Looking to buy a new "larger" PSP battery for extended game time. Was wondering what ones to look out for and what ones to avoid. Don't want something that is going to blow up on me after a week! Not really sure where to look so I just checked eBay. http://cgi.ebay.co.uk/5200mAh-Mega-HI-POWE...%3A1|240%3A1318 Any ideas?