Battery health management
If your Mac notebook has Thunderbolt 3 ports and uses macOS Catalina 10.15.5 or later, you can use battery health management to help extend the life of your battery. Battery health management is designed to improve your battery's lifespan by reducing the rate at which it chemically ages. The feature does this by monitoring your battery's temperature history and charging patterns.
When battery health management is turned on, you might occasionally see ”Not Charging” in the battery status menu of your Mac, and your battery's maximum charge level might be lowered temporarily. This is normal, and it's how battery health management optimizes charging. Your Mac resumes charging to 100 percent depending on your usage.
Other reasons for not charging
You might also see "Not Charging" when your Mac isn't getting enough power to charge the battery, such as when it's not using the correct power adapter and cable, or it's plugged into a power source that isn't delivering enough power.
Learn what to do if your USB-C power adapter isn't charging your Mac.
If none of these reasons apply, and your battery continues to discharge when connected to power, please contact Apple.