Apple's battery supplier has registered two cells for the rumored iPhone Ultra, rated at 1,921mAh and 2,962mAh for a combined minimum capacity of 4,883mAh. The dual-cell layout mirrors book-style foldables from Samsung and Google, splitting capacity across the device's two halves. Supply chain sources predict a final rated capacity between 4,800 and 5,000mAh.

That figure slots between the Google Pixel 10 Pro Fold at 5,015mAh and the Samsung Galaxy Z Fold 7 at 4,400mAh. For context, the upcoming iPhone 18 Pro and 18 Pro Max are expected to carry 4,288mAh and 5,567mAh cells respectively. An earlier rumor claimed Apple tested a 5,400–5,800mAh pack, but that appears to have been an engineering prototype since revised.

Analyst Ming-Chi Kuo reports Apple is using high-density cells to offset the modest capacity, while a March leak emphasized power efficiency and component thinning as priorities. The foldable is rumored to pack a 7.8-inch inner display, 5.5-inch cover screen, Touch ID, an A20 chip, and Apple's C2 modem in select regions.

IDC forecasts a $2,500 average selling price, with top-tier storage hitting $3,000. At that premium, the battery spec looks conservative — Apple is betting silicon efficiency can match rival endurance in a thinner chassis. If the September launch alongside the iPhone 18 Pro holds, we'll see whether that trade-off pays off.