Apple's announcement that it's going to reduce the price to replace some iPhone batteries gives those holding on to older phones a cheaper way to make them last longer, and adds a little nuance to the debate over whether to upgrade or not.

Upgrades have already been slowing over the years. When smartphones were a new technology, each year's model brought significant improvements. But now many more people hold on to their phones for three years or longer, according to the marketing firm Fluent. As of June, analytics firm Newzoo reported that the most-used iPhone in the world was still the iPhone 6, first released in 2014.

The slower upgrade trend has continued as new phones continue to go up in price and haven't offered as many new features to send people rushing to stores. Making it less expensive and less of a hassle to get a new battery may extend that trend, as many more people will find battery replacement attractive, said analyst Patrick Moorhead of Moor Insights & Strategy.

"I think more people will update their battery than buy a new phone, globally," he said.

iPhone owners have always been able to replace their batteries. But many may not have realisedthat it was an option worth exploring until Apple's disclosure that it slowed down its older phones. The controversy prompted Apple to slash the price for replacement batteries for the iPhone 6 and newer models. In Australia the price will fall to $39 from $119.

Apple did not immediately respond to a request for comment on whether it is concerned that the replacement program will hurt sales.

But Moorhead said he doesn't think everyone is going to hold on to their phones for several more years. There will always be new software which work best on new hardware. Newer iPhones have chips that track more of your data, or work more smoothly with new features such as augmented reality.

Those are the types of changes that drive sales, surveys have shown over the years. When asked why they want to buy a new iPhone, for example, many people point to new features such as improved cameras as the prime reasons they want to upgrade. Apple also constantly makes changes to its software, improves security and offers other updates that won't work with all older models.

In other words, replacing a battery in an old phone may make it act like it did when it was new, but it won't actually make it a new phone. So while Apple will take a hit in the short-term due to the price drop on its battery replacements — on which, analysts say, Apple also makes a profit — Moorhead said he doesn't think any dip will last long.

"I think that Apple wins regardless here," he said.

Washington Post