The purpose of this project is to make a solar charger for any phone or any device that supports USB charging The charger is fully dependable on solar energy as the only power source. The main objective is to create it using affordable materials and make to whole process easy enough to understand and reproduce for other people around the world.
Step 1: What You Need
Black (negative) and Red (positive) wires
4 “AA” Battery Holder (RadioShack) $3
4 AA Batteries
PARALLAX Solar Panel 6V@1W,125x63mm (eBay from China) - $13
PLA Filament for 3D Printer (optional)
Altoid Tin (optional)
3D Printer (optional)
There are two version that you can make depending on wether you own a 3D home printer such as Maker Bot. If you do, you can either download my design and print it or design you own. If you don't have 3D printer and want to go more low-budget, you can use Altoid Tin or anything else as the main structure for this charger.
Step 2: Wire Terminal
Wire terminal is basically the brain of this charger. It is necessary to bring energy from the sun to the batteries and then from batteries to the actual device. The wire terminal can be easily purchased either in Radio Shack or anywhere else online. I have personally used one from IKEA SUNNAN LED table lamp because of the reverse-engineering process. After you get your wire terminal, you have to solder and connect the wires to solar-input, battery-input and energy-output as indicated on a chart above.
Step 3: Pick the Right Batteries
We will need some rechargeable batteries that are reliable and can provide enough current to charge a phone. I have decided to use Dantona "AA" 1.2V/1000mAh Ni-Cd Batteries, which provide enough current and are also very cheap and reliable and you can get them in any Radio Shack store.
Step 4: Pick the Right Solar Panel
The choosing of the right solar panel is the similar process as picking the batteries. We need to make sure that the solar panel will provide the batteries with enough power and also enough voltage. The minimum voltage should be 5 Volts but I have decided to go with 6V Solar Cell because of the diode and the switch, which can consume some volts too. I bought one on eBay for about $13 PARALLAX Solar Panel 6V. It is also important to pick a prefect measurement for the tin or your own design so it fits perfectly.
Step 5: Connecting Everything Together
Now we will need to connect everything to the terminal to create a circuit. First, let's start with the bottom, which will connect to the solar panel. Than we can work our way up and connect the wires to the battery holder. And then lastly, connect the top to the usb cord or a usb port that you can purchase in Radio Shack also.
I have decided to use a USB cord that I had in my disposal and just connected the wires together. By connected I meant either solder everything together, which will hold everything much tighter and safer or you can just use non-conductive tape, which should aslo work fine.
Step 6: Testing the Prototype
The next step will require little patience but don't worry. It will pay-off. Since we already connected all major parts together, we need to test if everything works. Put the solar panel on the windows for a while (three or four hours) and just leave it charge. After you come back, it's time to cross your fingers and connect usb charger to the usb cord and hope that everything will charge. It did? Awesome!
If you had any problems, just check if all the wires all properly connected and also if the device doesn't require more volts than you can provide. You should measure it with the Voltmetr if you have any issues and then check if the device doesn't require more. But it really shouldn't.
Step 7: Create a Structure
Now, it is important to create something to cover the wire terminal with. I have decided to go with the harder, more expensive way but it is also very efficient and can be easily personalized. I have decided to go this way because I wanted my iPhone 5 to charge on the back of the cover. If anyone is interested in my design and can 3D print, you can download it here. I used Google Sketchup to design it and I can highly recommend it to anyone who is interested in creating his own. It's a great program and it's avalaible for free!
Also, if you want to go with the cheaper way, you can just buy an Altoid Tin and put verything inside. It's your choice.
Step 8: Put Everything Together
Now, It's time to add everything together and seal the deal. Put the wire terminal inside of the structure, cover it with the top and finally connect the solar panel again. After that, I used super glue to make everything hold better.
Step 9: Charge Your Phone!
If you follow the instructions closely, you should be able to charge your phone right now without any issues. Thank you for following my tutorial and hopefully you enjoyed it!