Hydrogen vs. Battery Electric Cars

I just don't think hydrogen makes much sense for applications where batteries can do the job. If we could generate limitless power the efficiency losses of Hydrogen wouldn't matter, but also the drawbacks of batteries wouldn't matter, so let's not consider that.

Instead of Battery powered cars killing the grid, with some smart switching and back feeding car batteries could be used to save the grid during heat waves and such, and charging could be postponed to times where the cost of electricity is lowest (Grid under least load).  Say I'm home in the evening when the grid is under peak load but my car has 3/4 battery, use that to run the house for a while and charge at night when the grid is OK.