The battery life of the old iphone is reduced after upgrading ios 17.

After the old iphone was upgraded to ios 17, the battery life decreased due to the recalibration of the battery health.

Every time the system is upgraded, the new system will integrate the underlying architecture data of the mobile phone, such as index, underlying data integration and so on. Because everyone's iPhone usage is different, this process will last for several hours or even a week. In addition, a large number of applications need to be updated to adapt to the new system, which will take some time.

In fact, this is because the battery will be recalibrated every time the system is updated. In fact, the battery efficiency has also decreased before, but it was not shown before upgrading the system.

From the three-hour endurance test, the remaining power of iOS 16.6 is 62%, while that of iOS 17 is 69%. Thanks to the better battery optimization of iOS 17, the battery life has indeed improved.

After the update, you can feel that the new transition animation is smoother. In addition, although the function of the updated version is limited, it also includes many minor upgrades and widget support, such as being suitable for remote delivery and its new sleep clock and wallpaper.

Causes of low battery health and frequency reduction

Apple's A series processors have strong performance and high power consumption, so they also have high requirements for the output power of batteries. If the battery voltage is unstable, it is easy to cause the phone to suddenly shut down and restart. In the past, Apple's mobile phone was easily turned off automatically outdoors in winter, and it could hardly be used normally, which was also caused by insufficient power supply of lithium polymer battery in cold environment.

Therefore, in order to avoid the accidental shutdown and restart of these old small-screen mobile phones during use, Apple added a processor frequency reduction mechanism to the iOS 10.3 version. When the system detects that the battery is in low health, the CPU and GPU of the processor will automatically reduce the frequency and power consumption. In this way, there will be no accidental shutdown and restart caused by insufficient battery power supply, but the phone is disconnected and stuck.