As long as Octopus is controlling your dynamic charging, everything is at the lower rate. I have my Ohme Pro set to be ready by 5 a.m. (I had this confirmed by Octopus). I plug it in, and regardless of the time of day, it will be charged at 7p per kWh. I have the charger set to add 100% and just leave the car plugged in when not in use.