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. Limiting the charge to 80% significantly reduces the risk of battery damage through overcharging.

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With iOS 13, Apple introduced Optimized Battery Charging, a technology that extends the lifespan of the iPhone’s battery by reducing the time it is spent fully charged. The tech uses on-device machine learning to learn your daily charging routine, holding the charge at 80% and only completing the charge to 100% shortly before you typically unplug your phone.

With iOS 17, Apple introduced an 80% charge limit option that halts at 80% and only resumes when the charge level hits 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 — Apple’s operating system allows the user to take a more hands-on approach to minimizing battery wear by introducing a new set of charging options — 80%, 85%, 90%, 95%, and 100% — to choose from. You can find the new charge limit recommendation in the Settings app under Battery > Charging.

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 based on my phone usage. While I’ve been more than happy with limiting my charge to 80%, 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.

The good thing about this feature is that you can adjust these settings to suit your changing needs. If you have a long day without access to a recharge, you can temporarily disable the limit to get a full charge and either set that as a new permanent limit or have it roll back the next day.

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With the release of iOS 18, the charge limit feature is only found on the iPhone 15 and iPhone 16 handsets; the option is not available on older iPhones.

Early beta versions of iOS 18 had a feature that would display a warning for slow chargers, but I could never get this to reliably work and it seems to have been removed from the release version.