Lwiddis,
Perc for one thing, double sided panels for another.
I wish I could find a "traditional" panel that had diodes between every cell.
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.