Apple promises to warn users if it plans slows down their iPhones to save battery life

Apple has made a binding agreement with Britain's consumer watchdog to warn users if it plans to reduce the speed of older iPhones following a scandal that saw software updates deliberately slowing the performance of users' phones.

The Competition and Markets Authority said it had raised consumer law concerns with Apple last year after iPhones were found to be slowed down by software updates in an effort to manage battery life without a user knowing.

The watchdog said Apple had “committed to be clearer and more upfront with iPhone users about battery health and performance” - which will include notifying users during iOS updates if the software will cause their phone to slow down.

Two years ago, Apple admitted that it had been limiting the processing power of its iPhone 6, 6S and 7 smartphones to prevent damage to older batteries.

The revelations prompted a backlash from iPhone users, an apology from Apple chief executive Tim Cook and legal claims that the so-called “throttling” of phone speed was “deceptive”.

The CMA said that at the time there was not adequate information on this performance limiting update, meaning consumers may have tried to repair or replace their phone.

Following uproar from users, Apple later offered discounted battery upgrades to users and added additional features to its iOS smartphone software that showed how strong a phone's battery was relative to its original peak performance.

The CMA said Apple had now agreed to make binding commitments to clearly notify users in future if an iOS update would slow the phone's performance. If Apple is found to breach these terms, the CMA can make court action against the company.

The agreement said: “If a future iOS update materially changes the impact of Performance Management when downloaded and installed on an iPhone, Apple will notify consumers in a clear manner of those changes in the installation notes.”

The CMA agreement said it “does not amount to an admission” that the law had been broken.

Similar investigations by regulators have led to fines. In Italy, Apple was hit with a €10m over claims customers were “induced consumers to install software updates that are not adequately supported by their devices".

An Apple spokesman directed The Telegraph to a Apple website page on iPhone battery life and declined to comment further.