Apple has admitted that it was deliberately slowing down older iPhones to save battery life - even on handsets that were barely three years old. Following an outcry over this revelation, the company has offered to replace batteries for a reduced fee (and to give users the option to turn off the 'feature' in an upcoming iOS update).

However, some iPhone 6s models are actually covered by a 2016 program that Apple started in response to an issue with shutdowns - and can have their battery replaced for free. Find out if you can get the battery in your iPhone replaced for free here.

Read on to find out why Apple was reducing the efficiency of old iPhones, and how to get your battery replaced.

Why is Apple slowing down iPhones?

This intentional slowdown of older iPhones (particularly the iPhone 6 and 6s) began with iOS 10.2.1, which "dynamically manages the maximum performance of some system components" to reduce the instances of random battery shutdowns on older phones - in other words, sacrificing power and performance for longer battery life.

The company defends the action saying: "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." Emphasising that their goal was "making iPhones last as long as possible".

Apple claims it was attempting to address an issue where iPhones with old batteries would shut down because they were incapable of "delivering peak energy loads" which would cause them to shut down unexpectedly.

The company notes: "Customer response to iOS 10.2.1 was positive, as it successfully reduced the occurrence of unexpected shutdowns." Apple has since added a similar power management to iPhone 7 models.

As the iPhone's lithium-ion battery gets older it will start to need charging more frequently, and may even start to shut down your phone unexpectedly.

Of course the same is true for all rechargeable batteries in any smartphone, computer or other device - whether made by Apple or not.

However, the company says it has seen a number of issues with iPhone 6 and 6s models that it believes are a result of ageing batteries and as a result it is suggesting that the best solution may be to replace those older batteries.

Apple generally suggests you replace your iPhone's battery once it has passed 500 complete charges. Annoyingly, iOS doesn't actually tell you how many charges your iPhone has been through, but you can find out whether the battery needs replacing in Settings - the best start is to read our How to check if the battery in your iPhone may need to be replaced for full details.

Apple has now apologised for not being more open about its iPhone slowdown strategy, and makes a generous offer to iPhone customers.

Slowdown to become optional

As well as the reduced-price battery offer, Apple boss Tim Cook has said that an upcoming iOS update will give iPhone owners the option to turn off the automatic slowdown feature - although doing so will put affected and older devices at risk of unexpected shutdowns (which is precisely what the speed throttling is designed to avoid).

We would therefore not recommend that you turn it off. But if you are resolved, you won't have long to wait: the update will go into beta in February, with a full public rollout shortly after.

How much will Apple iPhone battery replacement cost in the UK?

In a sign of real contrition (helped by the threat of class-action lawsuits from angry customers and hungry lawyers) Apple is giving all users with an iPhone 6 or later the option of replacing its battery for just US$29 - down from the usual $79 out-of-warranty replacement price.

In the UK the price is just £25. Previously the cost of replacing the iPhone battery was £79, so this is a £54 discount. (If Apple needs to ship the repaired iPhone to you it will add a shipping fee of £7.44.)

If your iPhone is still under warranty then there is no fee for battery replacement. The Apple Limited Warranty covers against manufacturing defects for one year from the date you bought them. It doesn't cover damage caused by accidents or unauthorised modifications.

With a new battery the iOS operating system will no longer need to conserve power. As Apple says a replacement battery will return iPhone performance to normal, this official Apple battery replacement will be like getting a new iPhone for £30/$30 - with all the scratches you've lovingly added over time, of course.

Can I get my battery replaced for free?

Apple's offering to replace batteries for £25 ($29) but it may be possible to get yours replaced for free.

Back in 2016, a year after people first started to experience inexplicable shutdowns before their iPhones had run out of battery, Apple started offering free battery replacements for certain iPhones.

The free battery replacements were for iPhone 6s models manufactured between September and October 2015.

You can check to see if your iPhone is one of those that can have a new battery fitted for free by entering your serial number on this Apple webpage.

If you have already paid to have an iPhone battery replaced and it turns out it was covered by this scheme you can apply to Apple for a refund here.

Which iPhones are affected?

Affected handsets include: iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus, iPhone SE, iPhone 7 and iPhone 7 Plus. But not all of these models will require a new battery now - don't panic!

How do I get a new iPhone battery?

To get help with a battery replacement, take your iPhone to an Apple Authorized Service Provider or Apple Retail Store.

Apple warns against going elsewhere as some counterfeit and third-party batteries "may not be designed properly and could result in safety issues". Only an Authorised Service provider or Apple Store will ensure you receive a genuine Apple battery.

Your first step is to contact Apple Support. Online you'll find options to chat with an Apple Support person. We've found these extremely helpful when we have used Apple Support's Chat function.

Another option is to talk to Apple Support. Simply provide your phone number and Apple Support will call you back - often within 5 minutes.

You can also schedule a time for Apple Support to call you at a convenient time.

Apple has confirmed that it will replace batteries regardless of whether the iPhone fails an official diagnostic test that it usually uses to establish whether iPhone batteries are maintaining their charge.

You can even give Apple your contact information and they will call you when you're ready with all the details on record.

iPhone 6 battery

Should I get my battery replaced?

Before you rush off to an Apple Store to get the battery in your iPhone changed, there are a few reasons why you might want to hold off:

  1. You can expect a long wait to see a Genius.
  2. There are limited supplies of batteries in store and since many of these are being put in phones where the battery doesn't really need to be replaced, people who genuinely need new batteries are faced with up to a three three week wait while Apple orders more batteries, according to a Business Insider report.
  3. If you have an iPhone 6 Plus you can expect to wait longer to get the battery swapped as according to a MacRumors report those batteries won't be delivered until March or April.
  4. There is a two week wait for iPhone 6 and iPhone 6S Plus replacement batteries.
  5. If you don't need a new battery having one fitted will not speed up your iPhone, an Apple Store employee told Business Insider.
  6. Apple has promised to continue its battery replacement offer for the whole of 2018 so our advice is to wait until later in the year if you want to get your battery changed but aren't seeing a message in Settings > Battery indicating that there is an issue with your battery. Read: How to find out if my battery needs replacing.

How long will iPhone battery replacement take?

When Apple first announced the procedure, times were looking better than the reality outlined above.

The company said that if you send your affected iPhone to Apple it would take approximately 6-8 days for the battery replacement to be taken care of. This time is reduced to up to 5 days if you take the phone to an Apple Authorized Service Provider (AASP).

Apple suggests it can take up to 6 days if you take the affected iPhone to an Apple Store appointment, but the company does state that same-day repair options maybe available at Apple Store and AASPs.

As outlined above, it's possible, unfortunately, that it may take longer than expected to replace your battery if supplies for your particular model are low.

An internal Apple document leaked in mid-January revealed that batteries for the iPhone 6 Plus were in very short supply, and that matters wouldn't improve until March 2018 - so expect major delays for this model.

Apple may be able to offer you a loan iPhone while yours is off for repair, but only for those still under warranty - so unlikely for this battery replacement program: "If you bring your iPhone to an Apple Store or an Apple Authorized Service Provider, we'll try to fix it during your appointment. Some iPhone repairs require precise calibration on specialized equipment. If we need to send your iPhone to an Apple Repair Center, we'll check to see if you can use a loaner while your iPhone gets repaired. A loaner iPhone is available for most repairs that are covered under the Apple Limited Warranty."

Other battery saving tips

We've got nearly 40 tips for how to improve iPhone & iPad battery life, which is certainly worth reading.

We also recommend considering a battery case for your iPhone, which will extend the daily usage you can get from your phone and also protect it from everyday bangs and knocks. Read our round up of the best iPhone battery cases for some recommendations.