Near the half of December last year, Apple has launched an update Very important for Sierra macOS. Besides the solved bugs and the improvements made inSierra Macos 10.12.2, Apple decided to remove the battery autonomy indicator, when the MacBook is not connected to a power source.
Therefore those who used the remaining time indicator for the battery (Battery Time Remaining) from the menu bar, they will not be able to enjoy this function.

It is not exactly known for the reasons why Apple decided to give up this option. It is speculated that the hardware of the new MacBook models would no longer allow the battery life's time to be reported.
It is very true that this report of autonomy did not have 100�curacy, but users could have an idea of the working time remained available.
After this option has been removed from Battery status, a series of applications for macos appeared that show the remaining time of the battery. A simpler solution is to see “Battery Time Remaining” from the Activity Monitor application, which is present on all maccos operating systems.
How can we see Battery Time Remaining in Macos Sierra
All we have to do is open the utility Activity Monitor and let's go to the tab “Energy“.

Partly from the bottom of the utility you will see the status of the battery. Percentage of energy remaining, time left and how long it is on the battery.
For this tutorial I used a MacBook Pro (mid. 2012) with Macos Sierra 10.12.2, you can also find out Battery Time Remaining or MacBook Air.
 
			