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Exploring the Role of the CMOS Battery in a Laptop

CMOS battery is very crucial and important in a laptop. It has the capacity to cause a laptop to malfunction completely. These simply means that laptop cannot function accurately without the help of CMOS battery. It has a very significant role it plays in a laptop. If you have used your laptop for years, it’s possible that your computer is malfunctioning just because the CMOS battery is died. Stay tune as this article will be of help to you.

In this article, we shall be discussing everything concerning CMOS battery in a laptop. Ranges from the meaning of CMOS battery. The functions of CMOS battery in a laptop. How to identify when a CMOS battery is bad. How to replace a CMOS battery in a laptop? What causes the CMOS battery failure and many others.

Let’s delve into the business of the day.

CMOS battery in a laptop

What does CMOS stand for?

CMOS stands for Complementary Metal Oxide Semiconductor. CMOS battery is very tiny battery that is usually installed in a laptop or desktop. Is usually white in color. Though some of them is usually coated with black tape that makes it look black in color. That does not mean that CMOS battery is not white in color. It looks like wrist watch battery. CMOS battery is generally CR2O32 lithium coin cell. This cell battery has an estimated life of three years when power supply unit (PSU) is unplugged or then the PSU power is turned off. However, it could be replaced with a new one once it got bad or fails.

Is CMOS battery a hardware component? Yes, CMOS battery is a piece of hardware component that is so unique to laptop.  It can be seen, touch and feel.

Functions/roles of CMOS battery in a laptop.

There are basically two different function of CMOS battery in a laptop. There include the following:

  1. Bios function
  2. Time and date function
  •  Bios functions

There is need we understand the concept of bios in a laptop before coining it with the function of CMOS to it. Computer bios stands for Basic input/out system. it is an integrate program into the laptop hardware while it’s manufactured. It’s the program computer’s microprocessor uses to start the computer system after it is powered on.

It is all about sending information (signal) from one components to another as input and receiving and processing it and sending it back as out.  For instance, when a laptop is powered on, the CPU (processor) sends signals to other components like Random access memory (RAM) telling him wake up, are ready to display as an input. If the ram of the laptop is good, the RAM as well sends back the signal to the CPU saying am ready to display as an out. That’s when the laptop will display on the screen.

It’s the Bios that guides how operating system boot in your laptop from when you press the power on button. Keeping accuracy of this basic functions performed by the Bios is the duty of the CMOS battery. CMOS battery keeps the accuracy of every setting done at the bios menus. The CMOS battery powers the bios. Bios usually rally for power from CMOS battery when the laptop is plugged to power.

  • Time and Date Function

CMOS battery keeps the laptop or desktop time and date accurate. When the CMOS battery is bad, the laptop will be reset its settings including the time and date. If you manage to set the time and date to be correct. Once the laptop or system is rebooted, the time and date will go back to its normal wrong setting. Without new CMOS battery being replaced in the laptop, the laptop will keep having a back dated time and date.

Bios function, date and time function is the two basic function of CMOS battery in a laptop or desktop computer.

Symptoms of a bad CMOS battery in a laptop or desktop computer

There are several results or symptoms of bad/failed CMOS battery to the laptop or desktop computer. They include the following:

  1. It will interrupt the booting processes of the laptop/desktop computer.
  2. The laptop motherboard is likely going to produce beeping noise, reporting CMOS battery failure.
  3. The laptop or desktop computer may likely report error during the booting process (for the most recent laptop, once the CMOS battery is bad, it will report that the “boot device is not found” which will hinder the booting process)
  4. The time and date will reset continually (Every time you boot the laptop).

To prevent these problems, replacing the CMOS battery to a new one is crucial and important, which is very simple and easy to be replaced. To get it done, takes a lesser time.

The CMOS battery is not that expensive in the market. It is around $1 to $8 depending on where you are buying from. You can buy the CMOS online from any online market such as Amazon and AliExpress. It can as well be bought from retailers such as laptop technician and laptop and accessories dealers.

How to replace a bad CMOS battery in my computer or laptop

Replacing a CMOS battery is not difficult, just follow strictly to these guidelines and you will get it done at ease. They are as follows;

Firstly, ensure that your new CMOS battery is ready for replacement. Secondly, remove every source of power from the laptop such as unplugging the charger and removing the laptop battery if it’s not an inbuilt battery. Thirdly, remove the laptops back cover. In some laptops, once the back cover is removed from the laptop. It gives you access to where the CMOS battery is located.

Fourthly, unplug or unclip the CMOS battery from the motherboard and replace it with the new one and that gets the job done. This fifth step comes in if the CMOS battery is not located from the back cover of the laptop. You have to properly take the laptop apart and have full access to the motherboard where you can access your CMOS battery easily. Replace the CMOS battery and get the laptop assembled back and that get the job done.

Ensure that you set the date and time after changing the CMOS battery to keep the general setting of the laptop up to date.

How to replace a CMOS battery in desktop

CMOS battery in a desktop

  1. Remove the bottom cover of the desktop CPU
  2. Locate where the CMOS battery is installed in a motherboard.
  3. Unplug/unclip the CMOS battery from the motherboard.
  4. Install the new CMOS battery to the motherboard. That solves the problem. In less than 5 minute, you are through with the replacement of the CMOS battery.

 

What causes the CMOS battery failure in a laptop

CMOS battery naturally fails after three years of constant usage. It can as well fails when the laptop is parked for a long period of time without usage. By parking it for a long period of time, it will discharge itself.

Is CMOS battery of different types

Laptop CMOS battery is not of different types but of different kinds. Some laptops CMOS batteries are soldered directly to the laptop motherboard. For that type CMOS battery to be replaced, it must be DE soldered from the motherboard and re-soldered new one to it. There are some that comes with connector, just unplug the damaged CMOS battery and plug in new one to it.

CMOS battery in a laptop

The most common kind of CMOS battery in the market does not come with connector neither does it soldered directly to the motherboard. It just has clip that one can easily push back and the CMOS is out on its own without stress. White in color.

How many volts is in laptop/desktop CMOS battery

CMOS battery in a laptop

All CMOS batteries whether soldered, plugged or installed with clip has the same voltage. The volt is 3V for all of them. It has the capacity of damaging your motherboard if not properly installed.

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