With watchOS 9, Apple improved its battery saver mode. Although this extends the battery life of the watch, it reduces functions. An overview.
Apple Watch models from Series 4 should last up to twice as long if you activate the new power saving mode (Low Power Mode) in watchOS 9. This works in a much more sophisticated way than the previous power reserve mode (“power reserve”): while this only displays the time from a battery level of 10 percent, many functions are retained in the low power mode. However, not all of them are: You should therefore think carefully about when to turn on the savings feature and when not to.
WatchOS 9 is required
After installing watchOS 9, the new battery saver mode appears on the battery screen. This can be reached via the control center. Alternatively, you can also activate the function via the system settings under “Battery”. A yellow circle icon at the top of the screen indicates that Low Power Mode is running. In addition, when the battery level is 10 percent, you are automatically asked whether the function should be activated – the notification does not always appear in the short test, however. The power-saving mode is switched off automatically when the battery level reaches 80 percent – unless it has been active for several days.
In power saving mode, the always-on display of the watch is deactivated by default – if available. Heart rate notifications about irregular heart rhythms and high and low heart rates are no longer received, and there is no background heart rate measurement or blood oxygen measurement. The automatic recognition of the start of training does not take place either. Furthermore, both WLAN and mobile communications are suppressed as long as the iPhone paired with the watch is not nearby – which means that no more notifications or calls are then received.
Economical, but (relatively) usable
Apple also warns of some slowed-down functions. Apps and complications are updated less frequently in the background – how much less remains unclear. The watch makes calls more slowly and Siri use is also slowed down (answers no longer arrive as quickly). Apple also reduces the system performance, which can render “some animations and scrolling through scrolling” less fluid.
The sport continues to work in power-saving mode; this can even be activated automatically during training if you wish. According to Apple, values such as heart rate and pace would then continue to be measured – but it is possible that the accuracy will be lower. At best, it should be possible to double the battery life using the power-saving mode – i.e. from the 18 hours usually specified by Apple to up to 36 hours. In practice, this should depend on the type of application. However, if you really want to use the watch to the full for 36 hours, you still need the Apple Watch Ultra. Thanks to the larger battery, this lasts twice as long as regular models – with an adapted power-saving mode that will be released later this year even up to 60 hours. This includes, among other things, a reduced query of GPS position and heart rate, as Apple has announced.