The company said throttling devices that have old, aging batteries keeps them from randomly shutting down.
But users weren't thrilled Apple had been doing this for years without telling people publicly, leading to a handful of lawsuits within days.
Apple is now apologizing to its phone users, and on Thursday extended an olive branch: Anyone with an iPhone 6 or later with a battery that "needs to be replaced" out of warranty can have it done for $29 – less than half of the normal $59 price.
"We know that some of you feel Apple has let you down. We apologize," Apple wrote.
The discounted battery replacement deal will start in late January, and run worldwide through 2018.
The question, as Reddit users point out, is what Apple means by "needs to be replaced?" As a user, you might notice occasional slowdown and significantly worse battery life than 12 months ago – but maybe it doesn't meet Apple's threshold for "needs to be replaced."
The company said more details will be available on Apple.com in the near future, so keep an eye out there.
How the slowdown might affect your phone
The company on Thursday explicitly said the performance throttling is not about giving people a bad experience to try to push users to buy a new device.
"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 said.
The company is also rolling out a couple new guides so people can understand what happens with batteries and iPhone performance.
One is an iOS update in early 2018 that will give iPhone users an option to see if and how their battery is affecting performance.
The other is this new iPhone battery and performance help page, which explains why lithium ion batteries wear out, how Apple uses a power management system to adjust because of it, and what impacts you can expect to see.