iPhone 16 Pro Max could offer improved battery longevity

Apple’s upcoming iPhone 16 Pro Max is expected to feature a battery with increased energy density, as per analyst Ming-Chi Kuo. This advancement may result in longer battery life using the same battery size or maintaining the current battery life with a smaller battery.

Kuo’s recent supply chain survey indicates a boost in energy density (Wh/kg) for the iPhone 16 Pro Max battery cells. To address potential overheating issues, Apple could be introducing a stainless steel battery case for the first time as a thermal solution.

Although previous rumors suggested stacked batteries for higher capacity and longevity, Kuo doesn’t mention this technology in his report. The switch to stainless steel may not dissipate heat as effectively as aluminum, but it offers durability and corrosion resistance. This move also aligns with the European Union’s future requirements for battery replaceability.

Sunway is reportedly a key supplier of these stainless steel battery cases. If all second-half 2025 iPhones adopt this design, Sunway’s revenue and profit could increase significantly by 200–250%, according to Kuo.

If the mass production of this new battery design is successful, Kuo anticipates its adoption across all iPhone 17 models next year. The iPhone 16 lineup is expected to launch in about four months, likely around mid-September.