Received new MacBook Pro 15" i5 on 18th April from John Lewis. Cannot get this laptop battery to last longer than 4 hours doing light HTML web browsing in Safari, WLAN on, BlueT off, no flash, no other processes running (checked Activity Monitor). Very disappointed. Battery calibrated once laptop received, healthy use of battery during its 21 day life (no over charging or letting it die). Phoned Apple support, first tech sympathised and got me to reset PRAM and told me to re-calibrate the battery - didnt make a difference, second tech guy using same support call reference told me to return the laptop. Laptop going back to John Lewis this week for refund or replacement (cant make my mind up yet). Truly believe this is a manufacturing fault, as do 2 of the Apple Tech guys I spoke to on the phone from Apple support. Am 7 days over the 14 days return period with Apple.com, luckily John Lewis have a 28 day return as they are a retail shop and will accept it. What a saga for a £1500 laptop.  Also kept an eye on which GPU was being used - made sure Intel was being used during the period of testing and nVidia was not running. [edit2] Display brightness was at 50% and backlit keyboard was off.