I would think inspecting & maintaining the actual capacity of the battery would be part of the automated charging system. It would be recorded to a fine a amount of detail. Most airplanes have a more predictable energy consumption model than a typical consumer car also, and since the typical pilot is more sophisticated, can afford to show a more complicated energy display for more accurate energy consumption and range assumptions.
Electric aircraft currently would be very useful for people who live on an island or island cluster or want to do frequent short hop flights. For example Hawaii, the Caribbean, Indonesia, the Philippines, Seattle and the near by gulf islands, etc. I can take a ferry boat for 3 hours at scheduled times or I can hop on my plane for 30 minutes at any practical time at the same cost really changes things for island dwellers. I could live on an island and theoretically commute to work every day for 45minutes of total travel time. Going to Tahoe every weekend wont be a big deal, etc.
It would be also useful for future automated air taxis, since the energy costs would soon dwarf the cost of everything else in those situations.