Using Delta 3 Ultra for 30amp service off a 20amp plug.

Found out today when doing some exipimentation that I can utilize the 30amp plug on my Delta 3 uiltra to run an air conditioner on my camper while still charging the battery itself. Most window style air conditioners draw only a few hundred watts while being used so i figured i would have some overhead. Come to find out I can run basically my entire Aliner camper off of just a single 20amp plug by just using the delta 3 ultra as the middle man!