Apple unveiled its iOS 26 update on September 15, introducing a sleek new Liquid Glass design and other system enhancements across its ecosystem, including macOS 26, iPadOS 26, tvOS, and watchOS 26. However, this update also brought an unexpected change for many iPhone users. Regardless of whether they own a brand-new iPhone 17 or an older model, a “Slow Charger” warning now appears when charging with a USB Type-A to USB Type-C adapter. Interestingly, this alert doesn’t show up when using Apple’s official chargers or other 20W (or higher) USB Type-C to USB Type-C adapters. The update also added a handy feature that displays the estimated time to reach an 80 percent charge.
Understanding and Solving the ‘Slow Charger’ Issue on iOS 26
Many iPhone users, like yourself, have noticed this “Slow Charger” warning when using USB Type-A to USB Type-C adapters that deliver less than 20W of power after installing iOS 26. Our team at Gadgets 360 independently confirmed this issue, observing the same message on an iPhone 15 and an iPhone 16 Pro Max running iOS 26 when using 18W USB Type-A to USB Type-C adapters from brands like Samsung and OnePlus.
While seeing this warning might be concerning, it’s generally not a problem for most users. The message simply indicates a slower charging speed and, crucially, does not harm your iPhone’s battery. In fact, slower charging can actually be beneficial for your battery’s long-term health, as it generates less heat, which can reduce wear and tear over time.
If you typically charge your phone overnight, the slower speed won’t be an issue. However, if you need to power up quickly before heading out, a slow charger can definitely be inconvenient. In such cases, you might want to switch to a compatible charger that delivers 18W or faster charging.
The latest iPhone 17, iPhone 17 Pro, iPhone 17 Pro Max, and iPhone Air models, launched by Apple on September 9, come pre-installed with iOS 26. The launch of the iPhone 17 series also introduced faster charging capabilities for the standard iPhone 17.
For optimal charging speeds on the iPhone 17 lineup, Apple suggests using their ‘Apple 40W Dynamic Power Adapter with 60W Max’. Similar speeds can also be achieved with other third-party 40W USB Type-C to USB Type-C adapters.
However, if fast charging isn’t a priority for you, there’s no need to replace your current charging adapter. For iPhone 16 and older models, Apple’s 20W USB Type-C adapter is an ideal choice for faster charging. Alternatively, you can explore Made for iPhone (MFi) certified 20W or 40W adapters from other reputable manufacturers.
Beyond the charging warnings, iOS 26 also brings helpful battery management features. Supported iPhone models now display the estimated time until they reach an 80 percent charge. This is particularly useful for users keen on preserving their battery life. Apple also allows you to set a maximum charge limit between 80 percent and 95 percent and activate optimized charging, which intelligently adjusts charging patterns to reduce battery aging.