Hail to the MagSafe: A deep dive into Apple's new wireless charging connector

In October of last year, Apple rolled out its latest smartphones with the iPhone 12. While there are some similarities to previous iPhones, there’s one notable difference under the hood that enables a new accessory: MagSafe, a magnetic connector that can wirelessly charge your phone.

What’s so special about MagSafe?

MagSafe is both a magnetic induction charging and a magnetic connector technology. The MagSafe trademark is re-used from an entirely different magnetic charging connector for older generation Macbook Pro laptops phased out in early 2019. 

The disc-shaped connector contains rare-earth magnets that allow it to snap and firmly attach to the back of an iPhone. It is about twice the diameter of the magnetic charging connector already in use on the Apple Watch. Unfortunately, the two are not compatible with each other. 

The MagSafe charging specification allows for up to 15W of power to be transmitted using the Qi (pronounced CHEE, from the original Chinese) wireless standard created by the Wireless Power Consortium in 2008. It is the same Qi we have been using for the past 12 years on hundreds of models of smartphones and devices, so if you use it as a charging pad, it also works with older Qi devices but at a lower-wattage charging rate. 

If you place an older model iPhone on top of it — or an AirPods charging case or an Android phone — it will still work but slower. However, the magnetic attachment part only works on an iPhone 12. If you put the iPhone 12 in a case, it needs to be in a MagSafe-compatible charging case; otherwise, it might not stick to the connector, and the induction charging may not work. 

What about cases?

In addition to Apple’s official MagSafe cases, there are other good MagSafe-compatible cases, such as OtterBox and Gear4, that have also hit the market. Be aware that, for a case to be MagSafe-compatible, an adhesive ring made out of a ferrous material has to be affixed to the inside of the case to allow the MagSafe disc to connect.

So far, I have only been able to find “mid-range” protective cases that use this magnetic adhesive. Ultra-thick cases like the classic rubber-coated OtterBox Defender do not have these rings yet; they have to do some additional engineering work to embed them into the plastic and the rubber or create appropriate cutouts for the connector (which would not be ideal). If you have to use a super thick case, forget about MagSafe; use the traditional charging pads or Lightning cables.

Do we like it?

Initially, I was skeptical. Whenever you see Apple talk about something magical and wondrous at one of their events, you have to take a lot of this stuff with a grain of salt until you get to use it. I have not been a fan of Apple’s wireless charging technology to date. It’s slow, especially compared to what Samsung and Google offer with their own Qi implementations, and it isn’t foolproof. 

When using the various third-party charging pads — as Apple did not have its own up until now — it was always an alignment and placement issue; it took too much fiddling. I can’t tell you how many times I put the thing on the pad and hear the “bloop” and then come back an hour later, or even the next morning, and it didn’t charge because the placement was off or it got bumped or whatever. 

MagSafe does not have this inherent problem. The connection from the rare-earth magnet is solid. If the phone is sticking with the magnet, it’s charging, plain and simple. It’s a low tech, keep it simple, stupid solution, which Apple needed to make after aborting that AirPower fiasco that would have never worked.

Can MagSafe replace Lightning or USB-C?

There are a bunch of technical things Apple needs to solve to replace Lightning with Magsafe. For starters, there are inherent power output limitations of MagSafe (15 watts). We don’t know what the actual upper limit is and what they have tested it with. The heat dissipation at higher wattage levels will always be a serious issue with wireless power induction — after all, a not so dissimilar technology is used on magnetic induction cooktops in kitchen applications. 

If Apple wants the iPad and future M-series MacBooks to have this technology, MagSafe will need to transmit upward of 30W to 100W to replace the USB-C/Thunderbolt connector. I don’t see that happening soon. 

There is also the issue of data transmission. Right now, the MagSafe connector appears to be strictly for power transmission. But suppose we lose the Lightning connector in future iPhones. In that case, there will need to be a way for those phones to talk to legacy devices like older Macs, for developers, and for stuff like CarPlay (my 2016 GM car uses a USB-A to Lightning cable to talk to the iPhone).

USB 2.0 has a 480 megabit per second (Mbps) maximum transfer rate. USB 3.0 is about ten times faster. Bluetooth alone can only do about 2 Mbps, so that is not fast enough to transfer video and other types of data. 802.11ax, WiFi-6, has a maximum data rate of about 1.2 Gbps using a single transmit/single receive antenna configuration and approximately 2.4 Gbps with a dual/dual-antenna configuration. Current iPhone models are 4×4 configurations, so their upper limits are comparable to USB 3.0 and 4.0 providing they are communicating with a device that can also communicate that quickly. 

Some of the newer cars can do CarPlay using a combination of Bluetooth and Wi-Fi, and it would seem that this would be the preferred way of doing CarPlay going forward. 

There are some third-party products to adapt your USB ports in existing vehicles to do wireless CarPlay. Still, suppose we want to talk to older devices in an officially supported fashion besides using Wi-Fi directly. In that case, MagSafe will need to do data and emulate a Lightning connector. We are going to need some type of wireless USB-A/USB-C Apple adapter dongle that allows an AirPlay connection to work with legacy USB hosts or some host software that communicates over Wi-Fi with iOS. 

While CarPlay is not the most demanding application using direct iPhone communication, others, such as bulk photo and video exports to Macs and PCs, and uploading developer firmware versions of iOS, require a high-speed connection. If Apple decides to only do data transmission with Bluetooth and Wi-Fi, we’re going to have many angry end-users if that happens.

The official Apple MagSafe connector cable and the ridiculously overpriced Duo charger

The official Apple MagSafe cable is a metal disc attached to a USB-C cable, and you need to use it with a 20W USB-C charger adapter, minimum, to deliver the maximum 15W of power to the iPhone 12. If you own a 12 Mini, the max you will get is 12W. If you use an 18W charger, such as the extremely common Apple A1720, which shipped with the iPhone 11 Pro Max, and you kept it when you upgraded, or another member of your household uses it, this charger will only deliver 11W of power through MagSafe. The MHJA3AM/A 20W USB-C power adapter that ships with the 2020 iPad Pro looks nearly identical to the A1720, and you can only tell the difference if you look very closely at the tiny labeling by the plug.

The USB-C ports on a Mac and USB-C equipped PCs only deliver up to 15W of power, so the output to the iPhone through the MagSafe is going to be significantly degraded. It’s much more efficient to charge your phone using a USB-C to Lightning cable through your computer than using the MagSafe.  Apple has a Support Document that details the power output of MagSafe when connected to various devices and chargers, and it is a bit confusing. 

Apple’s new and ridiculously overpriced Duo Charger (which is $129 and doesn’t even come with a charging block) is a little screwy because it requires 15W of power minimum if you want to use both the Magsafe and the Watch charger at the same time, at a degraded charging speed. 

To get full charging speed on the Duo — 14W, not 15W on this device — you need at least 20W of power output from a USB-C adapter. But according to Apple’s support document, the relatively common 29W MJ262LL/A OEM adapter will not work. So, you will want Apple’s 20W adapter, minimum, or a comparable third-party adapter with at least 20W of USB-C power output to use this one.

Suffice to say; you want at least 20W of power to get the 15W to the iPhone using MagSafe. So you lose 5W in the process. Magnetic induction charging is not very green or efficient, and that’s one of the disadvantages of using this technology.

Using the MagSafe cable and knockoffs

If you use the Apple MagSafe charger by itself and not a third-party product like the Belkin stands, I find that it is annoying and unwieldy to try to place the iPhone on it flat on a table, especially with a case. If you get one of these OEM cables as opposed to one of the other third-party solutions, such as the new Belkin 2-in-1 or the 3-in-1 or the aforementioned Duo charger, I would get one of the cheap MagSafe stands from Amazon, like the KOOPAO, which I bought for my home office. You snap the official MagSafe disc in it, and presto, you have a charger stand. 

That said, I think Apple’s charging connectors and cables are usually overpriced compared to what the third parties do. However, other than the big partners like Belkin and OtterBox, which license Apple’s components to make their products, I would steer clear of third-party MagSafe-compatible products unless they are designed to accommodate the official Magsafe connector cable, or have undergone thorough testing and reviews.

In the past, I have had issues with third-party Apple Watch cables, such as during OS upgrades, and with MagSafe, I don’t expect this to be any different. Don’t cheap out and buy third-party MagSafe connector cables until they are MFi-certified — and right now, I don’t think Apple has rolled out a program like this yet like it had done for USB-C to Lightning cables. It took them over a year before we saw those, and I would expect a similar timeframe for MFi MagSafe cables.

Anker and RAVPower — two companies that I feel to be very reputable with their cable and charging accessories — currently have their own USB-C MagSafe discs, and they are less expensive than Apple. Still, they have not certified their products yet, and while I have asked for production samples, I haven’t used them yet.

Are you using MagSafe yet? Talk Back and Let Me Know.