Ok so I dont know if this is a stupid question or not. I have a 2009 model Macbook Pro 13", original it stated that the battery would last up to 5 hours. Now the same style of Macbook pro can last up to 10 hours or so. Is this because of the battery or technology. Can i simply install one of the new batteries in my older Macbook pro and get the benefit of the extra battery power? thank you for your time.