As you see on my other thread I am also trying not to use these expensive slots by holding charge in the battery if it could be more useful for a later even more expensive slot.
I would never want to charge during the evening peak - that's typically the most expensive 6 slots in a day. Also pretty much I don't want to charge in the lower morning peak of 4 slots as there are generally better slots later in the day for charging. So I would probably use a setting that I wouldn't use the top 10 slots in a day (possibly even as many as the top 20 slots in a day leaving 28 to choose from).
In addition I wouldn't want to charge if all the slots were expensive and similarly priced. I might as well run the house from the grid and not add the battery losses to the costs. So anything above say 25p would be a no-no.
