The indicator light is not lighting, battery is dead, not charging
Mac Pro
Either the charger is faulty or the battery is finished. Either way, take it in for diagnosis.
Barry
Either the charger is faulty or the battery is finished. Either way, take it in for diagnosis.
Barry
I had a problem like this, then I fixed it. Light was sometimes off, sometimes green, sometimes red. Battery menu said it was not charging; plug icon but no lightning bolt icon.
I did the SMC reset http://support.apple.com/kb/HT3964
Actually, just the preliminary things to try, and got it to work. In my case, unplugging the charger, BOTH ENDs, then plugging in the wall side first, then the mac side, fixed the problem. (I keep this charger plugged in all the time so it never occurred to me...) If I unplug, then plug, the mac side again, the problem comes back, gotta do it again.
Are you by chance using a MagSafe to MagSafe2 adapter? We have a bunch of those at work on our thunderbolt displays and they go bad and either need to be cleaned with an erasor or replaced.
If not try the SMC reset that TooManyBoxes suggested and if that doesn't work then Barry is likely right and either the adapter or battery needs to be replaced.
Battery not charging no indicator light
