How do I test my solar panels?

If you are concerned that your solar panels are not performing properly, or if you just wanting the confirm the specifications of a solar panel, they can be easily tested using only a multimeter and sunlight.

The two values you will be testing for are Open Circuit Voltage (Voc) and Short Circuit Current (Isc). They should be listed on the back of the panel, or in your owner's manual. If you have an Enerdrive solar panel, the values can also be found under the specifications tab of the relevant solar panel product page. The steps to test each value are listed below:

Testing for Open Circuit Voltage (Voc)

STEP 1: Ensure that your solar panel is disconnected from all regulators and batteries

STEP 2: Ensure that you are working full sunlight with the panel angled toward the sun. Poor sunlight conditions will prevent you from reading the panels accurately

STEP 3: Set your multimeter to the DC Voltage setting (typically shown as "V - - -")

STEP 4: Connect the positive multimeter lead to the positive wire/terminal of the solar panel and connect the negative multimeter lead to the negative wire/terminal of the solar panel.

STEP 5: Take note of the value displayed on the multimeter and compare it to the Voc listed in the panel specifications.

Testing for Short Circuit Current (Isc)

STEP 1: Ensure that your solar panel is disconnected from all regulators and batteries

STEP 2: Ensure that you are working full sunlight with the panel angled toward the sun. Poor sunlight conditions will prevent you from reading the panels accurately

STEP 3: Ensure that your multimeter is capable of handling the Isc value of your panel. Many multimeters are limited to 10A of current and will be damaged if this limit is exceeded. You may need a shunt or clamp multimeter to measure larger panels.

STEP 4: Set your multimeter to the DC Current settings (typically shown as "A - - -")

STEP 5: Connect the positive multimeter lead to the positive wire/terminal of the solar panel and connect the negative multimeter lead to the negative wire/terminal of the solar panel.

STEP 6: Take note of the value displayed on the multimeter and compare it to the Isc listed in the panel specifications

Small discrepancies between your test values and the specifications are normal. The listed specifications are measured when the panel is subject to standard test conditions (STC), which will always be different than real world conditions due to variables such as angle of the sun, shading, and temperature. More information on STC can be found here.

Solar panels also degrade slowly as they age and it is normal for them to lose around 0.5% of their total output annually.

If you find a large discrepancy between the values on the multimeter and the values listed in the specifications, double check that your panels are clean, angled toward the sun, and receiving full sunlight. If you continue to receive large discrepancies between test readings and specifications after confirming ideal testing conditions, please take photos of your multimeter readings and solar panel testing setup and send them to support.enerdrive@dometic.com