Hi. I just bought the new MBP 13'' (late 2011). I installed an app and it shows that my battery health is 89%. I've only used my MBP for 1-2 weeks. Is it normal? What is more, how long does a 13'' MBP last in general use? P.S. I will go for a trip and it will last 5-6 hours. Will my MBP last the whole trip for watching movies with a single full charge? Thank you in advance.