So, what’s going on here, and how can it be fixed? The good news is that, in most cases, the fix is simply a bit of patience. Hard as it may be to believe, ignore it and the problem will likely go away on its own.
That’s because when you download a new version of iOS, a lot of stuff happens in the background. Data is optimized for the new software, battery settings may be recalibrated, apps might need patches and you may even find your photos being rescanned if the update has included new algorithms.
All of these things use up juice, but it’s a temporary problem. After a couple of days, your battery should have adjusted and things should return to normal.
Indeed, Apple has said as much in the past. “It's normal for your apps and features to need to adjust up to 48 hours after an update,” the company’s Twitter support account told users when it was iOS 15.4 drawing complaints last Spring.
In other words, you shouldn’t let the warnings worry you — although, maybe delay the upgrade to a time when you won’t be without a charger for an extended period.
Personally, I updated my iPhone 14 Pro to iOS 16.5 a couple of days ago, and didn’t notice any battery drain issues. But if there is anything systemic, you can bet your life that Apple will put out a further update soon tackling the root of the issue (as it did with iOS 15.4.1, which arrived within a fortnight of widespread issues being reported).
But what if you’ve waited 48 hours and your iPhone is still struggling for stamina? The first thing to do is to check your iPhone’s battery health, which is hidden in the Settings menu. Simply scroll down to “Battery,” tap it, and then select “Battery Health”.
At 80%, Apple will tell you to get a battery replacement, but if it’s sub-90 and you’re struggling, you may want to go before the prompt. But don’t forget there are ways to make your iPhone battery last longer that don’t require surgery at the Apple Store too.