As first reported by Mac Rumors, Apple has updated its support documents that shine light on the functionality between the iPhone 12 models and the new MagSafe chargers.
iPhone 12, 12 Pro, and 12 Pro Max will reach peak wireless charging speeds of 15W while the iPhone 12 mini will reach peak speeds of 12W. Actual speeds will vary on a number of factors including temperature, current battery charge, and system activity. The support document recommends to use at least a 20W USB-C charger for optimal charging speeds of 9V@2.22A or 9V@2.56A and higher for the three higher-tier iPhone 12’s, and at least 9V@2.03VA to reach peak speeds on the iPhone 12 mini.
It’s also recommended to first connect the MagSafe charger to power before attaching an iPhone 12. If you dock the iPhone before plugging in the MagSafe charger, it will default to a lower current until you remove it for three seconds – this will ensure maximum charging speeds. The MagSafe charger will default to 7.5W output when charging AirPods, and possibly even slower if it’s a Qi-compliant device.
The iPhone 12 Mini and the iPhone 12 Pro Max are not yet on sale. They will become available starting this Friday November 6. Meanwhile, the MagSafe wireless charging is available from Apple for $39.