How iOS 18 changes the way you charge your iPhone

Apple has been putting a lot of effort into helping iPhone users prevent premature battery wear -- an issue that's plagued the iPhone for years.

One of the main ways that Apple has addressed this is with overcharging prevention. Lithium-ion batteries can suffer from overcharging, which can lead to the production of metallic lithium inside the cell, posing a fire hazard. By limiting the charge to 80%, the risk of battery damage through overcharging is significantly reduced.

Also: The best iPhone power banks: Expert tested and reviewed

With iOS 13, the company introduced Optimized Battery Charging, a technology that extended the lifespan of the iPhone's battery by reducing the time it spent fully charged. The tech uses on-device machine learning to learn the user's daily charging routine, holding the charge at 80% and only completing the charge to 100% shortly before the user typically unplugs their phone.

With iOS 17, an 80% charge limit option was introduced; charging would be halted at 80% and only resume when the charge level hit 75%. Every so often, the battery is charged to 100% to ensure that information about the battery's health and capacity is accurate.

Now -- with iOS 18 -- the operating system will take a more hands-on approach to improving battery life by recommending a specific charging limit to users through a notification. The latest iOS introduces a new set of charging options -- 85%, 90%, and 95% -- to choose from. The charge limit recommendation can also be found in the Settings app under Battery > Charging.

In the example below, the iOS 18 beta is suggesting to me -- via highlighted green text -- that I could get away with setting the limit at 85%. 

So, what's going on here? Wouldn't limiting charging to 80% be the best option for long-term battery health?

Probably, but not by a huge amount, and this is a compromise that will make people happier. While I've been more than happy with limiting my charge to 80%, there are a lot of people see a 20% cut in battery capacity as unacceptable. Additionally, newer batteries can handle being pushed more than batteries that have been through many months or even years of charge/discharge cycles.

The older the battery, the more sensitive it will be to overcharging, and the more wear it will suffer from being pushed too hard. 

Also: The best iPhone models you can buy right now (and if you should wait for iPhone 16)

As of the latest iOS 18 beta, this charge limit feature is only found on the iPhone 15 lineup; the option is not showing up for iPhone 14 handsets or older. I hope that Apple will roll this out to older handsets, as it will help keep older hardware in use for longer.