You updated your iPhone.
Everything installed successfully.
Then you noticed something:
Your battery life suddenly seems terrible.
Maybe your iPhone feels warmer than usual.
Maybe the battery percentage is dropping faster.
Or perhaps a phone that normally lasts until bedtime suddenly needs a charger halfway through the afternoon.
Before assuming the update ruined your battery, there's something important to understand:
Your iPhone may continue performing update-related work even after the installation appears to be finished.
That background activity can temporarily increase power consumption and heat.
Here's why it happens, how long you should give your iPhone to settle down, and what to check if the battery drain doesn't improve.
Why Does Battery Life Get Worse After an iOS Update?
Installing iOS isn't always the end of the update process.
After your iPhone restarts and becomes usable again, additional tasks may continue in the background.
Your device may be processing, organizing, updating, synchronizing, or optimizing information related to the new software.
All of that requires processing power.
Processing requires energy.
And energy consumption means:
More battery usage.
That's why battery drain immediately following an update doesn't necessarily mean something is wrong.
Your iPhone May Tell You an Update Is Still Finishing
Before changing a dozen settings, check:
Settings → Battery
On newer versions of iOS, you may see an Insight indicating:
Ongoing iOS Update
This means a recent software update is still completing work in the background.
While that activity continues, you may temporarily experience:
- Shorter battery life
- Increased background activity
- Additional processor usage
- A warmer iPhone
Once the work finishes, battery life should begin returning to normal.
How Long Should You Wait After an iOS Update?
Don't judge battery life immediately after installing an update.
Give your iPhone some time.
Apple recommends waiting a few days if battery life seems worse following an update.
That gives background update tasks time to finish and also gives you enough normal usage to determine whether there's actually an ongoing problem.
So if you installed iOS last night and today's battery life looks terrible:
Don't panic yet.
Use the phone normally and monitor it.
Why Does My iPhone Get Hot After an iOS Update?
Battery drain and heat often appear together.
That's because both can result from increased processor activity.
If your iPhone is performing substantial background work, you may notice it feels warmer than usual.
Some warmth can be expected during intensive activity.
However, excessive or persistent heat deserves additional investigation.
If your phone continues becoming unusually hot after the update activity has finished, read:
Why Is My iPhone Getting Hot While Charging?
Heat is particularly important because repeated exposure to excessive temperatures can contribute to long-term battery aging.
Step 1: Check Battery Usage
The first troubleshooting step isn't restarting the phone.
It isn't resetting everything.
And it definitely isn't replacing the battery.
Start here:
Settings → Battery
Your iPhone provides detailed information about what's actually consuming power.
Depending on your version of iOS, you may see:
- Daily Usage
- Battery level history
- App activity
- System activity
- Battery Insights
- Suggestions
Look for anything unusual.
Step 2: Look for Ongoing iOS Update
If Battery settings show:
Ongoing iOS Update
you've probably found the explanation.
Your iPhone is still completing update-related work.
Rather than immediately changing settings, give the device time to finish.
Once the Insight disappears, continue monitoring battery life.
Step 3: Compare Today's Usage With Normal Usage
Current iOS battery information can compare today's power consumption with your recent usage.
This is useful because perception can be misleading.
You may think:
My battery is draining twice as fast.
But perhaps you've also spent considerably more time:
- Watching video
- Using navigation
- Taking photos
- Browsing social media
- Gaming
Battery usage information helps separate an actual problem from simply using the phone more heavily.
Step 4: Find the Apps Using the Most Battery
Scroll through Battery settings and review app usage.
Look for applications consuming significantly more power than expected.
An iOS update may coincide with an app problem without actually causing the battery problem itself.
For example, an app may:
- Need its own update
- Be performing excessive background activity
- Be repeatedly crashing
- Be using location services
- Be synchronizing large amounts of data
If one application suddenly dominates battery consumption, investigate that app first.
Step 5: Update Your Apps
After a major iOS release, app developers frequently release compatibility updates.
Open the App Store and check for available updates.
Keeping apps current can help eliminate bugs or compatibility problems that contribute to abnormal power consumption.
If one app appears unusually high in Battery Usage, make sure it's updated before doing anything drastic.
Step 6: Restart Your iPhone
If the update has completed but battery usage still seems abnormal, restart the device.
A restart can clear temporary software conditions and restart processes that may not be behaving correctly.
You don't need to erase your phone.
You don't need to reset every setting.
Start with the simplest option first.
Step 7: Check Background Activity
Battery settings may show Background Activity beneath certain applications.
This means much of that app's power consumption occurred while it wasn't actively displayed on screen.
Background activity isn't automatically bad.
For example, it can make sense for:
- Music apps
- Navigation
- Location-related services
- Cloud synchronization
But excessive background usage from an app you barely use is worth investigating.
We've created an entire guide for this:
Does Background App Refresh Drain iPhone Battery?
Step 8: Check Your Cellular Signal
This one gets overlooked constantly.
Battery settings may identify:
No Mobile Coverage and Low Signal
when network conditions contribute to increased power consumption.
Your iPhone may consume additional energy while trying to maintain connectivity in weak coverage areas.
So if you updated your iPhone and then spent the next day:
- In a basement
- Inside a large office building
- Traveling
- In a parking garage
- Somewhere with poor carrier reception
don't automatically blame iOS.
The network environment may be contributing to the battery drain.
Step 9: Check Screen Brightness
Your display can consume a significant amount of power.
Battery settings may provide suggestions when screen brightness is unusually high.
Check:
Settings → Display & Brightness
You can also review Auto-Brightness settings.
If you're trying to maximize battery life, running the display at full brightness all day isn't going to help.
Step 10: Check Auto-Lock
If your screen remains active long after you've stopped using the phone, that's wasted power.
Open:
Settings → Display & Brightness → Auto-Lock
Choose a setting that makes sense for the way you use your iPhone.
Battery settings may also recommend enabling Auto-Lock when excessive idle screen time is detected.
Step 11: Use Low Power Mode Temporarily
If you need your iPhone to last longer while update-related activity finishes, Low Power Mode can help.
Depending on your iPhone model, go to:
Settings → Battery
or:
Settings → Battery → Power Mode
Then enable:
Low Power Mode
Low Power Mode reduces or disables several power-consuming features and background behaviors.
This can be particularly useful if you're away from a charger while waiting for your phone to settle down after an update.
Step 12: Don't Immediately Disable Everything
This is one of the biggest mistakes people make.
Battery gets worse after an update.
So they disable:
- Bluetooth
- Wi-Fi
- Background App Refresh
- Location Services
- Notifications
- Always-On Display
- Automatic updates
- Every widget
- Half their apps
Then battery life improves.
But now they have absolutely no idea what actually caused the problem.
Change one or two things at a time.
Observe the result.
Troubleshooting works much better when you can identify cause and effect.
Does Always-On Display Cause Post-Update Battery Drain?
Always-On Display does consume some power on supported iPhones.
But don't assume it's responsible simply because your battery life changed after updating iOS.
If you want to test it, disable the feature for several days and compare your normal battery usage.
We've covered that separately in:
Does Always-On Display Drain iPhone Battery?
That lets you determine whether the feature makes a meaningful difference for your particular usage.
Could Background App Refresh Be the Problem?
Possibly.
Applications may perform certain tasks while you're not actively using them.
If Battery settings show substantial background activity from a particular app, review its permissions and behavior.
You can check:
Settings → General → Background App Refresh
But again:
Don't automatically turn everything off.
Start with applications showing abnormal activity.
See:
Does Background App Refresh Drain iPhone Battery?
Did the iOS Update Damage My Battery?
Usually, sudden battery drain immediately after an update isn't evidence that the update physically damaged the battery.
Battery capacity declines through chemical aging over time.
An update can change:
- Software behavior
- Background processing
- App compatibility
- Power management
- What battery information is displayed
But if your physical battery is already significantly aged, a software update may make an existing battery limitation more noticeable during periods of heavier activity.
That's why Battery Health is worth checking if the problem persists.
Check Your Battery Health
If several days have passed and battery life remains poor, check the condition of the physical battery.
Depending on your iPhone model, open:
Settings → Battery → Battery Health
or:
Settings → Battery → Battery Health & Charging
Review the information provided by iOS.
If your battery has significantly degraded, software troubleshooting can improve efficiency—but it can't restore lost chemical capacity.
Read:
How to Check iPhone Battery Health and What It Really Means
What If Battery Health Says Service?
That's different from temporary post-update drain.
If iOS displays Service for Battery Health, battery replacement may be worth considering.
A worn battery can cause:
- Reduced runtime
- More frequent charging
- Performance limitations
- Unexpected shutdowns
Our complete decision guide is:
Does Your iPhone Need a New Battery? Signs It's Time to Replace It
Should You Factory Reset Your iPhone?
Not immediately.
A factory reset is a major troubleshooting step and shouldn't be your first response to temporary battery drain after an update.
Before considering anything that drastic:
- Give update-related activity time to finish.
- Check Battery Usage.
- Update your apps.
- Restart the phone.
- Check background activity.
- Check network conditions.
- Check Battery Health.
Only escalate troubleshooting when simpler explanations have been eliminated.
Should You Downgrade iOS?
For most users, trying to downgrade iOS isn't an appropriate first response to battery drain.
There are also practical limitations around which iOS versions Apple allows devices to install.
Instead, determine whether the problem is:
- Temporary update activity
- A specific app
- Background activity
- Poor signal
- Display usage
- An aging battery
- An actual software problem
Troubleshoot first.
Why Is My Battery Percentage Dropping Faster After Updating?
There are several possible explanations.
Your iPhone may be:
- Completing update-related background tasks
- Synchronizing information
- Running updated system processes
- Using an app with compatibility problems
- Experiencing poor network conditions
- Being used more heavily than usual
The battery percentage dropping faster doesn't automatically mean the physical battery suddenly lost capacity.
Check Battery Usage before drawing conclusions.
Why Does Battery Drain Continue Overnight?
If you're losing substantial battery while the phone isn't being used, inspect Battery Usage during those hours.
Look for:
- Background Activity
- Location usage
- System activity
- Poor cellular coverage
- Apps consuming power overnight
If your phone is connected to a charger overnight but still isn't charging normally, that's a different issue.
See:
Is It Safe to Charge Your iPhone Overnight?
and:
iPhone Won't Charge? 12 Fixes That Actually Work
How Long Should You Monitor Battery Life?
Give yourself enough time to establish a pattern.
One bad afternoon isn't enough.
After update-related activity finishes, use your iPhone normally for several days.
Compare:
- Morning battery level
- Midday battery level
- End-of-day battery level
- Screen usage
- App activity
- Charging frequency
If the same pattern continues consistently, then you have something worth troubleshooting further.
Frequently Asked Questions
Is battery drain normal after an iOS update?
Temporary increased battery usage can occur because update-related tasks may continue running in the background after installation.
How long should battery drain last after updating?
Apple recommends waiting a few days and checking again because background update tasks can temporarily affect battery life and thermal performance.
Why is my iPhone hot after updating iOS?
Background processing associated with the update can temporarily increase processor activity and heat. Persistent or excessive heat should be investigated separately.
Should I restart my iPhone after updating?
Your iPhone already restarts as part of many updates, but another restart can be a reasonable troubleshooting step if abnormal battery behavior continues after the update has finished.
Should I replace my battery after an iOS update?
Not simply because battery life temporarily decreased. Check update activity, Battery Usage, apps, and Battery Health before considering replacement.
Does an iOS update reduce Battery Health?
An update doesn't magically reverse or recreate the battery's physical chemistry. Battery Health reflects the condition of a consumable lithium-ion battery, although software determines how battery information is measured and presented.
Should I turn off Background App Refresh?
Only if your usage data suggests background activity is contributing to the problem or you don't need the feature for particular apps.
Will Low Power Mode help after an update?
It can extend runtime by reducing certain background activities and other power-consuming features while your phone completes update-related work.
Continue Troubleshooting Your iPhone Battery
This article is part of the iPhone4Idiots iPhone Battery Help collection.
Continue with:
- iPhone Battery Draining Fast? Here's How to Fix It
- 25 Ways to Improve iPhone Battery Life
- Does Background App Refresh Drain iPhone Battery?
- Does Always-On Display Drain iPhone Battery?
- How to Check iPhone Battery Health
- How Long Does an iPhone Battery Last?
- Does Your iPhone Need a New Battery?
- Why Is My iPhone Getting Hot While Charging?
- iPhone Won't Charge? 12 Fixes That Actually Work
- Why Is My iPhone Charging So Slowly?
- What Is Optimized Battery Charging?
- Is It Safe to Charge Your iPhone Overnight?
Final Thoughts
If your iPhone battery starts draining faster immediately after an iOS update, don't assume something has gone permanently wrong.
Your iPhone may simply still be working.
Update-related processes can continue after the installation appears finished, temporarily increasing battery usage and heat.
Start by opening:
Settings → Battery
Look for an Ongoing iOS Update Insight.
Check which apps and system activities are actually consuming power.
Give the device a few days to settle down.
If battery life returns to normal, there was probably nothing to fix.
If it doesn't, you now have the information needed to investigate apps, background activity, cellular signal, display usage, and Battery Health systematically.
Don't troubleshoot an iPhone battery based on fear after an update. Troubleshoot it based on what the Battery screen actually tells you.
