Hey guys I have a Late 08 unibody macbook pro that im thinking of replacing the battery of. But after researching a lot, I have learned that the replacement battery from apple will only give me 2 - 3 hours max. So I was just wondering why that is the case since when I bought the macbook pro used in 2011 I would get at least a good 5 - 6 hours. What is the difference between the replacement battery and the original battery that makes such a big difference? Personally, I do not find it worth the money to spend $130 on a battery that will only give me an hour more than my 6 years old original battery. Thank you for the input.