OP…. Looking at your convertor (WF-8955PEC) it is a three stage charger. That means you can have your camper plugged in 24/7 all year to shore power. You just have to refill the batteries with distilled water when they get low. Look at them three times a year or more.
I do that so I do not have to remove the batteries in the winter. I should also add it gets real cold up here.
To keep it plugged in all year you should have 20A rated extension cables to your 30A RV from a 20A outlet. If the camper is close to the 20A outlet you may be able to run the AC even. Depending on the size of the AC unit. A 15A cable will work if all you want to do is charge the batteries, nothing else all year.