Very true!! This has been happening since the beginning. I remember I first experienced this when I updated my iPhone 6s (which came with iOS 9) to iOS 10. I immediately lost an hour of screen on time. And an hour of SOT was a lot on that phone. I could only get around 7 hours at best. Was down to 6 hours on iOS 10.
Then when I updated my 7 Plus to iOS 11, I lost 2 hours of SOT!
Funny enough, updating my iPhone X to iOS 12 did not decrease its SOT. I’m assuming it’s because iOS 12 was focused on fixing all the iOS 11 issues. However, updating it to iOS 13 ruined it.
That made me get an 11 Pro. I don’t think the 11 Pros SOT reduced when I updated to iOS 14. Even if it did, it was very gradual. Maybe 30 mins less. And then another 30 mins less on iOS 15.
I held onto my 11 Pro until this year, when I finally upgraded to a 14 Pro. I updated this puppy to iOS 17, and my SOT went down by 2-3 hours. It’s unacceptable! I have gone back to iOS 16.6.1. Gonna stay here for as long as I can.
And in case anyone’s wondering, I always restore and set up as new when doing major updates. I never restore from backups. I always make sure the OS is “fresh”, because I do not want to deal with battery issues! With the iPhone X, I tried multiple restores, DFU restores, and even used the phone without signing into iCloud. It still drained faster and was running warm. Terrible!
Yeah, this happened to every iPhone in existence, barring the iPhone 15 (because it hasn’t been updated... yet).
There’s nothing you can do afterwards. That’s the sad part. Battery health doesn’t matter. You can replace the battery, it won’t get what it got on its original iOS version. Once you hit that update button, it’s over.
Updating has its advantages, of course. But users must be aware that there is no solution once they update and this happens.
The few older devices posts I’ve seen about iOS 17’s battery life have been very, very poor. It’s sad, because say, an iPhone Xʀ, an iPhone 11, those devices are completely usable today. Yet users will struggle for absolutely no reason. Plus models! The iPhone 6 and 6s plus were iOS’ initial foray into good battery life. Both were obliterated by iOS 12 and 15, respectively. There’s no battery size, replacement, or health that can save an iPhone if it’s updated far enough.
I’m running the Xʀ on iOS 12. Is it old? Sure. But that doesn’t mean it has to be pathetic. 16 hours of light Wi-Fi SOT, 11-12 of heavier LTE use. Massive camera use with full brightness is still close to 10 hours. It’s incredible. I’ve been using it for four years and I’ve never needed a middle-of-the-afternoon charge. Not once. Even with heavy usage. Like original Xʀ users said, with moderate usage it’s a 2-day phone, easily. There’s no reason why that should be any different.
I would be the first person to praise Apple and update everything I have as soon as they guarantee like-new, original iOS version’s battery life on subsequent updates. I have to recommend people to stay behind as long as this isn’t the case. People who upgrade every year don’t care. The majority who doesn’t will be thankful.
From my circle, those who follow my recommendation to stay behind have never complained about battery life, and their numbers are amazing. Many have followed my advice after being burned by iOS updates before. I’ve checked that this works myself, with over a decade of experience doing this. Like many, I was burned once. After that episode, I told myself I’d try to stay behind and I’d see what happens. It was a one-way road. Never again hitting that update button.
There’s no reason why amazing devices like the iPhone Xʀ, 11, 13, 10.5-inch iPad Pros, and others should forcibly struggle just because they are a few years old.