Building a Charge Controller Guide

Step 1: Introduction to Charge Controllers

What is a charge controller? A charge controller is essential to any renewable energy system for one important reason. A charge controller simply controls where the power from your solar panels or wind generator goes. Overcharging your batteries is very bad for them and can cause costly repairs. A charge controller simply lets the solar panels and wind generator charge the batteries until they reach full charge. When they're fully charged the charge controller shunts the power to a dump load. A dump load can be anything from a hot water heater or an old block heater. Read more »

Step 2: Placing Components

Alright, lets get to building a charge controller. This is probably one of the more complicated steps so take it slow and watch the video a couple of times if you have to. Without further ado... lets go! Read more »

Step 3: Soldering The Parts Together

Alright, we're almost finished with the complicated stuff. In this step you will be soldering the components together. It's not that hard, just make sure to watch the video and take close looks at the pictures. Read more »

Step 4: Initial Testing

Now that we have everything hooked up together we have to test and make sure everything works. Don't worry if it doesn't work right when you turn it on. As you'll see in the video I made a mistake, but I show you how to look for and correct any mistakes you may have made. Read more »

Step 5: Increasing Capacity

It's great that we have a charge controller, but with one relay we're limited to around 500 watts. Lets take a look at how to increase that. Read more »

Step 6: Building The Case

Now that we know that everything is working lets make it pretty by building a case for our charge controller. We're almost ready to hook our charge controller up to our system. Let's begin... Read more »

Step 7: Adding Switches

As it stands now our charge controller is somewhat limited. It's important that we be able to run a full discharge cycle as well as be able to go to the dumpload at will. We'll be adding a couple switches to accomplish this task. Read more »

Programming The Microcontroller

The great thing about using a microcontroller in the charge controller is we can easily change the high/low values of our charge controller. Fully charged voltages for batteries range from 12.6 volts all the way up to 14.8 volts. Let's take a look at how to tell our charge controller what our batteries voltages are. Read more »