I get my charger installed at home on Thursday, I believe on Octopus EV Tariff or whatever it is called will cost me 0.10p P/KWH to charge it between the hours of 11:30pm to 5am or thereabouts. So the battery on the Model 3 is 75 KW approximately, so I believe it will be 75kw x 0.10p KWH i make...