Apple Watch Series 4 and 5 Will Recalibrate Maximum Battery Capacity With watchOS 9 - MacRumors
Skip to Content

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

by

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 Seeds watchOS 27 Beta 2 to Developers

Tuesday June 23, 2026 11:18 am PDT by
Apple today seeded the second beta of watchOS 27 to developers, with the update coming two weeks after the launch of the first beta. The beta can be downloaded through the Watch app on the iPhone with a free developer account. The Apple Watch will need to be on the charger, connected to Wi-Fi, and have a battery level of 50 percent or above for new software to be installed. The beta is...
Read Full Article • 65 comments
General visionOS watchOS and tvOS Betas Feature Redux

Apple Releases Third watchOS 26.6, tvOS 26.6 and visionOS 26.6 Betas

Monday June 29, 2026 10:08 am PDT by
Apple today provided developers with the third betas of upcoming watchOS 26.6, tvOS 26.6, and visionOS 26.6 betas for testing purposes. The software comes two weeks after Apple seeded the second betas. The software updates are available through the Settings app on each device, and because these are developer betas, a free developer account is required. There's no word on what's in the...
Read Full Article • 1 comments
TMRS 198 Platform Discussion Thumb

The MacRumors Show: Hands-On With iOS 27, Brutal watchOS 27 Cuts, and More

Friday June 19, 2026 9:17 am PDT by
On this week's episode of The MacRumors Show, we continue unpacking WWDC 2026 and take a closer look at iOS 27, macOS Golden Gate, and Apple's other new software updates coming this fall. Subscribe to The MacRumors Show YouTube channel for more videos iOS 27 supports the same iPhones as iOS 26, including the iPhone 11 and second-generation iPhone SE, giving the update the widest device...
Read Full Article • 35 comments

Top Rated Comments

A
applefanboysince93
53 months ago
instead of a %batteryLife estimate there’ll be a $BuyANewWatch message ;)
Score: 16 Votes (Like | Disagree)
Blackstick Avatar
Blackstick
53 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
SantaFeNM
53 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
wwooden
53 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
Shirasaki
53 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)
B
bubsdaddy
53 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)
Read All Comments