1. Find the technical specifications label on the back of your solar panel. For example, this is the label on the back of my Renogy 100W 12V Solar Panel. Note:If your panel doesn't have a label, you can usually find its technical specs in its product manual or online on its product page. 2. Enter the open circuit voltage (Voc).My. Here are a couple more ways to find your max solar panel voltage besides using our calculator. Use one of these methods if you'd like to understand. Now that you know your maximum solar array voltage, it's time to pick a solar charge controller. When shopping for a charge controller, look for its maximum PV voltage (sometimes called. Based on my experience -- and lots of reader emails and comments -- here are the most common mistakes I see people make when trying to find their solar system's max open circuit voltage: 1. Forgetting to correct for.
