The irony about the new PSP Slim is that while it gets twice the battery life, Sony shrunk the battery capacity in half...defeating their own engineering. While modders have been sticking old, larger PSP battery packs in new PSP Slim models, Sony has decided to make the whole idea official.
Their new extended battery pack is 20% larger than the original PSP battery at 2200mAh, and comes with a special PSP replacement cover to accommodate its larger size. Running about $45 when it's released in December, the extended battery will keep PSP slims running for 10-12 hours...which is almost enough reason for us to upgrade our PSP and our battery pack. [electronista]