An Apple battery lawsuit could compensate millions of iPhone users. The lawsuit accuses Apple of misleading users about an upgrade that it said would boost performance but actually slow down the phones.

The complaint filed with the Competition Appeal Tribunal accused Apple of slowing down the performance of older iPhones in a process known as “throttling” to avoid costly recalls or repairs.

Justin Gutmann, a consumer advocate involved in the case, is seeking damages of around 768 million euros for up to 25 million British iPhone users.

The allegations against Apple relate to a power management tool released in January 2017 in a software update for iPhone users to combat performance issues and prevent an abrupt shutdown of older devices.

Gutmann explained that the information about the tool is not included in the description for downloading the software update and that the company has not yet explained that the tool would slow down the devices.

Affected models include iPhone 6, 6 Plus, 6S, 6S Plus, SE, 7, 7 Plus, 8, 8 Plus and iPhone X.