While searching for a battery kit in the web for a PSP, I came across the genuine Sony PSP extended 2200mAh battery for $30 which comes with both extended black/silver battery covers due to the bigger size. This battery/kit was discontinued by Sony in August 2008. Play-Asia.com sells the imported Japanese version for $60 USD but with much more variety of colors in battery covers. Future Shop and Best Buy now only sell the standard slim 1200mAh for $40. Personally, the extra juice is worth the bulging, although any hard cases will likely no longer fit while soft ones should be fine. The 2200mAh claims game play of 8-11 hours vs 1200mAh claims 5-6 hours. There were about 6-8 left hanging on the rack literally collecting dust. Most were clearly unopened but 1-2 looked like the box was chewed up by someone’s dog. I had been hunting around a few months ago but gave up, so I’m glad I stumbled across it.