After a flurry of bad press and outrage from consumers, Apple issued an apology Thursday for not being transparent about how it manages the performance of iPhones with older batteries.

Last week, the tech giant issued a statement admitting that it used software updates to limit the performance of iPhones with old batteries. The company cited the lifespan of lithium-ion batteries, which degrade over time and can cause phones to shut down unexpectedly.

The admission caused an uproar, with some suggesting Apple was using the tactic to force consumers into buying a new device.

However, Apple has stood by the practice, saying the intention is to prevent sudden shutdowns.

On Thursday, Apple posted a letter on its website apologizing for not being more transparent about the practice. The company also added an article to its Knowledge Base explaining the degradation of lithium-ion batteries and the steps the company’s software takes to maximize battery performance.

“[W]e have never — and would never — do anything to intentionally shorten the life of any Apple product, or degrade the user experience to drive customer upgrades,” the letter reads. “Our goal has always been to create products that our customers love, and making iPhones last as long as possible is an important part of that.”

Apple explained that a software update included in iOS 10.2.1 sought to improve “power management during peak workloads to avoid unexpected shutdowns on iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus, and iPhone SE.” The support was extended to the iPhone 7 and iPhone 7 Plus in iOS 11.2.

The company said only iPhones with older, “chemically aged” batteries experienced slowed performance.

“When a chemically aged battery is replaced with a new one, iPhone performance returns to normal when operated in standard conditions,” the company said.

In an effort to address concerns, Apple is taking a number of steps to “regain the trust of anyone who may have doubted Apple’s intentions.”

  • Apple is reducing the price of an out-of-warranty iPhone battery replacement by $50 — from $79 to $29 — for anyone with an iPhone 6 or later whose battery needs to be replaced, starting in late January and available worldwide through December 2018.
  • Early in 2018, Apple will issue an iOS software update with new features that give users more visibility into the health of their iPhone’s battery, so they can see for themselves if its condition is affecting performance.
  • Apple is working on ways to make the user experience even better, including improving how it manages performance and avoids unexpected shutdowns as batteries age.

Following the company’s admission, Apple’s stock slid by as much as 4 percent in premarket trading earlier this week. The tumble also comes after reports that Apple had dramatically lowered its iPhone sales expectations from 50 to 30 million.