1) I just bought my 13"rMBP. Are there rules to perserving battery life on these things? Is it "healthy" to let it run on battery power once it's charged up or does that no longer apply. Part of me says I'm supposed to let it run down every once in awhile and another part of me says that that is for out-dated tech. Is it bad, fine, or good to leave it plugged in the majority of the time? 2) I have noticed that on two occasions now in the two weeks that I have had the device, that sometimes when I plug in the power cord, the light on the cord does not come on and the battery meter on the screen does not indicate charging. This is remedied only by unplugging the cord at the wall and then plugging it back in. Has anyone else encountered this? Thanks for you help. I hope everyone in the U.S. is having/had a good holiday and everyone internationally...enjoy your Friday.