Charging battery from Generator

I'm brand spanking new to RV'ng, but have been a boater for many years, spending a lot of time on the hook or a mooring. Conservation is key. It was always the fridge that sucked up battery power. An additional house battery will do great if you have the space, but you always have to use diligence when dry camping. Luxury items such as ice cream may suffer when conserving power, but most food that requires refrigeration does very well if you utilize power conservatively. Of course, a cooler filled with ice will keep that beer cold!