Truck camper owner hunting used solar panels asks what to avoid, and if voltage matters

A truck camper owner turned to Reddit for advice on selecting used solar panels for a system with a 100Ah AGM battery and a Renogy Voyager 20A PWM charge controller. He was searching Facebook Marketplace for two 100W panels but also considered larger used panels, different voltages, and residential models. Commenters said regular panels can be used and advised against flexible panels due to lack of airflow. When buying used panels, key checks include specifications, condition, compatibility with the charge controller, and physical fit on the camper roof.