The OHME you just tell it that you’re on say the Octopus Agile tariff & how much you are willing to pay for electricity, & then it computes which half-hour slots to charge the car, so it will be charging during some half hour slots & not others.The clever bit is the OHME communicating with Octopus to know exactly how much electricity costs for each half-hour slot automatically.
The OHME does the same with Octopus Go which I’m now trying, so you simply plug it in when you get home & it charges automatically when electricity is less than say 6p/kWh & it picks up all the 5p/kWh half-hour slots & charges during those, so 8 of them in a row which you could program easily enough using BPs charge box.
What we don’t know is what happens at the end of the 3 year OHME contract.