This is a great question and I would love to know how people are monitoring this?
We have just had a guest stay and has left £20 as they have charged their car. They hadn't asked prior and as far as I am aware this is the first person who has done it. At least they were honest!
My question is, how do you know someone is charging their car if you are not local to the property?
As it is 2.5kw per hour, that is not far from having heating on all night, running oven, washing machine, tumble drier etc.
How are other hosts controlling it?
How do you know, they are charging their car?
I don't believe adding it to T&C's will make any difference. If they have a 3 pin plug, they are highly likely to charge their car.
We are with British Gas and whilst it is smart meter, there is no option to read the meter unless you are in the property. So no option to see/track continuous usage.