Solar Powered USB Charger (phones, MP3 Players Etc)




About: 2econdhand maker and Teacher

This is my take on a already well documented little project. Very simple to make and a good introduction to electronics and solar powered stuff. Works just fine too. You need to generate 5-6V to charge a phone.
You will need:
Solar panels. I used 2 panels. (3V I think )
5V voltage regulator
USB female jack/connector
Insulated wire
Soldering Iron
Epoxy or hot glue


Step 1: Bits & Pieces

Gather together all your stuff. You need to make sure you know which side is top and which side is the bottom of the USB plug and the voltage regulator so that you solder the correct pins.

The regulator keeps the power output to 5v.

Step 2: A Series of Solar Panels

A USB port from a computer puts out 5.5V for charging of phones and mp3 players. So you need to get about 5-6V from your solar panels. In this case I need to solder the solar panels in series in order to double the voltage output. (3V each panel).  Solder the positive of 1 panel to the negative of the other. (Its just like putting 2 batteries in a flashlight)

Step 3: Solder It All Together

Hook it all up!
The positive wire from the solar panels goes to the LEFT pin of the regulator. (mine is upside down in the photo)
The negative wire from the panels goes to the MIDDLE pin of the regulator and is also connected to the RIGHT pin of the USB plug. (Again, mine is upside down in the photos)
Then connect the last pin of the regulator to the other outside pin of the USB connector.
The 2 middle pins are not needed.
If you follow my pictures it will be OK....

Step 4: Glue

I used hot glue to hold it all together but an epoxy or duct tape will work fine.

Next time I would make it so that the 2 panels hinged in some way so that it could fold together.

Step 5: It Works!

Here it is charging my HTC.
I have it under an incandescent bulb as it was dark outside when I finished....but it works!



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    38 Discussions


    2 years ago

    I bought a 5.5V solar panel from amazon with charging nodes for mobile. When i plug it in my phone it flashes the charging notification for a moment but doesn't show the charging indication thereafter and doesn't charge as well. What could be wrong? Please help...thanks in advance


    Reply 6 years ago on Introduction

    In theory all should be working...
    Maybe LG like the evil Apple empire and the phone needs a data connection in order 'to know' its connected and will then beging charging??


    Reply 6 years ago on Introduction

    A guy on youtube said (and I agree) that if you want a fast charge that wont take all day get a 1.5w or higher.

    I just got five 3.3 Watt 6 Volt Solar Panels for 20 bucks. Granted there not small and light like the ones listed but there great for starting and testing a DIY project before spending a lot on these nice little ones.


    6 years ago on Introduction

    i've hooked this up to my phone and it says its charging but when i check back my phone has less battery. I've tried up to 1 amp since thats what my voltage regulator is rated at. I've put an 2n4001 diode on but still no luck. Any idea's?

    5.25 v input
    5v output

    3 replies

    For those asking where to get the solar cell, why not salvage some from dead solar yard lights?


    8 years ago on Introduction

    Hey, thanks for a great instructable but I have a problem.
    I built the charger but I don't think I am getting enough voltage. I am using two 3 volt cells and I put them under a bright spiral CFL bulb and it can hardly light a very bright LED. My phone and other devices are not being charged. Any tips?
    I am going to try putting it under the sun tomorrow.

    3 replies

    Reply 8 years ago on Introduction

    Solar panels won't work under a CFL bulb. Needs an incandescent to test indoors.
    How did it go in the bright sun?


    Reply 8 years ago on Introduction

    Thanks for the reply,
    Okay, I'll stick to incandescent bulbs. I am using a USB hub with a bright blue LED as my load. On a sunny day, the LED was much brighter than indoors, but not as full as when the hub is plugged into a USB port. Even in the sun my phone isn't getting charged. I am currently using two 3 volts cells but I own four. Do you think it would work if I used three or maybe all four cells? (My only worry is that the regulator will not be able to handle 9-12 volts and it might get fried.)


    8 years ago on Introduction

    I don't know if the voltage regulator chip does it but I always thought you needed a diode to prevent power back flow from just killing your devices battery in low light.