A new rumor claims that both Apple and Samsung are having difficulty making thinner batteries, thereby limiting just how thin phones like the expected iPhone 17 Slim can be.
What’s currently rumored to be called the iPhone 17 Slim is believed to be an iPhone with a 6.6-inch screen, and to be significantly thinner than regular iPhones. Just how thin has not been known, but a new rumor says battery problems may mean it can be no less than 6mm.
The rumor comes from yeux1122, who has a mixed track record — most recently claiming the Apple Ring project is still on, and regularly if erroneously claiming that there will be a 2TB version of the Pro iPhone models.
“[The] supply of new internal substrates will not be possible next year,” writes yeux1122 in his or her blog (in translation). “It was expected that the new substrate would be thinner and secure more batteries, but due to the unadoption of the new substrate, the slim model in the industry is around 6mm.”
If correct, a 6mm iPhone 17 Slim would compare to the current iPhone 16 Pro and iPhone 16 Pro Max’s 8.25mm. The current iPhone 16 and iPhone 16 Plus are each 7.8mm thick.
It’s likely that a difference of 2.25mm or 1.8mm will be noticeable, but it’s not known how much slimmer Apple had been aiming to achieve.
According to yeux1122, Samsung is facing the same difficulty with its plans for a slimmer phone.
The rumors of an iPhone 17 Slim go back to October 2023, and a report by analyst Ming-Chi Kuo. At the time, the report claimed that Apple was working to make its future iPhone mainboards using resin coated copper (RCC), which can reduce the thickness of the board.
Kuo’s report also said that RCC was fragile and, at the time, unable to pass drop tests.
As well as being intended for an expected iPhone 17 Slim, though, the thinness has been believed to be a step toward Apple finally releasing an iPhone Fold. Such a folding iPhone would benefit from being slimmer, since folding obviously then doubles the width.