SAN FRANCISCO — Apple apologized to customers Thursday for not being clear that the company slows down phones with aging batteries.

Apple CEO Tim Cook promised that, in the future, Apple will “give users more visibility into the health of their iPhone’s battery” and let people see if their battery’s age affects their phone’s performance.

Cook rejected allegations that Apple slowed down phones with older batteries as a way to push people into buying new phones.

“First and foremost, we 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,” he said.

The company said previously that unless it reduces the performance of its phones, the older batteries run a higher risk of spontaneously shutting down. This explanation makes technical sense, many experts have said.

But many customers had interpreted the slowdown as a way to juice demand for newer models.

Apple is offering a discount on battery replacements to anyone with an iPhone 6 or later, the company said. A replacement will cost $29 instead of $79 starting in late January 2018.

Apple will issue an update to its operating system early next year to give users a better understanding of the health of their battery.

Apple still faces lawsuits from iPhone owners in places including California, New York, New Jersey and other countries that claim Apple owes its customers money for not previously disclosing the slowdowns. The suits ask the company to pay iPhone owners varying amounts.

Apple stock picked up 48 cents, or 0.28 percent, to close at $171.08 Thursday.

Washington Post and Associated Press contributed.