If you’ve finally gotten your hands on an all-new solar panel without the polarity labels, you’re going to need to figure some things out before you can get to using it. One of the main ones is the positive and negative terminals because you’re going to either damage the panel or even cause injury to yourself if you get them wrong during connection. Our article features some important information on how you can easily determine the negative and positive terminals.

In order to determine the positive and negative of your solar panel is to examine the diode. You’re going to need to open your junction box in order to find the diode located inside. If you didn’t already know, diodes are used in order to aid with power loss. In this case, power loss easily occurs when the electricity within your solar panel has been shaded.

In essence, the diode goes on to create an alternative route for the potentially generated electricity whenever your panel experiences shading. However, this is done at a relatively higher resistance. Some panels have only one diode which essentially bypasses the entire panel while others have more than just one. When multiple diodes are present, they also easily bypass your panel as they come into operations.

After you’ve opened the junction box, you’re going to observe that the diode’s cathode is pointing to your positive side. This, therefore, means that the other side is obviously going to be negative. Additionally, if you’re still unsure you can easily measure the polarities with a voltmeter.

Commonly, the polarities of your solar panel can be successfully measured with a voltmeter. Voltmeters produce a relatively simple reading which goes on to indicate your panels’ polarity. In order to measure you’re going to need to measure across the wires or terminals. You’ll need to place the positive (red) lead on the meter on one side and the negative to the other.

Your negative lead is going to be black. Then you’ll need to ensure that you’ve set the meter to take DC readings. If for some reason you see a number with a negative, it simply means that you’ve placed your leads in the wrong direction. This can then be easily corrected by replacing each with the other.

After you’ve done this, you’ll then observe that the negative number has changed into a positive number, this now signifies that you’ve gotten the positive and negative side correctly. As we’ve mentioned before, when you’re inside the junction box, you’re going to observe the bypass diode. The striped side of the diode is usually on the red or rather positive lead. Hence, this method of using the meter is correct in determining both positive and negative.

Additionally, you’re only going to observe 3 volts being outputted. This is simply an indication of the solar panel being upside down within a building. Hence, only a small amount of light is getting to make contact with the panels. While it may be just a small amount, it is enough to successfully indicate the polarity readings.

However, if you attempted to measure the current within the panel at this time as well, there should be none since there is barely any light making contact. Voltages, on the other hand, are less likely to be affected in this way when it comes to light intensity.

As we conclude, we’ve just looked at how to successfully determine the positive and negative terminals on a solar panel. So, remember, you can check the diode as mentioned above, or you can easily use a voltmeter to determine them. Be sure to keep in mind that if you don’t determine positive and negative and the panels are set up, you can damage them pretty badly!