12volt DC vs 120volt AC question

I would guess you may have an inverter which is more sophisticated than a converter. I would assume the inverter or converter is charging the batteries and the batteries are powering you 12 volt system. Where is a EE when you need one.

bfkhome wrote:
I'm new to this RV stuff so bear with me and what is probably a very elementary basic question.

I have many lights in my interior coach that are 12volt DC fixtures. I know when the coach is turned off and not connected to shore power or the generator running, then the lights are working off of my batteries.

But if I have the generator on or am connected to shore power does the battery still get used to power these lights? In other words am I still putting a drain on the battery or does something switch over when it senses the 120volt AC and the battery is temporarily cut out of the loop?