In anticipation of picking up a MBP when they're eventually refreshed (though I'll wait a couple weeks to see if there are any reported problems, as I went through 4 defective 27" iMacs recently), I was reading about battery use/care in a forum thread. Then I just checked the Laptop Battery Guide ( http://guides.macrumors.com/Laptop_Battery_Guide ) listed at the topic of this forum section and found 2 issues I'm curious about: 1) There are 2 differing explanations of what a battery cycle is. In the "What is "full cycle"?" section, it says that a "cycle is when the total battery power is less then 50% before it is recharged." But in the "What this means" section, it says "every time your fully deplete the power equal to one maximum charge, your battery has gone through one cycle." Which one appropriately describes a full cycle? 2) The guide also says that "it is best to fully drain the battery before you charge it up again." However, this site ( http://www.batteryuniversity.com/parttwo-34.htm ) says the opposite. That lithium ion batteries prefer "a partial rather than a full discharge. Frequent full discharges should be avoided when possible." Is the forum guide incorrect? Thank you.