Apple sorry for deliberately slowing down old iPhones

APPLE has apologised for secretly slowing down older iPhone models, publishing a letter to customers in order to clear up the "misunderstanding".

The US tech company faced harsh criticism after admitting last week that new software updates deliberately slowed down certain phone models, citing the iPhone 6, 6s, 7 and iPhone SE.

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

The company wrote that they would never "do anything to intentionally shorten the life of any Apple product, or degrade the user experience", claiming that the slowing prevented older models from unexpectedly shutting down.

In order to "regain the trust" of it's customers Apple announced that it would be reducing the prices for replacement batteries on out of warranty iPhones models that are a 6 or later from $US79 to $US29.

Out of warranty battery replacements currently cost Australian iPhone owners $119 or $138.95 if shipping is required.

The offer will be available worldwide from late January 2018, with a new software update also giving users more insight into their phone's battery performance.

"At Apple, our customers' trust means everything to us. We will never stop working to earn and maintain it," the statement read.

"We are able to do the work we love only because of your faith and support - and we will never forget that or take it for granted."

Following the revelation of the initial slowdown rumours began popping up that Apple deliberately throttles phones with each software update to encourage people to buy the latest model - known as "planned obsolescence".

John Poole, the founder of software company Primate Labs, wrote on Geekbench that Apple had itself to blame for this theory taking hold.

"If the performance drop is due to the 'sudden shutdown' fix, users will experience reduced performance without notification," Mr Poole wrote.

"Users expect either full performance, or reduced performance with a notification that their phone is in low-power mode.

"This fix creates a third, unexpected state."

As a result of the recent controversy, iPhone users from several US states are suing Apple for not disclosing the slowing issue sooner, claiming Apple's silence led them to wrongly conclude that their only option was to buy newer, pricier iPhones.

The allegations were in a lawsuit filed last week in Chicago federal court on behalf of five iPhone owners from Illinois, Ohio, Indiana and North Carolina, all of whom say they never would have bought new iPhones had Apple told them that simply replacing the batteries would have sped up their old ones.

The suit alleges Apple violated consumer fraud laws, with a similar lawsuit filed in Los Angeles.

The Chicago lawsuit suggests Apple's motive may have been sinister, though it offers no evidence in the filing.

"Apple's decision to purposefully ... throttle down these devices," it says, "was undertaken to fraudulently induce consumers to purchase the latest" iPhone.

The lawsuit seeks class-action status to represent thousands of iPhone owners nationwide.