The battery life is equivalent with the current models meaning approximately 3 to 6 hours for gameplays and approximately 3 to 5 hours for playing back videos. Unfortunately, the battery cannot be changes so when it looses its life, Sony would need to replace the battery for you.
With older PSP models, Battery Information can be viewed from the [Settings] > [System Information] menu. With the PSPgo, this menu has been removed. The only indication of battery life is the battery icon on the top right corner of the screen.
The PSPgo’s battery cannot be replaced like the older PSP models. The unit must be sent to Sony for installation of a replacement battery. Sony will take several weeks to install a new battery and will charge for a replacement.