How to Make a Solar Cell Phone Charger





Introduction: How to Make a Solar Cell Phone Charger

If you think this instructable is worthy, please give me a vote in the "Apocalypse Preparedness", "Guerilla Design", and "Make Energy" contests!

In an emergency situation knowledge is power. If the SHTF and the world goes to chaos, you will want to have your hands on as much information as you can get. Of course you can prepare yourself by entrenching yourself in obtaining doomsday prep info, but no one really knows what information they might need. Anything can happen. To better prepare yourself it would be wise to pack a library of the best books on emergency prep. No, I don't mean an actual library; you need to pack light. Instead of packing away heavy books, you should bring a cell phone or tablet with a collection of E-books. What, no electricity? No problem, here you will find everything you need to build your own portable solar cell phone charger. Similar solar packs sell for over $100 (check out the Solarmonkey), but why buy it when you can build it for a whole lot less?

Solar charging packs can be used for any off grid situation, and not just in emergencies. Hiking, backpacking, and camping are all activities where this device can come in handy. It is easily implemented for entertainment purposes; however recent history has shown the importance of having such a device. Whether you want to play candy crush at the campout, are trying to stay in touch with family and friends after a natural disaster, or tweeting enemy activity, everyone has need for such a device. If you have a cell phone, then this is for you. So grab your soldering iron and let's get started.

Step 1: Parts and Tools



Step 2: Build the Charger

The portable battery pack should have two ports, an in and an out port. The cable that plugs into the in port should have a standard USB end. Cut this end and strip the exposed wires. You really only need two of them so if you are seeing four wires you will need to locate the + and Ground wires. Mine was easy because it only had two wires (pink and white). Pink and white are odd colors, you will generally see black ( negative, ground, -), and red (positive, +). If you're like me and have two wires that aren't common colors you will need to identify them. I did this with an LED, but a voltmeter can be used if you have one.

Testing with an LED: the long lead on an LED connects to positive and the short leg connects to negative. Take the USB you have just cut, expose the two wires, and plug it into a wall charger. Take your LED and give it a go. Touch the long leg to the colorful wire (pink in my case, but typically this is red), and the short one to the other (white in my case, typically black). If your LED lights up you have identified your wires, long is positive, and short is negative. If it doesn't light up then reverse it.

Now that you have your positive and negative wires you will need to solder them to the back of your solar cell. There should be two pads identified +, and -. Solder the positive wire to +, and the negative wire to -. The solar cell should now be equipped with a micro USB charging cable. Now is a good time to test out the charger. Plug the solar cell into the portable battery pack, and with a spare USB charging cable plug in your electrical device. If everything is connected properly your charging light should be coming on. If you're still not convinced, run your battery pack dead by charging your device without the solar cell. Once it's dead, try it with the solar cell. The solar panel should charge the battery pack, and the battery pack should charge your electronic device.

Step 3: Make the Charger Pack

I wanted to be able to charge my phone while I was on the move so I made a custom pack to hang from my backpack, similar to the solarmonkey. I used an old lunch box my son doesn't use anymore. It was just lying around collecting dust so I repurposed it for this project.

Whatever you use you will probably want a way to attach your solar panel and battery pack. For this I used sticky back velcro and it worked great. The lunchbox I used has a compartment for an ice pack, convenient for storing a cell phone in this case. I just cut a small hole for the USB cable to connect my cell phone to the battery pack. I can keep this pouch zipped up with my cell phone safely inside while the pack is open and charging.

Step 4: Prepare Your Device

You'll need an E-Reader App for all your books. The Kindle App is free for download, and can handle all your .mobi ebooks. For other versions other than .mobi, I like to use Google Play Books because it supports so many formats.

Step 5: Recommended Books

3 People Made This Project!


  • Oil Contest

    Oil Contest
  • Creative Misuse Contest

    Creative Misuse Contest
  • Water Contest

    Water Contest

18 Discussions

Hello I have a question please: I only have access to 5v 220mA cells can I wire them in series? appreciate your feedback and thanks a lot

Hello I have a question please: I only have access to 5v 220mA cells can I wire them in series? appreciate your feedback and thanks a lot

You'll need a larger solar panel with a higher voltage. Typically those types of Power Banks need 4.5V - 5.5V of input to charge. Granted, you are using a 5V solar panel, HOWEVER, you almost never get the rated output of a solar panel except under super ideal conditions. The typical rule in solar is that you want 1.5X the amount of voltage that you actually need. So in this case you'd want something around 7-8V. Though the flip side is that you can blow out the electronics on the charge controller inside your Power Bank if you throw too much voltage at it.

What I've seen people do is use a 9V solar panel at 500mA (so a 4.5W panel) and then throw a 5V regulator into the mix. This kind of fixes a lot of problem and allows you to charge under less than ideal conditions as well.

2 replies

saw your altoids tin charger a while back and had trouble with the USB female jack, as in pos neg location

It charges my phone pretty quick. My goal here was to make a simple design that is actually quite functional (and it is) without over complicating things.

I like the fact that you have links to all the parts for us non tech savy ppl helps out a lot waiting on my parts now

1 reply

I figure it helps to show people exactly what I'm talking about rather then just making a list and hoping everyone understands.

I MADE IT! I'm still putting together a case for it. But this worked like a charm! Thanks for the instructable!

1 reply

For those of you who cut the USB cable and find 4 wires, you want the RED (+) and the BLACK (-). The other two will be unnecessary for this project.

Thanks for this instructable, is excellent...

I am not a tech savy individual. I am not following the last part regarding having the cell phone in the other pocket and threading the wires through to the phone. I I see and understand the where and how of the solar panel. I also am not getting where the charger is secured in the pack. Can you clarify or add one more picture ? Thanks

2 replies

The Cell Phone being in the bottom pocket of my pack isn't crucial to the instructable. I was just commenting on my own setup. The charger is secured in the pack with sticky velcro. I'll post a few more pictures to clarify a little.

Very useful! I love the originality. If we did have an apocalypse, we'd definately need this!

Yes. Just know that the battery pack puts out 5V, so as long as your device receives 5V (most do) this should work for you.