Android phone makers are testing steel-cased batteries that could reach 9,000mAh or even 10,000mAh. That is according to a new leak reported by Android Authority.
The leak came from Digital Chat Station, a well-known tipster who posts on the Chinese social media site Weibo. The tipster said a large Chinese smartphone maker is testing a steel-shell battery design.
Android Authority said the brand is most likely Xiaomi, based on the way Digital Chat Station wrote the post. The company has not been confirmed.
The tipster pointed to Apple’s use of steel-encased battery cells in the iPhone 18 Pro Max. That battery reportedly has a rated capacity of 5,391mAh, with a typical capacity of around 5,500mAh.
According to the leak, the Chinese brand would combine the steel shell with stacked-cell manufacturing. Together, the two methods could allow batteries of 9,000mAh to 10,000mAh in future top-end phones.
Metal battery cases first drew wide attention when Apple used an aluminium casing for the battery in the iPhone 16 Pro. Early teardowns of that phone showed the change, Android Authority reported.
Most phones use soft-pouch batteries wrapped in soft aluminium-laminated film. Android Authority said this design needs extra space inside the phone because the cells can swell. It also does not spread heat well.
A hard aluminium shell lets makers pack the cells more tightly. It also helps heat move away through the body of the phone and makes better use of the space inside.
A steel shell is stiffer again and can be made thinner. Apple first used steel battery shells in the iPhone 17 Pro and iPhone 17 Pro Max. It kept them for the iPhone 18 Pro series.
Stacked-cell technology changes how the battery layers are built. The cathode and anode layers are laid flat and stacked in zig-zag sheets, instead of being rolled up like a jelly roll. Android Authority said this lowers internal resistance and raises energy density.
Chinese phone makers have already pushed battery sizes past 6,000mAh by using silicon-carbon anodes. Reaching 10,000mAh in a flagship phone would be a big jump, the publication said.
The new Xiaomi 18 Pro Max already uses an 8,500mAh battery in China. The phone also carries advanced camera hardware and a second display on its back.
If the tests work, users could get battery life lasting several days, Android Authority said. The phones would also keep their strength and stay cool without creating a battery hazard.
There are trade-offs. Steel adds weight, and fitting such a large cell will test how much room makers can find inside a phone, the publication said.
No Android brand has announced a phone with a 10,000mAh steel-cased battery so far. It is not known which company will bring one to market first.
Source: this article is based on reporting by Android Authority. Image: Android Authority. Written with the help of AI and published by the Tzaneen Voice Technology desk. See our Editorial Standards.
Werner Jacobs covers technology for Tzaneen Voice. Werner reports on mobile networks, data prices, internet access, smartphones, apps, AI, cybersecurity and South African tech companies. Each story explains what a new product, price change or policy means for ordinary users in South Africa.