I keep my Engle fridge running always and don't always drive enough too keep everything charged. This keeps the batteries charged with enough extra charging power to keep everything cold in the fridge and run other accessories.
Panels bolted on to Inti rack with rubber spacers and metal washers. Washers were threaded to keep bolts retained on panels for installation on roof rack:
Solar charging Controller:
Two 30 watt panels. So 60 watts total.
Both panels wired parallel into the the controller. It's a 3 Stage PWM type controller.
All that remains of the install is to route the power cables properly. They've been installed on the roof for a couple of months and it's great to have the fridge cold and the batteries completely charged even when the truck has not been driven for several days.