If you go for a ev check that see if they are compatible with ovo charger anytime which I think is best tariff, they charge you standard rate for home so 32.8p a kw at the moment and how it works is you give them permission to start the charge and when ever grid is low use they will start it, it works well and you still get daytime charging during low grid use times and most of the night at 10p a kw