I don't know how old your battery is but they don't last forever -- they have a limited lifespan which can be severely shortened if left attached to the laptop for long or frequent periods when the laptop is being run on mains power. In those scenarios you are supposed to remove the battery to prevent it from being overcharged (this happens when the battery is fully charged but is still getting charged beyond that point because the laptop is being run on mains power). If your laptop came from a previous owner, they may have used it incorrectly (running it from the mains over long periods with battery attached). In such cases the battery will reach the end of it's life much sooner and will have to be replaced with a new one.
Edited by pip22, 15 December 2007 - 03:39 PM.