How 2.0: Make a Solar Cell Phone Charger





Introduction: How 2.0: Make a Solar Cell Phone Charger


A little soldering is all it takes to make this cool little emergency cell phone charger. Keep it in the glove box of your car, in case you ever get stranded in the woods and start to hear banjo music!

You might be able to find the mini solar panels at a store that sells science or electronics equipment; otherwise you can order them online. Please note, you'll also be cutting the wire on the cell phone charger, so make sure it's not the only one you have! You can often find cheap chargers at discount stores like Big Lots -- it doesn't matter if it's AC or car compatible, since you'll only be using the end that plugs in your phone.


1 Altoids Tin case
2 Mini Solar Panels (3V 20mA each)
1 Solder (3")
1 Small Heat Shrink Tubing (4")
1 Large Heat Shrink Tubing (4")
1 Double Sided Tape (3")
1oz Flux
1 Solder Iron
1 Heat Gun
1 Wire Stripper
1 cell phone charger

Step 1: Step1: Cut Wires & Tubing

Take the 2 solar power panels and cut all four wires to about 1" in length. Cut 1/4" of plastic off of the tip of each wire with the wire stripper so copper wires are exposed. This exposed wire is called a 'lead.' Cut the small heat shrink tubing into four equal pieces (1" each). Slide the small heat shrink tubing onto both black wires.

Step 2: Step 2: Solder Solar Panel Leads

Using a toothpick, paint leads with flux on a red wire from one solar panel, and a black wire from the other solar panel. Put those two leads together, and solder using your piece of solder and the soldering iron.

Step 3: Step 3: Heat-shrink Tubing

Slide small heat shrink tubing over the leads you just soldered together. Heat the tubing with heat gun just enough for it to shrink.

Step 4: Step 4: Cut Phone Charger Wire

Cut off the wire from your old charger to about 2.5 feet and strip off 2.5" of outer plastic from the loose end. Cut 1/4" off of each of the inside wires to make leads. Slide the full length of the large heat shrink tubing onto this main wire for later use in Step 6

Step 5: Step 5: Flux, Solder and Heat-shrink Loose Leads

On your main wire, slide a piece of small heat shrink tubing onto the red wire. Flux all loose leads of main wire as well as the solar panels with the toothpick. Solder red leads from main wire and solar panels together. Repeat with black wires. Slide heat shrink tubings over these soldered leads and use heat gun to shrink.

Step 6: Step 6: Test Charger

Test the charger by connecting it to a phone under bright light.

Step 7: Step 7: Heat-shrink Solar Panel Leads

On your main wire, slide large heat shrink tubing over the two soldered leads which connect to the solar panels. Use the heat gun to shrink the tubing.

Step 8: Step 8: Tape and Close

On the back of the solar panels, cover the two brass rivets with double-sided tape (so they don't make contact with the Altoids tin.) Tape the two solar panels on the inside lid of the tin. Tuck the main wire into the case and close. Go somewhere sunny (Florida is nice) and charge it up!

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    54 Discussions

    What’s the difference between 20 mA and 70mA when it comes to solar panels? Should I definitely use 20 mA or does it not matter?
    Thank you!


    1 year ago

    Could you explain why doesn't it need an inverter?

    30mA solar panels will they charge also a modern smartphone?


    1 year ago



    1 year ago

    it was a little hard but i made it

    Wow, that's a nice little instruction guide for generalized electronics/charging.

    What I'd like to do is take some solar cells I have laying around and build a small charger incorporating a battery bank (or buy a premade bank and incorporate that) that way you could charge anytime.


    Where will I get the mini solar panel

    The design will be such as an attachable solar stripe. Flexible enough to be attached to the back of any mobile phone with a power cord and switch. Anyone with such ideas please? Tunde

    2 replies

    have you found the instructables to you query? or anyone making clothes out of solar?

    Awesome thanks I'm going to use this to make a little diy wind mill phone charger as a test then go full scale with a battery wall or a little thing with batteries in like a backpack with wall outlets so I can use it to plug in like a lamp or a phone charger I'm thinking about it for a science fair project ?

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    I'm not certain about this but I would recommend using a diode in the design somewhere to protect your phone battery from over charging or current flowing back into your phone and possibly shorting it, like I said, I'm not certain and I could be wrong

    1 reply

    Yes, you should manage your current flowing. Otherwise, if it is dark, the battery will drain through the solar panel!

    Please read this document to understand how to properly charge your Lithium battery with a solar panel/

    can i use 3 , 1.5v solar cell from road marking light which are used to charge 1 NiMH 800mah battery.

    Plz reply fast.

    1 reply

    Yes you could, please look here how to PROPERLY wire a solar panel and add a recharge module on your NiMH


    2 years ago

    where i can download PDF of this project ?

    what can I make of 1.5 x3 solar cells.