[dunmalg]

>charging at night at home is cheaper today, only because power company makes it so.

They make it so because there's excess capacity at night, when most everyone is asleep. This is not an arbitrary decision.

>Ideally cars should charge when the sun is up, in day time

That's not even remotely true. Someday MAYBE, if massive solar deployment shifts our excess capacity from night to daytime, but that's certainly not the case right now.