The one substantive hardware change expected on the Apple Watch Series 12 is the processor. The Series 11 kept the S10 chip from the Series 10, and the S10 was functionally the same as 2023's S9, so a new one would be the first in three generations, and evidence of it turned up in Apple's internal code this month. A known leaker on Weibo said in May that Apple is also chasing battery life with a physically larger cell, against a Series 11 rated at up to 24 hours, or 38 in Low Power Mode. The Series 12 and the Ultra 4 are both expected at the September 9 event, alongside the new iPhones.
Ceramic comes back after six years, which Gurman reported this month and the prototype collector known as Kosutami has since attached to the Series 12. DigiTimes points to a blood pressure notification feature awaiting FDA clearance, building on the hypertension notifications Apple shipped last year. Leaked code included references to AppleMesa, Apple's codename for Touch ID, and Gurman does not expect a design change on either watch large enough to carry a fingerprint sensor. Kosutami also claimed in July that a health sensor could ship inside a band, no other source has corroborated it, and every existing model houses its sensors in the case. There is no new Apple Watch SE this year.