Uses
The Pandora battery was created to modify the Sony PSP. It is an actual battery that replaces the manufactured battery the PSP comes with.
"Unbricking" PSPs
Unbricking is a term PSP users coined to describe a "useless" PSP that is limited in some way. The Pandora battery is a means to unbrick the PSP and enhance its performance.
Downgrading
The Pandora battery allows users to downgrade their PSP. The PSP is often downgraded because newer PSP models are not easily modified.
Magic Memory Stick
The Magic Memory Stick usually accompanies the Pandora battery. The memory stick gives the PSP substantially more memory. This stick also aids the battery in changing the device's firmware.
Cost
The Pandora battery varies in price depending on how much memory it comes with. The cheapest battery and memory stick totals around $25 and the highest is around $75.