What I have been told is that batteries eventually get less and less charge on them. Sometimes on eBay someone who has used an iBook for a long time and travelled alot will explain that their battery only holds at maximum a 30 minute charge. How much time does it usually take until a significant portion of your charge is gone (in months/years) with just normal use? Also, is this covered by Applecare? If so how low would the charge have to go before Apple replaces the battery?