I've always kept my laptops plugged in whenever it's reasonable to do so and I get great life out of my batteries. My 2008 T61 ThinkPad had 85-90% left when I

I've always kept my laptops plugged in whenever it's reasonable to do so and I get great life out of my batteries. My 2008 T61 ThinkPad had 85-90% left when I sold it in 2010. My 2010 15" MBP had nearly the same battery life after 2+ years as it did when it was new. Here are the numbers from my current 2012 15" rMBP: Age: 13 months Cycles: 117 97% original capacity And that's with 70+ hours a week of use.