I have a brand new retina Macbook Pro late 2013 15-inch high-end. I've been trying to research how to keep the battery lifespan as good as possible but have found several conflicting sources. Before I started researching the issue, I thought that the best thing was to first charge until maximum, then use it on battery until 10% or so and then charge back for the first few days. However, some sources say that using the computer below 40% during the first 10 cycles is bad, while others say the opposite. So what exactly should I do to maintain battery health? I'm a bit worried since I've only had the computer for two days and it already has 3 cycles. Anyhow, I have to say that I've been impressed by the computer's battery life - at 91% charge while web-browsing, the battery life estimate was fluctuating between 7:43 and 8:31, and when I got down to 31% it was saying 2:50 left.