Apple Watch Series 4 and 5 Will Recalibrate Maximum Battery Capacity With watchOS 9 - MacRumorsOpen MenuShow RoundupsShow Forums menuVisit ForumsOpen Sidebar
Skip to Content

Apple Watch Series 4 and 5 Will Recalibrate Maximum Battery Capacity With watchOS 9

With watchOS 9, Apple is adding a new recalibration feature for the Apple Watch Series 4 and Apple Watch Series 5, according to the watchOS 9 release notes. The recalibration will result in a more accurate estimate for maximum battery capacity.

apple watch series 5

After updating to watchOS 9, your Apple Watch Series 4 or Series 5 will recalibrate and then estimate its maximum battery capacity more accurately.

Following the watchOS 9 update, Apple Watch Series 4 and Series 5 owners who have noticed battery life being misrepresented should be able to get a better read on how long their device will last.

Apple has previously introduced recalibration functionality for the iPhone 11 to make iPhone battery life estimates more accurate, but there has been no similar feature made available for the Apple Watch until now.

The recalibration process will happen during the update and will be complete once it's installed.

Related Roundups: watchOS 26, watchOS 27
Related Forum: Apple Watch

Popular Stories

watchos 27

Apple Releases watchOS 27.2 With Siri AI Enhancements

Monday October 26, 2026 10:47 am PDT by
Apple today released watchOS 27.2, the first major update to the watchOS 27 operating system. watchOS 27.2 can be downloaded through the Settings app on the watch or the Apple Watch app on a connected iPhone. Software can only be installed when the Apple Watch is on the charger and has over 50 percent battery. According to Apple's release notes, watchOS 27.2 introduces new Siri AI...
watchos 27

Apple Seeds Updated watchOS 27.2 Release Candidate

Friday October 23, 2026 12:28 pm PDT by
Apple today seeded an updated version of the watchOS 27.2 release candidate, four days after the first RC became available. Registered developers and public beta testers can download software through the Apple Watch Settings app or using the Apple Watch app on iPhone. watchOS 27.2 adds new Siri AI features and extends Siri AI to more languages. This update provides enhancements to Siri...
siri recap live rewind

watchOS 27.3 Brings Live Rewind and Siri Recap to Apple Watch

Tuesday November 3, 2026 10:35 am PST by
With the first beta of watchOS 27.3, Apple is introducing new Audio Intelligence features it previewed for the Apple Watch Series 12 and Ultra 4 earlier this year. Powered by the S11 chip, Audio Intelligence includes Live Rewind, Siri Recap, Sound Recognition, and Shazam Music Recognition. Sound Recognition and Shazam are already on the watch, but Live Rewind and Siri Recap are now available ...

Top Rated Comments

57 months ago
instead of a %batteryLife estimate there’ll be a $BuyANewWatch message ;)
Score: 16 Votes (Like | Disagree)
Blackstick Avatar
57 months ago
End of the day... the issue is those cells are pushing 4 years old in the case of a well used/loved Series 4. Software optimization can only go so far when you're talking about a 4 year old battery with 1400 cycles on it.
Score: 9 Votes (Like | Disagree)
SantaFeNM Avatar
57 months ago

For a $79 battery replacement fee does the Apple Store change the battery or just give you a new AWS4?
I had the battery replaced in my AW S4 in March of 2021. I had a significant scratch on the screen when I sent it off. Apple sent back to me a new AW S4, of course with a new battery and pristine screen. A big win-win in my case and opinion.
Score: 3 Votes (Like | Disagree)
wwooden Avatar
57 months ago
My Series 4 is at 80% battery health. Doesn't affect any of my day-to-day: I still can workout in the morning, wear it all day at work, and still do more activities in the evening before it starts to get close to 15-20%. When it starts affecting my daily activities, I'll just pay to get the battery replaced. The feature set of the Series 4 meets all my needs.
Score: 3 Votes (Like | Disagree)
Shirasaki Avatar
57 months ago
My series 4 still hold strong after all these years (4 years). 88% battery health. Good enough feature set to last incredibly long. Wonder how this “calibration” would work.
Score: 3 Votes (Like | Disagree)
57 months ago
My series 4 cellular is at

My series 4 still hold strong after all these years (4 years). 88% battery health. Good enough feature set to last incredibly long. Wonder how this “calibration” would work.
My series 4 which, I purchased the first day they were available, battery health is at 87% and I can get through a day with 20-30% left on days I don't workout. On days I do workout - and by that I mean take a run - I have to throw it on a charger for 30 - 60 minutes at some point to make it to the end of a day. In all fairness, I am asking a lot of the watch during a run as that's all I take with me. The watch provides GPS, Heart Rate, bluetooth audio, and cell service for typically 45-60 minutes. I haven't felt the need to upgrade yet due to performance or additional features. I'm kind of hoping the next version pushed me to upgrade due to some amazing feature.
Score: 2 Votes (Like | Disagree)
Latest Stories
Apple Store Subscription Sign-Up Controversy Exposed
Apple Store Subscription Sign-Up Controversy Exposed
2 hours ago
Siri AI Rumored to Become 'More Like an Agent' as Early as Next Year
Siri AI Rumored to Become 'More Like an Agent' as Early as Next Year
13 hours ago
Apple Taking New Approach to Developing iOS 28 and macOS 28
Apple Taking New Approach to Developing iOS 28 and macOS 28
14 hours ago
Early Apple Black Friday Deals on Apple Watch, MacBook Air, and More
Early Apple Black Friday Deals on Apple Watch, MacBook Air, and More
1 day ago
'Backglow' Lets You Customize New MacBook Pro's Glowing Apple Logo
'Backglow' Lets You Customize New MacBook Pro's Glowing Apple Logo
1 day ago
Top Stories: Apple Product Launches, iOS 27.3 Beta, and More
Top Stories: Apple Product Launches, iOS 27.3 Beta, and More
2 days ago
More Fun iPhone Duo Apps: 30 New Picks to Try
More Fun iPhone Duo Apps: 30 New Picks to Try
2 days ago
Hands-On With Apple's New OLED Touchscreen MacBook Pro
Hands-On With Apple's New OLED Touchscreen MacBook Pro
2 days ago
Apple Store With All-New Design Opening Soon in Southern California
Apple Store With All-New Design Opening Soon in Southern California
2 days ago
Control the Glowing Apple Logo on Your New MacBook Pro
Control the Glowing Apple Logo on Your New MacBook Pro
2 days ago
Apple Shares New 'Apple Card: Apply and Use in Minutes' Ad
Apple Shares New 'Apple Card: Apply and Use in Minutes' Ad
3 days ago
Apple Says More Than 100,000 Apps Optimized for iPhone Duo, Here's What's Still Missing
Apple Says More Than 100,000 Apps Optimized for iPhone Duo, Here's What's Still Missing
3 days ago
Early Black Friday Deals Kickoff With Steep Discounts on Apple Watch Ultras and More
Early Black Friday Deals Kickoff With Steep Discounts on Apple Watch Ultras and More
3 days ago
The MacRumors Show: iOS 27.3 Looks Like a Huge Update
The MacRumors Show: iOS 27.3 Looks Like a Huge Update
3 days ago
Best Buy's Black Friday Event Begins With Sitewide Savings on Apple, TVs, More
Best Buy's Black Friday Event Begins With Sitewide Savings on Apple, TVs, More
3 days ago
Apple Releasing Yet Another Two New Products Next Week
Apple Releasing Yet Another Two New Products Next Week
3 days ago
MacBook Air Drops to Lowest Price in Months With Amazon's $250 Discount
MacBook Air Drops to Lowest Price in Months With Amazon's $250 Discount
3 days ago
Apple Rumored to Drop the iPhone's Action Button Next Year
Apple Rumored to Drop the iPhone's Action Button Next Year
3 days ago
Apple's Extended Return Policy Now in Effect for 2026 Holiday Season
Apple's Extended Return Policy Now in Effect for 2026 Holiday Season
3 days ago
Apple Music Classical Updated With New Icon and Refreshed Design
Apple Music Classical Updated With New Icon and Refreshed Design
3 days ago
OLED iPad Mini, M6 iMac, and New MacBook Pros Available From Today
OLED iPad Mini, M6 iMac, and New MacBook Pros Available From Today
3 days ago
Apple Surveys iPhone Duo Buyers About Crease and Camera
Apple Surveys iPhone Duo Buyers About Crease and Camera
3 days ago
Apple's First Touchscreen Mac is Now Arriving to Customers
Apple's First Touchscreen Mac is Now Arriving to Customers
3 days ago
Claude Gets Personal Finance Feature With Bank Account Linking
Claude Gets Personal Finance Feature With Bank Account Linking
3 days ago
Apple Arcade Adds Crossy Road Rush and NBA 2K27
Apple Arcade Adds Crossy Road Rush and NBA 2K27
3 days ago
Apple's New HomeView Smart Home Hub: Here's How Much RAM It Has
Apple's New HomeView Smart Home Hub: Here's How Much RAM It Has
3 days ago
iPad Mini vs. iPad Air Buyer's Guide: Now Just $50 Apart
iPad Mini vs. iPad Air Buyer's Guide: Now Just $50 Apart
3 days ago
First iOS 27.3 and macOS Golden Gate 27.3 Public Betas Now Available
First iOS 27.3 and macOS Golden Gate 27.3 Public Betas Now Available
3 days ago
Apple Announces a New Mac Sales Record
Apple Announces a New Mac Sales Record
4 days ago
Paid $200 for Logic Pro? Apple Says You Won't Get This New Feature
Paid $200 for Logic Pro? Apple Says You Won't Get This New Feature
4 days ago