Installing solar, got a question...

Well I will make this as short as possible! Just bought a truck camper to take to the mountains when we go, we will be boon docking the whole time when we go. So I need to install a solar panel to keep the battery charged up. I took al the amp readings and did all the math and found I need a 100w panel to get me by. I ordered it up, also ordered a charge controller as well. To do the install I had figured I would just remove the wires from the battery, tie in the charge controller to the battery, then tie the wires that where previously on the battery to the load side of the controller. But then I got thinking when I am plugged into shore power there would be 12V coming from the load wires from the converter to charge the battery. So there will be 12v getting to the charge controller load side. Will it fry the charge controller for the solar panel? How does everyone wire up their solar panels? Thanks all!