or more.

    This post is not conjecture, but straight from Cree, and in the last case observed by me.

    what is you power converter/how did you build/buy?

    1 reply

    As mentioned, I used the video (top of instructable) as inspiration. I used the parts mentioned in it. There is a Google docs link to the parts.

    i might make one, but make it good for 12v to use as deer spotlight in car.


    2 years ago

    Hahaha, these two projects appeared next to each other in my Featured Tech feed, and the cord goes between them :P

    Skjermbilde 2016-03-10 kl. 12.38.46.png

    Prosím Schéma elektroniky ? To je tajné ?

    spec and measurements of performance are missing.


    2 years ago

    Looks very interesting, could you post a parts list with specs for the components ?


    1 reply

    The parts are listed in the link, at the top of the instructable, that inspired me to build this.