Apple Watch Ultra 4 pushes battery life to 50 hours and adds Readiness

Apple Watch Ultra 4 is official, and Apple has finally pushed standard battery life to around two days. But the bigger update goes well beyond battery, with new heart rate hardware, Readiness and a collection of Apple Intelligence features also making the jump to the wrist.

Battery life gets a useful boost

Battery remains one of the biggest differences between the Ultra and the regular Apple Watch, and Apple has stretched it further this time around. Ultra 4 is rated for up to 50 hours of normal use.

For longer activities, Apple quotes 18 hours with GPS running and up to 45 hours using the extended workout mode. That should make the Ultra more practical for longer endurance events without having to think quite as much about charging.

The design remains unmistakably Ultra, with black and natural titanium finishes available.

The heart rate sensor gets a major overhaul

Ultra 4 shares Apple’s new Health Sensing system with Series 12. The electrodes have a larger surface area, while redesigned photodiodes and larger green LEDs sit inside the optical heart rate system.

More important is the increase in sampling frequency. Apple says background heart rate can now be measured every second, around 60 times more frequently than before. HRV is measured every five minutes, a 24-fold increase in frequency.

HRV has also been brought into the Vitals app more prominently, complete with a daytime view. That extra data feeds directly into Apple’s new Readiness feature.

Readiness looks at sleep, vitals and recent activity each morning and produces a score intended to show how prepared the body is for the day ahead. The interesting twist is that the score can change during the day as new information comes in rather than remaining locked to the morning reading.

Health Age and a new Longevity section

The Health app is getting a sizeable redesign later this year. Apple Intelligence sits at the centre of the new experience, with the app using collected data to provide more personalised guidance.

Health Age estimates a user’s health age alongside their actual age, while the new Longevity tab pulls together metrics from Apple Watch and iPhone. Blood results and other medical records can also be added, giving the system more information to work with.

Apple is also introducing an at-home VO2 max test. This uses the iPhone camera to track movement while the user follows live pacing instructions and on-screen guidance.

For an Ultra watch, these additions arguably matter as much as the extra battery life. Apple has traditionally collected plenty of training and health data, but Readiness and the new Health experience put more emphasis on interpreting it.

S11 powers new Audio Intelligence features

Inside Ultra 4 is Apple’s new S11 chip. It combines a faster CPU, Neural Engine and GPU derived from the A20 Pro with an always-on processor designed to support the new intelligence features.

Sound Recognition can identify noises such as alarms, sirens, traffic and doorbells. Live Rewind lets the wearer double-press the Digital Crown to retrieve a transcription covering the previous 15 seconds.

Siri Recap can use ambient listening to create high-level notes. It can be enabled manually or set to operate on a schedule.

Apple says the underlying audio is not recorded or stored, speakers are not identified and synced information uses end-to-end encryption.

Apple Watch Ultra 4 starts at $799. Pre-orders begin today, with availability from September 18.