Public EV charging points

My knowledge of the world of electric vehicles is rather scant, hence the topic.

For those who have no access to off street parking, can these charging facilities be used with the correct equipment and charge cards for charging leisure batteries as and when necessary? Some windies just don't do enough daily mileage to fully recharge their auxillary leisure battery.

Also, if left overnight, could they provide 230 volt heating using a small oil filled radiator.

Or would another solution be a 230v electric element in the tank to heat the water sufficiently for several hours to be a heat source to keep the internals from freezing overnight.
There appears to be different types of plugs as well as 230v and DC charging. So I'm guessing we could use a fixed 230v to 12v battery charger through an rdc protected consumer unit that would also cover the power point for the frost heater or electric element.

@spruce we ask us mere mortals a technical question most of us are stumped as we usually rely on you to give us the answers, I thought @AGlassAct or @Nudelmight be more knowledgeable 

I am no expert in this at all, but I have looked into it a bit. The connector is basically just a three fase plug with some extra wires for communication. The chargers can supply up to 80a or more, so you need to have some sort of current limiter. That is done via the extra wires/data bus lines of some sort between the charger in the car and the station. It needs a square wave one one output and some other wave to confirm the power needed.

This is where I stopped researching as I felt it would be easier and more convenient to find a regular 240v socket instead. But I am not familiar with how chargers work, so might be simple stuff.

I suppose you could build a charge box you plug in the electric vehicle charger, and limit the output out to a regular socket where you can plug in your van charger or whatever you want.

I would like to have an electric van someday, and would love if you could tap into the charge port or even the van battery. Maybe our leisure batteries are a thing of the past soon?

I'd imagine that electric vehicles will come in big time before too long. As did mobile phones.