How to Test Solar Panels

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Switching to solar power can be a game-changer. While there might be an initial investment cost, you can eventually look forward to lowering your energy bill by a large amount. What’s more, solar panels give you a practical way to significantly reduce your carbon footprint. This is why millions of people all over the globe have already made the switch, with more doing so every day.

Of course, installing large power generators on your roof comes with its own set of challenges, and one of them is testing. Because your home’s energy depends on whether your system is functioning efficiently, testing these panels to see if they are doing their job should be seen as a basic maintenance procedure. Even if you only have one or two solar panels and are using them for other applications, understanding the process of testing a solar panel is important.

What You Should Know Before You Begin

Before you test your panels, you need to know a little bit about electricity in general. Electricity comes in two forms, AC and DC. AC stands for “alternating current” and DC stands for “direct current.” You don’t need to know the ins and outs of each one, but you do need to know that most household items use DC.

Also Read: Difference Between Inverter vs Converter

You also need to know that electricity is measured in different ways, using amps, watts and volts – three very common electrical terms. Most household appliances measure their power usage in watts, so it’s important to know how many watts your panels are producing. To get this number, though, you’ll also need to look at the voltage.

Getting Ready 

Before you can test your panels, you need to make sure everything is set up correctly. Check the solar panel and make sure it’s in a high-sun placement. Naturally, a solar panel doesn’t function efficiently if it’s in any shade. Also, look on the panel somewhere where it lists its wattage and voltage rating. This will give you an idea of what numbers you should be getting when you do test it. Compare them to what you eventually find.

Next, purchase a multimeter. This handy device can be used to test the electrical output of solar panels, electrical outlets, batteries and more. It’s a useful little thing, and you can not test your solar panels without one, plain and simple. Make sure you familiarize yourself with how it works, how to switch it to various settings and what its readings mean.

How To Test Solar Panels

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To test the solar panel with your multimeter, follow these steps:

First, locate the converter box. This will usually be found at the back of the panel. Find it and take off the cover to get to its connections, Test, find the positive and negative connection terminals. Third, set your multimeter to DC and adjust the settings to read higher than the rated voltage. So, if the panel is rated for 25 volts, for example, you will need to set the multimeter to measure an output greater than that number. Finally, connect the multimeter with the clips. Put the red clip on the positive connection, and the black clip on the negative connection, like you would when hooking up jumper cables to a battery.

When that is finished, the meter should give you an accurate reading of the power produced in your solar panel.

Testing the Charge Controller

When testing your solar panels, another part of the system you need to look at is the charge controller. The charge controller is responsible for making sure that the energy is collected, stored and used properly, which makes it a vital part of any solar panel system.

To test the charge controller, follow these steps. First, set the meter to measure DC, but this time switch it to measure amps. Set the multimeter to 10A. Next, make sure the controller is connected to the solar panel and the battery.

Also Read: How To Connect Solar Panels To A Battery Bank Charge Controller & Inverter

This is where this procedure gets a little tricky, so make sure to follow along carefully. Disconnect the positive cable from the battery to the controller. Take this positive cable and connect it to the positive lead on the multimeter. Then, take the negative lead on the multimeter and connect it to the positive terminal on the battery (yes, that’s right – connect the negative lead to the positive terminal! So, positive lead = positive cable. Negative lead = positive battery terminal). 

Then, you should get an accurate reading of how the charge controller is working.


As you can see, a degree in electrical engineering is not needed. All you need is a multimeter and a basic idea of how your panels work. Of course, knowing what to connect where is also very helpful! By following these steps, you should be able to help keep your solar panels running at maximum efficiency, ensuring your electrical needs are being met, cheaply and cleanly.

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