I have a PSP model 2001 that's about seven years old, and after years of use and recharging, I think it's about time for a new battery. However, when I go on Amazon to look for replacements, I find lots of batteries that are either weaker than my stock battery or have lots of 1 and 2 star reviews. My question is, what is a good replacement battery for my PSP? I remember back in the day Sony offered an upgrade kit with a more powerful battery and a new battery cover for the Slim, is that still something I can get in some form? If not, a stock power battery is just something I'll have to live with.