iPhone + Magnets + Qi + NFC = ✨fun✨
In late 2020, the iPhone 12 series was released with a new feature: MagSafe
MagSafe, that sounds familiar..
MagSafe was (and now is) also what Apple called their magnetically attached power cord for their MacBook lineup. It’s totally different to the tech found in iPhones and I’ll be referring to “MagSafe for iPhones” as just “MagSafe” for the rest of this post.
So, what is MagSafe?
MagSafe is a method for attaching devices magnetically to the back of your iPhone (12 or newer except SE). The Magnet array and Alignment magnet in the below “exploded view” are what allow for that attachment. In addition to attaching, the Charging coil allows for charging and the NFC allows for communication with the attached device.
Exploded view of iPhone 12 showing internal MagSafe hardware (Reference)
Attachable devices will need a corresponding magnet array to attach to the phone as well as corresponding charging coils and NFC to provide charging and/or communication.
This opens up an ecosystem of MagSafe accessories that can attach to iPhone 12 and 13 models and presumably be forwards compatible with iPhone 14 and later.
Diving into each component of MagSafe:
Magnets
Apple has made the magnetic and physical specifications for MagSafe cases and Accessories publicly available (see p117 of Accessory Design Guidelines for Apple Devices) which let me infer the magnetic layout of the iPhone:
Looking at the green cutaway sections, you can see the North and South magnetic poles and a non-magnetized area separating them.
Leaving out the non-magnetized area and extending the poles gives you the magnetic layout “A” below:
Devices with the “A” MagSafe Magnet Arrangement are the iPhone (and presumably the Magsafe AirPods cases) and devices with the “B” arrangement are designed to attach to “A” devices. Note that I’ve given them the A and B designation, you won’t find this in Apple’s docs. Since the north and south are swapped on A vs B, this allows for the magnetic attraction.
Blue (North) attracts Red (South) on the inner circle, outer circle and alignment lines.
*click*
This is also why you can’t perfectly align two “A” or “B” devices. They may magnetically attract to each other but won’t align properly due to them having opposing magnetic fields.
MagSafe Wallet and Magsafe Battery (both “B” devices)
I’ll leave it as an exercise to the reader to figure out whether the MagSafe case for your iPhone is an “A” or “B” device 😉.
That the MagSafe specs are public means it’s possible for anyone to build a device that sticks to the back of your iPhone (or “A” device) and can claim to be “compatible with Magsafe”. This is referred to as MagSafe Attach in Apple’s Documentation.
Charging Coil
iPhones have had built in wireless charging using the Qi Standard since the iPhone 8 and ones with MagSafe retain compatibility with existing Qi chargers.
Charging iPhones that have MagSafe
Using a Qi-Certified Charger – up to 7.5w
Using Apple’s (or Made for MagSafe) Charger – up to 15w
iPhones sending power to Accessory
iPhones with MagSafe can also send up to 5w to an attached accessory (currently only MagSafe Battery Pack is supported)
NFC
On iPhone
There isn’t any publicly available information about the MagSafe NFC chip on the iPhone or it’s capabilities. For the moment, it’s used to show MagSafe-related animations, charge levels and interface changes when compatible accessories with NFC are attached.
On Accessory
It appears that only Apple and Licensed third parties (ones with “Made for Magsafe” logo on boxes) can add compatible NFC chips to accessories. That hasn’t stopped some manufacturers from adding these NFC chips:
- You can buy a case NFC sticker from Zeera that gives third party cases the MagSafe case animation on iPhone. I highly doubt a licensed manufacturer would be allowed to do this.
- You can buy accessories like this charger stand that shows the Magsafe charging animation on iPhones.
If you want to dig deeper into reverse engineering or understanding the NFC used in MagSafe, pick up these reddit threads here and here.
Time to look at accessories!
Accessories fall into three main categories (with the 4th included with caveats):
- Magnets only
- Magnets + NFC
- Magnets + NFC + Charging Coil
- Magnets + Charging Coil (No NFC)
1. Magnets Only
You can attach things to the back of your phone like this Moft Wallet:
And this Anker Ring Holder:
You can also attach your phone to things using various mounting options like these from Moment:
2. Magnets + NFC
Adding NFC to accessories allows for special features:
- Apple Silicone/Leather/Clear Case with MagSafe – Shows animation when putting on case.
- Apple Leather Wallet with MagSafe – Shows animation and vibrates iPhone when attached, vibrates iPhone when detached and Enables Find My support.
- Apple Leather Sleeve with MagSafe – Changes background color to match sleeve and shows notifications through the cutout in the sleeve.
These are the currently available Apple accessories, I haven’t seen any third party “Made for MagSafe” accessories yet in this category.
3. Magnets + NFC + Charging Coil
Adding a Charging coil to the NFC and Magnets gives you ⚡️charging⚡️. Very important note here is that only MagSafe accessories with the NFC chip (Apple and Licensed third parties with the Made for MagSafe logo on the box) can charge your phone at up to 15w.
You can get charging stands like this one from Belkin:
Wired Chargers like Apple’s:
And attachable and portable battery packs like the MagSafe Battery, also from Apple:
4. Magnets + Charging Coil (No NFC)
Here’s where a lot of the confusion regarding chargers lies. Since iPhones already support Qi wireless charging, some accessory manufacturers are attaching magnets to Qi chargers and marketing them as “MagSafe compatible” with only 7.5w charging. If you want the real deal with 15w charging, make sure the accessory is either made by Apple or has the “Made for MagSafe” logo on the box. More information can be found here.
Commentary and Closing
This was a fun one! I particularly enjoyed looking over Apple’s mechanical drawings and figuring out why the magnets are arranged like they are. I could have gone into more depth about my speculation regarding the design but I’m no magnet engineer 😃. Suffice it to say, the design is pretty smart.
MagSafe is interesting because it’s the first time that a major phone manufacturer has standardized an accessory attachment that is expected to last multiple phone models. The downside is the available accessories have been fairly unexciting due to what’s allowed by Apple. The upside is that you can take all your MagSafe accessories with you if you upgrade your phone. One question remains, when’s Samsung copying MagSafe?
If you have any questions/would like to share your experience with MagSafe, leave a reply below. To get an email when I write another post, click here to subscribe. Thanks for reading!
(Featured image (the one at the top of this post) remixed from this photo by Studio Proper on Unsplash)
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