My wife's G4 iBook (12") has a battery that no longer holds a charge, and the power cord is fraying. I'm going to the Apple Store today to see if they would replace the cord, but if not, I'll buy a new battery and cord. There are several 3rd party adapters and batteries out there. I've read a few poor reviews for several of them. Any advice on which 3rd party batteries and cords are reliable? Or is it best to simply buy from Apple?