Ordered 3 panels for my Sprinter Camper, as per Renogy installation instructions glued then to the roof of my van. Output was low to start but I live in MN so wrote it off to less Sun. Went to California for 2 months, output has dropped even more, 3 panels in parallel in bright clear sunshine are producing less than 5 amps. Bought two cheap Harbor Freight panels, layed them on top of the Renogy panels, the cheap panels are over 10 amps with just two of them, exactly what they are rated at. TalkeSee full review