Simple Solar Powered USB Charger and Speakers




Before making this, I figured out what people (9+ years) use a lot nowadays and I came up with: cell phones and mp3 players.
A lot of people waste energy using these two items by buying the speaker systems for their mp3 players and charger their phones. Both uses usually end up with leaving the charger or system plugged into the wall, which is a big big waste of electricity.

So I developed a simple, green and cheap solution that everyone can do. This whole instructable can be made with recycled materials around the house, as long as you keep broken stuff like I do. If you don't that's totally okay, but you will have to order/go out to buy a few things.

Depending on your experience, it should take about 1.5hours for full assembly.

*Please read*
The black charger below is one that I made for me. I like the color black and I designed it based on what I like. I think that it's better to design something that you like and that you can put in you're own creative input into. So, I'm going to show you the basics on how to build one and I'm going to leave it up to you on how it looks. Have fun with it.
By following this instructable step by step you will have charger that looks like the white one pictured below

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Step 1: Tools and Materials

Soldering Iron
Electrical Tape
Wire cutter/stripper
Multimeter (not shown)
Crazy Glue (not shown)

5 Volt Regulator
4 AA Rechargeable batteries
4 AA battery pack holder
1 An iPod box
1 Speaker (not too big, it needs to fit in the box along with other materials)
2 Solar powered outside lights
1 USB plug (female)
1 set of old head phones

You can buy these all brand new if you'd like. I used all recycled materials for the black one pictured on the intro page. This white one is almost all recycled except for the USB cord.

If you'd like to find these parts around the house here are some places to look:

An iPod box - this doesn't need to be an iPod box, it could be anything you want, as long as everything fits. Have fun with this, it's for you so make the box something you like.

Volt Regulator - I found mine in a broken laptop. Most electronics have volt regulators, you can see what kind of regular it is by typing the number on it and google searching it. It does take time to find, if patience isn't your thing, you can probably pick one up at Radioshack for $2.

AA Rechargeable batteries/Solar powered outside lights - These were gotten together and considered recycled because they were broken (not the solar cell, but the light were broken from their base)

AA battery pack holder - These are found in a lot of toys. Mine was taken from a remote controlled car.

Speaker - I got mine out of a broken printer. You can also use the ones from those singing cards or a broken laptop.

USB plug (female) - this is really hard to find, but they can be found an pulled out of laptops.

head phones - I used a set of headphones that busted on one side.

Step 2: Soldering Info

This is a video I found on youtube, just in case you're unsure of how to solder.
If you know how to solder, skip this step and carry on.

Step 3: Speaker Setup

Take the headphones and cut of the ear buds.
Strip about 1inch of the headphones so that you can see the wires.

You're going to see that the wires are intertwined with some fiber.
(see second image below)

Use your soldering iron to melt the fiber
If you don't do this the speakers will not work!

My speaker doesn't have anywires, if your does that's fine leave them on (it'll be easier to check if the speaker it working).

Plug the headphones into your iPod or mp3. Place one headphone wire to each wire/prog on your speaker and make sure that everything is working okay. If you have wires on your speaker, twist the speaker and headphone wires together. Do this for bothsides.
Once you check that everything's working, solder the wires together; this will help connect the headphones to the speaker and prevent them from separating during travel.

Use the electrical tape to cover up the each of the exposed wires.

Now the speaker part is complete.

Step 4: Solar Panel/battery Assembly

Use the screwdriver to take the outside lights apart.
Cut out the solar panels; make sure keep the wires to the panels. You also want the wires to be as long as possible.

Strip off about 1inch of each of the wires (all four) and twist the positive wire (white or red) of one panel to the negative wire (black) together. Solder them together, this helps to keep the connection between the wires. If you have confidence in your soldering abilities and are sure that the wires are not bad, you can tape them up as seen in the second image below.

Strip off about 1inch of the both wires from the battery pack. Twist together the positive wire of the SOLAR PANEL and the negative end of the BATTERY PACK. Solder them together. Once again, if you're confident in your soldering abilities and are sure that the wires are not bad, you can tape them up as seen in the third image below.

Place this aside, it will be used again soon.

Step 5: USB Cord

Okay, the USB cord/piece is the most important part.

If you only have the single piece found in laptops:
I apologize for not having any images so I will explain as best as possible.
Place the piece so the prongs are on the left and the opening is on the right.
The prong that is furthest away from you is the positive prong and the prong closest to you is the negative one. The two prongs in between are for data and are not going to be used.
*You might want to consider soldering on some wires; it will make the next step easier for you*

If you have a cord:
- Cut the wire leaving yourself about three inches.
- Strip about 1.5inches of the outerwire covering to expose the smaller wires.
You will find multiple wires inside; only two are important: the black and the red. See image below.
You can cut the other wires if you'd like.
- Strip an inch off the black and red wire.
These wires are small and stripping them is hard, but that's why I said to leave three inches when you initially cut the wire. There's always some room for error. :-)

Step 6: Wiring It All Together

You will see in the pictures that I taped up some wires. Do not do this yet. You have to make sure that you have the correct voltage running through the circuit first.

Turn the 5V regulator upside down and bend the side prongs out slightly (you can see how much in the image below). Be careful when you do this, if you bend them too much or bend them back and forth too much you will break the prongs and have to go get a new one.

I think the best way to solder the wires on is by getting solder on the 5V regulator and the wire separately and then melting the solder on both together.

The first thing that needs to be soldered on is the positive wire from the battery to the "in" prong on the regulator. (See first image below)

Next solder the positive wire to the remaining outer prong (the "out" prong).
Solder the negative wire to the middle prong of the 5V regulator.
(See second image)

Finally, solder the negative wire from the solar panels to the middle prong of the 5V regulator.
(See third image)
Adding this wire to the middle prong completes the circuit and now as long as the next step runs smoothly all the electrical stuff it done. :-)

Step 7: Checking the Voltage

If you don't know how to use a multimeter, here is a link to a video that can show you how.

Here are important spots to check:
- Across the USB cord (this should read 5V) <-this is the most important one
- Across the batteries (this should read about 6V, it may read more, it's okay, that's what the volt regulator is for)
- Across the solar panels.

If no voltage is detected:
- A wire might be bad, move it around if voltage shows up for a second then goes away, it's a bad wire and you'll need to replace it by taking out the old one and soldering a new one.
- A connection may have come lose.

After you make sure that the voltage across the USB cord is 5V, you can now tape up any exposed wires.
- The solar panel to solar panel connection
- The solar panel to battery connection
- Each prong on the regulator

Also, I think it's beneficial to tape the solar panels as seen in the image below.

Step 8: Box Assembly

The last step, yay!!!

Start with tracing a hole in the box for your speaker. Don't trace the speaker, you need the hole smaller than the speaker so that you can glue and tape it in.

Cut out the hole. Make a ring around the speaker with crazy glue and glue it as centered as possible on the hole. Apply pressure for about 30sec then tape the outside of the speaker to the box for extra support.

Next, cut a slit in the box as seen in the third picture. This slit made so you can place the solar panels on the outside of the box and slide the wires through the slit so that they can be on the inside.
Once the wires are in tape the slit shut and glue/tape the batteries down. (See image four)
Glue and tape the panels down to the front of the box.

Plug in your mp3 player all in and you're ready to go!!!
(see image 5)

Two things you should know:
- You can use this to charge your cell phone too!
- Some iPods don't show that they're charging like you'd normally see it when it's plugged into a regular charger. Don't worry, as long as the voltage is consistently 5V, it should be charging. Some iPods will have their backlight turn on when it is unplugged from the charger and some will charge normally. iPods are really stubborn.

Enjoy! I really hope you can make yours completely with recycled parts and that you get creative with the box. It's always 100% better if it, in a way, represents who you are and what you like.


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    23 Discussions

    i love the project!! i really want to create one.. can i have the circuit diagram for that project? i really really love the concept..


    8 years ago on Step 5

    the best wire strippers I've used is a good pair of finger nail clippers. In my tool box i have snap on pair a craftsman and a generic set of wire strippers but for small electronic/electrical wires finger nail clippers work the best


    9 years ago on Step 4

    each of my solar panels has 3 wires due to a light sensor on top, how do I know which two are the electrical wires?

    1 reply

    10 years ago on Introduction

    The problem with this design is that it is not compatible at all. If you think about it you are charging the battery, not running the phone or iPod of the solar panels. The only thing you would be able to charge is a larger model iPod like the 5G video or the Classic. Phone-wise the battery on a usual phone is only about 3.7 volts to 4 volts. when you are sending in 5 volts into the battery you are running the high risk of damaging your battery. A solution to fix this is to get rid of the voltage regultor and put in a potentiometer with a volt meter in order to get a safe voltage for the device. Also have the amperage at around 400-800 ma. This may charge a bit slower but it keeps your device safe.

    *** Speakers are a smart idea but you need to have better speakers other than headphone speakers and have an amplifier to increase the volume.

    10 replies

    Reply 10 years ago on Introduction

    I believe the point of the batteries would be in case the voltage from the Solar panels drops below around 6V. In this case without the batteries the volt regulator would stop working properly, however with the batteries the volt regulator can still work, and hence the iPod can still be charged. Also you can buy USB phone chargers which makes your voltage point a moot one, as if they run off the standard power supplied by a computer's USB (5V) then they clearly change the voltage supply before allowing it into the battery, otherwise there would be a lot more angry people out there!


    Reply 9 years ago on Introduction

     False, it sends 5v, batteries need more voltage than they put out to charge, also the charging circuits are designed to take (usually) a decent amount over what is rated as a "just in case". If the phone charges from a usb port, it can take up to at least 5.5 volts no problem, the phone regulates the incoming current, the computer can't control the outgoing volts (it can't even keep it's own voltages in its rated range, so thusly 5 volts goes from 4.5-5.5volts without problems).


    Reply 10 years ago on Introduction

    a USB port from a computer delivers 5volts and a maximum of 500ma. The iPod nano charges directly from a usb port to the device so i assume it uses 5volts and a max of 500ma :)


    Reply 10 years ago on Introduction

    i was not commenting about the charging capacity of the iPod but of cellular phones.


    Reply 10 years ago on Introduction

    I've been researching building something like this. Most iPod models have 3.7 volt batteries, rated from 300 mA/h (for the nano) to 800 mA/h (for the Touch). Ironically enough, cell phone batteries, or at least my very basic Motorola model, are also 3.7 volts! I imagine most iPod chargers tone down the 12V from the outlet to the voltage required, probably via a regulator, but I have never personally dissected one. After looking at this I-ble and many similar devices, however, my advice is don't worry too much about getting the exact voltage rating, since Solar panels tend to pump out a little less than they are rated for. If it were any more efficient, the world and its atmosphere would be a cleaner place... This is all speaking as an EE n00b, so please please correct me if I'm wrong! I like Rali929's comment about adding a pot. instead of a regulator, Much more versatile! Happy wiring!


    Reply 10 years ago on Introduction

    Well thanks, but I have actually bought some solar cells from Radio Shack that actually go beyond what they are rated. I have some solar cells that should be producing 1.5v at around 300 mah but produce 1.8 -1.9v at 450 mah.


    Reply 10 years ago on Introduction

    Crazy! Woot for efficiency! I should look into those when I make my device. Thanks!


    Reply 10 years ago on Introduction

    But thats in full direct sun... plus I live in California, so I guess it will adjust accordingly.


    Reply 10 years ago on Introduction

    or... you could look on the back of the nano or on the web and find the battery rating.


    9 years ago on Introduction

    Do you know the voltage of the solar cells combined?


    10 years ago on Introduction

    Won't the audio quality be quite poor due to the fact that you are running a Stereo output, from the iPod, into a Single speaker? Also what power ratings are the speakers you've used in the black model?


    10 years ago on Introduction

    Well it would probably be better to connect the batteries in parallel to the solar cells in order to charge the batteries faster. Usually those solar powered lanterns have low amperage and this would increase the amperage. Not much but some what... Overall you should probably use different solar cells if you amp this project up.


    10 years ago on Step 6

    I think you forgot to mention that the positive lead from the solar panels should connect to the negative lead from the batteries


    10 years ago on Introduction

    Hey guys.. I was looking at a similar tutorial onlines. I found some great voltage regulators here: . They give out free samples of the 5V 0.5 amp.. that's what you want