LED Maglite (CREE XM-L Modification)




This Maglite Modification transforms the Maglite from a 19 lumen to a 900-1000 lumen monster! Many flashlight DIY'ers familiar with CPF (Candle Power Forums) may have already seen modifications similar to this, but most of the modifications on there use all web based parts, as this one uses "less" online ordering, and more localized hardware store items.

This project will run you at about $50 not including batteries. There are other cheaper DIY alternatives and production flashlights that may give you the better deal (dollars to lumens), but if you love flashlights and DIY, then this project is right for you.

This modification can be done by a "beginner" with limited flashlight knowledge, soldering skills and a basic idea on how to utilize limited resources.

Other Helpful Links (how I learned to build this): 
Candle Power Forums 
Budget Light Forums 

Step 1: Parts & Tools

Materials needed are as follows: 
- Maglite 2D (local hardware store)
-3/4 inch diameter pvc coupling (local hardware store) 
-3/4"x1/2" Reducer Coupling Copper (local hardware store)
-Aspherical Lens 
-LED-Cree XM-L (Bin T6 or U2- I used U2) 
-LED Driver 
-Heat Sink
-Arctic Silver Thermal Adhesive or similar item 
-Wire Stranded 22 AWG 
-O ring 50mm 
-small spring (salvage off of old/cheap flashlights)
-insulation foam (2"x2") 
-18650 Batteries - Panasonic or any reputable brand will work. Do not purchase ultrafire 18650 batteries despite their price. There are too many fakes out there and the quality of them is terrible. You can also avoid purchasing the Recharagable CR123A's shown in the pictures. [10/12/2013 UPDATE]  
-Thick Small Diameter Rubber band 
-heat-shrink tubing 

-Hot Glue Gun 
-Soldering Iron
-Wire Cutter & Stripper 
-Alligator Clips 
-Electrical Tape 
-Torex T-8 screwdriver 
-Pipe Cutter 1/8"-1-1/8" 
-2x Small Staples 
-Masking Tape
-Rubbing Alcohol 

You Might Need: 
-Replacement Switch
-Steel Punch 
-Digital Caliper 

Make sure you check all parts before and during assembly to make sure everything works. 

Step 2: Battery Tube Modification

Because the Maglite uses D Cell batteries, you need to convert the battery tube to fit CR123A batteries.

To do this, you take the 3/4" PVC coupling and wrap it in electrical tape until it fits the diameter of the flashlight chamber. Insert it in to check the fit, then take it out. (cut a rubber band and wrap it around the pipe to save some tape)
Next, you must replace the spring, as the tail spring is too big to make contact with the small batteries. Take out the spring and the replacement bulb. Then, take the insulation foam and cut it so it will fit flush inside the tail cap. Take a piece of wire and make sure it makes contact with the metal in the tail cap and solder it in place. Place the already cut insulation foam inside the tail cap, making sure the wire sticks out. Solder the wire to the tail cap and make sure the wire stays in place on the foam. The tail cap modification is complete. (**DO NOT TURN ON THE LIGHT- once the tail mod and new batteries are inserted, you will burn out the incandescent bulb if you turn it on)- but then again, it is basically trash now. The spring can be kept for future projects. 

Step 3: Taking Out the Switch and Preparing the Switch

To do this step, you must have a torex t-8 head in which you have grinded the shaft to fit down the hold. First unscrew the lens assembly and take out the bulb, then take off the rubber cap, then, insert the grinded screwdriver inside. (if you feel resistance, that means the screwdriver shaft is too fat and it is getting in the way of the spring, so you must grind the wrench more)  Proceed to bottom paragraph if you completed this step without a drill. 

**I was not able to grind down the shaft enough, so I destroyed the switch assembly. **

In case the same happens to you, take a drill and drill down into the whole until you see the torex screw. Then insert the torex wrench and take out the screw. Throw out the destroyed parts, only leaving the black cylinder. 
For more information, google how to take out maglite switches. 

Once you have isolated the black cylinder (housing of the switch assembly), take out the assembly on the top of the switch and cut off the tower part that sticks out. Proceed to sand the surface of the switch assembly until it is flat. 

Step 4: Heat Sink and Copper Pipe Fitting

The heat sink (bought from ebay), is too large to fit into the top of the maglite. To sand down the aluminium, wear a pair of work gloves and go outside and begin to rub the sides evenly on concrete so that the heat sink becomes the right diameter. Use a digital caliper to check. 

The copper reducer coupling is also acting as a heat sink in this project. You must cut it to the right size to have the correct focal distance between the lens and the LED. First, take the caliper and measure out .45" from the bottom and mark it with the sharpie. Proceed to cut that portion off with the pipe cutter. This may take some time, as it is very tedious. Use a clamp and some tape to make the job easier. (use youtube if you are not sure how to use the pipe cutter) Proceed to next paragraph. 

The copper now needs to be tapped. (drilled): First, mark .30" from the top and make an indention with a steel punch. Move .25" over and repeat. Next measure .30" from the bottom and mark it with the steel punch (only if you messed up the switch assembly). You should now have 3 indentations in the copper. Cover the copper in masking tape except in the indented areas. (in case the bit slips)Clamp down the copper and use a 1/8" drill bit to drill through the copper. Make sure to drill at a very low speed. 

Step 5: Heat Sinking LED and Driver

Heat Sinking will dissipate the heat so the components will not overheat and burn out. The Arctic Silver Thermal Paste is a non conductive glue material that will transfer the heat to the metal. It is impossible to remove once it has set. Arctic Silver Instructions

Attach the LED to the Aluminium Heatsink using the Arctic Silver thermal adhesive (following the instructions in the attached link) 

Next step is to prepare the driver and heat sink the driver. Test fit the driver in the copper heat sink with the wire side up(output wires). Test to see if the two wires will go through the two holes on the top. If it is good, then solder the input wires to the driver. See attached images. Once this step is complete, test fit the driver again inside the copper heat sink. Then, apply rubbing alcohol to the Q-tip and clean the inside of the copper. Mix the thermal adhesive as the website's instructions tell you to do so, and apply it liberally inside the copper heatsink. Excessive in this case, is okay. Insert the driver inside with the output wires sticking through the two top holes. Make sure there are no gaps between the driver's sides and the copper. Hold in place until it sticks by itself. Then, solder red and black wires to the output wires. (use heat-shrink tubing to cover up the solder) (about 3 inches of wire- red and black) 

Place the LED Heats sink on top of the copper one and strip the output wires to the desired length. It may help to only leave 3 strands of wire. 

Step 6: Preparing the Switch

If you were able to take apart the switch without a problem, reassembly it and solder the positive and negative wires from the input driver wires to switch. Heat shrink everything. Then move to paragraph 3. 

If you had to drill out the original switch, then connect the manafront switch to the tabs. First, solder a black wire to the spring and then another one to the outer golden ring. Then, connect the spring wire to the driver's negative input wire. and then take the other black wire and slip it through the bottom hole in the copper. (this is the ground) Then, solder the red wire to the silver tab from the battery terminal (positive). Heat shrink everything to ensure no short circuits. 

Next, superglue the copper heat sink to the black switch assembly. After that, insert the whole switch assembly through the back of the flashlight tube. 

If you had switch problems, read this paragraph. Before you insert everything into the flashlight tube, sand some of the anodized area inside the flashlight tube, near the opening. After doing so, solder a black wire to the part you just sanded and connect the black wire from the bottom hole to the wire that you just soldered. It is now a complete circuit. 

Step 7: LED and Lens

Place the LED unit on top of the copper piece and and pull through the red and black wires. Solder those onto the LED.

To mount the aspherical Lens, take out the original reflect and the plastic lens. Insert rubber O-ring on the top of the aspherical lens and place them inside the reflector body and tighten  up the crown. Then, twist back onto flashlight.

You should have tested all the parts to make sure they work before hand and also test things before you glue them permanently. With that said, now you are done with the project Insert the batteries and point the light away from your face and unleash the beast. 

Step 8: Pictures and Comparisons

These are the flashlight comparison photos. Of course the sun is always brighter, but this light is comparable to most car headlights and defineaty beats a Surefire in terms of brightness and price, but Surefire still has the reliability that someone could trust their life on. For a home flashlight, this is amazing, but on the streets, carry something that can take the abuse. Fenix, JetBeam, Surefire, O-Light, StreamLight among others are the ones that you can "truly" depend on. This flashlight  through my testing, is pretty reliable, just don't abuse it too much. And at night, make sure you know what you are shining it on, this thing can take away someone's night vision for a decent amount of time.

Post Questions in the comments if you have any. 
If you do this project, post your photo's in the comments! Good Luck! 

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    24 Discussions


    2 years ago

    Great instructable! Does anybody know how one would switch "modes" (low, medium, high) with this LED driver?

    8 replies

    Reply 2 years ago

    To switch modes, depress the switch and release - this particular light I built has a reverse clicky switch so I could switch modes with the light already on (light press on the switch without turning it on.)

    With a forward clicky switch, I would have to switch modes when the light is off (light click on the switch without turning it to constant on by fully activating the switch).

    This particular LED Driver switches modes based on a timer inside, so when it detects a switch cycle (on/off), it is programmed to go into the next mode.


    Reply 2 years ago


    So, I got the Driver and XM-L LED, but I seem to be having a problem. I can't switch out of Low Mode! Every time I wore my LED up, it remains on low mode and blinks every 5 seconds or so. I believe that this low-power-blinking is supposed to be for when the driver overheats, but obviously that can't be happening! Any idea how to fix this? Thanks.


    Reply 2 years ago

    Sorry you are having these troubles - I've had faulty drivers in the past before...but before we do that, lets troubleshoot each thing and see if we can determine what is at fault. Oftentimes, the drivers are programmed to flash when the battery is low. The Lithium batteries you are using (18650 or (R)CR123A) should be at 4.20V charged. Depending on how it is programmed, anything below 3.60 volts may cause it to start flashing.

    1) Battery - What batteries are you using and are they charged? Verify with a multi-meter.

    2) Measure the current the driver is putting through the emitter - use this tutorial: http://www.lygte-info.dk/info/Measurement%20UK.htm...

    3) Check all your solder joints...you could have a cold joint somewhere and that's what's making your driver act up.

    4) Maybe it is the driver this is faulty...sometimes that happens - email the manufacturer - they may reply, they may not.

    Feel free to add a few images of your progress to this comment thread - I'd like to see your project.

    Best of luck.


    Reply 2 years ago


    Thanks for responding!

    1) I'm actually using three different batteries wired in series to power the driver- one 3.75 V 32650 Lithium Ion battery; one 1.5 V D Cell Alkaline Battery; and one 3 V Lithium watch battery. (Long story short- I meant to order two 32650 batteries but only ordered one, so the Alkaline battery and Watch battery are providing the needed voltage boost until the new 32650 arrives.)

    When I tested the battery pack with a multimeter, it read around 8.25 Volts. I believe that should be enough for the driver, as on the website it says it accepts from 5.5 - 15 Volts.

    2) Thanks for that helpful link! I actually tested the current that the Driver was outputting to the LED, and it looks to be around 0.2 Amps, which seems like it would correspond to the Low-Power mode.

    3) I tested all of the electrical connections with the resistance setting on my multimeter, and everything seems to check out

    4) I emailed kaidomain... hopefully they'll get back to me!

    Here is a link to a video I took of the blinking pattern: https://streamable.com/aaqr

    Here's a few images of my project- I'm building a Bike Light out of parts for Mag-Lite flashlights, and right now I'm just trying to make sure that all of the LED parts work before permanently installing everything. The pictures are of my battery pack made from the barrel of an old maglite, and a multimeter measure of the batteries voltage.

    Thanks again! :D



    Reply 2 years ago

    Got it working- it was just my batteries that were the problem! Thanks again!


    Reply 2 years ago

    Hey MU5ICI4N, I am glad that you got your light to work. Great job!


    Reply 2 years ago

    OK, Thanks! I'm thinking of using your mod for a high-powered bike light I'm building :)


    3 years ago

    Great mod. Thanks for sharing.
    Here is another easy one to do.



    5 years ago on Introduction

    Nice conversion. I have two Maglite flashlite that I would like to convert. (1-2d cells & 1-6d cells). I guess the hard part is to get the Li-Ion batteries. Very nice project. Congratulations.


    5 years ago on Step 3

    An allen wrench fits into the switch assembly to remove the set screw that holds it in the tube. I want to say it's 5/32 or 3/32.

    3 replies

    Reply 5 years ago on Step 3

    I believe that works with the older "generation" of maglites that were produced before date X (I can't remember when). I remember reading on CPF or some other website that maglite changed to using Torx T-8's instead which proved to be true in my case because it was a torx screw when I finally pulled it out.


    Reply 5 years ago on Step 3

    Well, you learn something new every day! I wonder why Maglite would change something that has worked so well for so long.


    6 years ago on Step 5

    The driver comes with the output wires already connected, but where do you solder the input wires?

    2 replies

    That's a good question. I actually had the same question when I was looking at other posts about similar projects. The input wires are soldered on the opposite side of the input wires. The positive goes on the silver circle tab, and the negative goes on the side of the driver.(you can see it on the driver) I have included a couple picture is this comment. If you don't understand it, I have a video of the soldering process I can post on YouTube.

    Jess Apartment and Light 024.JPGSolder.jpg

    As of right now, I have not tested the run time, but based off of previous experiences, I'd say 2 Hours on high should not be a problem. If you want to go for a longer run time, buy some Panasonic 18650 batteries, as they have significantly more mAh than what the CR123a's have. More mAh means longer run time. But remember, running high power lights for extended periods of time will make the flashlight heat up some so be careful. The most I have run it for is 30 minutes on high without any noticeable dimming.

    *a member of CandlePowerForums, Jayrob, estimates that these can run 4 hours on high using 32650 batteries, which I believe is very possible.*