My retina Macbook Pro was asleep for a few days, unconnected from the charger, where the battery drained from 90% to 60%. Surley this seems like a lot - a 30% drain in less than 48 hours? My real concern is Apple touting up to '30 days of standby time' for the new Macbook - with a 30% drain happening so quickly, surely this would not be possible? Have I got a defective battery? iStatpro reads battery health as 99%, and the battery itself has only gone through 3 cycles and seems perfectly fine otherwise. How have other people's experineces been with the new Macbook's battery and the amount of charge retained while asleep?. P.S. Last night I let the macbook sleep - battery was 56%. This morning, less than 24 hours later, it's at 42%. No way would this battery last 30 days at this rate!