I have a Macbook 4,1 (2008ish) and a MBP100 Hypermac (the original that came with the Magsafe cord). Hypermac was purchased in November of 2009. Last September/October, I experienced significant decrease in performance and sent it back for warranty repair and received the product back in a timely manner. However, I have always suspected that the product wasn't truly fixed and have been running multiple performance tests to confirm this. Example: I start with fully charged Macbook plugged into Hypermac (charged for over 10 hrs), which is what Hypermac recommends for optimum performance. 50% brightness, web browsing. Hypermac lasts for 26:32 before it dies, so I will have approximately 4 hours total of browsing time with hypermac +fully charged macbook. The Hypermac website says that I should get 12.7 hrs battery life. Am I crazy? is it my laptop battery?