Apple’s iPhone X won’t be available to preorder until Oct. 27, but some new information on the upcoming device has already surfaced. A Chinese regulatory filing has revealed that the iPhone X will have a slightly bigger battery than the iPhone 8 Plus.

Leaker Steve Hemmerstoffer (@OnLeaks) shared on Twitter the iPhone X’s regulatory filing from TENAA, the Chinese equivalent to the United States’ FCC. The filing shows that the iPhone X will have a 2,716mAh battery, which is only slightly bigger than the 2,675mAh battery that’s on the iPhone 8 Plus. It’s important to point out that the footprint of the iPhone X is smaller than the iPhone 8 Plus.

AppleInsider speculates that the larger battery on the iPhone X might have been necessary to power the handset’s TrueDepth camera system up front. This is the camera system that makes Apple’s facial recognition technology, called Face ID, to work. It’s possible that it’s a power-hungry feature since it houses an array of sensors and a front-facing camera with built-in optical image stabilization.

Another thing to consider is the iPhone X’s different form factor from the iPhone 8, iPhone 8 Plus and the rest of its predecessors. It’s packing an edge-to-edge, “bezel-less” 5.8-inch Super Retina OLED display with an aspect ratio of 2.17:1. The aspect ratio is very important since this is the first time that Apple has deviated from the standard 16:9 aspect ratio.

AppleInsider also pointed out that the OLED display on the iPhone X might possibly draw more power than the usual iPhone LCD display. OLED panels are usually more power efficient, but this will still depend on the size of the display  and what type of tweaks Apple has done with the display controller.

How will the iPhone X’s battery life under real-life usage? Apple claims that the battery on the iPhone X can last up to two hours longer than the iPhone 7. If that’s truly the case, then the same can be said when compared to the smaller iPhone 8, which packs a 1,821mAh battery. Apple did say that the iPhone 8’s battery life is “about the same” as the iPhone 7.

Although the battery on the iPhone X is larger than what's in the iPhone 8 Plus, it won't actually offer better battery life, as pointed out by BGR. At best, the iPhone X will simply match the battery life of the iPhone 8 Plus. Apple’s listed tech specs for the iPhone X claims that the handset can deliver up to 21 hours of talk time, up to 12 hours of internet use, up to 13 hours of playback and up to 60 hours of audio playback. The jury’s still out on whether these numbers are accurate, but it does seem to be impressive enough especially if we compare it to other flagships with larger batteries.

Samsung’s Galaxy S8 for example houses a large 3,000mAh battery, while the Galaxy S8+ has a larger 3,500mAh battery. The Galaxy Note 8’s battery might not be larger than what’s in the S8+, but it’s still pretty big at 3,300 mAh.

Perhaps Apple is relying on software optimization to deliver flagship battery performance. Another thing to consider here is Apple’s new A11 Bionic processor, which isn’t only very powerful, but is also supposed to be incredibly power efficient.

Speaking of the A11 Bionic chip, the TENAA filing also shows that iPhone X’s processor is clocked at 2.4GHz, which is nearly identical to the iPhone 8 and iPhone 8 Plus. The iPhone X is also listed as having 3GB of RAM, the same one that’s on the iPhone 8 Plus.