Solar Battery Charger
How to Build a Solar Battery Charger
With a number of simple tools, a crumb of cabling coupled with persistence, one can have a solar battery charger that can keep a small appliance running in no time. Batteries, soldering iron, plywood, glass, diodes, and solar cells are a few of the essential tools required to make a solar battery charger.
First thing to do is lay out the wood and glass and assemble it in a shape of a window. Making sure that both sides of the glass are clean, making it big enough to let the light pass through to the solar cells with ease and so enough solar energy can be captured. Take your multi-meter and by placing the cells in a sunny spot, check the cell for voltage. The cells should get about .5 volts each. One should do this by gently putting the red voltage rod on the front face, on the metal lines and putting the black voltage rod anywhere at the back end of each cell. Cells are very, very fragile a little too much force can render the cells useless.
A minimum of six cells will make a good charger but for fast charging, doubling it can make a very big difference. Arrange all the cells on the assembled window and be certain that although everything fits, you still have sufficient room for any minor adjustments.
All cells output .5 volt. It doesn’t matter how big the cell is, they always produce .5 volts. Cell size establishes the amount of amps that can be pulled out of a single cell.
There are two methods on how to wire the electrical circuit power supplies together; parallel wiring and series wiring. Series wiring accumulates volts, while parallel wiring accumulates amps. Wiring a series holds the positive end from one power source to the negative end of another source together. For parallel wiring, it holds both positive ends of different power source and both its negative ends together.
Most rechargeable batteries are 1.2 or 1.4 volts. In charging the batteries, there should more volts coming in than coming out. If you want to charge two batteries at a given time, you will need a three (3) volt array. The side of a solar cell is the front side, usually shiny black or blue in color while, the negative side is at the back.
To do a 3 volt array, one should use 6 solar cells. Keep in mind that the solar cells are very fragile and easy to break. Wire three cells together in a series method. Be certain that you solder the wire lines on your cell. This allows the flow of electrons from the cells to flow into the load.
After assembling the three cells together, repeat the process again with another set of three with a slight difference. Instead of doing it from “negative to positive”, it should be from “positive to negative”. Because this second set should be connected to the first set in a way that it never losses the pattern of lining. Attaching the two sets together can be tricky, depending on the size of your assembled window. Connecting both sets of cells together, should give you an accumulated 3 volts. This can charge two AA batteries very efficiently.
Therefore, the picture should be a two array of 3 cells. It should be wired in a parallel method to increase the amps. This can be done by simply twisting the two positive (front) ends, soldering them together, and doing it the same way at the negative (back) ends.
Get a battery holder, this can be from a broken radio, flashlight or whatever is available as long as it connects and holds the batteries together. Simply attached the positive end of the panel to the red lead of the battery holder and the negative end to the black lead of it and you are almost done.
Attach a blocking diode to the negative lead going into the battery. This will stop out flowing of the current from the battery when the panel is shaded. At this point, the cells should work very well. Leave those under the sun and it will generate 3 volts and a sufficient amount of amps. Now to assemble the solar panel to the window frame you made earlier, going low-tech is fine. Good old duct tape will do.
Learning how to build a solar battery charger is really quite easy. It is very handy if you want to save electricity and run your electrical appliances of a battery. However, the most interesting part is learning all these new skills, and it gives you quite a buzz when you see it all working. Click on the link if you want to know how to build a solar panel.