Introduction: 100W LED - Flashlight

Picture of 100W LED - Flashlight

Welcome back!

And yes.. A 100W LED is alot... It is approximately 9000 Lumen. A car on high beam produces about 4000.

And that sums up why I made this. It's awesome!

Let's get to it.

Step 1: The Idea

Picture of The Idea

I have worked with some 10W LEDs in the past and they produced a lot of heat. Therefor I wanted to have a great cooling system that could cool down the LED.

The picture is more or less what I came up with.
This should somehow continuously cool down the led.

Step 2: The Electronics

Picture of The Electronics

Step 3: 3D Printing

Picture of 3D Printing

Because why not!?

While I was making the 3D model i saw online some other projects similar to this where they used PVC tubing, and was about to do that instead... But hey when I got an excuse to 3D print.. I 3D print!

Step 4: Assembly

Picture of Assembly

Now that the 3D printed model is printed to fit all the components it was very easy to screw everything to place.

I gradually soldered the electronics while I worked my way back to the end compartment with the batteries.

The battery was made by 4 old laptop batteri cells (18650). If you know how this process works you can see I have tested these and marked the capacity on the cells. this helped me to find 4 more or less similar cells.
I can definitely recommend to scavenge these batteries whenever possible. You never know when to use them!

Step 5: Test!

Picture of Test!

I made mine without a BMS system. this means i need to charge the battery on a battery charger as you can se here. If you just want a power input to charge the cell a 4s BMS is recommended.

Like this:

I will try to get some better pictures for you so you can se really how much it lights up. It's a lot....

I hope you enjoyed my instructable and i hope you want to make one of your own!
If you liked this projects dont forget to throw a little vote in my direction. It definitely helps me out and it helps me to know what you want to see more of nex time!

See you next time!


clazman (author)2017-11-20

Now this is a 3-D print that uses plastic printing in a PRACTICAL and EFFICIENT way! Not using tons of plastic!

3 cheers to an impressive design!!

Special EDy (author)2017-11-16

Not accounting for the fan's consumption or power losses inside the boost converter, a 4s battery pack is going to need to supply 6 - 7.5 amps at 100W, depending on its level of charge. Most 18650s are only rated for a maximum of 4~5 amps. Ive never seen a laptop battery 18650 over 2400mah and 5 amp maximum disharge rating, and I have over 100 cells out of laptops in my toolchest. Add to that the lack of protection circuitry, and it is a bomb waiting to go off.

The highest capacity 18650s currently available are only 3000-3500mah, and this mah rating is at a fraction of an amp. Storage capacity severely degrades at high discharge rates. It is physically impossible for those 4 18650 cells to supply 100 watts to the LED for 30 minutes with current technology. Please dont mess around with lithium ion batteries unless you really understand what youre doing.

Here is mine.

JohnC430 (author)Special EDy2017-11-19

i read your post on candlepower forum but i cannot seem to be able to get into it again. I thought of a very important safety issue that perhaps you did not think of. my email is john.conrad873 @ please contact me and i will explain

JohnC430 (author)Special EDy2017-11-19

yep!!! i give it 20 minutes approx. 2.5A-H batteries 2.5/7*60 = 21 mins and that's without taking the Boost converter losses into consideration

Special EDy (author)Special EDy2017-11-16

Also, in the circuit diagram, you need to move the power switch from between the boost converter and LED to being between the battery and boost converter. In your current layout, the boost converter will run even when the power is off. This will destroy the batteries since they dont have a low voltage cutoff, and the datasheet expressly states that you should never run the boost converter without a load.

TueBjørn (author)Special EDy2017-11-16

Thank you so much for the concern i have been using these 18650 for some time now. as i hear, you also have done the whole scavenging cells from laptops procedure. :-)
You are absolutely correct in you comment and it is definitely a mistake not to have some sort of safety lige a BMS with current cutoff.
Thank you so much for the input and i hope many others will read your comment befor making one similar.
Have a great day :-)

Eee1997 (author)Special EDy2017-11-16

100% correct.

If we want to employ Lithium battery cells we really need to know what we are doing. These cells have been known to explode or burst into extremely hot flames if misused.

AndrewB52 (author)2017-11-16

I have seen other builds using this 100 w LED. Of course it is really bright and could be useful. However, from a practical standpoint, the fact that one is limited to a half hour duty cycle. There are a few things I would like to add to make this more useful.

1) Control how bright it is either by PWM (pulse width modulation) or varying the current with something like this:

2) Perhaps double the number of amp hours by increasing the number of batteries or using 32650 sized Lithium Ions.

3) One definitely need some kind of BMS because if your Lithium Ions drop below around I think 3 volts it is more difficult to get them going again...although it can be done.

4) I build portable lasers which require a high current drain. For those I prefer to use IMR lithium ions because they handle the current demand better than others. However, the largest of the IMRs that I know of are 18650s.

TueBjørn (author)AndrewB522017-11-16

Yes! yes and yes!
A PWM module would be great :-)
And yes i thought about using 8 batteries instead. i have a lot of them :P
And the BMS is something i am planning to install in the future :-)

JohnC430 (author)TueBjørn2017-11-18

here is another way to adjust the power:

JohnC430 (author)JohnC4302017-11-19

hey how come nobody answered this post?

TueBjørn (author)JohnC4302017-11-19

Sorry I have been busy these days.. we have had pre thanksgiving and all sorts of stuff..
That resistor would be able to adjust the power but only down.. and by doing this it would use power to do so. This means that you would have to have a bigger battery and the life time would be poor.

It's my best guess.. :-)

JohnC430 (author)TueBjørn2017-11-19

LOL sorry it was a joke. I did not think you would answer it. I thought maybe one of the others on this page might.

The correct way to dim an
LED is by Pulse Width Modulation which applies the same voltage and by extension
the same current but with a different pulse width so the LED brightness does
not change with each pulse and just the eyes do the integration. Dimming by
reducing the current means reducing the LED forward voltage and that changes
the color rendition.

have a good thanksgiving. :-)

Special EDy (author)AndrewB522017-11-16

You dont need PWM, and you need an external power source to power a PWM circuit. One of the trimpots on the boost converter chip is for limiting current. You can either use a potentiometer screwed to the outside of the case in place of the trimpot, or replace it with a digital potentiometer run by a microcontroller. This will much more effectively dim the LED.

Special EDy (author)Special EDy2017-11-16

On this exact boost converter used in the instructable, connecting the input ground to output ground will destroy the chip. Similarly, connecting the input and output positive leads will burn it up. So there is no way to run a PWM circuit without a seperate battery pack, unless you build some complicated isolation circuit.
Ive fried two of these exact boost converters in this manner.

JohnC430 (author)Special EDy2017-11-19

the output voltage can be adjusted to be higher or lower than the input voltage. Is that what you have? i.e. the ones you fried?

Richard_g (author)2017-11-19

can u detail the steps of the assembly? thanks

TueBjørn (author)Richard_g2017-11-19

Sorry i dont have the time to take it apart at the time but if i have at some point i wil and i will try to take some more pictures then :-)

foxpup (author)2017-11-17

Next step: Build the Bat Signal. :-)

TueBjørn (author)foxpup2017-11-19

Yes! Yes indeed....

marderchen made it! (author)2017-11-16

nice but so big have tryed it little smaler but cellpower break down (discharde current far to high) have to order li-po flat cells.. also smal laptopfan and lens (relay get better results is creating stepupcircuit running with highte frequency on your own) and maybe calculate the 200 and 47ohm resistors or use other NPN/PNP transistors caused estimated this part (BD1340 is strong enough to switch some IRF1404 parralel)have fun [MEOW] =^.^=

TueBjørn (author)marderchen2017-11-19

Nice build! and great inputs i will try to improve my build :-)

GmanBB (author)2017-11-16

Cool idea! I would use Aluminum body.

GmanBB (author)GmanBB2017-11-19

JohnC430 (author)GmanBB2017-11-19

can u please put the link for that flashlight?

TueBjørn (author)GmanBB2017-11-16

Thanks man!

If i could print in alu i would ;)

carlos66ba (author)2017-11-14

Nice build! Do you run into problems with the fact your step-up converter is regulating voltage rather than current? (LEDs are normally better regulated by current, or so I hear...)

billbillt (author)carlos66ba2017-11-16


Izngood (author)billbillt2017-11-16

Cheaper, and both have at step up and current driver:

JohnC430 (author)Izngood2017-11-19

thanks for sharing this link. i tried to buy it on eBay but the price keeps coming up in Canadian $. do u know how i can change that to USD?

TueBjørn (author)Izngood2017-11-16

I should definitely have used that one!
I am only a mechanical engineer I don't know all those electronic modules :P

Izngood (author)Izngood2017-11-16

Arh! Only 75W

AndrewB52 (author)carlos66ba2017-11-16

I believe you are right about this. LED lights and laser diodes use current regulated drivers. This is from Digikey's website:

"Why do I need to use a driver for my LEDs?

Choosing the right supply is key to ensuring that you get the best performance from your LED. The long lifetimes of LEDs foster the perception that the weakest link is now the power supply. Excelsys has chosen design techniques, market leading components, and thermal management techniques in order to provide solutions for customers with lifetime matching figures. We also have incorporated a number of design features that fit in nicely with LED market requirements:

  • IP67 rated, waterproof metal casing and will probably be potted
  • LEDs are non-linear devices (If vs. Vf) with a forward voltage that is temperature dependent — that is, it needs to be controlled by regulating current
  • LEDs are low voltage DC devices with forward voltage requirements. LEDs also require protection against damage
  • Incandescent light bulbs are purely resistive loads, LEDs are not. Drivers are required to provide a power factor close to one over all line and load conditions
  • High efficiency (driven by lumens per watt demanded by luminaire designers)
  • High reliability
  • Long lifetime (power supplies now perceived as the weakest link in the chain), needs to be in the tens of thousands of hours
  • UL8750 approved
  • Future designs will have the capability to communicate with the power supplies

Now I know why I need an LED driver, should I use a constant current driver or a constant voltage driver?

We have stated that LEDs are current driven devices, so why do companies offer both Constant Current (CC) and Constant Voltage (CV) solutions for LED drivers?

The reason for this is to give the light fixture designers a number of options in optimizing their system. If many strings of LEDs are used in series, the most efficient way to drive them is to use a constant current power supply and connect the LEDs directly across the terminals of the power supply. However, if strings of LEDs are connected in parallel, there may be an issue in trying to match the current in all the strings. A possible alternative to this would be to place an external component or active circuit to control the current. This may result in a slightly less efficient overall number of lumens per watt, but it allows the user to have full flexibility in ensuring that an identical current flows though many LED strings in parallel."

YvesG21 (author)carlos66ba2017-11-16

If it's current what you need (as parts) to convert this build from voltage to current ? (sorry for this newbie question because I really don't know anything about electricity)

TueBjørn (author)carlos66ba2017-11-14

Thanks! I don't know if i have this problem.. but when It have been turned on for some minutes the light beam decreases to half strength. I haven't figured out if it is the Step-up or the just the batteries being drained to quickly :)

maxman (author)2017-11-16

Any way to make this in red?

TueBjørn (author)maxman2017-11-16

I guess with red PLA :D

jwzumwalt (author)2017-11-16

This is the type of project I love Instructables for. I will never build one but I appreciate the design effort and enjoy knowing how it is done - nice job.

TueBjørn (author)jwzumwalt2017-11-16

Thanks man! love your project as well with the Thumbdrive :D

peterlonz (author)2017-11-16

It's still rare for folks to have a decent size 3D printer.

To complete this instructable, IMHO, a case design that can be fabricated with by alternative means is needed.

Also the all up cost should have been mentioned.

Thanks good post

TueBjørn (author)peterlonz2017-11-16

It is still just an instructable. I showed you how I made mine and if you want to make one of your own, that is great! if you want to use the idea to make something different like without 3D printing then that is also great. :-)

The total cost was not meant to cheap. it was meant to be fun ;-)
and all the prices on the parts is to be found in the links :-)
I hope you enjoyed the Instructable :-)

ed-romes (author)TueBjørn2017-11-16

Your unit caught my eye as I have been concidering taking an 6volt lantern old style and replacing the bulb with an led set up but I need a smaller sized part than the one you chose to fit into the reflector while using the same book up points to the battery !

jwzumwalt (author)peterlonz2017-11-16

I don't own a 3d printer - I have been price watching. But, it looks to me like the body could be built in two pieces and the handle attached as another piece. I don't expect Instructable authors to provide EXACTLY what I need - just a good starting point. Should Instructables ban cooking and welding projects because not everyone ones a microwave oven or mig, tig, and plasma cutter?

rmrebob (author)2017-11-16

I made one using eighteen 18650 batteries in a 3s pack and consistently get more than one hour per charge with the fan running. And no issues with the "duty cycle". I have on multiple occasions turned it on and left it on until the BMS shut it down in slightly more than one hour.

Special EDy (author)rmrebob2017-11-16

Mine has 12 18650s in a 4s3p configuration. Maybe a 30 minute runtime before the low voltage cutoff.

TueBjørn (author)rmrebob2017-11-16

I thought about doing that but i wanted to make it more or less compact :)

bugsy1025 (author)2017-11-16

Can you make this dimmable? like a TTL like connecting it to an arduino or DMX control?

Special EDy (author)bugsy10252017-11-16

You dont want to PWM the output of a CC/CV boost converter. You can desolder the trimpot on the boost converter which controls the output current and use a potentiometer attached to the outside of the case.

TueBjørn (author)bugsy10252017-11-16

Yes that would be possible just like "AndrewB52" wrote further down with an PWM e.g.

StevenB170 (author)2017-11-16

This is awesome, I am thinking of building one. What material did you print with? What temp do you think you get to with the LED?

This is an awesome build though!

About This Instructable




Bio: I'm an educated engeneer, with a drive for learning new stuff! I hope to make many instructables in the future to inspire and help ... More »
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