Does the mobile phone consume more battery than the Apple Watch?
Jim Martin / Foundry
Yes. Cellular connectivity can drain an Apple Watch’s battery faster, especially when you use the Watch independently of your iPhone for long periods.
Apple itself says that battery life varies depending on cellular coverage. We also found in previous Apple Watch testing that battery life is affected by how much cellular connectivity you use. This is because an Apple Watch consumes more power when connected to your paired iPhone via Bluetooth. When the iPhone is not available, Wi-Fi consumes less power than a mobile network.
Signal strength also matters. Apple recommends connecting to a strong Wi-Fi or cellular signal whenever possible because maintaining a connection in an area with poor coverage can consume more battery power.
That means activities like making calls, streaming music, or using online apps on your phone for long periods of time are likely to have a greater impact than receiving occasional messages or notifications.
However, purchasing a GPS + Cellular model does not mean that the watch will constantly use your mobile connection. Apple Watch automatically chooses the most energy-efficient available connection: first Bluetooth to your iPhone, followed by Wi-Fi, then cellular when other connections are unavailable.
Interestingly, Apple has sometimes equipped mobile versions of a watch with a larger battery than the equivalent GPS model. The first-generation 44mm Apple Watch SE, for example, had a 1,129Wh battery in its cellular version, compared to 0.994Wh in the GPS model. However, this has not been consistent across generations of Apple Watch, and many subsequent cellular and GPS models have used batteries of identical capacity.
Apple rates the Series 12 for up to 24 hours of normal use and the Ultra 4 for up to 50 hours, while the SE 3 is rated for up to 18 hours.
We’ve also seen much better real-world results with the Series 12. In our first full battery test, the Series 12 lasted 51 hours before running out of power. However, battery life varies significantly depending on how you use the watch, and this was not a test of sustained cellular use.
If you’re trying to extend battery life, Low Power Mode can help. When your iPhone is not nearby, Low Power Mode typically disables Wi-Fi and cellular connections along with incoming calls and notifications. However, if you open an app that requires data, the watch may temporarily reconnect for the app to work.
If you expect to spend many hours away from your iPhone making calls, streaming, or using cellular data, battery life should be a more important consideration when choosing between GPS and GPS + cellular.
If maximum battery life matters more to you than staying connected when your iPhone isn’t around, the GPS-only model eliminates cellular as a potential source of additional power consumption.
