Apple's iPhone 12 and iPhone 12 Pro have reached the reviewers' hands, and while most reviews are fairly positive, no one has been praising battery life very much.

There are two more iPhone 12 variants coming soon: The 5.4-inch iPhone 12 mini, and the massive, 6.7-inch iPhone 12 Pro Max. And out of those two, it's the Max that should have the most battery life, as it will likely have the biggest battery — I have an iPhone 11 Pro Max and I've been very happy with its battery, which typically lasts me for one-and-a-half days of heavy usage.

However, a regulatory filing published by China's TENAA (spotted by MacRumors), indicates that the iPhone 12 Pro Max will actually have a significantly smaller battery than the 11 Pro Max, with a capacity of 3,687mAh vs. 3,969mAh on the older model.

Capacity isn't everything, and it's quite possible that Apple has made optimizations to make the battery last longer, even with a smaller capacity. Officially, Apple says the iPhone 12 Pro Max will provide up to 20 hours of video playback, up to 12 hours of streamed video playback, and up to 80 hours of audio playback. That's exactly the same as the iPhone 11 Pro Max, per Apple's official specs (they are no longer available on the official site, but Wayback Machine remembers).

The TENAA filing also reveals that the iPhone 12 Pro Max will come with 6GB of RAM, a notable improvement from the iPhone 11 Pro Max's 4GB.

Officially, we'll never hear the actual battery capacity or RAM figures for the iPhone 12 Pro Max; Apple simply doesn't share those numbers. We will find out the exact numbers when the devices are disassembled, though, which typically happens immediately after launch.