xmb battery icon editor
note this does flash and could brick your psp
Notes for this version: If you're already bored with the standard and sometimes boring battery image you see on the upper right side of your PSP, then you might find these as something that would tickle your fancy.
If you find this awesome, then you're just one of the many people who have been raving about it. Anyhow, to make use of these mods, all you have to do is flash it to vsh/resource. After that, you're all set. The download link contains all eight of them mods, so you'll have plenty of options to choose from.