iOS 18 will warn you if your iPhone charger is too slow

iOS 18 arrived on September 16, bringing a host of upgrades to iPhone just in time for the arrival of iPhone 16, iPhone 16 Plus, iPhone 16 Pro, and iPhone 16 Pro Max. 

All of the new iPhone 16 models support fast charging, and a new feature added with iOS 18 suggests the company is keen for users to make use of this capability. That's because iOS 18 adds a new “Slow Charger” warning to the Battery section of the iPhone’s Settings app, which will appear with continued use of a slow charger.

A new orange color will appear on the Battery Level graph to indicate periods of slow charging, as opposed to green for periods of fast charging. 

As of now, however, we don’t know what charging speed causes the Slow Charger warning to appear, and in turn we also don’t really know what Apple considers fast charging.

As MacRumors reports, the iPhone 16 series is rumored to support charging speeds of up to 45W, but the spec sheets on Apple’s website only quote a USB-C charging speed of 20W and MagSafe charging speed of 30W. It’ll be up to Apple to confirm whether the iPhone 16 series does indeed support 45W charging.

iOS 18 also brings users the option to set a charging cap at 85%, 90%, and 95%, in addition to the previously available 80% limit.

Like many other smartphones, iPhones allow users to cap charging at a certain level to extend the total lifespan of the battery, which is ultimately a consumable component and degrades over time.

Conventional wisdom holds that lithium-ion batteries, like the ones found in iPhones, last longest when charged between 20% and 80%, though this theory is not without its critics.

For the latest news and expert tips on the new features coming to iPhone, be sure to check out our iOS 18 hub.

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