I work in I.T so I am at a computer all day and leave my phone plugged in, when I am home I leave it plugged in as well. My theory is that if I'm not using battery, the battery will have a longer life. I do the same with my Macbook pro. I have done 2 discharges on both units to "calibrate" the battery. But my question, is my theory right, to prolong overall battery longevity not use it by using wall power instead? Am I a genius?