It would be nice if there were two buttons on the Charging user interface, one when clicked would do a full charge and the other when clicked would charge the car to some non-fully-charged level set-able by the user through the Options, and which would stay at that value unless changed by the user. In my case with a 250 mile maximum range I might set it to 215. With that second button you wouldn't have to guess what value you are setting using the slider as you do now.