Li-ion Phone Charger From Trash

Introduction: Li-ion Phone Charger From Trash

This is a quick and simple power bank from stuff that most people already have lying around in their house.



  • TV remote
  • 30 cm 12 awg solid copper wire
  • female USB port
  • lm7805 voltage regulator
  • two 18650 Li-ion batteries
  • 22 awg stranded copper wire

You can scavenge the lm7805 out of old electronics. Most scanners have at least one. I scrapped the batteries from an old laptop. Newer drill batteries and e-cigarettes are also common sources.


  • drill
  • soldering iron
  • solder
  • ruler
  • razor blade
  • wire cutters
  • wire strippers
  • multi meter
  • 1/16 and 5/64 drill bits
  • sand paper

Step 1: Cutting, Drilling and Sanding the PCB

Open up the TV remote. Remove the PCB. Cut a piece of PCB 9 cm long by 4 cm wide. Lay all the parts on the PCB and mark were the holes need to be. You can follow the pictures to get a rough idea of were the holes need to be. When you have drilled the holes you need to sand off all the green traces on the bottom of the PCB.

Step 2: Make the Battery Contacts

Take your 12 awg wire and strip all the insulation off of it. You will need about 30 cm. Cut one piece about 6 cm long and bend it into three sides of a square with sides of 2 cm. This is for tieing the positive of one battery to the negative of the other. I bent the ends to make a better contact. Cut two pieces 4cm long and bend them like the pieces in picture five. As an optional step you can add a piece of wire for battery support. When you have all the pieces cut and bent slide them into their respective holes and solder them in place.

Step 3: Wiring the Electronics

Insert the voltage regulator and the USB port and solder them in place. Follow the pictures to wire everything together. If their is anything unclear about the wiring feel free to ask me about it.

Step 4: Testing

When you have everything soldered together, get out your multimeter and test it. If it reads between 4.9 and 5.1 volts, then it should be ready to go.

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    2 years ago

    It's best to not make this out of trash-

    All stuff degrade after time.

    Your transistor could be on the verge of breaking, and your 18650 batteries could potentially be in bad shape.

    Using new components from reputable brands are the best way to go.

    Of course I get what you mean... I salvaged 10 18650 batteries from a battery so... we've all been there before.

    You could also add this in a future trash-treasure thing.

    You could use a cheap module for charging in power banks those are cheap.

    and I don't see a input power thing though...

    Add a TP4056. Wait no.


    Paul Mawhorter
    Paul Mawhorter

    Reply 2 years ago

    I get what you mean, but I was trying to design somthing that could be made by poor people in developing countries.


    2 years ago

    How do you recharge the batteries

    Paul Mawhorter
    Paul Mawhorter

    Reply 2 years ago

    At the moment there is no way to charge the power bank other than by removing the batteries and charging them in an external charger. You could make the board a little longer and add charging circuitry if you wanted.