The tech giant also said it will issue software in 2018 so that customers can monitor the health of their phone's battery. The moves come a week after Apple confessed to deliberately slowing down older iPhones. Many customers have speculated for some time that Apple slowed down older iPhones to encourage them to upgrade to a newer model.
In a statement on its website, Apple said: "We know that some of you feel Apple has let you down. We apologize. There’s been a lot of misunderstanding about this issue, so we would like to clarify and let you know about some changes we’re making."
"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. 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," it added.
Apple said it will cut the price of out-of-warranty iPhone battery replacements from US$79 to US$29 for anyone with an iPhone 6 or any later model, starting in late January and available worldwide through December 2018.
"Early in 2018, we 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," it added.
The moves are being taken to address "customers’ concerns, to recognize their loyalty and to regain the trust of anyone who may have doubted Apple’s intentions," it said.
Apple said all rechargeable batteries become less effective as they chemically age and their ability to hold a charge diminishes.
"Device use also affects the performance of a battery over its lifespan. For example, leaving or charging a battery in a hot environment can cause a battery to age faster. These are characteristics of battery chemistry, common to lithium-ion batteries across the industry," it said
"A chemically aged battery also becomes less capable of delivering peak energy loads, especially in a low state of charge, which may result in a device unexpectedly shutting itself down in some situations," it added.
When a chemically aged battery is replaced with a new one, iPhone performance returns to normal when operated in standard conditions, it said.
Apple shares on Friday lost 0.67% to US$169.94.