Not worth getting a split price deal for me as I only do about 4-5k miles a year so only charge the car once a week for around 4-5 hrs so just pay 28p Kwhr. Most of my electricity used is the other 20hrs a day and split rates would be 35p or so an hour for the 20hrs so saving would be negligible.
Still saving a lot though as my last car Tiguan diesel did around 38mph and would now cost about £47 for 200 miles where electric £15 for same miles.