I really love using my 12.9" iPad Pro in my office. I use it to review and edit documents, to do legal research, and to manage email — sometimes in connection with the computer on my desk, sometimes instead of using the computer. The battery in the larger iPad Pro lasts a long time, but sometimes after using it all morning and then into the afternoon, I notice that I am starting to run a little low. With prior models of the iPad, this was not a problem because I had a Lightning cable on my desk plugged in to a USB power adapter next to the desk, so I could just plug in the iPad and continue to use it, restoring power as I was using the iPad. For the 12.9" iPad Pro, however, that isn't a great solution because the 12W USB Power Adapter that Apple includes with the 12.9" iPad Pro just barely puts out enough power to keep a 12.9" iPad Pro going, unless the screen brightness is turned down. So if you plug in when you are at 17% and continue to use the iPad Pro, you are not going to get much higher than 17%. Last week, Apple introduced a solution to this problem: Apple's USB-C to Lightning Cable, to work with the Apple’s USB-C Power Adapter.
A little iPad power history
When Apple first released the iPad in 2010, it included a 10 watt (10W) power adapter along with a USB to 30-pin cable. In October of 2012, Apple introduced the iPad 4 and iPad mini, the first iPads to use a Lightning connector instead of the old 30-pin connector, and Apple included a USB to Lightning cable and a new 12W USB power adapter — a slight increase to keep up with the additional power needs of newer iPads. Since that time, Apple has included 10W or 12W USB power adapter with every iPad.
The 12.9" iPad Pro introduced in September of 2015 was the first iPad to support a feature called fast charging, the ability to charge more quickly by using a power adapter with more oomph than 12W. It is still the only iPad to support this feature; even the 9.7" iPad Pro introduced last week doesn't support fast charging. But for 12.9" iPad Pro users, the fast charging feature was inaccessible because there wasn't yet a way to get more than 12W of power to the 12.9" iPad Pro. Sure, Apple sold a USB-C Power Adapter with 29W of output, but it could only be used with Apple's MacBook laptop (which has a USB-C port) via a USB-C to USB-C cable.
Last week, Apple announced its new USB-C to Lightning Cable, a way to use that 29W USB-C Power Adapter with a 12.9" iPad Pro. Apple currently sells two versions of the cable: a $25 1 meter version, and a $35 2 meter version. I bought the 2 meter version from Apple, and I also purchased one of the Apple USB-C Power Adapters that have been available on Amazon for a while now for $49. (Although I paid $49 on Amazon last week, I see that they are currently selling for $58 on Amazon; I presume that the price will soon return to $49, or you can just buy it for $49 from Apple.)
USB-C Power Adapter
The 29W USB-C Power Adapter is square, just like the 12W USB Power Adapter, but is slightly bigger — about 2 1/8" on each side instead of about 1 3/4" on each side. The thickness stays the same, about an inch.
Just like the old power adapter, the prongs on the new power adapter retract, making it easier to carry around without scratching something.
The main difference, of course, is the support for USB-C instead of USB. I've never considered USB to be a big connector, but it is huge compared to the tiny slot required for USB-C.
USB-C to Lightning Cable
The new USB-C to Lightning Cable has on one end the Lightning connector that we've been using since 2012, and on the other end has the USB-C connector. Apple's proprietary Lightning connector is a little bit smaller than the non-proprietary USB-C connector, but the size is similar.
Like the Lightning connector (and unlike traditional USB), you can plug a USB-C connector in either way, which is big improvement over normal USB.
Performance
The reason that many 12.9" iPad Pro users will want to use the USB-C Power Adapter along with the USB-C to Lightning Cable is performance. The 29W of power makes a big difference.
As I noted above, with the 12W adapter, and with my screen brightness at 100% or something close to that, I barely noticed any charging at all while I was using my 12.9" iPad Pro. Thus, the only way to increase the battery percentage was to either (1) turn down the brightness quite a bit, which still only increased the charge marginally if you were still using the iPad while charging it or (2) turn off the screen completely, and then wait almost five hours to go from 0% to 100%. This was one of my biggest gripes with the 12.9" iPad Pro. If I used my 12.9" iPad Pro for much of the day on Monday and forgot to recharge it overnight, it was almost impossible for me to increase the battery percentage on Tuesday while I was also using the iPad Pro.
With the 29W USB-C Power Adapter and the USB-C Lightning Cable, I don't have this problem anymore. I can use my 12.9" iPad Pro with the brightness is at 100% and I'll still see about a 2-3% battery increase about every five minutes that it is plugged in. This means that in about an hour, I can get about an extra 25% or so of power added to my 12.9" iPad Pro, even if I have been using the iPad Pro during that entire hour. I can then pick up my iPad Pro to go work in a partner's office or in a conference room and have enough additional power to go for hours.
The performance increase that I saw is confirmed by a test performed by Federico Viticci over at MacStories, described in this report which is a must-read for anyone considering buying these products. Using special software that measures iPad charging, Viticci found that a 12'9" iPad Pro that is in use with 100% brightness takes over 12 hours to go from 0 to 80% with the 12W charger, but only 107 minutes with the 29W charger. With the screen turned off, charging from 0 to 80% went from about 3.5 hours with 12W charger to about 1.5 hours with the 29W charger.
Viticci also found that, at 100% brightness, the 12W charger charged the 12.9" iPad Pro by 1.1% every 10 minutes, but that was when the iPad was just on the Home Screen. As indicated above, if I am actually doing something with my iPad Pro while plugged in to the 12 W charger, I don't see any battery increase at all. He also found a 7.5% increase every 10 minutes on the Home Screen. In my tests where I was actually doing something with the iPad Pro such as read PDF documents in GoodReader, I saw about a 4 to 6% increase every 10 minutes.
Other devices
By the way, you can use Apple’s USB-C Power Adapter and USB-C to Lightning Cable to charge other devices, such as an iPhone. They won't charge any faster than they would with the older 12W charger, but they will charge. So if you purchase this as a solution for your 12.9" iPad Pro, you will also be able to charge your other devices with Lightning connectors.
Conclusion
The 29W charger is nice if your screen is turned off. You can charge your 12.9" iPad Pro more than twice as fast, useful if you are charging your iPad Pro while you are at lunch. But where you really see the performance increase is when you are both charging and using the iPad Pro at the same time.
If you own the 12.9" iPad Pro, should you spend $49 on the USB-C Power Adapter plus another $25 or $35 for the cable, depending upon the length? I think that the answer depends upon how you currently find yourself charging your iPad Pro. If your solution is to charge every night and that works for you, then you won't really care whether it takes five hours or three hours to charge. You are sleeping anyway. But if you want to be able to charge during the day, Apple’s USB-C Power Adapter and USB-C to Lightning Cable are an incredibly useful duo, and it was definitely worth $85 to me. Hopefully, in the future, Apple will include these products in the box with the 12.9" iPad Pro.
Click here for Apple’s 29W USB-C Power Adapter from Amazon ($49 or more?)
Click here for Apple’s 29W USB-C Power Adapter from Apple ($49)
Click here for Apple’s USB-C to Lightning Cable 1 m from Apple ($25)
Click here for Apple’s USB-C to Lightning Cable 2 m from Apple ($35)
