iPhone 15 Pro battery drain and iMessage crashes after iOS 27.0.1

I'm having issues with my iPhone 15 Pro right after updating it to iOS 27.0.1. My battery health is at 79% (which is what it was at BEFORE the update), and while I, of course, noticed some downsides in battery life, my phone still functioned as expected. However, after the update, my battery has been draining about 20% faster than it was previously. On top of that, my phone has started crashing in the iMessage app and been unable to reboot unless I plug it into the wall, and will report half the battery has drained. Again, this was NOT an issue in iOS 26, and my battery health hasn't changed. I've also had issues where, once the phone reboots, it takes anywhere from 10 to 20 minutes to receive texts again. What course of action can I take to fix/report this?

iPhone 15 Pro, iOS 27

Posted on Oct 23, 2026 8:49 PM

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4 replies

Oct 24, 2026 2:50 AM in response to builderdev212

builderdev212 wrote:
my phone has started crashing in the iMessage app

You may try some of these steps. Please check after each step...


  1. Having too many apps open may cause this issue, as RAM is being used by other apps, leaving less memory available for proper rendering. Close an app on your iPhone or iPod touch
  2. Overloaded system: Too many apps running in the background can cause stuttering. Refresh content in apps you're not actively using on ...
  3. Storage issues: Low or fragmented storage can slow down the camera. --> Manage and Clear Storage on your iPhone a… - Apple Community
  4. Sometimes, a simple restart can resolve temporary software glitches. Turn off your iPhone, wait for a few seconds, and then turn it back on.
    1. Restart the device. That's it.
    2. Still not solved --> Force restart iPhone - Apple Support
  5. If you're using a VPN, disable it and check if the error goes away. Go to Settings > General > VPN & Device Management and turn off any active VPNs. Disabling a VPN only from the iPhone settings may not completely turn it off. To fully disable it, you need to switch it off from the VPN service provider’s app or remove the configuration profile they installed. Only then is the VPN truly off, which can help if it’s causing issues with cellular or Wi-Fi connectivity.
  6. Reset Network Settings: Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings: Only network settings are removed.
    1. When you reset network settings, previously used networks and VPN settings that weren’t installed by a configuration profile or mobile device management (MDM) are removed. Wi-Fi is turned off and then back on, disconnecting you from any network you’re on. The Wi-Fi and Ask to Join Networks settings remain turned on.
    2. To remove VPN settings installed by a configuration profile, go to Settings > General > Profiles & Device Management, select the configuration profile, then tap Remove Profile. This also removes other settings and accounts provided by the profile. See Install or remove configuration profiles on iPhone in this guide.
    3. To remove network settings installed by MDM, go to Settings > General > Profiles & Device Management, select the management, then tap Remove Management. This also removes other settings and certificates provided by MDM. See “Mobile device management (MDM)” in the iOS Deployment Reference.
    4. Reset your Network Settings. Tap Settings > General > Reset > Reset Network Settings. This also resets Wi-Fi networks and passwords, cellular settings, and VPN and APN settings that you've used before.
  7. If the issue persists, you can try resetting all settings on your iPhone. This will not erase your data but will reset all personalized settings to their default values. Go to Settings > General > Transfer & Reset > Reset > Reset All Settings and confirm the action. Note that you will need to reconfigure your settings afterward. All settings—including network settings, the keyboard dictionary, the Home screen layout, location settings, privacy settings, and Apple Pay cards—are removed or reset to their defaults. No data or media are deleted.
    1. Reset All Settings: Return iPhone settings to their defaults - Apple Support:- Return iPhone settings to their defaults
    2. You can return settings to their defaults without erasing your content.
    3. If you want to save your settings, back up your iPhone before returning them to their defaults. For example, if you’re trying to solve a problem but returning settings to their defaults doesn’t help, you might want to restore your previous settings from a backup.
  8. Make sure you have the latest updates installed.
    1. Update Over-the-Air (OTA) —> Update your iPhone or iPad - Apple Support (IN)
    2. Update using iTunes/Finder —> Update your iPhone, iPad, or iPod touch - Apple Support (IN)


If none of the above steps resolve the issue, it is recommended to reach out to Apple Support or visit an authorized service center for further assistance. They can provide specific guidance based on your device model and iOS version.



Oct 24, 2026 2:49 AM in response to builderdev212

builderdev212 wrote:
my battery has been draining about 20% faster than it was previously. On top of that,

The measure of battery health deterioration/drainage is subjective and can vary depending on individual usage patterns. There is no universal standard to determine whether the battery health deterioration/drainage is normal or abnormal because it heavily relies on how the battery is used and maintained.



Protect & Prolong the Life of your iPhone's Battery:

  1. About the battery usage on your iPhone, iPad, and iPod touch ...
  2. Batteries - Maximising Performance - Apple (IN)
  3. iPhone Battery and Performance
  4. About Charge Limit and Optimised Battery Charging on iPhone - Apple Support (IN)






Try to monitor Battery usage by iPhone Activity as shown below


What is shown under battery usage? Checking that would give you an indication of the usage behavior.

  1. Background Activity
  2. Notifications
  3. Connected to Charger
  4. Or any Other




Try some of these options too.

To prolong the life of your iPhone battery, you can follow these tips and best practices:


To prolong the life of your iPhone battery, you can follow these tips and best practices:

  1. Optimize Battery Charging: Enable the "Optimized Battery Charging" feature on your iPhone. It helps reduce the wear on the battery by slowing down the battery aging process. You can find this option in Settings > Battery > Battery Health. About Optimized Battery Charging on your iPhone - Apple Support (IN)
  2. Avoid Extreme Temperatures: Extreme temperatures, both hot and cold, can negatively impact your battery life. Avoid exposing your iPhone to excessive heat or cold, such as leaving it in direct sunlight or in a freezing car.If your iPhone or iPad gets too hot or too cold – Apple Support (UK)
  3. Use Original Chargers and Cables: Always use Apple's original chargers and cables or certified third-party accessories. Low-quality chargers or cables can damage the battery and reduce its lifespan. Identify counterfeit or uncertified Lightning connector accessories - Apple Support (IN)
  4. Avoid Draining the Battery to Zero: Charge it whenever the charge becomes lower than 20%. The rest is up to you when to charge. how long to charge, how often to charge, which adapter to use starting from 5W to 140W USB-C Power Adapter etc.
  5. Optimize Display Settings: Adjust your display settings to optimize battery life. Lower the screen brightness, enable auto-brightness, and use shorter screen timeout durations. Adjust the display and text size on iPhone - Apple Support (IN)
  6. Minimize Background App Refresh: Limit the number of apps allowed to refresh in the background. Go to Settings > General > Background App Refresh and disable it for apps that don't require real-time updates. Switch apps on your iPhone, iPad, or iPod touch - Apple Support (IN)


Oct 24, 2026 2:48 AM in response to builderdev212

builderdev212 wrote:
I'm having issues with my iPhone 15 Pro right after updating it to iOS 27.0.1.

Not every issue an individual encounters on their device can be attributed to an iOS update. iOS 27 or later may have coincided with what you are experiencing, but that does not mean the issue was triggered by iOS. Coincidence in timing is not, by itself, evidence of causation.


If the update itself were the root cause, then every device running that same version of iOS would exhibit the identical problem. In such a scenario, the forums would be flooded with countless posts reporting the same malfunction, creating an unmistakable wave of complaints that no one could possibly overlook.


The absence of such widespread reports strongly indicates that the issue is not a general, system-wide problem with iOS 27 or later, but rather something specific to the individual device, its configuration, installed apps, settings, hardware, or another interacting factor.


In short: iOS 27 or later may be a coincidence in timing, but there is no basis to conclude that iOS itself triggered the problem simply because the issue appeared after the update.




See what each update does: About iOS 27 Updates, About iOS 26 Updates, About iOS 18 Updates, About iOS 17 Updates, About iOS 16 Updates, About iOS 15 Updates, About iOS 14 Updates, About iOS 13 Updates, About iOS 12 Updates, and so on...

Oct 24, 2026 2:51 AM in response to builderdev212

builderdev212 wrote:
once the phone reboots, it takes anywhere from 10 to 20 minutes to receive texts again.

If you connect to Wifi, doesn't necessarily mean you are connected to the internet. --> Internet not available WiFi and Cellular … - Apple Community


Wi-Fi Assist is on by default. This will automatically switch to Cellular Data if the device is not connected to the internet.


About Wi-Fi Assist - Apple Support



iPhone 15 Pro battery drain and iMessage crashes after iOS 27.0.1

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