IPhone 12 Mini will charge with MagSafe wireless at no more than 12 Watts, compared to 15 Watts for the other models, and in all cases the charging efficiency is very low.
Apple’s baby, the iPhone 12 Mini, will only support slow wireless charging, with the new MagSafe technology offering “casted” power at 12 W maximum. The standard iPhone 12, iPhone 12 Pro and iPhone 12 Pro Max models, on the other hand, will be compatible with MagSafe wireless charging up to 15 W. The confirmation comes from a new page of Apple’s online support, published on the Cupertino giant’s official website.
Apple also states, on the same page, that the actual power provided to iPhone 12s will vary depending on the power adapter’s one and system conditions. To be precise, the iPhone 12 Mini will charge at 12 watts if the MagSafe is connected to a power adapter of at least 9 V and 2.03 A, while the suther models will reach 15 watts with a power adapter of at least 9 V and 2.56 A. Indirectly this confirms that wireless charging, even MagSafe, has a very low efficiency: in the case of iPhone 12 Mini you consume over 18 Watts to charge at 12 Watts, on the other models it takes 23 Watts to charge at 15 Watts. In both cases, in fact, more than 30% of the power delivered by the charger is wasted.
MagSafe, convenient but not perfect
The MagSafe technology for wireless charging, like all similar technologies, is therefore very inefficient from an energy point of view. It’s a bit of a paradox, as Apple says it didn’t include a wired charger in the iPhone 12’s packaging in order to save on CO2 emissions.
The poor efficiency translates into a fair amount of heat production. Apple avverte che “Come con altri caricabatterie wireless, il tuo iPhone o il caricabatterie MagSafe potrebbe diventare leggermente più caldi mentre il tuo iPhone si carica. Per prolungare la durata della batteria, se la batteria si surriscalda, il software potrebbe limitare la ricarica oltre l’80%“.
MagSafe, attenti al campo magnetico
Come tutte le ricariche wireless, infine, anche MagSafe genera un forte campo magnetico mentre è in funzione. Per questo Apple consiglia di non mettere carte di credito, badge di sicurezza, passaporti o portachiavi tra l’iPhone e il caricabatterie MagSafe prima di iniziare il processo di ricarica. Wireless charging, with all technologies and not just MagSafe, can damage the magnetic strips or RFID chips of the cards and make them unusable.
As for cases, however, Apple specifies that explicit compatibility will be needed to allow charging and they must have a uniform maximum thickness of 2.1 millimeters, 2 millimeters is better. Speaking of compatibility, Apple also says that with MagSafe you can charge all Qi-compatible devices, but if your device is not compatible with MagSafe Qi then it may charge slower than with other regular Qi chargers.