Over the years, Apple has continued to improve the battery life of iPhones with bigger batteries and more efficient chipsets. The brand has also optimized the software to consume less power and added features that can help with better battery longevity. With iOS 26, the company added a new Adaptive Mode that is said to improve the iPhone Air’s efficiency by learning usage patterns. While the Adaptive Power feature didn’t improve the battery life much on our unit, it may end up being beneficial for you.
Another feature Apple rolled out earlier is the ability to limit the iPhone’s charging capacity, either to 80% or a custom number. Doing this should theoretically make your device’s battery last longer because you’re not completing a full cycle every time you charge it. However, for the second year in a row, MacRumors decided to cap its iPhone’s maximum charging capacity to 80% to see if it made a difference. Spoiler alert: it didn’t.
Last year, MacRumors performed the test with an iPhone 15 Pro. They would spend a lot of time using the phone with less than 20% charge, which some users suggested could be an issue. So with the iPhone 16 Pro Max, they were careful about maintaining their phone’s charge between 20% and 80%. With 299 charge cycles, the iPhone battery’s maximum capacity was reduced to 94% after a year. The test involved a mix of MagSafe and USB-C charging. MacRumors stated that capping the iPhone battery to 80% was fine as long as they were at home, but this turned into an inconvenience when using the camera or GPS for navigation outdoors.
What’s interesting is that although the iPhone maintained 98% battery health until a couple of months ago, it started to deteriorate faster as September approached. Of course, that doesn’t imply that Apple is purposely deteriorating batteries ahead of an iPhone release; these components deteriorate with time. For example, the publication’s iPhone 15 Pro Max unit has 352 cycles and 88% of capacity, down from 94% in September 2024.
The test conducted by MacRumors is a much better representation of a real-world scenario compared to a scientific test conducted in a lab. The outcome is that capping your iPhone’s battery level to 80% can be frustrating if you use it a lot outdoors. Moreover, it doesn’t improve battery health much even after a year. The simplest way to preserve battery life is to just use your iPhone without worrying too much. Batteries are designed to deteriorate over time, no matter what you do or how you use them.
Of course, the iPhone 17 Pro’s vapor chamber might help prevent some overheating issues present on previous generations — resulting in improved battery life. Don’t stress about your iPhone battery life; it will last around the same whether you cap your charging limit or not. So instead of charging it to 80% and then suffering from poor battery life throughout the day, it’s better to charge your iPhone fully and get the best out of it when using it daily.