So you're going to spend 300 quid a month on a car which, for 2/3rd of that time, 20 days, you can only use it for 12 hours a day because the rest of the time it is charging. Yes I know, most cars are used for much less than 12 hours a day.
Why put more power into the car than you need, which is then put back into the grid. Why not charge until it is full, then then stop charging. Just asking because I do not understand the logic, someone please explain.