But battery sizes are not growing anymore. The latest macbooks have under 60Wh batteries. Also it's very wrong that voltage is bad for batteries. The voltage g

But battery sizes are not growing anymore. The latest macbooks have under 60Wh batteries. Also it's very wrong that voltage is bad for batteries. The voltage going through the cable is transformed down to the exact voltage that the battery charge controller decides is appropriate for the charge of the battery at any given moment. If you really wanted even more power, which you don't really, there's no reason you couldn't go to 60V.