I want to talk about Open Circuit Voltage (Voc) since I know this important electrical rule is not understood by most people who buy solar panels. For example, lets say we have a nominal 12v solar panel and you take it outside on a sunny day without a load connected to the solar panel and test the voltage. The results might surprise you, if you don’t understand Voc since the voltage will read higher than the nominal or “rated voltage” on the solar panel.
Voc is the maximum voltage a solar panel is able to output when there is no current flowing through the solar panel, once you connect a load to the solar panel, the voltage will decrease closer to the nominal voltage. This is one of the basic building blocks of understanding how solar panels work, so I hope you got some value out of this short explanation. Does open circuit voltage make sense?