Apple rolls out $29 battery swap offer for select iPhones

San Francisco: Apple has already made available its promised $29 battery replacement offer for older iPhones it deliberately slowed down -- about a month earlier than expected, media reports said.

After apologising for slowing down ageing iPhone models, Apple reduced 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.

The Cupertino, California-headquartered company initially said that the batteries would be available at the discounted price from late January through December 2018.

But Apple ended the wait for the customers sooner than promised, The Verge reported on Saturday.

"We expected to need more time to be ready, but we are happy to offer our customers the lower pricing right away. Initial supplies of some replacement batteries may be limited," CNN quoted an Apple spokesperson as saying.

The slowing down issue affects older models, including iPhone 6, iPhone 6s, iPhone SE and iPhone 7.

Apple earlier admitted that it was slowing down older iPhone models to compensate for ageing batteries.

"We know that some of you feel Apple has let you down. We apologise," Apple said in a statement on Thursday.

"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," the iPhone maker said.

Besides the battery replacement offer, Apple said that in early 2018, it 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.