How to Recalibrate the iPhone Battery

Battery life not the same on your iPhone? Recalibration may help

What to Know

  • The iPhone's calibration tool (iOS 14.5 and up) runs automatically, but you can check its status in Settings > Battery > Battery Health.
  • You can recalibrate older iPhones by draining the battery, fully charging it, and immediately restarting the phone.

This article explains how to recalibrate the iPhone battery using Apple’s battery recalibration tool. It also explains the old style of battery calibration.

How to Recalibrate the iPhone Battery

Apple released a battery calibration tool alongside iOS 14.5 which you can use to recalibrate your battery. If you don’t have iOS 14.5 or newer, you’ll have to update your operating system before using this tool.

If your phone is fully updated and has the battery recalibration feature, it will run automatically and help improve your battery life over time. You can check its progress at any time in the battery health section of your iPhone settings.

Here’s how to use the iPhone battery recalibration tool:

  1. From the home screen, tap Settings.

  2. In the settings menu, scroll down.

  3. Tap Battery.

    Steps to find Battery settings on iOS 14.5.
  4. Tap Battery Health.

  5. Look for Important Battery Message at the top of the display for information about the battery recalibration process on your phone.

    Battery health information on iOS 14.5.

    If you don’t see a message, come back and check later. The calibration process is automatic, and it can take a while.

How Does iPhone Battery Recalibration Work?

The battery calibration tool introduced with iOS 14.5 calibrates your battery automatically, so you don’t need to turn on the feature. The calibration can take weeks, and even then, it’s an ongoing process. If you don’t see a message about the status of your recalibration, check back later. As it recalibrates your battery, you will see your Maximum Capacity and Peak Performance Capability change to reflect the actual status of your battery.

How to Calibrate Older iPhone Batteries

The iPhone battery calibration tool isn’t available for all iPhones, but another iPhone calibration process has been around a lot longer. This process requires you to fully drain the battery, which can be harmful to lithium-ion batteries like the ones found in iPhones. With that in mind, you should only use this calibration process if your battery life is already low, and you should only do it occasionally. If you only calibrate your battery every few months or when your phone needs it, the benefits you see from calibration should outweigh the potential harm done by allowing the battery to die completely.

If your phone has an automatic calibration tool, do not use this process. Allow the calibration tool to do its job, even if it seems slow.

Here’s how to calibrate an older iPhone battery:

  1. Use your phone until it shuts off due to the battery running down.

  2. Don’t touch the phone when it shuts off. Leave it alone for at least three hours, or overnight if possible.

  3. Plug your phone in using the original cable and charger or a cable and charger that are Apple-certified.

  4. Wait for the phone to power on.

  5. Turn the phone back off.

  6. Leave your phone plugged in until it's fully charged.

  7. Turn the phone on.

  8. Wait for the iPhone to start up, then perform a restart.

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