A Weibo post from leaker Digital Chat Station claims Apple's battery supplier filed regulatory documents for two cells — 1,921mAh and 2,962mAh — totaling 4,883mAh for the upcoming iPhone Ultra. The dual-cell design mirrors foldables from Samsung and Google, though the Ultra's capacity sits between the Galaxy Z Fold7 at 4,400mAh and the Pixel 10 Pro Fold at 5,015mAh. The previous Pixel 9 Pro Fold packed 4,650mAh.

The leak also includes specs for the standard iPhone 18 Pro and iPhone 18 Pro Max. The Pro model shows minimal gains: 4,288mAh (eSIM) or 4,056mAh (physical SIM), up just 36–68mAh over the iPhone 17 Pro. The Pro Max jumps significantly to 5,567mAh (eSIM) or 5,391mAh (physical SIM), a 479–568mAh increase.

Battery capacity alone doesn't determine real-world endurance, especially for a foldable with two displays and a novel hinge mechanism. Apple's silicon efficiency and iOS optimization will play outsized roles. The iPhone Ultra marks Apple's first foldable entry, arriving years after competitors.

If accurate, the Ultra's battery trails the Pixel 10 Pro Fold by 132mAh despite likely commanding a higher price. Apple will need exceptional power management to match rival longevity. The September launch will reveal whether the company's vertical integration can close that gap.