Apple recommends that before you try anything else, owners of MacBooks with removable batteries should reset the battery by fully removing it and re-inserting it. Any issues with its installation will be fixed by this simple step, and may save you a trip to the Apple Store.

If that doesn’t work, the next step is to reset the System Management Controller, or SMC for short. To reset the SMC, first you’ll have to shut down your MacBook. Once it’s off, connect the MagSafe power adapter and hold down Control, Shift, Option and the Power button for around four seconds, before releasing all at the same time.

Then, press the Power button to start up the MacBook and see if the problem has been fixed. If not, then your battery may be at the end of its life and you should take your MacBook to Apple for servicing.