PSP USB Charger Mod
Over on the AcidMods forums, member wesley_huddleston1 has posted about successfully connecting the USB power to the charging plug on this PSP, allowing the battery to charge using the PSP's USB port. There is a little bit of soldering involved with this one so please do this at your own risk. For this modification wesley_huddleston1 said that he used a 35 watt soldering iron with low temp small gauge solder and a multimeter to determine the positive and negative power connections on the PSP's USB port.
PSP Internal USB Charger Mod
Source: AcidMods