To test a 18v solar panel voltage output directly put your solar panel in direct sunlight set your multi meter to the dc volts setting.
How to test a solar panel using a micrometer.
To test a 12v panel meters should always be set to the dc voltage area which usually identified by the symbol below.
Testing the 12 volt solar panel.
Test your solar panel regulator.
In this section we outline how to do this using a multimeter to measure current amps and voltage.
Sometimes you will want to check that your solar system is performing properly or you may simply want to know what output your panel is giving.
Testing solar panels for volts to test solar panel voltage output put your solar panel in direct sunlight set your multi meter to the volts setting and.
You will want to ensure that you place the positive to positive and negative to negative when attaching your multimeter to the connection on the back of your solar panel.
You want to choose a voltage range capable of displaying the maximum possible voltage of the panel in open circuit this means that if you have a panel rated for 20 volts you should set the multi meter.
See how to test your solar panel for open voltage and current reading.
How to test a 12 volt solar panel vs other voltages.
As most solar panels are 12 volts the solar panel test methods are basically the same.