Q I have not used my MacBook for over six months. On connecting it to the mains now, it runs fine but will not charge the battery. How can I recondition the battery and get it working normally again?
A Modern lithium and similar laptop batteries need to be kept at least partially charged. If you leave them for a long time like this, despite the best efforts of your MacBook to go into hibernation mode, it appears that your old battery has undergone deep discharge and needs replacement.
You can try taking it to an Apple engineer, but there is no practical way to ‘recondition’ the battery in the way that you could NiCads, so you will need to replace it. Ensure that you run your MacBook and get its battery fully charged at least once every couple of months, or remove the battery to storage. See Apple’s recommendations.
Updated from the original, which was first published in MacUser volume 25 issue 22, 2008.