I have a 2009 model macbook pro. I am happy with the general performance. My only problem is with the battery life which doesn't last more than 1:30 hours. Coconutbattery shows that it's at 47% of its original capacity at 677 cycle. Also my battery might be faulty since the indicator doesn't always show correctly despite some SMC resets. My question is what would be the estimate battery life of a new Apple battery? In 2009, it was supposed to last 7 hours but is that possible with the power that today's applications and new yosemite features require? My daily usage consists of college note taking, pages and relatively heavy safari browsing. In other words, could I get close to 7 hours with normal usage or will I still be stuck to 4-5 hours. I read some comments that new macbook air's can get close to the advertised 12 hours with normal usage but should I expect that mine lasts less (than 7 hours) because for exemple the specs of my machine are old? Apple charges 129 euros for a replacement so I want to be sure that it will be worth it. Otherwise I'll stick to my ipad+keyboard combination which is slightly less useful for daily work but at leasts finishes a day without any problem. Thank you in advance for your answers.