Low Power Mode is a new feature that comes with watchOS 9, and activating it will limit some sensors and functionality in an Apple Watch.
Apple uploaded a new support document that shows which features will be affected or disabled once Low Power Mode is turned on.
According to the document, start workout reminders, background blood oxygen and heart rate measurements, heart rate notifications for low, high and irregular rhythms and Always On display will be shut off.
When the iPhone isn’t nearby, incoming notifications and calls will be disabled, as well as cellular and wi-fi connections.
Lastly, Low Power Mode may affect scrolling and animation, Siri requests, complication updates, background apps and making phone calls. The Cupertino-based company says that Fall Detection will continue to operate in Low Power Mode.
watchOS 9 users can enable Low Power by swiping up to go to the Control Center, choosing the battery percentage and turning on the option.