The iPhone XS may not hit shelves until Friday, but one team has already completed a teardown of Apple’s latest smartphone. The video published Thursday shows how the company has made some key changes to the internal layouts of the device, refining the battery design from the iPhone X.

The teardown, completed by FixjeiPhone, shows Apple has made some small tweaks to the internal design. The iPhone X that launched last November used a more expensive stacked logic board design to save internal space. The phone used two cells arranged in an L-shape to fill the gap, totalling to 2,716 mAh of capacity for a phone the same size as the iPhone 8, which only offered a 1,821 mAh capacity. With the iPhone XS, Apple has joined the two cells together, forming a single unit replaced as one component, although with a slightly reduced capacity of 2,658 mAh.

See more: iPhone XS Max Filing Shows Apple’s Largest-Ever Smartphone Battery

It’s unclear why Apple changed the design from the previous structure, which used a looser method of joining, but the company is boasting better battery life despite the smaller capacity. Apple claims the XS offers 30 minutes more life than the iPhone X, with talk time of 20 hours and internet use up to 12 hours. That’s no match for the XS Max, which lasts up to 1.5 hours longer than the X with 25 hours talk time and 13 hours internet use, thanks to its giant 2,942 mAh battery.

The iPhone XR could prove the winner of the battery life wars though. The 6.1-inch XR offers the same A12 Bionic chip and face recognition as the smaller phones, but offers a staggering 15 hours of talk time even though its battery is only rated as having a 2,942 mAh capacity. The phone has fewer pixels to push than the 5.8-inch XS and 6.5-inch XS Max, with just 326 pixels per inch instead of 458 pixels per inch.

Apple The XS and XS Max are set to hit shelves on Friday, while the XR will reach pre-orders on October 16 and consumers on October 23.

It seems the 75 percent of people that want an iPhone with better battery life may get their wish.