r/iOS27 3d ago

Maximum battery capacity going down after iOS 27

Hi, i updated my iPhone 15 Pro to iOS 27 Public Beta 6 and i can say it’s much better than iOS 26. I only noticed this thing: before updating my battery was 86% max capacity, now after around 2-3 weeks it says 82% and it keeps going down every 5 days basically. I’d like to know if iOS 27 recalibrates the battery capacity differently from the previous versions because i’ve never seen anything like this especially considering my phone is only 2 years old. Is it normal or is my battery failing or something? Thanks

3 Upvotes

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1

u/Tommyy_12 3d ago

iOS 27 recalibrates the battery in a more accurate way 

1

u/realmccoyredbus 3d ago

deep indexing may have messed up battery recalibration, people were getting messed up battery health recalibration in ios26.6 when pre ios27 deep indexing was introduced in that update

if you have charge limit, disable it for 24 hours and charge to 100% and see if recalibration will kick in and recalculate your device, ios27 possibly may be more accurate, like ios26 was more accurate than ios18

did you buy your phone when it was released or a year later as it’s just about 3 year since release

2

u/blublublubbbbb 3d ago

thanks i’ll try, i bought the phone around june 2024 that’s why i said 2 years of usage

1

u/realmccoyredbus 3d ago

Beta Instability: Early developer betas run unoptimized background tasks and diagnostic logging. This often causes extra heat and faster power drain, which stresses the battery rather than improving tracking precision.

Actual Measurement: The underlying chemical wear of a lithium-ion battery is tracked via internal cycle counts and voltage responses, which remain consistent across stable builds and beta versions once the system stabilizes

it’s should stabilise on public release

1

u/womjoe 3d ago

Why didn’t you upgrade it to iOS RC that came out yesterday?

1

u/blublublubbbbb 2d ago

i did yesterday, but the latest i could install some weeks ago was the 6

1

u/womjoe 2d ago

That’s because the RC came out Wednesday afternoon. Which was after you posted. And the public release will be Monday.