Your iPhone battery degrades over time, and you should replace it when it drops below 80 percent health or when your phone shuts down unexpectedly

iPhones show you exactly how worn your battery is. Open Settings, tap Battery, then Battery Health & Charging. The percentage you see there — called maximum capacity — tells you how much charge your battery holds compared to when it was new. At 80 percent health, your battery still works, but it is noticeably weaker. At 50 percent, your phone may shut itself off even when the battery indicator shows 20 or 30 percent remaining.

Apple designed iPhones to work with degraded batteries for years, but the experience gets worse as the percentage drops. If your phone is shutting down unexpectedly, running out of power by mid-afternoon, or struggling to handle apps you use every day, a battery replacement will restore normal performance. If your battery is still above 80 percent and your phone behaves normally, you can wait.

Key Takeaways

  • Check your battery health in Settings > Battery > Battery Health & Charging; anything below 80 percent is a candidate for replacement.
  • Unexpected shutdowns, rapid power drain, or slowdowns during heavy use are signs your battery is failing, even if the percentage seems higher.
  • Apple replaces batteries at their stores and authorized repair shops; third-party repairs are cheaper but may affect water resistance and warranty coverage.
  • Battery replacement takes one to three hours at an Apple Store or authorized shop, or one to two days by mail if you use Apple's service.
  • iPhones older than five years often have batteries below 50 percent health, making replacement worth considering before the phone shuts down on its own.

How to check your battery health right now

You do not need to read anything or visit a store to see your battery's condition. On any iPhone running iOS 16 or later, go to Settings, scroll down and tap Battery, then tap Battery Health & Charging. The first number you see — maximum capacity — is your battery's health as a percentage.

Write down that number. If it is 80 percent or higher and your phone works normally, you have time. If it is below 80 percent, a replacement will improve performance. If it is below 50 percent, your phone may shut down without warning, even with 20 or 30 percent charge remaining on the screen.

Below the maximum capacity number, you will also see a condition status. If it says "Normal," your battery is fine. If it says "Service Recommended" or "Service Battery," Apple is telling you the battery is degraded enough to replace. "Poor Condition" means the battery is failing and replacement is urgent.

When unexpected shutdowns mean you need a replacement

Some iPhones shut down suddenly even though the battery percentage looks fine. This happens because the battery cannot deliver the power the phone needs all at once, so the phone turns itself off to protect the battery. It is not a software problem and restarting will not fix it.

If your phone shuts down at 30 percent, 40 percent, or even 50 percent charge, go to Settings > Battery > Battery Health & Charging and check the maximum capacity. If it is below 80 percent, the battery is the problem. If it is above 80 percent but shutdowns are still happening, the battery may be failing in a way that does not show up in the health percentage — this is rare, but it happens. Either way, a replacement will stop the shutdowns.

Do not ignore repeated shutdowns. Each time your phone forces itself off, it risks corrupting files or losing unsaved work. If this is happening to you, plan a replacement within the next week or two.

Where to get your battery replaced

Apple replaces batteries at their retail stores and at authorized repair shops. You can also mail your phone to Apple for service. Third-party repair shops — including chain stores like Best Buy and independent local shops — also replace iPhone batteries, usually for less money.

An Apple Store or authorized shop will charge between $69 and $99 depending on your iPhone model. They will also may provide the replacement and maintain your water resistance seal. Third-party shops typically charge $40 to $60, but quality varies. Some shops use genuine Apple batteries; others use aftermarket batteries that work but may not last as long. Ask the shop whether they use genuine or aftermarket parts before you agree.

If you go to a third-party shop, understand that opening your iPhone voids some warranty protections and may affect water resistance if the seal is not properly resealed. Apple will still service your phone afterward, but they may charge extra if water damage is found later. For most people, the Apple Store or an authorized shop is worth the extra cost for peace of mind.

How long the replacement takes

At an Apple Store or authorized shop, battery replacement usually takes one to three hours. You can often make an appointment online and drop your phone off, then pick it up the same day. Some stores offer walk-in service, but you may wait longer.

If you mail your phone to Apple, the whole process takes five to seven business days. Apple will send you a prepaid shipping label, you pack and ship your phone, Apple replaces the battery, and they ship it back. During that time, you will not have your phone.

Third-party shops vary. Some replace batteries while you wait — 30 minutes to an hour. Others may take a day or two if they need to order parts. Call ahead and ask before you drop off your phone.

What to do before you go in for replacement

Back up your iPhone before you take it in for service. Use iCloud or connect to a computer and use Finder (on Mac) or iTunes (on Windows). This takes 10 to 30 minutes depending on how much data you have. If something goes wrong during the repair, you will have your data safe.

Bring your phone charger and your Apple ID password. The repair shop will need to verify your identity and may need to test the phone after the replacement. If you have a case or screen protector, remove it before you arrive — the shop will not work on your phone while it is covered.

If your phone is still under warranty or covered by AppleCare+, bring proof. Warranty coverage and AppleCare+ both cover battery replacement at no cost if the battery health is below 80 percent. If you do not have coverage, you will pay the standard fee.

Signs your battery is failing besides low health percentage

Battery health percentage is the clearest signal, but other signs point to a failing battery. If your phone drains from 100 percent to 20 percent in a few hours of normal use, the battery is degraded. If apps crash or freeze when you are using the camera, playing games, or streaming video — things that demand a lot of power — your battery cannot keep up.

Slow performance during heavy use is another clue. Your iPhone may throttle its processor when the battery is weak, making everything feel sluggish. Restarting the phone does not fix this. If your phone feels slow only when the battery is below 50 percent, the battery is the problem.

Overheating during normal use can also signal battery trouble. Batteries generate heat as they degrade, and a failing battery may make your phone warm even when you are just checking email. If your phone is hot to the touch and the battery health is below 70 percent, replacement will help.

Frequently Asked Questions

Will replacing the battery make my iPhone feel like new?

A new battery will restore normal performance and fix unexpected shutdowns, but it will not make an old phone feel brand new. If your iPhone is five years old, the processor and screen are also aging. A battery replacement will make the phone more reliable and last longer, but it will not speed up processing or improve the display.

Can I replace the battery myself?

You can buy a replacement battery and tools online, but opening an iPhone yourself is difficult and risky. You may damage the screen, water resistance seal, or internal components. Most people should use a repair shop. If you are experienced with phone repair, research your specific model first — battery location and difficulty vary.

What happens if I ignore a low battery health percentage?

Your phone will continue to work, but performance will degrade. Battery health below 50 percent often causes unexpected shutdowns. Below 30 percent, shutdowns become frequent and unpredictable. Eventually, the battery may fail completely and your phone will not turn on until you charge it.

Does AppleCare+ cover battery replacement?

Yes. AppleCare+ covers battery replacement at no cost if the battery health drops below 80 percent. Without AppleCare+, you pay the standard service fee ($69 to $99 at Apple). AppleCare+ costs extra upfront but covers two years of accidental damage and battery service.

Can I use my iPhone while I wait for the battery replacement?

If you are using an Apple Store or authorized shop, you can usually pick up your phone the same day, so you will be without it for only a few hours. If you are mailing it to Apple, you will not have your phone for five to seven days. Some people use an old phone or borrow one during that time.