Hack a Mag-Lite Torch Into a Rechargeable Led Torch




About: An earth mother's child and cybernetic human being

Replace cells on a torch is such a boring thing to do for some of lazy guy like me...
(get new cells, opening torch, throw cells in special boxe...blah blah blah)

So let's hacking your old Mag-Lite torch into a cool longlasting rechargeable led torch!

It's cheap and ecological so it's cool!

Let's go!!!

I read some pertinent comments, after this convertion your torch will not be waterproof anymore.
Dont modified yours if it is an important thing for you.

A suitable cap must be add to restore the waterproof ability (perhaps an iphone cap).

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Step 1: What You Need

• 3 cell Mag-Lite torch (from 2 to 5 cell, it's ok just check charger and led instructions)
• 3 ni-mh rechargeable cells (11000mAh suite well for me). Cost: 5 for 19€ on ebay
• 1 adaptive voltage ni-mh charger able to charge 3 cells (3x1,2V=3,6V dc). Cost: 9€ on ebay
• 1 Teralux 140 lumensled. Cost: 13€ on ebay
• 1 dc 3,5mm jack connector. Cost: 2 for 2,24€ on ebay
• 1 dc 3,5mm socket connector. Cost: 3 for 1,21€ on ebay
• 1 stick glue with his gun
• tools to cut plastic
• 1 drill to make a hole in the aluminium mag-lite body (JESUS! What a shame!!!)
• soldering tools
• 1 little hexa key
• some of self-control (not sold on ebay)

Step 2: Disassemble the Torch

Step 3: Hack the System

Try to understand my wiring diagrams

Replace the original bulb with the Terralux led

Change the Tamiya connector of the charger to the new dc 3,5mm jack connector

Step 4: Reassemble and Charge

My wiring avoid the use of the troch instead of charging (more safe for the charger)

The charger give from 100mA to 250mA

So for 11000mAh cells, 2 days of charge would be the minimum request i think.

Nb: This charger i bought adapts its charging voltage according to the number of cell it can detect!...same charger for different size of Mag-lite! YES YES YES!!!

Step 5: Runtime Test

-After the 1st charge (10hrs), it lights continuously 7hrs with a powerfull light! (my timing charge was wrong too short)

-After the 2nd charge (10hrs), it lights continuously 8hrs. After 10hrs, it still lights on, but much dimmer. (my timing charge was wrong too short)

-After the nearly 2 days charge (49hrs), it lights for sure 6hrs with a powerfull light. Unfortunately, after 13hrs the light has definitively dimmished. During night, it probably begun to dimmish after 9 or 10hrs rought job...

-So...After the 4 days and 18hrs charge, it lights for only 10hrs with a powerfull light. Then it dimmishes definitly...

10hrs would be the maximum runtime range of my 11000mah cells...

Terralux official data of 17hrs runtime lignt....is so far...

Possible causes of my bad results:
-longer time of charging needed
-cells quality
-Terralux official data
-My knowlege laks...

Finaly 9 or 10hrs with full power light is still a  good fact for me

Step 6: Terralux 140Lumens Led Test

Sorry for the bad quality pictures, another scene would fit better for this test. (too cold to test it in forest)

I'm entirely satisfy with the power of the Terralux 140Lumens led.

Other led test can be found on the great site: http://www.thetorchsite.co.uk/

Step 7: Conclusion

This hack cost under 40€, it sounds good for me...better than a new rechargeable Mag-lite over  80€...pff

Next steps:
-hack of my 2 cell torch
-find a car 12V dc charger for my torch
-find a usb charger system
-add a cap to restore waterproof ability. Perhaps this one can suite (a 3,5mm jack cap for iphone):
had just order it!

Thank you for reading.

Advices and comments are wellcoming
Will apreciate pictures of some of your own convertion in comments


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    22 Discussions


    5 years ago on Introduction

    Another interesting addition to this would be to put a USB port and converter so you can charge all of your devices from it?

    2 replies

    Reply 5 years ago on Introduction

    Actually you don't need a charger all you have to do us build a converter that changes the voltage from the batteries into the voltage for any usb device.


    5 years ago on Introduction

    Bravo, well done. We use the rechargeable 3 cell maglites with the terralux conversion and the situation works very well. I would suggest the one led head as it will produce enough light to do what ever you would like it to do. The three led head sucks more power from the batteries and gives you more light but to what end. Also if you drop the Maglite from the body of a B-1 or B-52 onto hardened concrete the head will break and then you will have to buy another which is expensive. They will last through Swing shift and Graveyard shift with no problems.

    1 reply

    5 years ago on Introduction

    Nicely done..

    I wouldnt mind about the waterproof thing, if it's an old maglite it's probably start to leak in some water anyway..

    If i need to take it out on a rainy day, i'd just do the trick i did with my non-waterproof flashlights: cover the whole thing with a clear plastic bag, or even better: condom (wash first to get rid of the lubricant).. :D

    1 reply

    5 years ago on Introduction

    and... if you want your torch batteries to last a long time, try this:

    and this: https://www.youtube.com/watch?v=ITK7rCiWjq0

    1 reply

    5 years ago on Step 7

    I think I might try this but I may put the charge port in the end cap if I can. i think a thin stip of foil inside 2 pieces of tape to insulate it will act as a wire to connect to the positive terminal for the battery and then connect the negative to the spring. I think i saw some rechargeable D Cell batteries at the store the last time i was there to use so this would allow me to chare it without removing the batteries every time for charging.

    1 reply

    Reply 5 years ago on Introduction

    "thin stip of foil", great idea. there are still thin free space beside D cell to do this.

    Definitly more esthetic.

    Next step, inductive charger in the botom!


    5 years ago on Introduction

    super awesome!! i found an old maglight going through some stuff the other day. project time!!!

    1 reply
    Mark AJA

    5 years ago on Introduction

    Wiring diagram will come later.

    Please add your circuit diagram as soon as possible.


    Reply 5 years ago on Introduction

    thank you. I don't have tried it yet. have to find the suitable charger. mine is only ni-cd and ni-mh.

    Good idea, due to the better ratio of Li-ion cell...it surely worth with reuse batteries.


    5 years ago

    Great Project. Will do this one for sure!!!!

    1 reply