My 17" mac book pro (2008) is having issues, when running from battery power it will randomly cut out. I've tried a few things but it looks like I'll have to book an appointment at my local apple store and I get the feeling I'll have to cash out £100 for a new battery. However, I had a look on ebay and theres a bunch of batteries that are 50% to 80% cheaper than buying from Apple. From the price and the pictures I'm guessing they are unofficial batteries. Does anyone have any experience or information regarding these?