The solution may be as simple as a new battery but I thought I'd check here first.
Basically, my PSP is going dead even when not in use. I fully charge the battery, play it for a couple hours then turn it off. When I come back to it a week or two later it's totally dead despite being turned off and untouched. Also it takes HOURS to charge. Like, if I plug it in at noon I might be able to play it by midnight.
In case it matters, this is one of the original PSPs, not a slim go vita or whatever the new models are.