iPhone 12 mini battery capacity dropped after iOS 26 update

The iPhone 12 mini was first released 5 years ago and discontinued 2 years ago. A 94% Battery Health lies in the range of being normal to exceptional based on that time frame and Cycle Counts, and likely indicates the battery has been replaced at some point. The phone is only expected to get 500 charge cycles before the battery needs replaced when it drops below 80%. The Battery Health drop is not linear, so you should not expect a regular drop rate and it is not unusual to see no drop at all for some months and several the next month. No single drop seen in a month is what should be expected in future months.

In some cases the updated Battery Settings will not be possible if the device has not been allowed to charge to 100%. There are some that will manually try and control their battery charge by unplugging before it has reached 100% and that just delays any updates seen for Battery Health until they accidentally allow it to make a full charge where a larger drop than expected will be seen since it was not able to do it previously.

That has been true for all iOS versions and the iOS 26 update does not change your Charge Cycles which is the biggest contributor to Battery Health, besides an aftermarket battery install.

The same non-linear drops have been seen across all iOS versions. The usual pattern is that it remains around the 98%-100% area for a longer period of time, where you will see it drop quicker from 85%-98%, then slow once again from 80% - 85%.

With the expected 500 Charge Cycles on the battery, you will not see it drop 1% after EACH 25 charge cycles exactly, but on average over the life of the battery it is expected to be a 1% drop for every 25 charge cycles. Viewing the Charge Cycles is not as easy on the iPhone 12 as it is on newer devices.

michafoto wrote:

As mentioned the battery in my 12 mini that lasted almost four years before needing a battery replacement.

I also find it slightly unusual to see multiple reports online of sudden battery health drops after updating to iOS 26 and 26.1. Some suggest this may be due to iOS recalibrating how battery capacity is measured, but the size and timing of these drops still seem surprising compared with normal battery aging??

Your battery health cannot change overnight. However, yes, iOS26 may calculate (estimate) it differently.

We would have an easier time on here if they changed it to either Normal or Replace your battery.

michafoto wrote:

Thank you for the explanation. I have used the iPhone 12 mini since its release and the original battery lasted about four years before it needed replacement. What I find unusual is that the new, original Apple battery showed a sudden five percent drop within one month, and this happened immediately after updating to iOS 26 and then 26.1. My usage patterns have not changed and I charge to 100 percent regularly, so the system should have had enough opportunities to update the battery metrics. This makes the abrupt decline inconsistent with my previous experience, and my cycle count is not particularly high.

I am also concerned that the battery health may continue to drop at this pace. I know several users with models such as the iPhone 14 and iPhone 16 who have seen the same pattern directly after updating to iOS 26. Their batteries were stable before the update, which makes me wonder whether the update changed how battery health is measured or whether another factor is causing simultaneous drops across different devices.

Who replaced the battery, Apple?