I have the charger/converter that's in the first post -
12v/5A Battery Tender Plus. That's what powers my onboard lights and fan when I'm plugged in to the campground .... I have minimal 12vdc items, so the 5A from the charger is more than enough. I don't even have a battery yet, so the charger is working strictly as a
converter (12vDC to 120vAC) right now.
Since I don't have a trailer battery yet, If I'm not able to plug into campground power, I just have power wires run from my tow vehicle that I use for my onboard lights and fan.
Also, If I cant plug into a campground and need AC power for a small radio or to charge my laptop, then I have a $35
400W Black & Decker Power Inverter (12vDC to 120vAC) that I just hook up directly to the tow vehicle battery and run an extension cord to wherever I need it.
That 400W inverter also has a battery drain protection circuit, so that if the battery drops below a certain point, it will kill the power.