Ok, so I needed a replacement battery for my psp slim, so I bought one of those 2200 ma batteries. It was an official sony battery etc etc. So anyway, I put it in my PSP but it would not power on. So I plugged in the ac cord and checked the battery under system settings, but it shows as if there were no battery in there. So I reseated the battery a few times, made sure it was in etc. I ended up replacing the battery, with a 1800 one. This one does not power up either, but it will charge. If I have my PSP on with the AC cord in, and the battery, it shows the charge level and stuff, but the psp auto shuts off after like 5 minutes when then battery is in. So I tried fully charging it with the external battery charger, and it still wont power on. If I power on with the AC cord then take it out, it stays on for 0-2 seconds then shuts off. Can anyone help me out here?