This is my first instructable. I am Dutch, so I'm sorry for the crappy grammar^^
I was looking all over the web and I found a lot of people how did make an usb charger with batteries and some people how made a solar usb charger without batteries. But I wanted to make an usb charger with both. So that it can charge itself when lying in the sun and charge my usb devices (mobile phone, Ipod touch) when I want to. I couldn't find anything like it on the web, so I made this instructable so you guys can make one too:)
I forgot to take a lot of pictures during the building process, so I apologize for that too.
Step 1: Materials and Tools
- 4x solar garden lanterns (I used the one you can see on the picture)
- 4x rechargeable AA batteries
- a double usb port
- 4x 150k ohm resistor
- 4x 560k ohm resistor
- 1x diode (no LED)
- a little bit of plywood
- a little bit of some kind of strong wood
- some isolation tape
- a little bit of wire
- some green spray paint
- some white paint
- some hot glue
And here's a list of the tools I used:
- wood saw
- soldering iron
- a really small brush
- sanding paper/sander
- a hot glue gun
Step 2: Taking Apart the Solar Garden Lanterns
From all this, you will need all 4 solar panel, one switch and all 8 battery connectors. You could also use some wires from here.
Step 3: The Circuit (usb)
The double usb port has 8 pins. 4 in a row for each usb port. The one to the left is the one through which the electricity will flow to the usb device. Then, from left to right, there's the data- pin, then the data+ and then ground. Maybe yours has no pins, but wires. Than the red one is the 5V, the white one is the data-, the green wire is the data+ and the black wire is ground.
You will need to solder some resistors to the pins/wires to make your usb device recognize the solar usb charger as a charging device. You will need to solder one 150k ohm resistor to the data- pin/wire of port 1, as well as to the data+ pin/wire and also to both data pins/wires of port 2. So you will need 4 150k ohm resistors. Then you need to solder a 560k ohm resistor to both ground pins/wires and both 5V pins/wires. So here you will need 4 560k ohms resistors. Then solder the other sides of all resistors connected to port one together, and do the same with port 2.
Now you solder 1 wire to both 5V pins/wires an 1 wire to both ground pins/wires. Now you take one switch from one of your solar garden lanterns and solder it to one of the wires. Then you solder the battery connectors including wire from one of your solar garden lanterns onto the switch and onto the other extending wire.
Step 4: Preparing the Solar Panels (part 1)
If you have solar garden lanterns with easy to take out solar panels, you can skip the rest of this step. If you don't, like me, you will have to saw the plastic around the solar panels.
My solar panels looked like you can see on the picture after taking off all loose parts. As you can see there is a peas of blue tape at the end of the red wire of one of the solar panels. Inside this peas of tape is a diode. I will explain that to you in step 6:)
To do so, I used a hacksaw. First I sawed all the plastic parts I didn't need. Then I used sanding paper and a sander to smooth the sides.
After you have sawn the solar panels, they will look like those on the picture. Like this, they are much smaller and much easier to work with.
Step 5: Preparing the Solar Panels (part 2)
Step 6: The Circuit (solar)
Solder a diode to the + wire, for me that's the red one. Make sure you solder it in the right way. This means you will need to solder it with the grey tip away from the solar panels. This way the electricity can flow from the solar panels to the batteries, but not the other direction.
You can also solder the diode to the other wire, but if you do so, make sure you solder it with the grey tip towards the solar panels.
I already attached the diode to one of the solar panels before I sawed the plastic, because I didn't really thought that one through...
Step 7: The Box
Now the hard part. If you have a fretsaw, this part ain't that hard. I did not have that kind of luxury, so I had to do it the hard way. To saw the hole in one of the sides, you will have to measure the size of your usb ports and switch and saw a hole at the right size. I did this with a normal handsaw by sawing vertical lines through the place of the hole, so the really thin pieces of wood will break. Then when the hole is a little bit to small, you need to use sanding paper to make the hole the right size.
When you have all pieces at the right size, it's time to smooth them. Just use some sanding paper or a sander. The 'battery holder' you don't have to sand, because these won't be visible then your solar usb charger is finished.
Then you can glue everything on place. First glue the sides to the bottom. Don't yet glue the cover onto the box, nor the circuit into the box! Place the 'battery holder' by measuring the right place with the batteries. Place the batteries against one side of the box and put the 'battery holder' not directly against the batteries, but about 1 cm off them.
Now your box is finished:)
Step 8: The Cover
If you have really thin solar panels which can be placed on top of your box, drill eight little holes, for the wires to get into the box.
Before you glue your solar panels in place, be sure your cover is smooth, because after you've glued them on place, you won't be able so sand it again.
When your cover is smooth, you can glue your solar panels on place.
If you have really thin solar panels you placed on top of your box, you can now solder the wires together.
Step 9: Finishing the Circuit
Then take all the battery connectors from your solar garden lanterns and solder three times one flat battery connector to one with a spring.
Now your circuit is officially finished.
Step 10: Glue Everything in Place
Step 11: Embellish Everything
You need to make sure you do not paint the solar panels and usb ports, so put some tape over it, before spraying. Also do not place the tape on top of the protection sheets, because the protection sheets won't stick to the solar panels.
To finish everything, I've painted a little 0 and 1 beneath the switch, so I could see if the solar usb charger is on, without having to plug in my usb device.
And now your solar usb charger is finished:) Have fun with charging:)