About This File
This is the battery kexts which is working fine on my 10,7 Lion and 10.8 Mountain Lion. It shows accurately the percentage of the battery charged or discharged.
let me know if it works on not. But, remember to remove (or,backup the original kext) before using this kext otherwise it might not work. I removed the original kext from S/L/E and put the kext in Extra/Extension.