I have never said that I know anything about solar energy. I am just someone that knows about electronics. This is my first attempt at solar energy. I am learning, and I am starting to figure it out, but I had a problem. My solar panels, the ones I had made, put out a total of 15 volts at 8 amps at max. The solar panel I purchased put out 20 volts at 1.5 amps. This poses a problem that I did not foresee. Different voltages was a problem.
I first wired the panels up parallel. That added the amperage together. So I was getting quite of bit of amps, but the voltage drops to the lowest voltage, which was 15 volts at best. This didn’t seem to charge very fast and didn’t seem any better than what I had. So I decided to wire it up in a series. Technically, it should add the voltage up, but the amperage should be the lowest of the panels. It should have, but there was an anomaly. I have no idea what was going on. You shouldn’t be able to push 8 amps through a 1.5 amp hole, but I was. When I put it in a series, it started charging a lot better too. Way better than before. If you went by my meter, and multiplied the voltage and the amperage, I was getting over 300 watts, and I know that can’t be right. They aren’t even rated to make that much. Even though it was working better, I still felt like I wasn’t getting as much out of the solar panels that I could.
I decided to use the broken solar cells I had left over and make two small panels, and I figured out how to make the frame better. This time I ripped down strips of wood three quarters square and built a very simple frame, but with lapped joints. I then used some of the super lightweight corrugated plastic board to skin it. I then did the same thing as before and trimmed it out with corner molding. Then like my last update, I poured expanding plastic foam in the frame. This is the way to do it. Extremely light and rigid. As for the soldering of the solar cells…. yeah.. still a pain in the ass.
I wired the new panels in a series with the other panels that I built, which maxed out the voltage at 20 volts. That is now the same as the other solar panel that I bought. I then wired the other solar panel parallel with mine. Now I was getting close to 20 volts and almost 10 amps. This made a huge difference. I now know that my charging controller I built works like a charm, because since I hooked it up to my new solar array, it charges the battery in nothing flat. I turned on the fan, all the lights, and I plugged my computer in to the AC inverter, which uses a lot of power, and I watched. Even with all of that usage of power, there was still a trickle of power going into the battery. I say that’s good enough for now.
I can’t complain. I built a solar array that works, out of a bunch of broken solar cells. If I can do this, just think what someone that knows what they are doing can do. Solar energy is no pipe dream.
The video below first shows the voltage of the electricity coming out of the solar panels. Then when the button is pushed, the voltage shows the battery being charged until it cuts off, and returns to just the voltage of the panels.