Curious as one of the campgrounds on the island charges 25.00 a night for EV charging
How do they know what you're using a 14-50R for? If you can plug in your motorhome, you can plug in an EV. If you're afraid you may overload their outlet, there are many ways to handle that also, such as unplug the RV or adjust the charge current inside the EV.
The EV chargers (inside the EV) can use any AC voltage from around 90 to 250 VAC and often the draw current can also be set.
But if you're NOT staying at an RV park, how they handle EV charging varies greatly. Same with motels. Some will charge a fee, some will even let you charge for free KNOWING you are not and never have been a customer.
Others will not let you do it, even if you're willing to pay, even if the charge stations or outlets are not being used.
Example is how I charged for
free here and
here at a motel I have NEVER stayed at. That is my electric motorcycle in both photos. Some places are just very pro-EV and they try to help out all EV owners. Often, they are themselves EV owners.
Some want you to ask permission in advance, usually where they only have one charge station such as there in Downieville, CA. Of course, their customers have first priority. But it is NOT used most of the time during the day. More likely to be used by a guest overnight.
The motel above in Portola, CA has several charge stations, no need to ask, just plug in. It's their policy, don't even need to ask. That is my electric motorcycle charging (at no cost to me) in both photos.
-Don- Auburn, CA