Solar Powered Speaker

Want to learn to create a fully solar powered speaker? Then this Instructable is for you. If you like what you see feel free to vote for this project for the Audio contest. Thank you!

Step 1: Select Your Speakers!

Find some speakers or order some to work with. This system utilizes a subwoofer (Teac), 4 midranges (Boston Acoustics), and 2 tweeters (Boston Acoustics). All were sourced from garage sales for about 20 bucks total and originally came from higher end desktop computer sound systems that were broken.

Step 2: Design an Enclosure

Next you will want to design an enclosure for the speakers. This will of course have to accommodate your solar panel and electronics as well which will be covered in the next steps. Use MDF as it is cheap and performs well for acoustic applications. In this design, the electronics were compartmentalized from the acoustic chamber. Another consideration is box volume for the speakers. For my project I simply added the volume of the individual donor speakers and placed the separating panel accordingly. For even better results, you may wish to separate the subwoofer from the mids and tweeters.

Step 3: Create Your Solar Panel

Choose the solar cells you would like to use for the project based upon a couple of considerations:

1) Try to aim for an 18 volt panel to supply to a 12 volt battery

2) Attempt to make a panel that will supply a reasonable amount of amps to keep you speaker running continuously. The panel used in this project is able to provide about half of the max amperage that the amplifier can draw. This is acceptable as the draw of an amplifier is far from constant and will often only be a fraction of its highest draw in any song. In testing, the speaker was able to run continuously for 9 hours on a sunny day and remain charged the whole time (starting from a lightly charged battery).

Once you have chosen the cells, you will need to solder them together and encapsulate the cells. In this Instructable I used EVA film, a relatively easy to use material. To make the panel follow these steps:

1) Apply flux to a cell and slide a soldering iron across the cell with a piece of tabbing wire. Once cooled be sure to check that a strong bond has been made. This takes much practice to get right. By file a flat spot in the tip of your soldering iron you can make this process easier. I used a 30 Watt Harbor Freight Iron and found it to provide a perfect amount of heat for the job.

2) Flip the cells over and solder them to each other in lines. Be sure to keep in mind that you are creating a circuit. It usually takes 36 cells to get an 18 volt panel, you will want to wire them in series to achieve this.

3) Solder the lines together at the ends.

4) Prepare a piece of glass (in this specific project, I applied the cells directly to the top of the speaker, however, if a mistake were to be made it would be better to have the cells on glass for easy removal).

5) lay down a piece of EVA film larger than the glass by a few inches on each side.

6) Place your cells over top of the glass

7) Place another sheet of EVA film on top.

8) Use packing tape and a spare piece of wood or MDF to tape the glass, EVA film, and cells to. Leave a spot for a vacuum hose.

9) Use your household vacuum cleaner to pull a vacuum on the cells.

10) Use a heat gun to permanently seal the EVA film to the cells. Heat until they are clear.

Step 4: Electronics Design and Testing

Design an access panel to mount boards on. See the labelled picture for what to include. You will want to do some research on what amplifier will properly power your speakers. Not pictured is the ac to dc inverter (originally I placed it inside the access panel, I have now taken it out as it was back feeding from the battery). The labelled picture is not wired to make it easier to view. Now is a good time to test out your system as a whole and make sure it works properly. For this project I used a 12 volt 5 amp hour battery which gives the system very a long battery life. You will need to calculate the proper size of the battery for the size of your speakers and amplifier.

Step 5: Finish Line!

Mount your electronics panel and speakers. Be sure to design some sort of top cover that rests above the EVA encapsulated cells (not on). I made a simple plexiglass cover for this. You will also want to add a speaker grille to protect your hard work. I used some left over wood scraps to fit a grille into the recess on the front panel. Thank you for reading and feel free to ask any specific questions about the project!

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    10 Discussions

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    Keegster

    5 weeks ago on Introduction

    Wicked cool, I’ve been doing a lot with building speakers and this is one of the coolest designs, quick question, is it Bluetooth or aux and how many watts is the amp what kind of current from a 12v battery does it draw?

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    kpotier16Keegster

    Reply 5 weeks ago

    It is currently just aux, though it would be fairly simple to add a small Bluetooth module inside and connect it to the battery. Personally, I like the sound quality of an aux vs. the convenience of Bluetooth but really depends on your need to use the phone while playing music. As for the amp, it was purchased from eBay and is 100 watts total 2.1 channel, I keep the volume on it down so I can max it on my phone without blowing the speakers. As per the current draw, it really depends on how loud you like your music. Using your standard I=P/V you would likely draw less than 1 amp average even at significant volume. Your mileage will vary based on the sensitivity of your speakers, resistance of wires, etc. If you are worried about draining the battery completely you can always add a shutoff board to protect it. Hope this helps!

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    MarioL111

    7 weeks ago

    Excellent use of old computer speakers. I don't think it has the power to make a sub enclosure necessary. I would probably shield the electronics from the drivers (or vice-versa) with an aluminum plate, a common thing to see inside the sub cabinet in an X.1 system. And while we're at it, snatch a couple of used computer case fans to keep the electronics cool. Run at a low voltage to minimize noise. I use 12 volt e-mac fans running at 7 volts.

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    Tura Street

    7 weeks ago

    Great idea. I love it. Now if we go somewhere or to the beach or something, I can make this and bring it with me. Thanks so much for sharing.

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    Gadisha

    8 weeks ago

    Nice project, I'd like to learn more about solar powered device.

    2 replies
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    kpotier16Gadisha

    Reply 8 weeks ago

    Let me know if you have any questions, I may be able to help

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    DIY Hacks and How Tos

    2 months ago

    Awesome. This would be a great way to get music to remote places without easy access to an outlet.