I think I found a nice way how to do both, and wanted to share it.
What you'll need:
- "Raw" solar cells at any size
- Wires, soldering iron, solder
- Transparent (Polyester-)Resin
- Fibreglass mats
- Sanding paper
- Dremel or such
--- Diamond blade
- A piece of wood
- Hammer and chisel
- Optional: Paint (Lacquer)
Gathered the stuff? Good, let's start!
As usual: You are responsible to what you do. If you damage any property, human or animal or get harmed in any other way, I can't be held responsible, even if I told you to do so.
Working with the Dremel, the soldering iron, the belt sander, resin or any other tool or material may be dangerous and happens on your own risk.
Any measurements are in the metric system.
1 mm = 0.0393700787 inch
1 cm = 0.393700787 inch
Please use Google-calculator or any other calculator if you want to know the sizes in inches (or any other system).
Step 1: Custom solar-panel: Cut 'em!
To do this, you have to plan what sizes you want to have in the end. ( Watch out: Try to let the cells as big as possible,
the smaller the cells the more work, the more loss etc you will have!)
Think of following points:
-What voltage do you need in the end?
-How many cells do you have?
-How big are they?
-What shape do they have?
-How many mA do you need in the end?
-Where are the main strives? (The thicker solder-lines, it's hard to impossible to solder the thin ones)
-You will lose some cells (they are so fu**in thin, they break so easily)
Every cell has normally 0.5V. How much mA per cm² they give you have to measure*².
Now you always can either put them in:
Series raises the voltage (three cells in series provide 3x0.5V=1.5V etc), but only the amperage of the smallest cell (so try to use cell of similar sizes)*³.
Parallel raises the amperage (three similar cells with 0.5A provide 1.5A etc). Size doesn't matter here (you can put whatever you have).
Only if you have this plan ready, continue.
I tried several techniques to bring solar cell to the right size, but in the end only one worked: Cut 'em!
I took the diamond-blade for my Dremel and build a little table* on which I could precisely cut them.
Here is the howto-vid:
* Instructable may follow.
*² Think of the resistance of you device. Don't take the shortage-voltage.
*³ You can combine both techniques. Think of following example
cell A and C are the same size, cell B1 and B2 are half that size. To get 1.5V and the full amperage put them together like this:
plus --cell A --|-- cell B1 --|-- cell C -- minus
.........................|-- cell B2 --|
| and - are cables . is not!