How to connect solar panels together in parallel: Join the positive (+) cables of all the panels into a single one, then do the same with all the negative (-) cables. For this, you will need branch connectors or a combiner box. This setup is common in 12V or 24V systems where you want to safely charge batteries or run low-voltage inverters. In this guide, we'll walk you through how. Use our solar panel series and parallel calculator to easily find which common wiring configuration maximizes the power output of your solar panels. Find the technical specifications label on the back of your solar panel. Whether you're installing panels on your RV, building an off-grid cabin setup, or expanding your residential solar array, understanding parallel wiring can help you maximize energy. Definition: This calculator determines the total voltage, current, and power output of solar panels connected in series and parallel configurations. Purpose: It helps solar installers and DIY enthusiasts properly design their solar array to match their system requirements.