iPhone 15 battery upgrade could unlock 40W charging speeds and a big MagSafe boost

iPhone 14 Pro Dynamic Island
(Image credit: iMore)

One of the most exciting recent rumors around the as yet un-announced iPhone 15 is a substantial upgrade to its battery tech in the form of a stacked battery pack. Using the same kind of tech as EVs, a stacked battery will not only extend the battery life of the iPhone 15, but could also facilitate much faster charging, with speeds reaching up to 40W. Considering that Apple says that Apple's current best iPhone, the iPhone 14 maxes out at 30W, this is a significant bump in charging speed.

Leaker RGcloudS on Twitter says that they've seen 40W charging over wire, and then an increase in MagSafe as well to 20W. Whether it's coming to iPhone 15 however remains to be seen, and the same leaker says that it could also be for iPhone 16 instead.

Faster charging for all

It's likely that the switch to USB-C has helped the charging speed here, although it's not the sole reason that the batteries will be able to fill up faster. Getting the stacked batteries to work properly as well is likely an absolute nightmare for Apple as well, as they can get super hot when charging and in use. In an electric car that has more space for cooling systems, this is less of a problem, but in a phone that's supposed to slip into your pocket, it's a much bigger problem.

Of course, these numbers don't reach the lofty heights of some Android handsets which boast charging speeds of 100W or more, but the effects of this kind of charging on battery health can be detrimental the longer into the phone's life you go. 40W will likely be a happy medium — faster speeds, but more reliable and less risk of destroying the battery.

Until the iPhone 15 is announced in September, we'll remain in the dark as to whether this is coming to the next iPhone, or the next next iPhone.

Tammy Rogers
Senior Staff Writer

As iMore's Senior Staff writer, Tammy uses her background in audio and Masters in screenwriting to pen engaging product reviews and informative buying guides. The resident audiophile (or audio weirdo), she's got an eye for detail and a love of top-quality sound. Apple is her bread and butter, with attention on HomeKit and Apple iPhone and Mac hardware. You won't find her far away from a keyboard even outside of working at iMore – in her spare time, she spends her free time writing feature-length and TV screenplays. Also known to enjoy driving digital cars around virtual circuits, to varying degrees of success. Just don't ask her about AirPods Max - you probably won't like her answer.