Click on the battery status icon in the menubar and you see something like this:
Hold the Option key down before clicking on the battery status icon and you get this:
You can select “Condition: Normal” (or whatever it says there for you) and learn more about what “Condition” really means.
Batteries can only be recharged so many times. Someday yours will not hold the same amount of energy that it used to. This Option key technique will help you stay informed.