I don't know exactly how to flash a battery icon thing, and I fear if I flash it as XMB Menu then It would semi brick. Thanks

make sure ur icon is named system_plugin_fg.rco
Go into recovery, enable flash0, open vsh/resources, drop in you icon, confirm overwrite.

Note: U should make a back-up of your entire flash0, just in case u royally screw something up

*u should check out johny_5's flasher

Firstly back up your flash0. You can recover from any messup with editing icons, etc and just reflash the original file.

Then just flash the appropriate rco file and youll be fine.

Thank you Sledge and Night it worked

Thanks for the instruction. I may try.

If youre on 3.03 OE-C follow sledges guide. If youre on a lower custom fw use a program like flash agent.