Apple announced a number of features that got people excited for the Apple Watch Series 4, and its redesigned internals show how much thought the company put into its latest smartwatch. iFixit tore down the Series 4 and found a few interesting tidbits about the Watch that prove it represents a thorough redesign of the original device, making it a more repairable wearable.
Despite having the same estimated battery life as the Series 3, the Series 4’s new battery stands out among the details of the teardown. A 1.113Whr battery powers the Series 4, which is larger than the 1.07Whr battery in last year’s 38mm Series 3 but smaller than the 1.34Whr of the 42mm Series 3 (iFixit tore down a 44mm Series 4, which is the new equivalent to a 42mm Series 3).
It appears Apple tried to achieve a solid middle-ground with the battery’s size, while relying on other hardware and software improvements to do extra work in maintaining overall battery life for both the 40mm and 44mm models. Both are expected to last up to 18 hours on a single charge.
Much like the new user-facing features of the Series 4, the small internal changes in the Watch make a big difference in its overall design and repairability. Apple used the same rounded-edge effect on the Series 4’s display as it did on the iPhone X and the new iPhone XS and XS Max to achieve a larger screen area. The Taptic Engine is longer and thinner now, although it still takes up a lot of room inside the device. iFixit hypothesizes that the barometric altimeter uses the speaker’s grille to access the external atmosphere—a clever design choice on Apple’s part. The speaker itself is bigger by volume as it takes up the space left over by the moved microphone, which now lives nearer to the digital crown.
Overall, there’s much less glue inside the Series 4 than in previous Apple Watch models—even the S4 chip is secured by screws only. iFixit notes that all these changes inside the device make it much easier to repair, but most users probably shouldn’t attempt to open up the device and fix problems on their own.
It’s not surprising that Apple had to rethink the entire inside of the Apple Watch—the Series 4 had to account for the new electrodes that measure electrocardiograms, or ECGs. Engineers had to account for the back, circular electrode and the tiny electrode on the flat edge of the digital crown (and the communication between the two) when designing the Series 4, along with all the other sensors inside the device.
Look for Ars’ review of the Apple Watch Series 4 in the coming days.