fx_powerspoof makes your PSP think you are having a 100% full battery.

readme.txt:

Quite simple, just stick it in seplugins, than add it to your game.txt and/or vsh.txt, then watch your system settings always think you have a battery at 100%, when it reality, you (probably) do not.

The main use for this is those games that install updates sony-style, and require 75% or so battery, when that is totally unnecessary and a waste of your time, because if you run out of battery – oh well, start over, nothing harmed, as it does not flash a thing.

How NOT to use:
During flashing(specifically flash0) things that require 75% battery. Not a bright idea. You can, but if you screw up, not my problem .

How it works:
Patches
1. scePowerGetBatteryPercent to always return 100 via jr ra->addiu $v0, $zero, 100
2. scePowerIsLowBattery to always return 0 via jr ra->addu $v0, $zero, $zero
3. scePowerIsBatteryExist to always return 1 via jr ra->addiu $v0, $zero, 0x0001

THEN

Unloads itself, so it won’t make your kernel memory all lame and sliced up

http://forums.qj.net/psp-development-forum/147037-release-fx_powerspoof.html