This is my solar setup, its messy but it works. There are units that you can buy that do the same thing that I have built. This setup take the charge from my solar panels, charges the battery, and gives me 12v DC and 120v AC. This setup is a continuation of my other instructables: http://www.instructables.com/id/How-to-Solder-Solar-Cells-Together/ http://www.instructables.com/id/Building-a-Solar-Panel-EVA-film-style/
UPDATE 8/23/2013--- I have not added a new photo, but I added a second battery in parallel to the one in the photo. Also I found a place that I could drill a hole from my garage into my basement. Now I have a cord running from the UPS unit into my basement so i can use the power inside the house as well as in the garage. I am in the process of reconfiguring this system into a storage tote so that if i needed to I can take my power with me.
1. Let’s start on the right side. That black box contains a marine deep cycle battery. For those that do not know, a normal car battery will not work very long for a solar system. This is because it cannot handle being drained very low and recharged very many times without damage. Marine deep cycle batteries are made to be completely drained and recharged many times. I do not recommend draining these batteries just because they can be, but it can be done many times.
Now on the left, all the devices that are screwed to the board.
2. Starting at the top I have a 20A PWM solar charge controller. This is a very critical part of any charging system. It monitors the incoming power from the solar panels, the battery charge, keeps from back feeding the panels, and keeps from over charging the battery. This controller is actually made for street lights. How it works is, when there is no power input from the solar panel it turns on an output. That output is 12v dc, and is timed, and adjustable in 1 hour increments. This would normally be used for the street lights. Last winter I used this for our Christmas lights. I connected the 12v output to an inverter, and that to the Christmas lights. I used all LED lights to keep the amp draw down and set the length of time I wanted them on.
3. Below the charge controller there are 4 terminal strips mounted vertically. The 2 on the left are the positive and negative input from the solar panels. Using terminal strips are an easier way to connect your wires if you ever need to change something, it also makes it much neater and easier to trouble shoot then soldering everything together or using wire nuts.
4. The 2 terminal strips on the right are the positive and negative outputs from the charge controller. Also the 12v connection from the battery, and other device connections that need the 12v power. When the charge controller is outputting power to these strips the power will go to any devices that currently are requiring power, the remaining power will go to or from the battery as needed.
5. The last 2 terminal strips are horizontal; these are the timed output from the charge controller. Currently I do not have anything connected to these terminals. This winter I will connect an inverter again for my Christmas lights.
6. In the middle of the board there are 2 square black items. These are 20A dc thermal circuit breakers. The left one is connected to the UPS unit below the breakers. The right one is a spare.
7. Next down is a 12v dc auxiliary plug, just like in a car. Also called a cigarette lighter plug. It connects to the 12v terminals, number 3 above. What you see in the picture is a 12v to USB 5v converter with a charging cable plugged into it. This cable has a male USB plug on one end and 10 plugs on the other ends for connecting devices like cell phones that need charged. I use this a lot when I am working in the garage. I plug my phone in to charge and also play the music from my phone.
8. Now the biggest item on the board, a UPS unit. This is my inverter. For those that don’t know what a UPS unit is, UPS stands for Universal Power Supply. These are found in many offices, these are used to power computers and other electronics for a few minutes if the power goes out so the work can be saved and powered down correctly. These units have a battery in them, some are 6v, and some are 12v. This unit that I have uses a 12v battery like those that are found in emergency lighting. The battery went bad in it, but I kept the unit because it works the same as an inverter. It turns that 12v DC battery into 120v AC. What is nice about using this old unit is that it already has multiple 120v AC plugs, USB outlet, and a built in circuit breaker. If I had to I could also plug in the UPS unit into a 120v AC receptacle and trickle charge my storage battery if it was dead. In this picture you cannot see any of the connections. The 120v AC cord I tucked under the unit where the battery was located. There are 1 red and 1 black wire that connected to the old battery. They had female crimp on connectors on them, so I put male crimp on connectors on a red wire that connects to the circuit breaker from #6, and a crimp on connector on a black wire that runs up to the negative 12v terminal strip from #4. Then plugged red to red, and black to black wires in the battery compartment of the UPS. It actually has 2 circuit breakers doing it this way, but I know that the unit is off and drawing no power when I shut the black breaker off that is above the UPS. If I turn the power switch off on the UPS, it actually draws some power, that’s why I use the circuit breaker as an on/off switch. The last modification that I made to the UPS before I started using it was to take out the beeper. When the unit is running off the battery it would beep once a minute to let you know its drawing from the battery. I de-soldered the beeper from the internal control board. If I ever wanted, or needed, I could put a new battery in the UPS and use it for what it is made for. It just wouldn’t beep unless I put a new beeper in it.
9. The last box on the picture shows red and black wires. These are coming from my solar panels.
This may not be the best looking setup, but it works for what I use it for at this current time. I hope someday to add more batteries, and to also build a box to put everything in that is portable.
The second image is a CAD drawing of how everything is connected. Red is positive wires, white are negative.