Why Do Laptop Run Slow When Not Plugged in?

Laptops are designed to maximize performance on AC power and conserve power when running on a battery.  But when laptops run slow when not plugged in, clearly something is wrong.

Most commonly, the reason is that the power plan is set to battery saver on windows.  And this plan reduces overall operation when the laptop isn’t plugged in, which causes the computer to run slower to conserve power and extend battery backup.

Why Do Laptops Run Slow When Not Plugged?

If you’ve noticed your laptop does not operate at the speed it used to, it is possible to get it performing as new again.  And there are chances that it could have been corrupted with a virus or probably have an old operating system.

Laptop Run Slow When Not Plugged in

Numerous startup programs and temporary files might have caused the computer to perform poorly.  Below are some of the possible reasons why a computer is operating slow and how to fix it.

1. Fragmented Files are Slowing Down the laptop

Some of that data becomes fragmented whenever files are created, deleted, or edited on a computer.  And files stored in several components of the hard drive, over time, can cause the laptop to perform slowly since the hard drive has to search every piece of data information.

The laptop should be fragmented to centralize and consolidate the data.  Although a computer operating on Windows 10 defrag files weekly, this should be done conveniently.


To defrag a drive, click on the glass icon at the screen’s bottom-left corner.  Search the word defrag and click open.  To know the amount of space consumed by the fragmented files, click on analyze in the Pop-Up window.

Where many of the files are fragmented, click on optimize.  Then wait for the drive to get to 0% fragmented before using programs and open files.

2. Low RAM space

When a computer is low on RAM space, the performance reduces because the Random-access memory (RAM) serves as momentary storage.  It also organizes and saves valuable files which a computer might need.

A computer would require about 2–4GB for fundamental computer operations such as browsing the internet.  However, it’ll need a larger RAM size of 8-16 GB for multi-tasking or graphics-intensive programs.

Although purchasing more RAM might not help the computer run fast, having an average amount of RAM for specific operations to work correctly is essential.


To know the amount of RAM left, use the cursor to the bottom of the screen and write in about, then click open.  This is immediately going to display the RAM size under Device specifications.

3. Update hard drive

Laptops run slow when not plugged in if the conventional disk drive is used.  And upgrading to a new solid-state drive could increase the computer’s overall performance.  When the hard disk runs low on space, the computer starts lagging, and performance issues become noticeable.  The hard drives file the program operates on, and once it is out of room,  the laptop starts to run at a slow pace.


Most times, computers are designed with empty M.2 slots that install the solid-state drive.  All which is required is to initiate small hard disks.  And keeping the old hard disk connected when the computer contains open M.2 slots is desirable.

4. Loads of Temporary Files

Files are created and modified result of temporary files stockpiled.  And most times, the files are stored up in folders like “.tmp” and are erased when a program is closed.  Regardless, sometimes the computer does not instantly erase the temporary files.  Therefore, they consume a large amount of capacity on the hard disk drive, which results in the low performance of the computer.  However, it’s vital to delete temporary files manually to avoid this.


To delete temporary files on a laptop, click the magnifying glass icon in the screen’s bottom-left corner.  Type Disk cleanup into the search bar and click Open.  Select the drive to clean and click OK in the pop-up window that appears.  Finally, check the box next to Temporary files and click OK.

5. The Computer Is Corrupted With A Virus.

When a computer momentarily crashes during running programs, it is likely to be corrupted with a virus – malware (malicious software).  Also, a computer can be corrupted when emails are received from foreign senders or documents downloaded from suspicious websites.

 Numerous types of malware cause a computer for several reasons to operate slowly.  Likely, some viruses may corrupt the computer’s memory and circulate into several files on the computer.  Also, computer hackers use the malware to have into the system and steal personal information, like residential addresses and bank details.


To eliminate the virus from the computer, click the magnifying glass icon.  And type Security into the search box and click Open.  Then, click on virus and threat protection and finally click on Quick scan.

6. Too Many Running Programs

When various programs are running in the background, it causes the computer to operate slowly.  And one of the ways to resolve this is to shut down as many programs as possible.  Though, some files and programs proceed to run in the background.  And these programs consume the processing and operating power of the laptop, causing it to slow down.


To close the programs, Windows Task Manager should stop them from running in the background.  To perform this, click on more details.  This enables choosing the programs that use up the laptop’s memory and CPU.

7. Too Many Startup Programs

Having too many programs running simultaneously on the computer can be another reason why laptops run slow when not plugged in.  Most programs ask for permission to operate when booting the computer.  Though, not all programs work this way, as some programs will run automatically when the laptop is turned on even without asking permission.


To know the programs set to run when the laptop is booting, click on the startup tab at the top of the Task Manager window.  There will be a display of the application name, status, and startup impact.

8. Hardware Failure

An easy way to know if a laptop may be running slow is when the components fail.  Be it the hard drive, CPU, RAM, or any other part, there are likely cases where it could be replaced or upgraded.  However, it will be advisable to purchase a new laptop when this persists.

Hardware failure

How To Make A Laptop Run Faster

When a computer begins to acquire more files and programs due to its regular use, it could make daily procedures longer to complete and reduce productivity.

However, it can be remedied by performing routine supervision, including freeing up some space on the complex- disk drive and operating Windows hard drive utilities.

Check Your Power Plan Settings

This is frequently the first thing to check when having power-related issues.  Go to Windows search, type in “edit power plan,” and open it.

The window displayed will appear;

Click “Restore default settings for this plan” hit yes in the confirmation window.  And the problem should be resolved.

Check your Power plan settings

Take Out The Battery

Sometimes, a faulty battery could cause laptops to run slow when not plugged in. If the battery is removable, it should be removed, and then the computer should be run on AC power.  If the problem persists, it’s a battery issue, and it should be replaced with a new one.

Reinstall Battery Drivers

While rare, a corrupted battery driver can also cause this problem.  So, to resolve this, remove the old battery drivers so Windows can reinstall a new version.

  • Go to Device Manager.
  • Select Batteries.
  • Right-click on the “Microsoft ACPI-Compliant Control Method Battery.”
  • Click Uninstall.
  • Put a check in the box to remove the current driver at the prompt.
  • Restart the laptop.
  • Go to Device Manager again.
  • Right-click on the “Microsoft ACPI-Compliant Control Method Battery.”
  • Click “Search automatically for updated driver software.”

Go to Device Manager again

Reset UEFI / BIOS settings

UEFI or BIOS is a piece of software that performs hardware initializations.  The software turns on the laptop and starts the OS when the computer is turned on.

Some laptops include power management features in the UEFI/BIOS.  A poorly configured BIOS can be a possible reason a computer runs slow when not plugged in.  So it’s always a good idea to reset BIOS settings.

It’s also easy to access BIOS settings when the laptop boots by pressing specific keys (commonly Esc, Del, F12, F2, etc.).

Update The Bios

If resetting the BIOS doesn’t work, try updating it.  Even if no update is available, reflash the current version.  You can find the BIOS firmware and flash tools on the manufacturer’s website.

Other Battery-related Issues

Apart from laptops running slow when not plugged in, other battery-related problems may arise from the regular use of a computer, resulting in poor performance.

The Battery Dies Down When Unplugged

Sometimes the operating system shows the battery is at 100% and fully charged, but the laptop dies almost immediately when unplugged.  And this is also a sign of heavy battery damage.

Possible Reasons

Any lithium battery starts to lose capacity after a certain number of charge-discharge cycles.  Most likely, the laptop battery has reached the end of its life.

Although rare, sometimes the connector from the battery to the motherboard gets damaged.  Or maybe the connecting port on the motherboard has become faulty.  And if that is the case, the battery is not damaged but only needs the connector to be replaced.

Final Thoughts

There are several possible reasons why laptops run slow when not plugged in.  Still, once you’ve been able to identify the root cause, it becomes clear effortless to navigate through, following the remedies provided in this article.

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