Is it fast to upgrade iphone7 to 15.3?

Iphone7 upgrade 15.3 consumes a lot of power.

After the IPhone7 was upgraded to iOS 15.3, the battery life has indeed improved significantly. Under the previous iOS 15.2. 1 system, the power consumption of headline brushing was 1 1%, and it was 8% when upgrading to iOS 15.3.

After upgrading iOS 15.3, the battery health test results of nine iPhones show that the battery health of only iPhone8 has decreased from 99% of iOS 15.2. 1 to 98% of iOS 15.3, and the battery health of other iPhones has not changed.

Basic information

Battery life of iPhone, iPhone6s, iPhone7, iPhone8, iPhoneXR, iPhone 1 1, iPhone 12, iPhone 13 and iPhoneSE2.

They are 2 hours 47 minutes, 2 hours 29 minutes, 3 hours 14 minutes, 3 hours1minute, 5 hours 9 minutes, 5 hours 28 minutes, 6 hours 28 minutes, 8 hours 13 minutes and 3 hours 14 minutes respectively.

The longest battery life is iPhone 13, followed by iPhone 12, iPhone1Kloc-0/,iPhoneXR, iPhone8, iPhone7 and iPhoneSE2, iPhone 7 and iPhone6s.