Hey Justin,
I gotta tell ya... I bought one of those cheapo 3rd party batteries off ebay for under $5.00, and the thing works great. Even official sony batteries will die one day too, and when it comes to PSP batteries.. start ballooning... until one day you notice your battery cover popped off
honestly, the 3rd party ones are just fine. Just order from a seller in the US.
regards,
Retromangia