How to use your iPhone 15 as an external battery pack — reverse charge your AirPods, other smartphones, and more

(Image credit: Future / Apple)

One of the biggest changes to this year’s iPhone 15 lineup compared to every iPhone before it is the addition of USB-C. Not only does USB-C make charging far easier than ever before, allowing you to charge most of your devices seamlessly, but it also makes connecting peripherals to your iPhone hassle-free.

However, one of my favorite uses of the USB-C port on my iPhone 15 Pro Max is using my iPhone to charge my other tech products. Using reverse charging from the USB-C port allows me to easily top up my AirPods Pro 2 or even charge my partner’s iPhone when out and about.

While it will never compete with some of the best battery packs out there, my iPhone 15 Pro Max has become a great external battery pack for the times when I’m desperate for power, and that’s why everyone should know how to reverse charge their accessories and other tech products from an iPhone.

How to reverse charge using an iPhone 15

Reverse charging using your iPhone 15 is incredibly easy, but you’ll need one of the newest iPhones like the iPhone 15, the iPhone 15 Plus, the iPhone 15 Pro, or the best iPhone, the iPhone 15 Pro Max to do it.

If you own one of the models above, all you need to do is connect a USB-C cable to your iPhone and then plug the other end of your cable into the device you want to charge. Bear in mind that the iPhone’s reverse charging is limited to 4.5W, so you won’t get fast charging here. From testing, the iPhone with the lowest battery percentage will receive power, while the iPhone with the most power will give battery.

One more thing… Why not use the battery pack in your pocket?

I’ve tested reverse charging on several devices to see whether there is actually any benefit to using your iPhone 15 as a power bank. Some products, like my Analogue Pocket, show as charging but never gain any power as the output is just far too low.

When charging my partner’s iPhone 15, I noticed the battery gain to be minimal but decent enough to help fuel up your smartphone in desperate measures. Where I think reverse charging really excels, however, is when you want to give your AirPods a quick top-up if you’ve forgotten to charge them before leaving the house. You won’t charge your AirPods fully, but you’ll get just enough power to listen to your favorite tunes or podcasts.

USB-C on iPhone has been a great addition to Apple’s smartphone, and reverse charging is just one of many small improvements that make your life that little bit easier.

John-Anthony Disotto is the How To Editor of iMore, ensuring you can get the most from your Apple products and helping fix things when your technology isn’t behaving itself. Living in Scotland, where he worked for Apple as a technician focused on iOS and iPhone repairs at the Genius Bar, John-Anthony has used the Apple ecosystem for over a decade and prides himself in his ability to complete his Apple Watch activity rings. John-Anthony has previously worked in editorial for collectable TCG websites and graduated from The University of Strathclyde where he won the Scottish Student Journalism Award for Website of the Year as Editor-in-Chief of his university paper. He is also an avid film geek, having previously written film reviews and received the Edinburgh International Film Festival Student Critics award in 2019. John-Anthony also loves to tinker with other non-Apple technology and enjoys playing around with game emulation and Linux on his Steam Deck.

In his spare time, John-Anthony can be found watching any sport under the sun from football to darts, taking the term “Lego house” far too literally as he runs out of space to display any more plastic bricks, or chilling on the couch with his French Bulldog, Kermit.