This is the
etiquette that I picked up during this trip for AC chargers:
Hotels with Tesla chargers or charging options listed on plugshare:
Always book a room in advance, and always mention that you'd like to charge your car overnight. (on the phone or in the comments of the booking form)
This way they will often put you in a room near the charger, and stop other cars parking (ICE'ing) the charger.
Roadhouses with a AEVA 3 phase plug:
Dont bother asking reception where the plug is, most of them wont know because it hardly gets used. Just take a look at the photos on plugshare and find it yourself, plug in, and then go back to reception and let them know. Usually pay 50c / kwh based on your honesty.
Caravan Parks with 15 amp plugs:
I dont even bother telling them I am an EV driver. Just book a powered site. They dont care if you use it to charge your car, or run your caravan's A/C
You will need a minimum 10m 15amp extension cord. Not all power points are right next to your site.
Showgrounds with 3 phase plugs
Almost all towns of over 5000 population will have 3 phase plugs at the local showground. Most listed on plugshare, some not.
The best approach here is to find the number of the caretaker, and give him a call a day or two before arrival to arrange a time. It may be on plugshare, or you may need to ask via the tourist office. A caretaker will find the plug for you (showgrounds are big) and will advise if they arent available due to an event on at the showgrounds, or maybe the gate is locked after hours.
In some of the popular towns like Winton in QLD, the showgrounds act as the over-flow caravan parks for the grey nomads, so you can just book a powered site at the showgrounds, and then find the 3-phase plug yourself. They never get full, so you dont need to book in advance, just talk to the tourist office when you arrive.
And one more thing, if you cant get into a plugshare listed hotel, you can call other hotels and ask them if you can use a 10 amp plug overnight, or if you are lucky, they'll have a 15 amp (for me, in Cloncurry, QLD). Most will be able to find one somewhere in the hotel.