When you are plugged into 120v (shore power) at a campsite the converter in your PC will charge the house batteries. In the old days, just a few years ago, the converters had one stage of charging, full power. Todays converters have two or three stages and can they can read the status of the batteries. When you plug into the shore power, the converter comes on full power, then as the batteries get to full charge the converter goes into a maintenance level (about 2 amps) to maintain the batteries. The older converters would keeping trying to charge the batteries even after they became fully charged. This would cause the water in the batteries to boil out of the batteries, thus killing the batteries. This was called "cooking" the batterers.
I don't know exactly when PC started using the multi-stage converters, but I think it was around 2008 or 2009. Since you have a 2011 PC, you can and should leave the batteries on when plugged into shore power. The only time you should disconnect the batteries is when you need to store the PC for two or more weeks without hooking up.
I hope this answers your question.
