DIY Solar Setup: A Simple DIY Beginner’s Guide

In this blog, we’ll do an introduction guide to building your own DIY Solar Setup.  If you’re trying to understand and learn this for the first time, this blogis for you.  We will not overburden you with technical terms but rather provide a high-level overview while still showing the step-by-step process of assembling everything that we believe anyone can perform.  The advantage of learning how to build one of these is that you easily customize your setup, modify it in the future as your needs change, and, most importantly, develop an important skill set.   So let us  start off by giving you a quick overview to explain how this system works.  There are four primary components.  Solar panels collect energy from the sun and then pass the energy via cables to what’s called a charge controller.  A charge controller regulates the energy from the solar panels that it then passes to the batteries where the energy is stored.  In order to get the energy out of the battery, we need to convert it to useable electricity through a device called an inverter.  This is the device we plug in the items we want to power, such as our phones, laptops, or refrigerator.  As far as connecting all of these components, there are three primary sets of cables that you can purchase that already have the proper connectors on the ends and are set up to be used in this system.

• Cables to connect the charge controller to the battery
• Cables to connect the battery to the inverter
• Cables to connect the solar panel to the charge controller

We will cover a few other miscellaneous items throughout the video, but at the core, that’s it.  As far as tools go, here’s what you’ll need:

• Phillips screwdriver (large and small)
• Crescent wrench or socket wrenches
• Needle pliers will also come in handy

Step 1: Connecting the charge controller to the battery

Let’s grab our battery, charge controller, cables to connect our battery, and our small Phillip’s screwdriver.  Please do this step before connecting the solar panels to the charge controller as it will damage the charge controller without first connecting to the battery. If you look at this charge controller, and this is common amongst most of these devices, you have six places to plug in cables.  On this one, you’ll see:  

• Two holes with PV+ and PV- … PV simply means photovoltaic.  This is where we’ll connect solar later.
• The next two holes are what we’re interested in at this step: BAT+ and BAT- … this is where we’ll connect the cables from the charge controller to the battery.
• The last two holes are LOAD which we won’t cover in this blog.

Let’s grab our cables to connect the charge controller to the battery.  These particular cables have lugs on one end that we’ll connect to the battery, and the other ends are stripped, which we’ll connect to the charge controller.  You will notice that these cables are both black, so we’ll need to pay special attention to these when connecting them to the battery in order to keep the positive and negative connections correct.   OK, let’s connect our two cables to the charge controller by inserting the stripped ends of the cables into the charge controller.  Use your Phillips screwdriver and turn counterclockwise on both the BAT+ and BAT- terminals which opens a connector.  Then we’ll take our two cable ends which are stripped, and slide them in one at a time to the terminal.  As we slide each in, we’ll tighten the screw down, turning clockwise.  You want to tighten these firmly to avoid the cables coming out.  Be sure to test by giving a light pull on the cables to ensure they don’t slip out. Next, we’ll connect the cables to the battery.  To do this, first, we’ll unscrew the bolts in our batteries.  Next, we’ll take the negative cable and connect it first to the battery.  Before you do this, double and triple-check that your negative cable is connected to the BAT- connector on your charger controller.  We then place the negative cable lug to the negative battery post and insert the bolt tightening it down.  I won’t tighten it overly tight at this point as we’re going to add the inverter cable later.  Finger tight at this point is fine.  Now we’ll connect the positive cable to the battery using the same approach as with the negative cable.  Again, let’s finger tighten down the nut. Now that we have the charge controller connected, you’ll notice the charge controller screen is turned on.  You can go through it at this time and configure settings based on your model.  We found this particular model is easier to configure with their app than using the interface options on the charge controller itself, but do whichever is easier for you.  There are two primary settings you’ll want to configure.  You’ll want to define the battery type you’re connected to.  In this case, we’re connected to a Lithium battery.  Next, we want to define whether we’re connected to a 12 or 24V battery.  In this case, we’re connecting to a 12V battery.  This charge controller comes with a temperature sensor which can easily be plugged in.  If you buy a charge controller without one, it is highly recommended you purchase this to monitor the temperature of where you store your batteries.  Additionally, this charge controller has an optional Bluetooth module that you can connect that allows you to observe the information for the charge controller through your app. This completes step one. 

Step 2: Connecting the charge controller to a solar panel

For this step, we’ll grab our 100-watt solar panel (you can add more panels, but for simplicity’s sake, we’ll stick with one panel in this blog) and extension cables with MC4 connectors on one end and are stripped on the other end.  For this step, you’ll need just the small Phillip’s screwdriver. During this process of connecting the cables, it’s important to observe the plus and minus signs on these cables that come off the solar panels when connecting to the charge controller.  In order to go from the cables on the solar panels to your charge controller, you’ll need the extension cables with MC4 connectors on one end and are stripped on the other end.   OK, we’ll keep the solar panel out of the sun, connect our extension cables to the cables coming off the solar panels that we’ll run to the charge controller.  We have two black cables, that’s fine, just be careful to keep track of which is positive and negative.  Even adding a small piece of tape on the end and writing a plus or minus might help a bit to keep things straight.  Now, with the stripped end of the cables, We’ll start with the negative end and insert it into my charge controller.  Give it a slight tug to ensure it doesn’t come out.  Next, insert the positive cable into the PV+ connection and tighten it down.  Remember, we have two holes on our charge controller marked PV- and PV+.  Again, PV is short for photovoltaic power, which is the power coming from our solar panel.  Now, let’s put our solar panel into the sun and see what happens.  So now our solar panel is in the sun, and we’re now connected.  As you can see on the front of the charge controller, we’re showing a charge coming in, and we’re now officially charging our battery.  With this setup, I can view this information on my app as well, along with information on how charged the battery is.  So we’re now harvesting power from the sun and storing it in the battery to be used later to power appliances and devices.  Pretty cool, right?   So up to this point in the video, we have now confirmed our solar panel, charge controller, and battery setup work.  Now we’ll move forward to our final step of pulling power from the battery. This completes step two.

Step 3: Connecting the battery to an inverter

Before we proceed to this next step, we need bring in the solar panel and disconnect it.  When working with this system, we don’t want to interact with our setup when actively pulling power from the solar panels.  To do this, we’ll simply disconnect the cables from the solar panels connected to the PV+ and PV- connections on the charge controller.  We’ll also want to disconnect our charge controller from the battery.  To do this, unscrew the positive bolt first on the battery and remove the positive charge controller cable.  Next, unscrew the negative bolt on the battery and also remove the negative charge controller cable.  Now that we’ve disconnected our solar panel and charge controller from the battery let’s connect our inverter to the battery.  To do this, let’s first connect our cable to the inverter first, not the battery first.  Connect the positive inverter cable to the positive inverter post and then connect the negative inverter cable to the negative post on the inverter.  Now we’re ready to connect the inverter to the battery, but before we do this, it is recommended that we put a fuse on our positive inverter cable to protect the inverter.  We have a 2000-watt inverter, so a 175 to 200 amp fuse works fine.  We’ll post a link below to where we purchased mine.  When connecting the fuse to the positive inverter cable, be sure that the fuse is flush with the lug.  Make sure there’s no washer in between the inverter cable lug and the fuse. Now, bring the negative cable from the inverter and connect it to the battery.  Then, using the bolt on the cable that connects the fuse to the cable, place it on the positive battery terminal.  It will spark, but this is to be expected.  Finger tighten these bolts down to allow us to test this out.  We’ll tighten it much tighter momentarily when add the charge controller back on. We have completed the connection of the inverter to the battery.  We can plugin devices and appliances and power them as shown here. Earlier, we disconnected the charge controller, but we’ll add it back now.  We’re basically just repeating step 1 at this point.  We’ll begin by removing the inverter from the positive terminal and negative terminal of the battery.  Bring the negative cable from the charge controller and connect it to the negative post on the battery along with the lug connecting the negative cable to the inverter and tighten down the bolt with a wrench.  Next, we’ll bring the positive cable from the charge controller and add it to the positive post on the battery along with the lug from the cable connecting to the inverter.  Again, we’ll tigthen this down with a wrench.  It’s important to note that when tightening the lugs on the cables to the batteries that there’s no washer in between the battery post and the lugs on the end of the cables.  You want these lugs flush on the battery post.  We do want the washers on top of the lugs, pushing them down to the battery post, though. Finally, we’ll connect the solar panel back to the charge controller.  Connect the negative cable first, then the positive cable.

Step 4: Testing our setup

Alright, it’s the moment of truth.  We’ve got solar charging the battery, so let’s turn on the inverter and power some devices.  Excellent, everything is operating as expected.  We’ve got a pure sine wave coming off the inverter which means we can safely power our electronics and appliances.  You can power most devices that you could normally power through a typical wall socket in your home, such as a T.V. or refrigerator. One important detail about discharging this battery.  There’s a level of charge you don’t want to exceed when drawing power with the inverter.  You can safely discharge down to 20% of the battery’s capacity under load with the inverter powering devices.  If you go under 20% while you have a load on it, it can damage the battery.  You can buy a battery monitor to add to the battery to keep track of that.  For this battery, it does come with Bluetooth, and we can monitor that information in the app.

Conclusion

Hopefully, this blog shows just how easy it is to build out a system like this.  By building a DIY setup, you have options, and can modifications as you need them.  If you have any questions, please post those below.  Again, we’ll post links to all the items we covered in this blog.   As always, stay safe out there!