watchOS 9 adds a new power management feature to the Apple Watch called Low Power Mode. Here’s what to know about it and how to activate it.

Low Power Mode has been a feature on the iPhone for years. The energy-saving mode throttles many of the iPhone’s power-hungry features in an effort to conserve battery life – and thus extend the overall usage of the phone until you can get to a changing station.

With watchOS 9, Apple has brought Low Power Mode to the Apple Watch – arguably a device where the feature makes much more sense given the smaller battery size.

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But with any low power mode, there are tradeoffs. Here’s what you need to know about the Apple Watch’s Low Power Mode in watchOS 9, including how to activate it.

How To Activate Apple Watch Low Power Mode In watchOS 9

Let’s get this out of the way first. Here’s how to activate Low Power Mode on an Apple Watch running watchOS 9 or later:

Swipe up from the bottom of your Apple Watch screen to bring up Control Center.
Tap the battery percentage button.
On the Battery Remaining screen that appears, tap the Low Power Mode switch.
A screen will appear telling you what Apple Watch features will be impacted by enabling Low Power Mode. If you want to proceed, tap the Turn On button.
Alternatively, you can tap the Turn On For button and select how long you want Low Power Mode enabled: 1, 2, or 3 days, after which time it will automatically turn off.

Your Apple Watch will now be in Low Power Mode and this will be signified by a yellow circle that appears at the top of your watch face.

How To Deactivate Apple Watch Low Power Mode In watchOS 9

Once you’ve enabled Low Power Mode, you can manually deactivate it at any time. To manually deactivate Low Power Mode on Apple Watch, do the following:

Swipe up from the bottom of your Apple Watch screen to bring up Control Center.
Tap the battery percentage button. It will be yellow when Low Power Mode is enabled.
On the Battery Remaining screen that appears, tap the Low Power Mode switch.
Tap Done.

Low Power Mode is now disabled.

What Apple Watch Features Does Low Power Mode Disable?

Low Power Mode saves battery life by disabling certain Apple Watch features. Apple says these Apple Watch features will not work when Low Power Mode is enabled:

The Always On display, which is found on the Apple Watch Series 5 and later (excluding SE models).
Background blood ox measurement (you can still measure blood ox manually)
Background heart rate measurements (you can still measure heart rate manually)
Heart rate notifications for low and high heart rates, and for irregular rhythms.
Reminders to begin your workout.

Apple also warns that additional Apple Watch features could be impacted by Low Power Mode. These feature impacts include increased Siri processing times, watch face complications that update less frequently, background app refreshes could take longer, it taking longer to make a phone call, and more jittery animations.

The trade-off, of course, is that your Apple Watch lasts longer than the usual 18 hours.

When Should I Activate Apple Watch Low Power Mode?

That’s up to you, but times you might want to activate it is when you are on long plane flights, when you are on a trip and have forgotten your Apple Watch charger, and when your Apple Watch has less than 10% of its battery left.

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Michael Grothaus

Apple expert and novelist, Michael Grothaus has been covering tech on KnowYourMobile for the best part of 10 years. Prior to this, he worked at Apple. And before that, he was a film journalist. Michael is a published author; his book Epiphany Jones was voted as one of the best novels about Hollywood by Entertainment Weekly. Michael is also a writer at other publications including VICE and Fast Company.