At some point it was also used as a way to get a custom firmware onto a PSP. Then modders somehow managed to update the batteries' firmware (cf "Pandora batter

At some point it was also used as a way to get a custom firmware onto a PSP. Then modders somehow managed to update the batteries' firmware (cf "Pandora battery") and use that. Sony couldn’t patch it, and it was basically game over for them until they released a new generation of hardware, with motherboards immune to the trick. Fun times.