One of the concerns that many of face with Laptop devices is that their battery needs to be replaced when N number of charging cycle is completed.
One great thing about MacBooks are that their battery lasts long, much longer than the other competitors in market - but still it has a lifespan and you should use it wisely.
What is a battery cycle?
When you consume your MacBook battery without being plugged-in to power, every % of battery that goes down adds to the loss in charge and when this count reaches to 100%
Example of a battery cycle:
Your battery is at 100%, you remove your power supply.
After some use your battery goes to 75% (that's 25% = 0.25 of a a cycle)
You charge it to 100% again.
You unplug it again and battery goes down too 55% (that's previous 25 + 45 = 70% i.e. 0.7 of a cycle)
You charge it to 70%.
You unplug it again and battery goes down 40% (that's previous 70% + 30% = 100% = 1 full battery cycle)
How to identify how many battery cycles your MacBook have completed?
Click on the Apple icon on your Menu bar:
Now select About this Mac
Click on System Report
Now under Hardware select Power and look under Health Information, you would see something like this,
Health Information:
Cycle Count: 83
Condition: Normal
Maximum Capacity: 97%
As you can see my MacBook has completed 83 full battery change/discharge cycle and is at 97% of its maximum capacity.
The recent MacBooks are rated for 1000 charge cycle before they reach to 80% capacity.