After a full discharge I plugged my Macbook in to find it already at 99%. This is simply the mac claiming it is at 99% however, as when I unplugged it, it shut down. When plugged in, if I click on the battery icon in the taskbar it says "Battery is finishing charge", but I suspect that this isn't the case, as the amber light is still on for hours after the fact. So I left it to charge for a couple of hours (my battery usually takes 3-4 hours for a full charge) and unplugged it to see what it said. It said there were 10 hours left on the battery, so, filled with some vague hope that my mac had somehow (possibly through exposure to cosmic radiation?) become a super-powered juggernaut, I left it unplugged to see if this was true. Regretfully the laptop's claims of a 10 hour battery life were unsubstantiated. It shut down after an expectable amount of time (about an 1:30), considering how long it had been on charge for, and when plugged back in nothing had changed. Still saying 99% after just being plugged back in. So, if anyone has seen this type of behaviour before, can guess at what might be causing it, or can provide a solution, please help. PS: I am currently doing a full cycle of the battery (full charge/discharge) and hopefully this will solve my problem, but any information above and beyond this would be much appreciated.