Teardowns have revealed the Apple Watch 3 battery has a capcity of 1.07Wh (279mAh at 3.82 volts), which is a 4% boost over the Series 2 and 32% on the Watch Series 1. These numbers are almost redundant, though, because Apple quotes the same standard, 18-hour runtime across all three models. This should give you “90 time checks, 90 notifications, 45 minutes of app use, and a 30-minute workout with music playback from Apple Watch via Bluetooth.”
In our tests, this sells the Watch 3 a little short. At the time of writing our 38mm Watch is on 42% and this after using it from 5.30am the previous day, taking it off at 10pm and with 30 minutes of exercise, for a total of 24 hours so far. The longest we’ve got from the Watch was when it pushed into a third day, totalling a highly impressive 40 hours, with an hour of moderate exercise.
At the same time, I’ve also noticed the battery on my iPhone 8 Plus is lasting longer as I split usage across the two devices.
Another thing that hasn’t changed all that much is that the Watch 3’s still charges using Apple’s proprietary MagSafe charger, and doesn’t work with Qi-enabled plates like the iPhone 8 Plus does. I don’t know the full details of Apple’s AirPower plate but, if as the pictures attest, the Watch 3 will work with the AirPower, the plate must have both MagSafe and Qi technology inside.