Monitor your portable Mac computer’s battery
If you use a portable Mac, you can show the battery’s charge level in the menu bar.
Display the battery’s status in the menu bar
On your Mac, choose Apple menu > System Preferences, then click Energy Saver.
Select “Show battery status in menu bar.”
Show the percentage of battery charge in the menu bar
Click the battery icon in the menu bar, then choose Show Percentage.
See how much time it will take to charge the battery
Connect your Mac to a power supply, then click the battery icon in the menu bar. The estimated amount of time that it will take to fully charge the battery is shown at the top of the menu.