With the Apple Watch Series 4iPhone XS, and iPhone XS Max now widely available, iFixit has completed its annual teardowns of the latest Apple Watch and iPhone models. The findings took into account a handful of small and obvious tweaks this year, including confirmations of the techniques and components Apple used to thin its new devices.

For the Apple Watch Series 4, iFixit’s teardown discovered:

  • A slimmed down Low-Temperature Polycrystalline Oxide (LTPO) OLED display, which is estimated to consume 5 to 15 percent less power than before and enable other components to occupy more space.
  • A 1.113 watt-hour battery in the 44mm model, a drop of 20 percent in capacity compared with the 1.34 watt-hour battery in 42mm Apple Watch Series 3 models; the 40mm model loses a similar 20 percent (via MacRumors), even though Series 4 offers similar battery life.
  • A thinner, longer Taptic Engine.
  • More internal breathing room for the speaker, increasing its peak volume, and a relocated barometric sensor with greater access to the outside atmosphere.
  • A screw-removable S4 system-on-chip, which is easier to remove than previously glued-in processors.
  • A substantially redesigned antenna system.

On the iPhone XS and iPhone XS Max, iFixit found:

  • The XS Max features a redesigned, larger Taptic Engine that’s capable of spreading haptic vibrations out across the device’s larger footprint.
  • The XS has a 10.13 watt-hour battery, which appears to be a single and now L-shaped cell, while the XS Max has a 12.08 watt-hour battery consisting of two separate cells.
  • Only Intel modems, apparently, with no sign of Qualcomm parts.

Above: The iPhone XS and iPhone XS Max, torn down by iFixit.

Image Credit: iFixit

As a repair shop, iFixit tends to focus on whether the new devices are easy or hard to fix, and though it generally praised some repairability improvements, it ultimately rated each of the new devices a 6 out of 10 on its repairability scale — with 10 the easiest possible repair level.

Perhaps the biggest concerns were reserved for iPhone XS and XS Max, which iFixit said had one positive and one negative compared with earlier aluminum-bodied models. Both devices can have damaged front glass and displays swapped without removing the biometric Face ID hardware — a major issue that impeded the repair of some Touch ID devices. But damage to the rear glass will require a complete chassis replacement, requiring a lot of time and money.

Unsurprisingly, the disassembly and repairs also call for quite a few custom tools and types of expertise that the vast majority of users won’t have. For that reason, virtually any iPhone XS or Apple Watch Series 4 repair will require the services of a professional rather than a DIY solution.

Updated September 25 at 11:10 a.m. Pacific: Though the teardown originally suggested that the 44mm Watch gained 4 percent battery life versus the prior 42mm version, the difference was actually between the 44mm and prior 38mm watches — an issue corrected above.