How fast charging works on the iPhone 8 and iPhone X

Included in the box with your iPhone is a standard Lightning-to-USB cable. It's the same cable Apple has included in the last several generations of iPhone, and it connects to the same power brick Apple has also included. This power setup will charge your iPhone at the same rate previous iPhones have charged, which is good enough for an overnight fill-up but a little on the slow side when you need a quick top-off to get through the day.

Did you know the iPhone 8 and iPhone X can be charged using a different kind of cable, and that by using this cable your phone will actually charge from totally dead to 50% full in right around 30 minutes? It's called Fast Charging; it's new to your iPhone this year, and this is how it works!

Moar juice please

Put simply, the power adapter Apple includes in the iPhone 8 and iPhone X box is the bottom shelf of what your phone is capable of receiving. That little white brick fits nicely in the iPhone box, and gets the job done just fine over time, but as batteries get larger because things on your phone drain the battery faster there's occasionally a desire for more. If you own an iPad as well as an iPhone, you may have noticed the lager power brick included with your tablet will charge your iPhone slightly faster. It's a nice little boost and very cool to know you only need to bring one brick with you places, but it's just the start of what these new phones are capable of.

To fully understand what is happening here, you have to take a look at what these power adapters are capable of. The small white brick included in your iPhone 8 box will provide whatever you plug into it with 5W (watts) of power rated at 1A (amp). Compare this to the iPad charger, which provides whatever you plug into it with 12W at 2.1A, and it becomes a little more clear why one is better. The larger power brick is providing a lot more energy, and these newer phones are capable of receiving a great deal more than what that standard brick is capable of delivering.

How much power is your iPhone 8 or iPhone X capable of receiving? Actually, more than the cable included in box with your iPhone is capable of safely delivering. This is why in order to actually enjoy the new fast charging feature included with your iPhone you need a few things that aren't included in the box.

What you need for fast charging

According to Apple, fast charging is possible with:

  • Apple-made USB-C power adapters
  • Third-party batteries and power supplies with USB Power Delivery (USB-PD) support

The thing both of these options have in common is you need to also have a USB-C-to-Lightning cable, which thankfully isn't difficult to track down these days and will only set you back $10. The thing you connect that USB-C end into is very important though, and it's the kind of thing you have to pay special attention to what you are using in order to avoid any unwanted damage to your phone.

Apple's big suggestion here is to find something that supports USB-PD, and the reason for that is the additional circuitry in that technology to keep your hardware safe. By design, USB-PD devices communicate with each other upon connection to determine how much power is safe to transfer from one source to another. This means when you connect the phone to a big portable battery, for example, the battery knows it can send more power safely because the iPhone has indicated it is capable of receiving that power.

Apple's other suggestion means you can use any of the USB-C adapters Apple makes to power its new MacBooks to power your phone. This is way, way overkill if you don't already own a new MacBook, because some of these power supplies are capable of providing orders of magnitude more power than the phone is able to receive, but it's a nice way of letting you know if you already have a MacBook which uses USB-C to charge you can use that to also power your phone. If all you are doing is charging your phone, there are approved options on Amazon for under $30.

Really, that's all there is to this. If you use an approved charger, and you keep a USB-C-to-Lightning cable nearby instead of what was included in the box, your iPhone 8 and iPhone X will charge much faster every time. Enjoy!

Russell Holly

Russell is a Contributing Editor at iMore. He's a passionate futurist whose trusty iPad mini is never far from reach. You can usually find him chasing the next tech trend, much to the pain of his wallet. Reach out on Twitter!