cross posting this as I typed this reply in another thread on this topic this morning and my original response sounds a bit harsher than I intended.
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To be fair (as I am the one who clipped the text from the manual and posted it), as I mentioned there are a ton of discussions here about battery maintenance, how often to plug in, etc etc and tons of opinions on this topic. I have read a ton of threads, and there is no consensus in general.
The general advice from the forum would be to plug it in, set the charging threshhold to something like 70-80 percent, and the go about your business and not worry about it. Still others only plug in when their car is down to 30 percent etc.
So, if you search you will find tons of discussions about the topic. For myself, I found myself getting wrapped up in "what do I do to protect my investment in this car, as I did not lease it and I want it to last!!!" thoughts.
I read the manual (actually before I got the car, and again after, and again.. I have read the 182 page manual cover to cover at least 3 full times)... and realized that tesla is exceptionally clear about what THEY want you to do.
Of course, there are plenty of people on the forums who dont believe them, and have only plugged in "when needed" on model S and X and not had much issues over several years of ownership.
I ultimately decided I would not stress about the battery, charge to 90 percent or so, and plug in when not in use. I also decided that around 1 time per month I would run down to 20-30 percent, then charge to 100 percent to help the battery management system (BMS) re calibrate itself in my car.
I also decided that it would not hurt it at all if I left it plugged in all the time, as thats what tesla is telling me to do, and if I had a problem in the 8 years 120k miles warranty that comes with the car, tesla WILL be able to see charge cycles etc, and "doing whats in the manual" is the safest / easiest way to get warranty coverage.
your mileage may vary, of course.