That charging at 23:30 was yesterday, which worked fine. On the day it failed the first charging session was 00:00. I don't set the schedule, Octopus does. All I have to do is to tell Octopus how much I want to charge and when I want it by and Octopus creates the schedule. That's the deal with Octopus - they set the schedule based on when it's cheap for them, therefore they can charge you the low 7p rate even outside the normal cheap electricity period.
Thanks, I didn't know that. Just checked for Tesla ones and there is a bank of four quite near to where I need to go, though it says all occupied when I checked at 10:45 but yes they are quite a bit cheaper. Thanks for the tip