Apple Watch Ultra 4 review: a more accurate heart sensor, 50-hour battery life, and new AI audio features
S11 chip checks heart rate every 5 seconds, HRV sampled 24x more often, plus a Readiness Score and four Audio Intelligence features; Thai price 29,900 baht
Heart and health — Health Sensing System + S11 chip measures heart rate every 5 seconds · HRV 24x more frequent · Readiness Score 0–10 · New Health app with Longevity tab + Health Age
Battery — General use: 50 hrs · Low-power mode: 84 hrs · 15-min charge = 18 hrs · Extended Workout GPS: 25 hrs · Max Extended Workout: 45 hrs
Audio Intelligence — Sound Recognition · Live Rewind (15-second recap) · Siri Recap · Shazam · Processes in S11's Secure Exclave, deletes audio immediately
Case — 49mm titanium (natural/black) · 45% recycled materials
Software — watchOS 27 · Apple Intelligence-powered Siri · Single-hand gesture control
Pricing and availability — Thailand: 29,900 baht / US: $799 · Pre-orders Sept 10 · US sales Sept 18 · Thailand date not yet confirmed
Source: Apple
