Apple’s MagSafe charging puck does peak at 15W with iPhone 12 in new testing shows. However only when it paired with the company’s 20W adapter. Aaron Zollo of YouTube channel Zollotech found this explicit restriction. In a comprehensive assessment of Apple’s MagSafe uploaded on Monday, Zollo found two Apple adapters. It’s a new standalone 20W USB-C device and the 18W unit that came with iPhone 11 Pro handsets achieved high rates of charge.
In the video, it measured energy throughput with an inline digital meter. And it revealed MagSafe hits the advertised 15W peak charging rate when paired with Apple’s branded 20W adapter. Zollo notes the system takes some time to ramp up when speeds drop to about 13W with the 18W adapter.
Apple’s own 96W MacBook Pro USB-C adapter created out 10W with MagSafe. It match a high seen by Anker’s PowerPort Atom PD1. Third-party models and older adapters with high output ratings do not fare well in the test. Similarly, charging rates hovered between 6W and 9W when attached to other adapters. For example: Google’s Pixel adapter, Samsung’s Note 20 Ultra adapter, Aukey’s 65W adapter. To stable energy, ensure fast delivery when connected to iPhone 12 series devices, third-party devices will need to adopt a MagSafe-compatible power delivery profile
As can be expected with any charging solution, temperature plays a significant role in potential throughput. Zollo found MagSafe significantly throttles speeds as temperatures rise, meaning actual rates are not a constant 15W even when using the 20W adapter. In some cases, this could prompt users to remove their iPhone from its case — including Apple-branded MagSafe models — to achieve maximum thermal efficiency.