Your Magic Keyboard Could Be Charging Your iPad Pro More Slowly (Here’s Why)
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When Apple unveiled its new Magic Keyboard for the iPad Pro earlier this year, one of the features that came along with the revolutionary Smart Connector-based keyboard was a USB-C port to offer a more convenient way to hook up a charger to your iPad Pro, or even Apple’s newest iPad Air.
It turns out, however, that if you’re not using the right USB-C adapter with your Magic Keyboard, you won’t be getting the fastest charging speeds. In fact, you may find that your iPad is charging at a glacial pace compared to plugging a USB-C cable directly into your iPad’s USB-C port.
This was actually something that came up during the early reviews of the Magic Keyboard last spring, with Daring Fireball’s John Gruber originally noting slower charging speeds that didn’t match what other reviewers were seeing.
While this discrepancy was never addressed at the time, we recently figured out exactly what was going on in light of other recent reports of charging inconsistencies with Apple’s new MagSafe Duo.
The Culprit
Just like the MagSafe Duo, it seems the culprit is once again Apple’s original 29W USB-C Power Adapter — the one released back in 2016, and the only USB-C adapter that Apple offered for Fast Charging the original iPad Pro models as well as the iPhone 8 and iPhone X when they first debuted.
It’s unclear whether it’s the circuitry in the Magic Keyboard itself or a function of the new Smart Connector found on the 2018/2020 iPad Pro and 2020 iPad Air models, but in either case it appears that the USB-C charging connection through the Magic Keyboard only supports 9V for higher-power USB-C adapters — exactly like the MagSafe Duo and the HomePod mini.
Since Apple’s 29W USB-C Power Adapter doesn’t support the 9V spec, this means that when you use it with the Magic Keyboard, it has to fall back to the standard USB 5V charging level, which provides only 12W of power (5V @ 2.4A), rather than the full 29W that would otherwise be available. This of course is noticeably slower than the 18W USB-C adapter that Apple ships with the iPad Pro, much less the 20W adapter that comes with the new iPad Air.
In other words, if you use Apple’s 29W USB-C Power Adapter with the Magic Keyboard, you might as well be using the 12W USB Power Adapter that came with Apple’s Lighting port iPad models, as you’ll be charging at the same rate.
After bringing this up on Twitter, John Gruber clarified that he was in fact using Apple’s 29W adapter when he did the original review, confirming our findings.
Former colleague Nick Guy, of Wirecutter, also helpfully chimed in with an actual measurement illustrating that the Magic Keyboard does in fact draw around 2.4A at 9V when charging from a proper USB-C adapter (Apple’s much more powerful 87W charger, in this case), effectively drawing around 21W.
We’ve since confirmed these measurements as well, noting that the Magic Keyboard does in fact only draw 12W — 5V at 2.4A — when connected to Apple’s 29W USB-C charger.
The Bottom Line
To be clear, this problem will only occur with the 29W USB-C Charger that Apple discontinued in 2018. However, it’s an important distinction, since it’s a charger that many Apple users are likely to have in their collection, since it was the only first-party USB-C charger Apple offered back when it added fast charging to the iPhone 8, iPhone 8 Plus, and iPhone X in 2017.
By June 2018, Apple had quietly replaced that earlier 29W charger with a 30W version, and while the distinction seemed very subtle at the time, the new charger actually introduced support for the USB-PD 3.0 spec, which includes 9V charging at up to 27W (3A), although based on our testing the iPad Pro, iPad Air, and Magic Keyboard won’t draw quite that much.
That said, the iPad Pro and iPad Air — as well as all of Apple’s recent iPhones — still support the 14.5V spec used by the original 29W USB-C power adapter; in this case it’s only the Magic Keyboard that’s the problem. So if you find yourself forced to use an adapter that doesn’t offer the 9V spec, you can still power up your iPad Pro or iPad Air just as quickly by plugging the charging cable directly into the iPad’s USB-C port, instead of the one on the Magic Keyboard.
However, as long as you’re using a newer USB charger that offers 9V charging — basically any USB-C power adapter that Apple has released in the past two years — you should get the same charging speeds with the Magic Keyboard’s USB-C port as you get from a direct connection.