Instructions
Disconnect your PSP power adapter from your PSP.
Disconnect the AC power cord from the power adapter. Examine all areas of the power cord and adapter for physical damage or dirt. Clean off the power cable and adapter, if necessary.
Reconnect the power cord to the power adapter. Plug the power cable in to an outlet. Connect your PSP to the power adapter and turn the system on. Turn the WLAN button to the off position when the PSP boots up. Find this button on the top of the PSP. If WLAN is enabled, your battery cannot charge.
Turn off your PSP and disconnect the power cable. Press the battery release button and remove the battery cover. Pull the battery out of the PSP by using the tab on the bottom of the battery. Reinsert the battery. Reconnect the power cable and turn your PSP on. If the battery still won't charge, use a replacement battery.