It is important to regularly check the state of your battery to ensure that your laptop is working at its optimum. Of course, once it has bloated and bulges out of the casing, it is an obvious indicator that it is time to change the battery. However, if you would like to find out more information about the status of your battery, carry out the following steps.
1. Turn on your Macbook.
2. Click the Apple Logo in the top left hand corner.
3. Click on 'About This Mac'.
4. Click on 'System Report ..'.
5. Once you have done so, you will be able to have an in-depth review about your device. To check on your battery specifically, you may scroll down on the left column til you see the 'Power' tab.
6. Click on the 'Power' tab. The battery cycle indicates the number of time your battery has reached the zero percentage and has been charged back up, and it also shows the condition of the battery.

Most of the time, the battery condition should remain at 'Normal' if you take good care of your device. Once it shows 'Service recommended', you should send your item for replacement to prevent further deterioration of your battery and laptop itself. Most batteries remain good for about 700 cycles. Beyond that, it is recommended for you to change your battery.