Update: It is required for an adapter to be compatible with USB-C PD 3.0 and the PPS standardsin order to support 15W wireless charging via MagSafe.
Correction: Earlier, we stated that Aaron from ZolloTech achieved the test results due to inconsistencies in factors such as the temperature of the phone and the charging puck. However, Aaron clarified to The 8-Bit that he conducted the tests multiple times and also tried to place his iPhone 12 Pro in the freezer for some time to cool it down. He discovered that third-party adapters require USB-C PD 3.0 support for MagSafe to output 15W.
Earlier this week, YouTube channel ZolloTech posted a video in which the creator, Aaron Zollo, tested different power adapters of varying wattages to see if they support 15W charging on Apple’s MagSafe Wireless Charger. As a result, he concluded that only Apple’s 20W power adapter was capable of doing that.
However, another YouTube channel by the name Alvin Lim posted a follow-up video embedded at the end of this story) in which he claims to have “debunked” Aaron’s claims. It turns out, other third-party chargers indeed support 15W through MagSafe.
How it works is simple, too. According to Apple, a power adapter of 20W or more is required in order to overcome any inefficiencies in wireless charging. But what Apple didn’t clearly mention is that not every power adapter will work. Only USB-C PD adapters that follow a specific power profile, which, reportedly is 9V 2-3A over Apple PD 3.0 and PPS (Programmable Power Supply), offer 15W charging via MagSafe. Although, the requirement that they should be equal to or more than 20W still holds true.
There aren’t many PD chargers out there that support this profile, but enough of them exist. However, the adapters that Aaron used in his testing weren’t compatible. We’ve reached out to Apple for comment and will update this story once we receive a response.
Other factors like battery level, the temperature of the MagSafe Wireless Charging puck, if Optimize Battery Charging feature is enabled on the iPhone also matter when it comes to the amount of power your iPhone draws. In Alvin’s video, even Apple’s official 20W charging adapter couldn’t reach full 15W on the MagSafe Wireless Charger because of the increased temperature of the puck.
Alvin also tested a 120W PD adapter that supported the charging profile that Apple uses for MagSafe. As a result, the adapter was able to output 18W. However, it’s unclear if the iPhone 12 accepts that much. Apple’s 18W power adapter consistently pushed less than 15W, which was expected.
Apple stopped including a power adapter along with a pair of EarPods in the box along with the iPhone 12 lineup in hopes of reducing electronic waste. By extension, the MagSafe Wireless Charger does not ship with one as well. This has got users scrambling for USB-C adapters that support 15W charging wirelessly via MagSafe as there have been considerable amounts of confusion relating to that. Now, thanks to Alvin Lim’s video, it’s established that any 20W USB-C PD charger having the power profile of 9V~2.2-3A will support 15W on MagSafe.
Although buying the correct power adapter for MagSafe seems complicated because of inadequate transparency, it will become easier in the future as third-party manufacturers begin marketing their supported USB-C power adapters as MagSafe compatible.