When I purchased MBP 13" Retina two weeks ago, I started browsing through the forum and searching on google on how to keep battery healthy. Most people said that at night they put their MBP to sleep instead of shutdown; they do shut down only once or twice per week so updates can be installed properly. An Apple technician told me that he recommends shutting down instead of sleep. Sleep is created for when the computer will not be used for 2-3 hours and shutdown was created was 3 or more hours. I also told him that most of the time I use my MBP at home constantly plugged in. I asked if I should unplug it and use battery power at least twice a week to keep the electrons moving. He told me it is not necessary because MBP is using smart charging. So now I am confused on what is the right way. Most people tell me sleep is better than shut down, and to uncharge MBP once every two weeks down to 30%. And here Apple technician, who I suspect should be well trained, tells me the opposite.