If you are a current user of a new MacBook, there is high chance you will not encounter any battery problems and issues. However, the MacBook battery does have a lifecycle and it would not last as long as the MacBook itself. If you start to encounter problems such as your MacBook battery not charging, it could be a hardware problem that requires you to change the battery or probably it could be other problems as well.
First of all, if you have status showing your MacBook is not charging even though you have plug in the power cord, you first need to ensure whether you have the correct adapter as well as the correct power watt. Different power adapter is required for different countries.
But sometimes, your MacBook is charging but not reaching the 100% status for a long period of time. Based on MacBook Apple support, this is normal as long as it still reach within the 93 to 99 percent. If your MacBook has been totally out of power for a long period of time, it may take some period of time for the battery to start charging. Once plug in, you will not see any response from the battery up to four to five minutes.
This is due to battery has been in a low state of energy for some time and needs time to start receiving power again. However, if the problem persists and you still could not get the power charging, it can also cause by a malfunction power adapter. Try changing and using a different power adapter to see whether that is the cause of the problem.
However, after all the trouble shooting you have done and the problem of the battery not charging still persists, it can be caused from the hardware itself. As similar to all Apple devices, the battery is built-in and therefore you cannot change it by yourself.
Please bring it to an Apple Authorized Service Provider or Apple Retail Store to have your battery diagnose and also change if damage. All MacBook Air, MacBook Pro with Retina Display and MacBook late 2009 and above has a built-in battery in which you need to bring to the Authorized Service provider to change or repair.