that is the only issue. But it does not mean that you cannot set the batteries to charge during off-peak slots.
Quote by NewbieT was that it's hard to make it to charge in specific slots.
but at the same time, if battery, which let's say has 7 kwh remaining by the time slot is being allocated, is being used during the off-peak slot, then it will deplate in 1 hr and then it will be charged, with off-peak slots immediately, as car charges... no?
only issue is if you have a gap between off-peak slots which are outside off-peak hrs. :/