I've had my Powerbook G4 for 3 1/2 years now. Have the original battery and it only lasts for 1 hour as opposed to the 2 1/2 when it was new. Will buying a new battery bring it up to that long again? Also I see from the applestore a new battery costs $130. I've seen them on other sites for as low as $75. Are these batteries legit? Can anyone recommend a site with these discounted batteries. Also...the laptop runs very hot...hasn't caught fire yet but I'm wondering if this is because of the battery too or just the nature of apple laptops?