Couple times lately my macbook has just turned itself off when on battery. Infact it did it earlier today one moment 91% then the macbook went off. LED's on the battery was showing 1 flashing led. Reseated the battery, plugged in the ac adaptor booted back up and Windows (yes im using windows) showed 90% + Now i'm not sure if its the macbook, the battery or a combination of them both. I would use cocanut battery but i don't actually have OSX on the hard-drive at all currently. It's a core duo 1.83ghz macbook, 2gb ram, 120gb hdd and the combi drive. It must be getting on for 2 years old now, so i wouldn't be surpised if the battery has had it. Is there anyway to check to find out if it's the laptop or the battery?