We won’t get to test battery life for the Apple Watch until it lands on wrists starting on April 24. CEO Tim Cook didn’t go into much battery detail at the Apple Watch keynote, merely promising “all-day battery life,” which apparently means 18 hours, according to Cook.
But Apple posted a helpful page on its site shortly after the event, detailing what you can expect from Apple Watch’s little battery. Surprise: Its battery life varies widely based on what you’re asking it to do.
The “all-day” claim was tested on a prototype device using 90 time checks and 90 notifications over 18 hours, or about every six minutes. It also took into account 45 minutes on an app, and a 30-minute workout. This is also the first time that Apple has publicly estimated how many times you’ll look at an Apple Watch per day — about every five minutes.
When you reach for Apple’s magnetic inductive charger, it should be able to top off your watch’s battery up to 80 percent in 90 minutes, and fully charge it in two-and-a-half hours. Apple also noted that the 42mm Apple Watches generally experiences longer battery life than the 38mm models.
If you’re using the device intensely, you can expect battery life to decrease. For instance, you’ll only be able to squeeze three hours of talking out of an Apple Watch, and 6.5 hours of using it as an iPod while listening to music through Bluetooth headphones. You’ll also need to wrap up your run in under seven hours before the battery gives out.
Tests on competing Android Wear smartwatches, which also need daily charging, have generally been close to Apple’s estimates. Ars Technica tested the LG G Watch’s battery and found it lasted just under 24 hours with normal usage — which might not be the same amount of usage as Apple’s tests.
But if you’re just using Apple Watch as a, well, watch, you can expect to eke out more time without a trip back to the charger. If you check your watch every 12 minutes, you can expect two days of battery life. If you turn on Power Reserve mode, you can eke out 72 hours.
Apple’s battery predictions tend to be on the mark; it doesn’t usually exaggerate how long you can work on one of its products. So — expect to get a full day of moderate usage out of your Apple smartwatch, as long as your day only has 18 hours.