Set when your Mac shuts down when using a UPS
Reduce the risk of losing data during a power outage by using an uninterruptible power supply (UPS). In the event of a power failure, a UPS provides power to your computer for a period of time.
Some UPS devices run until their batteries are expended and then shut down. With other UPS devices, you can connect the device to the computer’s USB port and set shutdown options for it using Energy Saver or Battery preferences.
On your Mac, choose Apple menu > System Preferences, then do one of the following:
Click UPS, then click Shutdown Options.
Select one or more options to determine when to shut down after a power outage. Then use the slider to specify the time or battery level at which the Mac shuts down.
If you choose more than one option, the Mac shuts down when the first condition is met.