Need to charge your phone? Have nothing but a clothespin and some P-N junctions? Have no fear! The (solar) power is in your hands!
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Signing UpStep 1: The Big Idea
So, what's the plan, stan?
Well, we're going to make a solar panel from scratch that can charge up a simple phone.
See, cheap phones like mine are real simple to charge--they just need 5V and they'll take care of the rest. They'll draw as much power as they can (my little nokia will draw up to an amp while charging), but they're smart enough to limit their current draw to whatever the source can provide.
So, that means we need to make a 5V solar panel. Solar panels are made by wiring up a set of solar cells--big silicon P-N junctions. A solar cell puts out a very low voltage--0.65V open-circuit, or around .55V under an ideal load. To get the 5V that we need to charge a phone, we have to wire up a bunch of solar cells in series.
But how many solar cells? Well, a solar cell without anything connected to it will produce .65V in bright sunlight, but as I draw power from the cell, the voltage will drop. This relationship is called an I-V curve. The max current the cell can output is based on the area of the cell, the intensity of the sunlight and the temperature of the cell, but the max voltage is always the same, regardless of the size of the cell.
Every solar cell has a peak power point, a current-voltage combination that gives me the most possible power for that cell. For my panel, I want to run my cells at their peak power point. I happen to know that the peak power point of my cells is .5V at 130mA. So, if I want to put out 5V, I need to stack up at ten solar cells in series, giving me an output of 5V. If I'm drawing less than 130mA, my output voltage will "float" up, and if I draw more, my voltage will get pulled down. Now, it so happens that phones are pretty smart and robust, so I can actually give them a bit more than 5V, and they'll be fine. I'm actually going to add an extra cell, giving me a total of 5.5V coming off my cell. This makes my panel a little more robust--the higher voltage means that, in lower light, it'll still put out enough voltage to charge up my phone, and it'll be less sensitive to shading or pointing it away from the sun.
So, I'm going to make a solar panel with eleven solar cells in series, I'm going to wire the output into a phone, and it's going to charge. Cool, right? It's pretty quick and easy to do, too. Here's a video of the whole process:
Well, we're going to make a solar panel from scratch that can charge up a simple phone.
See, cheap phones like mine are real simple to charge--they just need 5V and they'll take care of the rest. They'll draw as much power as they can (my little nokia will draw up to an amp while charging), but they're smart enough to limit their current draw to whatever the source can provide.
So, that means we need to make a 5V solar panel. Solar panels are made by wiring up a set of solar cells--big silicon P-N junctions. A solar cell puts out a very low voltage--0.65V open-circuit, or around .55V under an ideal load. To get the 5V that we need to charge a phone, we have to wire up a bunch of solar cells in series.
But how many solar cells? Well, a solar cell without anything connected to it will produce .65V in bright sunlight, but as I draw power from the cell, the voltage will drop. This relationship is called an I-V curve. The max current the cell can output is based on the area of the cell, the intensity of the sunlight and the temperature of the cell, but the max voltage is always the same, regardless of the size of the cell.
Every solar cell has a peak power point, a current-voltage combination that gives me the most possible power for that cell. For my panel, I want to run my cells at their peak power point. I happen to know that the peak power point of my cells is .5V at 130mA. So, if I want to put out 5V, I need to stack up at ten solar cells in series, giving me an output of 5V. If I'm drawing less than 130mA, my output voltage will "float" up, and if I draw more, my voltage will get pulled down. Now, it so happens that phones are pretty smart and robust, so I can actually give them a bit more than 5V, and they'll be fine. I'm actually going to add an extra cell, giving me a total of 5.5V coming off my cell. This makes my panel a little more robust--the higher voltage means that, in lower light, it'll still put out enough voltage to charge up my phone, and it'll be less sensitive to shading or pointing it away from the sun.
So, I'm going to make a solar panel with eleven solar cells in series, I'm going to wire the output into a phone, and it's going to charge. Cool, right? It's pretty quick and easy to do, too. Here's a video of the whole process:
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It's the same video, but with creative commons music. Another guy, also from germany, had the same problem. I learned my lesson--all movies I put up from now on will have cc soundtracks.
--me
Thanks.
"...or stay tuned for a DIY solar kit kickstarter my friend and I are launching soon"
when???????????
Kickstarter kit is coming August 15.
Where can I buy them here? I'm in Bohol but I'm willing to get to Cebu or Manila to buy a bunch of these and make with my friends and family here. What Filipino doesn't use these Nokia phones? lol
Salamat!
We're running a kickstarter right now, and kits of solettes are one of the rewards. Check it out at http://www.kickstarter.com/projects/alex9000/the-solar-pocket-factory-an-invention-adventure.
Salamat naman!
Thanks
I also read in the newspape that there there is a T-shirt what has a special procedure and it also work as a charger when you wear it. A wire from the T-shirt to your cellphone and your CP will be charged via your t-shirt.
Amazing.
Please does anyone know wher to buy these wafers ? - I just can't find an outlet on the net.
Thank you.
I look forward to the kit.
You can get the solettes from various guys on ebay, taobao, aliexpress, or anywhere else you search for "solar cell piece"
This project won't "break" your IPhone as the iphone will simply say charging device not recognised. this project currently won't work for newer iDevices as they require a special circuit.
To quote Chunkyhampton
"Actually, charging Apple's devices is a little more complex than just supplying 5V on the USB port. You must also tell the device how much current to draw. This is done by supply a potential to the D+ and D- lines, using a couple of resistors.
This was reverse engineered by and is explained in detail by Lady Ada here:
http://www.ladyada.net/make/mintyboost/icharge.html
and also a bit on my attempts at doing it here:
http://www.re-innovation.co.uk/joomla15/index.php?option=com_content&view=article&id=167:voltage-regulators-a-go-go&catid=48:blog&Itemid=75"
So yeah hope this helped
dealsbookie.com, ebay.in also one of the sites where you can get solar cells
6v 100ma, 6v 200ma, 7v 100ma, 3v 100ma
resin laminated, cabinet, small kit, soldered with clip all available at just 4-6$
can charge mobile phone by that, even can charge AA AAA batteries, can make solar lantern's and all
I started experimenting with making my own small solar panels after I was dissatisfied with the existing resin-laminated panels--I was finding panels with shorted solettes, putting out a lower voltage than I needed, the resin would yellow in the sun after a couple years, making the whole panel unuseable, and after looking into how the panels are made, I started wondering if there could be a better way to make them.
Now, I'm not claiming that this instructable is a better way to make solar panels. There are plenty of flaws with the fanned design I used here. But it's just cool to make your own solar panel from scratch, and I put this instructable up to share that coolness. Because making something yourself is always more interesting than buying it.
i wish to say, resource and knowledge availability is very important, which always vary from country to country..
think about the country which are growing, knowledge they have towards solar
even now, millions of people seeing solar only in books, they think its complicate, unreachable, misunderstanding concept. because of above.
and all of sudden, u can except all to do as u said, level of knowledge, understanding capability and resource and patience and support all these must required to do it.
i suggest to buy resin, cabinet at 1st, test it, be practice, become friendly with the subject, then go deep to make ur own..
and the place where i mentiond, u get cabinet one. so no worries about disadvantages of resin..
who cant do all for themself atleast let them do this, i hope if they start slowly they reach goal for sure a day, a person who dont know anything, cant get satisfactory results when he done such deep experiments
let me say some info, i m a deep hobbyist, done many plenty.. still availability of these solar panel is tuff, and u mention copper tape, that too..
most are copy cat at beginning they dont use their brain to find alternative, so they think we cant do these. and drop their idea/wish
I tried one, and after fumbling and breaking my way through ten solettes, I got it! I actually drilled a hole in silicon, to my utter surprise. I'm using a ~1mm bit that's meant for fiberglass circuit boards--it's a rando bit from an electronics store in manila, so I'd bet against it being a fancy-schmancy diamond bit or anything like that.
I dig the rivet idea--my recommendation after a bit of drilling is to do it on a perfectly flat, hard surface. If the surface can compress at all, the solette will bend, build up stress, and snap where the drill bit is pressing into it. I like drilling from the back, too--the drill bit centers in the metal screenprinted layer before it starts cutting into the silicon, and it's easier to get the hole where you want it.
With the rivets, I'd use a nice wide rivet or a washer to spread out the force, otherwise it'll be snap city.
Now I want to build a solar necklace with magnets to hold everything together!
Not only would this solidify the thing a bit and make fanning it out easier, the extra security of the attachment would make it easier to fan the pieces out for maximum exposure.
You can use those solar cells--those are amorphous cells, which means that they're lower efficiency than the crystalline cells I use in this instructable, but they put out higher voltage in low light. A calculator uses a string of those cells--four or five cells in series, and to get to five volts, you'd need the panels from two or three calculators in series. It's definitely worth an experiment!