Solar USB Phone Charger with Battery Backup

In this instructable I will show you how to make a solar powered USB charger for your phone or mp3 player. This is item is great because it doesn't always have to be sunny for you to charge you phone or other USB device. The way the circuit is designed lets the solar panel be constantly charging the batteries and by flipping the switch the batteries start to charge your USB powered device. 

Hope you like it.
Remove these adsRemove these ads by Signing Up

Step 1: Supplies

To make the Solar USB Phone Charger with Battery Backup you will need:

6 volt Solar Panel
4 AA Battery holder
4 AA  Rechargeable Batteries
2 diodes (I used 1n4007 but any will work)
Female USB 
Solder and soldering iron (optional)
2 100 Ohm resistors (only for apple devices)
Heat Shrink (optional)

You can find all of these parts at your local Radio shack.  Lets start making it.

Step 2: Making It

To make it just follow the circuit diagram as shown. Make sure all of your wires have good electrical connection. If you don't have a soldering iron than you can twist the wires together and cover it with tape. The first circuit shown charges all USB devices except apple devices. To charge all devices including apple products add 2 100 ohm resistors connected to the two data pins on the female USB as shown in the second picture.

If you have any questions then post it in the comments.
geotheos1 month ago
What end of the resistors do you attach to the female USB
dgatchalian1 month ago

HI. :-) I Made my own schematic with 5v voltage regulator to get 5v voltage output.

Charly_ZA1 month ago
Hi. Thanks for the great tutorial. I'd appreciate it if you could help me with my take on this project.
gsteiner11 month ago
This is Fantastic! Could you make a tutorial/video on how to make a pure solar charger (no battery's.) I think you could use a 4.5v 1w solar cell and instead of a female usb you could use a 3-5v to 5v voltage step-up/inverter.
minetorials798 months ago
how long does it take to charge an iphone
xyndaen9 months ago
simple but effective. anyway there may be some improvement. for example i advice germanyum diodes in this project cause of gaining the voltage when it is compared with silisium ones. the other thing i advice is using and capasitors zener diode 5v for the usb connector to stop voltage changes. 10nf is OK. 7805 is also good choice for this kind of circuits.
mshbi (author)  xyndaen9 months ago
Good ideas. Thanks
rmarc9 months ago
Then how does the altoids container shut?
mshbi (author)  rmarc9 months ago
Good question. I can't get it to shut all the way. I would recommend using a different container
jclaudiu9 months ago
is this working? do u have a video on that?
Lars2239 months ago
You wrote that you need a 4AA Batteryholder but I only see a 2AA one. Which one do I need?
mshbi (author)  Lars2239 months ago
Its is a 4AA battery holder. In the picture there are two more AA batteries under it

Get More Out of Instructables

Already have an Account?


PDF Downloads
As a Pro member, you will gain access to download any Instructable in the PDF format. You also have the ability to customize your PDF download.

Upgrade to Pro today!