IMO somebody just made that up based on it sharing the outer dimensions of the iPhone 14 which also happens to have exactly 3279 mAh. I can't really figure out what "larger battery" could mean in their release video if it isn't larger than at least the 14 if not the 16.

I can’t understand how someone can say with certainty the capacity down to a single digit (3279).

There would be manufacturing differences that would induce at least some variation from phone-to-phone.

It is the capacity published by Apple. Apparently some regulatory bodies [1] require that information.

[1] https://www.mysmartprice.com/gear/mobiles/mobiles-news/apple...

But it is an interesting question: What is the manufacturing tolerance? Naively I had assumed that it's much smaller than a watt-hour. But that's based on ~no knowledge :D

You can still have a specific "normal"/expected capacity, even if you're producing them +-20 mWh.

Surely the battery is over-provisioned to be able to deliver the stated spec for at least some warranty period fraction?

Well it could be that the capacity is 3200-3349, and they publish the number that is in the center of confidence interval. Rounding up would be received badly, and rounding down suggests it has less capacity than it really does (on average)

It’s a nominal capacity that’s printed on the battery, and encoded into its firmware. In practice, batteries tend to exceed this nominal capacity when they’re brand new which is why you see new batteries stay on 100% charge for a long time. As it ages, the true capacity will degrade and eventually falls below the nominal capacity.

The iPhone 16e is based on the iPhone 14 chassis, with various internal hardware components swapped out. Just like the previous iPhone SE was based on the iPhone 8. So I guess there was an assumption that maybe it uses the same battery as the 14.

But given that the cameras got swapped out for a single lens, the MagSafe magnets were removed, etc, it’s certainly conceivable that they freed up space internally for a larger battery in the 16e!

Though, the youtube commercial states new internal design “optimized for new battery”.