Introduction: Solar USB Charger

Picture of Solar USB Charger

In this 'ible I will be instructing you on how to build your own simple solar USB charger!

Step 1: Gather Your Supplies

Picture of Gather Your Supplies

1. A 5v (or a little less) solar panel
Note: If your panel is under 1 amp or 4.5 volts, just use a boost driver or transistor. If your panel is too powerful use a regulator or resistor.
2. A female USB

Step 2: Prepare Your Wiring

Picture of Prepare Your Wiring

1. Strip an tin the tips of the wire on the solar panel.
2. Repeat step one for the USB port (same steps).

Step 3: Begin Soldering

Picture of Begin Soldering

1. Solder the positive wire from the solar panel to the positive on the USB port.
2. Repeat step 1 for the negative wire.

Step 4: Schematic

Picture of Schematic

Step 5: Optional

Picture of Optional

You could make/buy a case for this project, or use a switch.


sammydogjj (author)2013-12-28

Ask questions here.

dirtstarr (author)2013-12-30

How long does it take to charge your phone?

sammydogjj (author)dirtstarr2014-01-07

It depends on the specs of the panel and the conditions during the charging process.

ajensen27 (author)sammydogjj2014-04-06

not whats possible but for your own phone how long does it take to charge?

sammydogjj (author)ajensen272014-04-10

With my panel about 2-3 hours, but my panel is a lower end one.

SniffableTrash (author)2014-01-18

That's pretty cool Tim

thebeave0630 (author)2014-01-01

I mean no disrespect from my skepticism, but it is very well know that you have to have 5v at 1amp for an iPhone. And also it won't work with just any USB device, to show that it is charging there has to be an iPhone circuit (I think it's a resistor or series of resistors on pin 4 of the USB, it's been awhile). That's point one.

Now point 2 is even if you get it to charge at 4.7v that is the max output of your panel, meaning you will only be getting that output in optimum light conditions. You would only be able to get this to charge at mid day in direct light. And with no diode if your panel is in indirect light giving off less than the 3.7v (the actual voltage of the iPhones battery) it will be draining the battery vs charging it.

sammydogjj (author)thebeave06302014-01-07

As I said, I use a transistor or a boost driver to charge faster. As long as it is constant you should be able to charge at these ratings.

thebeave0630 (author)2013-12-30

How is it charging an iPhone if it doesn't even give off 1 amp? You need 1 amp to charge an iPhone. And at 5v for USB. Unless you have hacked the battery in your phone or hacked your charger, I don't see how this actually even charges. Pictures?

thebeave0630 (author)2013-12-29

You could add a fuse to make sure you don't exceed 2amps. I had a short ounce on a portable charger I made and I was VERY happy I had a fuse so I didn't fry my phone. Also a diode in the circuit would prevent discharge from the battery when the panel isn't getting enough light.

sammydogjj (author)thebeave06302013-12-30

There is no need for a diode either, for example if you were charging batteries with a solar panel it would be needed, but since I'm using it as a phone charger and not directly charging batteries it is the same thing as your computer turning off during charge, thus causing no loss other that your phone'a normal decrease in power caused by usage/standby.

sammydogjj (author)thebeave06302013-12-30

That is not needed for my build because the max output for my panel is only 125mA (as mentioned in the instructable).

ivanjacob (author)2013-12-30

Why can't the solar panel be above 2A?

sammydogjj (author)ivanjacob2013-12-30

It can, but you would need a resistor. This is because the max output for a us device is 2 Amps. I think you can go a tenth or less above, but just to be safe I keep it 2 Amps or below. If you're dealing with more you might also want to add a fuse to prevent it from frying or shorting the USB device. Great question, by the way.

thebeave0630 (author)2013-12-29

I do want to ask tho, how is the quality of this radio shack panel? I have never bought one.

sammydogjj (author)thebeave06302013-12-30

I can't complain since they were re-modeling my local radioshack certain items were on sale and I decided to purchase this for a great bargain (2$). I haven't had any problems with mine. The only thing is it doesn't have a very high current output, but it worked fine for this project. The tips came pre-tinned (which was a nice touch) and already has wires soldered to the panel.

About This Instructable




Bio: I have always enjoyed taking things apart and putting them back together as a child, and learning how they work. As I got older I ... More »
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