This is what the MagSafe external battery can (and cannot)
The external MagSafe battery can be magnetically docked to the iPhone and charges it. Apple has built in a few special features. The delivery date and price are also fixed.
Instead of the “Smart Battery Pack” solution from earlier times, which was hunchbacked in the true sense of the word, Apple is now selling compact MagSafe batteries as a piggyback solution. The piece costs 109 euros in this country and is initially only available via the Apple Online Store available. The manufacturer’s homepage currently states that the item is not available for collection in a stationary store. As a delivery date for last-minute buyers who have immediate access, Apple names July 21st to 23rd.
The MagSafe battery is charged with a standard Lightning cable. This also works if it is docked at the same time, i.e. the iPhone is charging. In this case, in particular, we recommend using the 27-watt USB-C power adapter that comes with MacBooks. It also works the other way around: if you connect a charging cable to the iPhone in addition to the battery pack, you can charge both devices. Only a few can do that in the now well-stocked MagSafe accessory market.
For all models of the iPhone 12
Apple specifically states that the MagSafe Pack is suitable for both iPhone 12 and 12 mini, 12 Pro and 12 Pro Max. According to the specifications, its capacity is 1,460 mAh. However, the built-in battery of the iPhone 12 Pro has a capacity of 3,687 mAh, that of the iPhone 12 / Pro 2,815. Obviously, you cannot fully charge these Apple smartphones with the MagSafe. Apparently Apple wanted to save weight and size and therefore forego this power. The charging power of the additional pack is 5 watts, which corresponds to the small charging plugs that were included with every iPhone up to the current version. Apple specifies iOS 14.7 as the minimum system, which will probably appear in the next few days.