Apple Inc. (AAPL  ) could have a new trick up its sleeve - the iPhone 15 could be powered by larger batteries using stacked battery technology, a method that is used in electric vehicles.

What Happened: The iPhone 15 series will likely be powered by larger batteries, helping them last longer than their predecessors. Now, a new rumor suggests that this won't lead to an increase in the iPhone 15's size by using a technology borrowed from electric vehicles - stacked batteries.

Earlier, a rumor suggested that the iPhone 15 series will see a significant boost in battery capacity by as much as 20%, with the top-end iPhone 15 Pro Max expected to be powered by a 4,852mAh battery.

The entry-level iPhone 15 is expected to see the biggest boost, with its capacity increasing from 3,279mAh to 3,877mAh.

Why It's Important: A 20% increase in battery capacity would usually result in an increase in the phone's overall thickness, but the rumor mill suggests that Apple will retain the thickness of the iPhone 15 series thanks to the stacked battery technology that is used in electric cars.

Simply put, stacked batteries have a much denser configuration compared to regular batteries. This allows for a higher capacity without increasing the size, so the iPhone 15's overall dimensions remain the same.

Previous reports suggest that the iPhone 15 Pro Max could burn a bigger hole in your pocket due to a new camera feature. This would be Apple's first price hike since it introduced the 'Pro Max' iPhone in 2018.

Apple is expected to launch the iPhone 15 series in September 2023.