it was a quick concept done in like 30 min, which often will function in that sense that IF there is enough "stuff" in there that will/could function, it is enought for a rough/initial concept and I will not spend more time on elaborate all angles/functionality/technical aspects of it - UNTIL/and if, it is needed. THEN I would execute on all design specifics on it. I and dont simply have the time to sit and elaborate all the ideas or possible angles/approaches of the charge mechanism - to you. no offense. It's in there and If I would have to specify to the client if there is something more/additional info needed, I would. But for my speed painted/quick concept I simply dont have time to sit down and write elaborated descriptions of specific details on each and every thing.
It would have been faster to say "I don't know yet." when I asked what the mechanism was. For all you knew, I'm a film producer who liked the look and wanted to see if you were intelligent enough to design something for one of my films. You just lost a client. None of that is true, but it is food for thought. Have a nice night.