The new watchOS 9 update for the Apple Watch finally brings a true power-saving mode to extend the watch’s battery life when needed. You can activate the power saving mode manually via the control center or via the settings menu. It is also displayed to the user when there is only 10% battery charge left. And it switches off automatically as soon as the Apple Watch reaches 80% again on the charger.
Apple Watch SE / Watch Series 8 / Watch Ultra
Battery saver mode saves power primarily by disabling some of the more demanding features. These include the always-on display, heart rate notifications, arrhythmia tracking, and heart rate and blood oxygen measurements. WatchOS 9 also turns off workout reminders.
Interestingly, the battery saver mode disables Wi-Fi and cellular connections when there is no nearby iPhone connected to the smartwatch. It also disables incoming calls and notifications. If you call up an app that requires a data or WiFi connection, the system activates it again. And if the watch stays within the connection range of the phone, notifications will still come in lumps once an hour.
Of course, the system also reduces the overall performance of the Apple Watch in the new battery saver mode. Thus, animations and navigation don’t run as smoothly overall.