You go to bed with your Android phone working normally.

By morning, something looks different.

Maybe your phone is asking for your PIN instead of fingerprint.

Some apps have restarted.

Notifications arrived late.

Your VPN disconnected.

Or you simply notice that the phone restarted sometime during the night.

If this happens once, it may not mean anything serious.

But if your Android phone restarts by itself every night or repeatedly while you are sleeping, there is probably a reason behind it.

Possible causes include:

• Automatic restart settings
• Scheduled device optimization
• Software updates
• Problematic apps
• Low storage
• Battery or charging problems
• Overheating
• Android system crashes
• Hardware faults

Google’s official Android troubleshooting guidance recommends checking software updates, storage, downloaded apps and Safe Mode before considering more drastic steps such as a factory reset.

In this Cyberhub ICT guide, we will explain the most common reasons an Android phone restarts at night and show you how to troubleshoot the problem safely.

First Question: Does It Restart at Almost the Same Time Every Night?

This is one of the most useful clues.

If your phone restarts around the same time every night, the problem may not actually be a fault.

Your phone may have an automatic restart or device-optimization feature enabled.

This is especially common on some Samsung Galaxy phones.

Samsung provides an Auto restart or Restart when needed feature designed to restart the device when it is not being used. Samsung says these restarts often happen during early morning hours when the screen is off and the phone is idle.

So before assuming your battery or motherboard is damaged, check whether your phone is intentionally restarting itself.

1. Check for Automatic Restart Settings

Search your phone’s Settings for:

Auto Restart

Automatic Restart

Restart When Needed

or:

Auto Optimization

The exact wording depends on the manufacturer.

Samsung Galaxy

On supported Samsung phones, try:

Settings → Battery and Device Care → Auto Optimization

Look for:

Restart When Needed

Older Samsung software may show:

Auto Restart at Set Times

Samsung confirms that Galaxy phones can restart automatically when certain conditions are met, including when the screen is off and the phone is not actively being used.

If you do not want the phone restarting automatically, turn this feature off.

Then monitor the phone for the next few nights.

If the overnight restarts stop, you have found the cause.

2. The Phone May Be Restarting After a Software Update

Android updates can require a reboot to finish installation.

If your phone downloads an update automatically while charging or connected to Wi-Fi, you may discover the next morning that it restarted.

Check:

Settings → System → Software Update

or:

Settings → About Phone → Software Update

Look at the most recent update information.

If the restart happened only once and an Android or manufacturer update was installed around the same time, the behaviour may be normal.

However, if the phone restarts every night without new updates, continue troubleshooting.

3. Check Whether a Recently Installed App Is Causing the Restart

Downloaded apps can sometimes cause Android instability.

Google specifically recommends investigating apps if your device:

• Restarts itself
• Freezes
• Crashes
• Becomes unusually slow

Safe Mode temporarily disables downloaded apps. If the restarting stops in Safe Mode, a third-party app is likely responsible.

Think about whether the problem started after installing:

• A battery saver
• RAM cleaner
• VPN
• Game
• Launcher
• Antivirus
• Modded APK
• Wallpaper app
• System utility
• Unknown APK

If yes, uninstall the most suspicious or recently installed apps one at a time.

Restart the phone normally after each removal and observe whether the problem returns.

4. Use Safe Mode

Safe Mode is one of the best ways to separate an Android software problem from a third-party app problem.

When Android runs in Safe Mode, downloaded applications are temporarily disabled.

If your phone no longer restarts overnight in Safe Mode, one of your installed apps is probably causing the instability. Google explicitly recommends Safe Mode when a device restarts itself, freezes or crashes.

The method for entering Safe Mode differs between Android manufacturers, so use the official instructions for your phone model.

After testing:

Restart normally.

Then remove recently installed apps one by one.

5. Check Your Available Storage

Low storage can cause more problems than many users realize.

Google states that Android phones can begin experiencing issues when less than about 10% of storage remains free.

Go to:

Settings → Storage

Check your free space.

If storage is almost completely full, remove unnecessary:

• Videos
• Downloads
• Old APK files
• Large games
• WhatsApp media
• Offline movies
• Duplicate files

Also clear unnecessary app cache where appropriate.

After freeing space, restart the phone and monitor it overnight.

6. Update Android

Software bugs can cause unexpected restarts.

Google recommends checking for Android updates when troubleshooting random restarts and crashes.

Go to:

Settings → System → Software Update

Install any official update available for your phone.

Also check:

Google Play System Update

if your device provides that option.

Restart after updating.

7. Update Your Apps

An outdated or buggy application can destabilize the phone.

Open:

Google Play Store → Profile → Manage Apps & Device

Install available updates.

Pay particular attention to apps that:

• Run constantly in the background
• Control battery behaviour
• Use VPN services
• Modify the launcher
• Handle security
• Were installed shortly before the problem began

Google recommends app updates as part of its troubleshooting process for restarting and crashing Android devices.

8. Check Whether the Phone Restarts Only While Charging

This clue is important.

If the phone only restarts overnight when connected to a charger, investigate the charging system.

Try:

• Another compatible cable
• Another approved charger
• Another wall socket
• Cleaning visible lint from the charging port carefully
• Charging without a power bank

Google recommends checking the cable, charger, wall outlet and charging port when troubleshooting power-related Android problems.

Do not use damaged chargers

A loose cable or defective power adapter may create unstable charging behaviour.

If the phone repeatedly restarts only with one charger, stop using that charger.

9. Check the Battery

An aging or failing battery can also cause unexpected shutdowns and restarts.

Possible warning signs include:

• Battery percentage dropping suddenly
• Phone shutting down at 20% or 30%
• Rapid battery drain
• Restarting when performing demanding tasks
• Restarting while charging
• Battery percentage jumping after reboot

If the battery is visibly swollen, stop using the phone and have it inspected professionally.

Do not continue charging a swollen battery.

10. Check for Overheating

A phone that becomes excessively hot may behave unpredictably.

Nighttime overheating can happen if the phone is:

• Charging under a pillow
• Covered by bedding
• Using a poor charger
• Running large downloads
• Performing cloud backups
• Updating apps
• Running a demanding background process

Never leave a charging phone under pillows or thick blankets.

Place it on a hard, ventilated surface.

If the phone becomes unusually hot during normal light use, stop charging it and investigate further.

11. Remove the Case Temporarily

This may sound strange, but Google recommends removing cases and external battery accessories when troubleshooting random restarts and crashes, because accessories can interfere with sensors or buttons.

A tight or damaged case could also press the:

Power button

or:

Volume button

without you noticing.

Remove the case for one night and observe what happens.

If the restarts stop, inspect the case and buttons carefully.

12. Check the Power Button

A damaged or sticking power button can make the phone appear to restart randomly.

Press the power button several times.

Does it:

• Feel stuck?
• Stay pressed inward?
• Respond inconsistently?
• Restart the phone when touched lightly?

If yes, the problem may be physical rather than software-related.

A factory reset will not fix a damaged button.

13. Avoid Aggressive “Cleaner” and Battery Booster Apps

Apps claiming to:

Boost RAM

Clean Memory

Cool Your Phone

Improve Battery

can sometimes create more problems than they solve.

Some aggressively close background services or interfere with Android’s own system management.

If your restarting problem began after installing a cleaner or battery optimizer, remove it.

Android already contains built-in battery, memory and app-management systems.

14. Check Whether Automatic Optimization Is Enabled

Some Android manufacturers include automatic maintenance features.

These may:

• Close background apps
• Clear memory
• Optimize performance
• Restart the phone

Samsung’s Device Care is a good example. Samsung states that its Auto Optimization feature may restart the phone automatically when the device is not being used, often during early morning hours.

Search Settings for:

Optimization

Device Care

Phone Master

Battery Optimization

or:

Scheduled Maintenance

Depending on your phone brand, similar features may exist.

15. Check Whether the Phone Is Actually Turning Off, Not Restarting

There is a difference.

A restart means:

Phone turns off → Android boots again automatically.

A shutdown means:

Phone turns off and stays off until you turn it back on.

If your phone is shutting down overnight rather than restarting, battery or charging issues become more likely.

Google’s troubleshooting guidance covers both devices that randomly restart and those that shut down unexpectedly.

16. Look for a Pattern

Keep a simple record for several nights.

Note:

Time | Battery Level | Charging? | Phone Temperature | Apps Running | Restart Happened?

Patterns are extremely useful.

For example:

Pattern A

Restart every night around 3:00 AM.

Likely scheduled restart or optimization.

Pattern B

Restart only when charging.

Check charger, cable, battery and heat.

Pattern C

Restart started after installing an app.

Investigate third-party software.

Pattern D

Restart happens randomly day and night.

Could be software instability or hardware.

Pattern E

Restart happens when battery reaches 25%.

Possible battery-health issue.

17. Check for Malware or Suspicious Apps

Malicious or poorly written apps can cause unusual behaviour.

Review recently installed apps.

Look for:

• Apps you do not recognize
• Apps installed outside Google Play
• Apps with strange names
• Apps demanding excessive permissions

Open:

Google Play Store → Profile → Play Protect

Run a scan.

Remove suspicious applications.

18. Do Not Ignore Repeated Restart Loops

If the phone keeps restarting repeatedly and cannot remain on long enough to use normally, that is different from one overnight reboot.

You may be dealing with:

• Serious software corruption
• Bad update
• Failing battery
• Storage failure
• Motherboard problem
• Damaged power button

Google’s Android troubleshooting guide recommends software updates, storage checks, app troubleshooting and Safe Mode before advanced troubleshooting.

If the phone cannot remain stable even in Safe Mode, professional diagnosis may be needed.

19. Back Up Important Data

If the restart problem is becoming frequent, do not wait until the phone becomes unusable.

Back up:

• Contacts
• Photos
• Videos
• Documents
• WhatsApp chats
• Important downloads
• Authentication information

This is especially important before advanced troubleshooting.

20. Should You Factory Reset?

A factory reset should be one of the last options.

Google recommends factory reset only after earlier troubleshooting steps have failed. A factory reset removes apps and associated local data, so backing up first is essential.

Before resetting, confirm that you have already tried:

• Turning off scheduled restart
• Updating Android
• Updating apps
• Freeing storage
• Removing recently installed apps
• Testing Safe Mode
• Checking charger and battery
• Removing the case

If the phone still restarts randomly after a clean factory reset before reinstalling your apps, hardware becomes a stronger possibility.

When You Should Visit a Technician

Professional inspection is advisable if:

• The battery is swollen
• The phone becomes dangerously hot
• Restarts happen even in Safe Mode
• Restarts continue after a factory reset
• The power button is damaged
• The phone suffered water damage
• The phone was dropped before the problem started
• Battery percentage behaves abnormally
• The phone cannot stay powered on

These symptoms can point to hardware rather than ordinary Android settings.

Quick Action Plan

If your Android phone restarts by itself at night, follow this order:

1. Check whether Auto Restart or Auto Optimization is enabled.
2. Look for recent Android or app updates.
3. Check available storage.
4. Remove recently installed or suspicious apps.
5. Test the phone in Safe Mode.
6. Check whether the restart happens only while charging.
7. Try another compatible charger and cable.
8. Remove the phone case overnight.
9. Check battery and overheating symptoms.
10. Back up important data before advanced troubleshooting.

Do not factory reset until you have ruled out the simpler causes.

Conclusion

If your Android phone restarts by itself at night, do not immediately assume the phone is damaged.

If the restart happens at roughly the same time each night, an automatic restart or device-optimization setting may be responsible.

Samsung Galaxy devices, for example, can intentionally restart when the phone is idle as part of their Auto Optimization features.

If the restarts are unpredictable, investigate:

Software updates

Storage

Recently installed apps

Safe Mode

Charging accessories

Battery condition

and:

Overheating

The most important thing is to identify the pattern before choosing the solution.

At Cyberhub ICT, we recommend:

Observe → Identify → Test → Fix.

Do not erase your phone before you know what is actually causing the restart.

Related Cyberhub ICT Guides

You can also read:

Android Phone Problems: A Step-by-Step Troubleshooting Guide Before You Reset

How to Fix Android Apps That Close Immediately After Opening

Why Does My Android Phone Say Storage Full After Deleting Files?

How to Stop Android From Killing Apps in the Background

Why Are Notifications Delayed on Android Until I Unlock the Phone?

How to Fix “App Not Installed” on Android Without Losing Data

These posts can form a strong Android Troubleshooting cluster on Cyberhub ICT.

About Cyberhub ICT

Cyberhub ICT Center provides ICT training and technology services including Internet & Cyber Security, Web Design & Blogging, Digital Marketing, Desktop Publishing, Graphics Design, Social Media Management, Content Creation and Forex Trading Training.

For practical Android troubleshooting, cybersecurity awareness and digital technology guides, follow Cyberhub ICT.

Website: cyberhubict.online
Email: cyberhubict@gmail.com
Phone: 08061601662

Frequently Asked Questions

Why does my Android phone restart every night at the same time?

If the restart happens at a similar time every night, an automatic restart or optimization feature may be enabled. Samsung Galaxy phones, for example, can automatically restart when the device is idle.

Can an app make my phone restart?

Yes. Google recommends using Safe Mode when an Android device restarts itself because downloaded apps can sometimes cause instability.

Can low storage cause random restarts?

Low storage can contribute to Android instability. Google says phones may begin experiencing problems when less than about 10% of storage remains free.

Why does my phone restart only when charging overnight?

Possible causes include a charger, cable, charging-port, battery or heat problem. Test with a known-compatible charger and cable and inspect the charging port.

Should I disable Samsung Auto Restart?

If you do not want your phone restarting automatically and the feature is enabled, you can turn it off. If the unexpected restarts then stop, you have identified the cause.

Will factory reset fix random restarts?

It can help if the cause is corrupted software or problematic settings, but it should be a late troubleshooting step. Google recommends backing up first because factory reset removes apps and local data.

What if my phone still restarts in Safe Mode?

If the phone continues restarting while downloaded apps are disabled, the problem is less likely to be caused by a third-party app. System software, battery or hardware should then be investigated.