Apple rates the Apple Watch Series 12 for up to 24 hours of normal use, up to 38 hours in Low Power Mode, and up to 10 hours of outdoor workout tracking. Reported tests have run longer than 24 hours, but their results come from different uses and conditions. Apple also says sleep tracking can work when the watch is disconnected from its paired iPhone.

If you’re also choosing among models, NeoTeo’s earlier Apple Watch comparison looks at the Series 12 alongside the SE 3 and Ultra 4.

In this article

What Apple’s battery ratings cover

Apple’s 24-hour estimate comes from a specific workload: 300 time checks, 90 notifications, 15 minutes of app use, a 60-minute workout playing music over Bluetooth, and six hours of sleep tracking. For the GPS model, the watch stayed connected to an iPhone over Bluetooth throughout the test. Apple’s GPS + Cellular profile included four hours of cellular use and 20 hours connected to an iPhone over Bluetooth.

The 38-hour Low Power Mode estimate uses a different workload: 530 time checks, 160 notifications, 26 minutes of app use, the same 60-minute Bluetooth-music workout, and six hours of sleep tracking. Apple’s GPS profile used an iPhone connection throughout; the GPS + Cellular profile used cellular on demand and 30 hours of iPhone Bluetooth. The two ratings therefore describe distinct tests, not one identical routine with a longer battery setting.

Apple rates outdoor workout tracking for up to 10 hours in a running workout without an iPhone, with the heart-rate sensor active. Apple notes that actual runtime varies with use, settings, cellular network and signal strength.

What reported battery tests found

Lexy Savvides’s English-language video follows her 42mm Series 12 battery test, which ran 30.5 hours with Always-On display, cellular running, streamed music and sleep tracking.

Macworld reported two Series 12 battery runs, lasting 51 and 40 hours, for a 45.5-hour average. It reported a 47.5-hour average for Series 11 and said its results did not show a consistent battery-life improvement for Series 12.

In a separate test, journalist Lexy Savvides reported 30.5 hours from a 42mm Series 12, starting at full charge and ending when the watch shut down. The Always-On display was enabled; her reported use included an outdoor cellular run with streamed music and sleep tracking.

Sleep tracking without a nearby iPhone

Apple says Apple Watch can track sleep while disconnected from its paired iPhone. By default, Airplane Mode turns off Wi-Fi and cellular while leaving Bluetooth on; you can change those radio settings. Apple’s guidance on using Apple Watch without an iPhone and Airplane Mode settings describes these functions separately.

What a short charge can provide

Apple estimates that a 15-minute charge can provide up to 12 hours of normal use, while five minutes can provide up to 10 hours of sleep tracking. Its fast-charging estimate is about 80% in 30 minutes with the USB-C magnetic fast-charging cable and a 20W Apple USB-C adapter. Apple’s charging tests used preproduction hardware, and actual charging times vary with the adapter, starting charge, settings, use and environment.

Macworld separately reported two 30-minute charging results: 58% and 72%.