Smartphones have become increasingly more powerful over time and this puts a strain on batteries. Battery technology has not progressed as fast as chip or display technology and lithium ion batteries have their limitations.
One of the key limitations of current battery technology that we have on smartphones is that they eventually degrade.
Last year, people complained that their iPhone started to feel slow when they became older. Apple later on confirmed this where they revealed that they released a fix for the iPhone 6, 6S and the SE which ‘smooths out’ CPU demand for when a battery is older. Interesting enough, when someone replaced the battery, the performance became better.
Apple will start ‘dynamically manage performance peaks’ to prevent shutdowns on the iPhone XS, XS Max and iPhone XR starting with iOS 13.1. The iPhone XS and the XR are only a year old and it seems Apple is proactively doing this to manage the performance of these iPhones.
Apple says that users will not see a perceived change with the newer models so you shouldn’t be worried. However, the perceived change will depend on the how much the performance management is required for a device.
The iPhone 11, 11 Pro and 11 Pro Max situation is a bit different
In a new support document, Apple has revealed that they have a new built in software and hardware system for the iPhone 11 , 11 Pro and 11 Pro max that will reduce performance impacts as their batteries age. According to Apple, this system is automatic and will work to give the best possible performance as battery aging occurs.
There is a way to check the battery health of your iPhone. Go to Settings > Battery > Battery health and it will give you information like maximum capacity, peak performance capability and a toggle to optimize battery charging to make it last longer.
However, Apple does not promise that it will be well if your shiny new iPhone 11/ 11 Pro will have performance issues when its battery ages. You will notice things like longer app launch times, lower frame rates, reduced wireless data throughput, backlight dimming or lower speaker volume with a degraded battery.