The suit, which seeks class-actions status, argues in a complaint filed Thursday in Los Angeles, that some iPhone users "notice that their older iPhone models slows down when new models come out," and that they "never consented to allow" Apple to "slow their iPhones."
The legal move comes after Apple revealed that its new software updates slow down older iPhone devices in order to allow the batteries in older models to keep up with new features.
"Lithium-ion batteries become less capable of supplying peak current demands when in cold conditions, have a low battery charge or as they age over time, which can result in the device unexpectedly shutting down to protect its electronic components," Apple said in a statement.
The statement continued, "Last year we released a feature for iPhone 6, iPhone 6s and iPhone SE to smooth out the instantaneous peaks only when needed to prevent the device from unexpectedly shutting down during these conditions. We’ve now extended that feature to iPhone 7 with iOS 11.2, and plan to add support for other products in the future."
While Apple declined ABC News' request for comment on the lawsuit, the tech company said in a statement that its "goal is to deliver the best experience for customers, which includes overall performance and prolonging the life of their devices."
"If you have an old iPhone with an old battery in it, Apple may be slowing down your phone via software so the phone doesn't automatically shut off someplace, or do something else wonky," Stern said.
Some iPhone users, however, told ABC News they believe slowing down older models is an intentional move by Apple in order to get more people to purchase new iPhones.
"I think once you upgrade your phone it works slower on the later models so that you are forced to go into the newer one and pay the extra $1,000 to get a new phone," Jessica Prozor told ABC News.
Another iPhone customer, Emily Peguero, echoed Prozor's sentiments, telling ABC News, "I feel like Apple keeps coming up with new products and new products and slowing down the other versions so that you have to buy the new version."
Stern said, however, that iPhone users can avoid buying a whole new phone and simply replace their older phone's battery to avoid having their processor slowed down with Apple's software updates.
"If you put a better battery in and the battery healthy is better, it is not going to downclock those speeds," Stern said. "The processor will run at normal speeds."
Replacing an iPhone battery in-store costs $79, according to Apple. Meanwhile, the price for Apple's latest versions of the iPhone, the iPhone 8 and iPhone X, start at $699 and $999 respectively.