#Solar panel diagram plus#

You’ll need some extra equipment, though: That’s right - you can use a multimeter to measure how much current your solar panel is outputting. Note: You can also measure PV current by connecting the solar panel to a charge controller, which I discuss below in method #2. Step 3: Measure Operating Current (aka PV Current) If your measurement doesn’t quite reach the Isc, it may not be your solar panel. Time of year also effects solar panel output.

Test the solar panel as close to noon as possible.

Make sure it’s a sunny day and the panel is in direct sunlight.

If your measurement is pretty far off the claimed Isc, try the following and measure again: However, if you want to keep at it, there are more ways to test a solar panel with and without a multimeter. If your measurement is similar to the Isc listed on the back of the panel, great! Your panel is working fine.įor most people, measuring open circuit voltage and short circuit current are all you need to do to test that your solar panel is in good working order. On a clear summer day at noon I’d expect it to be nearly identical to the Isc.

#Solar panel diagram plus#

There was a little haze in the sky when I tested, though, plus it was 11AM on a November morning, so I’m fine with these results. It doesn’t have to be the same, though.įor instance, I only measured 6.08A but my panel’s claimed Isc is 6.56A. The short circuit current you’re measuring should be close to the one listed on the back of the panel. Remove the towel, read the current on your multimeter, and compare it to the short circuit current (Isc) listed on the back of your panel.

Warning: There may be a small spark when you complete the connection. Throw a towel over it to stop it from generating power. Take your panel outside and put it in direct sunlight. For example, my multimeter has a fuse size of 10A and my panel’s Isc is 6.56A, so I’m okay. The fuse size is usually listed above the amperage terminal. Warning: Make sure your multimeter’s fuse size is greater than your panel’s short circuit current. Set your multimeter to the amp setting (A), choosing the right limit if yours isn’t auto-ranging. To do so, move the red probe to the amperage terminal. Locate the short circuit current (Isc) on the specs label on the back of the panel. Step 2: Measure Short Circuit Current (Isc) If your measurement is still off, your solar panel may be damaged. Make sure no part of the solar panel is shaded.Make sure it’s a sunny day, the panel is in direct sunlight and it’s angled toward the sun.If the voltage you measure is significantly less than the Voc, try the following then remeasure: You can move on to the next step - measuring short circuit current. If they’re similar, so far your panel seems to be in good condition. The voltage you measure with your multimeter should be close to the open circuit voltage listed on the back of the panel. The claimed Voc for this panel is 19.83V, so we’re spot on. (If your voltage reading is negative, reverse the probes and measure again.) Read the voltage on your multimeter and compare it to the open circuit voltage (Voc) listed on the back of your panel. Touch the black probe to the metal pin inside the negative MC4 connector. Touch the red probe of your multimeter to the metal pin inside the positive MC4 connector. The positive cable is typically the one with the male MC4 connector. Identify which cable on your solar panel is positive and which is negative. The positive cable is typically the one with the male MC4 connector, which has a red band around it. Locate the positive and negative solar panel cables. For best results, angle it toward the sun. Take your solar panel outside and place it in direct sunlight. It is indicated by a solid line above a dotted line next to the letter V. Set your multimeter to the DC voltage setting (and the correct voltage range if yours isn’t auto-ranging). Plug the red probe into the voltage terminal. To do so, plug the black probe into the COM terminal on your multimeter. Prep your multimeter to measure DC volts. Remember this number for later.įor this method I’m using the Newpowa 100W 12V panel. Locate the open circuit voltage (Voc) on the specs label on the back of your solar panel. Step 1: Measure Open Circuit Voltage (Voc)