Introduction: Simple, Cheap MP3 Player Solar Charger

Picture of Simple, Cheap MP3 Player Solar Charger

Make sure to check out my blog!

This is a really simple tutorial on how to make a solar charger for your MP3 player. This won't work with an iPod touch (The iPod ignores it, it's not an apple product), but should work with most generic players. I use it for my CreativeZen player.

I bought my solar cells HERE. It's the best prices I can find, plus free shipping!
This panel charges @
5.13 Volts
.8 amp to 1 amp; in full sun

Because MP3 players have built in battery savers, there is no need for an electronics board or battery sensor. It's physically impossible for the solar cells to spontaneously produce a higher voltage. If the voltage drops (for whatever reason) the MP3 player automatically disconnects the battery.

MP3 players automatically disconnect the battery before it overcharges
MP3 players will not discharge into the panels, they have built in diodes.

Putting it simply, the very worst that could happen is that it won't charge the player.
But I still have to say: do this project at your own risk :)

Step 1: What You Need

Picture of What You Need

1) 9 x 1 amp, .57 volt solar cells. I bought mine HERE
2) Tabbing wire or fine electronics wire. I bought mine HERE

3) 8 x 10 cheap plastic picture frame from Wall Mart
4) USB extender with female USB adapter. $1.00 at Dollar Tree.

Wood/foam core,Solder, flux pen/ normal flux, soldering iron, and soldering skills :)
I recommend you wear latex gloves when you work with solar cells. Fingerprints look bad...

Step 2: Solar Cells

Picture of Solar Cells

You'll notice these aren't the EXACT cells I used. I bought some larger cells from this same seller about week ago, for another project. I had a few of these large cells leftover, so I cut them down to the right size myself. The cells I used are the same size as the ones in the link, with the same specifications. The seller is a really nice guy, very trusted. I've never had a problem with my orders (I've made a few very happy purchases :) )

I recommend that you also buy 'tabbing wire' . Tabbing wire isn't totally necessary...regular wire works fine, but it's harder to use. Tabbing wire make soldering way faster and way easier!

Simple explanation:
The only unusual item you will need are solar cells. All solar cells put out .57 volts, no matter there size. The amperage is proportional to the size. Larger cells equal higher amperage. You are going to wire 9, 1 amp solar cells in series to produce 5.13 volts and 1 amp.

Complicated explanation, you don't have to understand all of this:
An electronic device will only take the amperage it needs. If the device needs 2 amps and it charges off 8 amps, it will only take 2 amps. You could charge 4, 2 amp devices off 8 amps.

For this project, you will need to make a panel (a bunch of cells) that puts out 5 v and 1 amp. Since each cell puts out .57 volts, you will need to wire 9 of them in series to reach 5.13 ( as exact as we can get to 5.00 volts). If you wire 9 cells in series, each large enough to produce 1 amp, you will get a panel that puts out 5.13 volts at 1 amp.

Got it? :)

Step 3: Soldering

Picture of Soldering

I'm not going to go into depth on how I solder, other than how my soldering iron is set up. There is a simple tutorial on how to solder solar cells here. If you're still having trouble, Google has the answers!

My soldering iron has a tinned tip. The solder sticks to the tip of the iron, so I have it when I need it. No fooling around with solder wire here!

I just touch the tip of my iron to the lightly fluxed panel and tabbing wire, and bam! Instant solder joint.
Oh, and I use regular flux. Don't use too much, a little goes a long way.

Solder the cells in series. That mean positive to negative, positive to negative, and so on. The top of the cell is the negative end, and the bottom is the positive end.
The second and third picture better explain this concept.

Step 4: Making the Frame

Picture of Making the Frame

After you solder together your cells, you need to protect them in a frame. You could build one out of wood, or you could modify a picture frame.

$2.00, 8x10 plastic frame with glass pane: Wall Mart
The following steps are in related to the pictures, in order:

-Remove the glass.
-Cut out the cross shapes structural support.
-File the inside corner, all the way around. You are trying to make a weak spot so you can break out the inside wall.
-Break out the inside wall. It is brittle plastic, it will break off in chips.
-The final image is what you should now have.

Step 5: Support Board

Picture of Support Board

You need to cut out a board that fits inside the frame, as if it was a photograph originally intended for the frame :). You are going to glue the assembled cells onto this.

I used wood, but foam core will work also.

Step 6: Gluing the Cells

Picture of Gluing the Cells

Use silicone caulk to glue the soldered cells onto the board you just cut. Solder the odd cell after you glue it all down.

Step 7: Leads

Picture of Leads

Drill 2 holes in the board, and solder the positive and negative lead to the cells. Feed the 2 wires through the two holes, and glue the board into the frame.

In order to better protect the wires, I put a bit of epoxy on them.

Step 8: USB

Picture of USB

Solder on the USB connector to the appropriate positive and negative wires. When you cut apart the USB, you will see 4 wires...you only need the red and the black wire. The red wire is positive, solder it to the wire coming from underneath a cell. Solder the black wire, the negative wire, to the wire coming from the top of a cell.

Glue the USB connector to the picture frame with epoxy. It needs to be a strong joint, or it'll get broken off. I put epoxy on the connections for further protection.

Step 9: Installing the Glass

Picture of Installing the Glass

Pop the glass back into the frame, and shine it up with a soft cloth. Clean glass means better light transmission, and that means more efficiency of the cells.

Only use this panel in full sun, do not allow a shadow to fall on any part of the cells. A shadow on a cell can cause reverse flowing current, and this could damage the cell. Also, a shadow will slow down the charge time and potentially cause the device to undock and stop charging.

This panel charges my CreativeZen player just as fast as the computer!

Comments

snotty (author)2010-05-01

Nice work!

Here's how you can make it work with an iPod:
Connect the two middle USB pins to about 3 volts. Do this by making a voltage divider. Make a voltage divider with two 100k ohm resistors (Brown - Black - Yellow). Connect one resistor to +5volts and the other end to the middle two USB pins. And connect the other resistor to minus, then connect the other end to those same two middle USB pins. Easy eh? Here's a diagram.

The Mr. Buzz USB charger uses this type of voltage divider as well as two 1uF ceramic capacitor somewhere in there but I have had some (limited) success without the capacitors.

Does anyone know if those capacitors really necessary?

Also some devices need a minimum rate of amperage in order to charge. What I did was trickle charge 4 AA NiMeHy batteries with a small 6v panel and a diode. Then I plug this into my iPod touch. The NiMeHy batteries provide the required amperage.



bobrigewitch (author)snotty2011-11-17

If you had enough current to supply 1A (1000mA), if you made a voltage divider to supply 3v to the green data wire and 2.2v to the white data wire. Which is:

150 ohms (brown green brown) from red (5v) to green
100 ohms (brown black brown) from green to black (0v)
220 ohms (red red brown) from red (5v) to white
270 ohms (red violet brown) from white to black (0v)

I needed to do this to get my homemade charger to charge my iPhone 4, iPod touch, and iPad 2. It charges just as fast as the apple charger, and I'm actually using it as I speak :) just be sure you can source 1A of current, and you'll be fine. I also used a switch, 5v regulator, and power indication LED in a metal zippo container.

PS any properly sized resistors would do. Ex 100 ohm and 150 ohm has the same effect as 10k ohm and 15k ohm or the same as 1M ohm and 1.5M ohm. The larger the resistor, the less wasted energy in the divider.

Todd Gehris (author)2011-09-24

As a precaution you could add a diode on the plus side of the panels to prevent a device's battery from discharging into the panels. It also would be safer to devices to have the power out of the panels regulated. It takes very few components to do that. If you really wanted to get fancy you could hook a few rechargeable AA batteries up to it as well to compensate for when the panel gets shaded.

songrotek (author)2010-11-23

It's really cool!

mariosk8s (author)2010-05-09

Cool instructable. I gave this a whirl this weekend: http://twitter.com/mariosk8s/statuses/13699610704 

nepheron (author)mariosk8s2010-05-10

 Twitter won't let me see the picture, I'd need an account. Could you post the pic here? 
Thanks!!!

churchman (author)nepheron2010-09-07

did you know that you can use a magnifying glass to upgrade power!
I did some tests if you don't use those cheepy once they won't burn when aplying a magnifyer if you hade a biger magnifying glass then it would give more power to!!

mariosk8s (author)nepheron2010-05-10

Can't seem to upload images. Posted it here:
www.schmut.com/pastebin/P1020506.JPG/view

nepheron (author)mariosk8s2010-05-10

 Wow! thats amazing! You did a great job. Where did you get your cells?
It's a really nice panel :D I love to see pictures of stuff people make :)

mariosk8s (author)nepheron2010-05-10

Thanks. Got the cells the same place you got yours. I just followed the link you placed. Worked out well.

nepheron (author)mariosk8s2010-05-10

 Twitter won't let me see the picture, I'd need an account. Could you post the pic here? 
Thanks!!!

drakesword (author)2010-04-30

I <3 my creative zen.

You should be able to substitute the cells you bought with ones salvaged from solar garden lights. I'm pretty sure you can cut most of the resin down to make them smaller. 3.0v @ 50ma each.

Make strings of 5 in series to get 15v then as many as you want in parallel to get the current you want. With a few of voltage regulators and diodes you can charge 12v 9v 5v and 1.5v

Once my collection is large enough I plan on doing that. If there is no instructable I will post one.

Cheers

nepheron (author)drakesword2010-05-01

 I've made a solar panel from garden lights I found at a yard sale. It charges at about 6 volts and fairly low amperage...takes awhile to charge the player, but it does work!!

drakesword (author)nepheron2010-05-01

fortunetly with my line of work I run into them all the time. If you hook the solar cells (a current source) and series it will produce more voltage. If you hook them up in parallel it will produce more current. What I was saying is if you can get a lot of them.  5 in series to produce ~15v @ 50ma in parallel with more identical strings. So 1 string would be 15v @ 50ma, 2 15v @ 100ma, ... 10 15v @ 500 ma which is what a standard usb port will output (unless the device requests more in which 750ma)

nanosec12 (author)2010-04-30

Nicely written 'ible, but I do have one comment:

I appreciate the fact that you sourced your suppliers and included links, but was it really necessary to link them several times each throughout the steps?  It seemed to me that you were almost at the level of getting paid to link them, with the number of times that you did.

Other than that, nice Instructible

nepheron (author)nanosec122010-05-01

 Oh LOL I see what you mean, about there being too many links. I inserted a step after i was was finished, and accidentally left the repeated information...thanks for catching that :D

Barcode80 (author)2010-04-30

FYI, if you search for some 'ibles about building homemade chargers, you'll find the simple info to have the ipod touch work too. It's something to do with making the voltage divider if I remember correct. Nice work!

KT Gadget (author)2010-04-30

One possibility why the Ipods are not charging is because they do not have a built in voltage divider which tells the ipod when it is "charging" and "full." Most older ipods used to have the built in divider because I had the first generation nano (or it could have been my Ipod mini back in the day) and it used to charge, on DIY battery chargers I made, without it. With my 3rd gen, however, it does not see that its being charged and hence does not show the indicator for it.

I just researched about the divider so I assume the older Ipods had them built in and I have not tried it myself due to school and other projects I'm working on, but when I have the time I will try it out myself.

Great instructable btw, those solar sells would be a good investment on a battery- free amplifier.

nepheron (author)KT Gadget2010-04-30

 A battery free amplifier is something I've been thinking about! I have a little ipod speaker I got from Goodwill, so I may make the modification!

Nerdz (author)2010-04-29

Cant seem to reply to myself, but nice job :D

Nerdz (author)2010-04-29

look on ebay for solar cells, theres a ton there.

About This Instructable

25,140views

48favorites

License:

Bio: Travelling since 2013. I'm currently in Australia for some reason. --- I’m Calvin Drews, and I love to learn, experiment, invent, create, repair, and ... More »
More by nepheron:DIY Michigan Shaped Cutting Board (video)DIY Wood Knife SheathDIY Camera Boom (Video)
Add instructable to: