Apple Watch Series 4 Teardown Reveals Battery Capacity, Heart Sensor Placement, and More

Apple Watch Series 4 was launched at Apple's special event held in Cupertino, California earlier this month. The successor to last year's Series 3 comes with substantial upgrades in the form of a new edge-to-edge display, thin form factor, a louder speaker, ECG capabilities, and a relocated barometric sensor. After testing out the iPhone XS and iPhone XS Max, the guys over at iFixit put the new Apple Watch Series 4 to the test to find out its repairability score, battery capacity, and location of internals. Let's find out what they discovered.

iFixit notes that the process of opening up the Series 4 model hasn't changed much from last year and the display still needs to be heated up in order to soften the adhesive. The video shows how the Force Touch gasket is sensitive and might get easily damaged during repairs. iFixit recommends keeping a spare one when performing a repair.

The teardown reveals that the Apple Watch Series 4 has an LTPO OLED Retina Display with a resolution of 368x448 pixels. The 1.113Wh battery under the hood has a capacity of 291.8mAh. The improved speaker now comes with ingress protection and the taptic engine is smaller than before. The new heart sensors are also seen in the teardown, with improved placement and functionality.

Finally, iFixit gives the Apple Watch Series 4 a repairability score of 6 out of 10. This score factors in positives including easy replacement of watch bands and backwards compatibility, difficult but doable screen replacements, and straightforward battery replacements. The tiny tri-point screws inside are a "repair hindrance".

The teardown also highlights some of the negatives of fixing an Apple Watch Series 4. Several component flex cables are mounted directly to the S4 package, making them tough to disassemble. Lastly, the resin-encased S4 system essentially makes "most board-level repairs impossible".

To recall, the Apple Watch Series 4 went on sale in its first batch of countries starting September 21 at a starting price of $399 for the 40mm model. While not officially announced yet, Gadgets 360 has learnt that India pricing for the Series 4 will start at Rs. 40,900.