The Charge controller takes the power coming from the solar panels, and routes it into the battery. It doesn't let the solar panel overcharge the batteries, and it provides a way for you to see what power is going into out of the battery.
This is a great video on how to size solar and what it does.
https://www.youtube.com/watch?v=sG6bErD3ZFAFor me and mine - a solar panel would only be used to recharge the battery that is providing power for small 12V things in the camper. Things like the roof vent fan, a 12V fridge, lights, charge my cell phone, power a diesel heater if I had one, or a 12V electric blanket (more on that later).
Making a camper that has solar ability to operate 110V appliances requires solar cells, a charge controller, a deep cell or Lithium battery, and a 12V/110V inverter....all of which gets to be pretty expensive and takes up a fair amount of room in the camper. I watched some tests on YouTube that folks did, and a 100AMP/Hour battery running through an 12V/100V inverter will power a 5,000 btu air conditioner for about 3 hours. Therefore the decision I have made - is that if I need 110V power to run things like a 110V heater, air conditioning, a microwave, etc. - that power is not going to come from a battery and a 12v/110V inverter....as that requires a lot of battery capacity and you will use up the power quickly. If I need to run things that take a lot of power I am either going to plug into the supply provided by the campground (shore power) - or it is going to come from a small generator. Large AC units on factory campers with electric water heaters, microwaves, etc. generally need 3,500 watt generators to get the AC unit started without overloading the generator. Campers with small AC units can normally get buy with smaller 2,200-2,400 watt inverter generators that are far less noisy. I already have a small 2,400 watt inverter/generator for use at home - so if I am going to a place I can't get 110V access I can take the generator.
Pages: 
