How to replace the BIOS battery

Many ordinary users do not even suspect that the computer has a regular battery. Moreover, sometimes it needs to be changed, since a voltage drop can cause many problems, sometimes very strange and unpredictable. Sometimes troubleshooting or finding out the reasons for the strange behavior of the computer does not give results, and even reinstalling the system does not help, but you just need to replace this battery. It costs quite inexpensively, and you can make a replacement yourself in a couple of minutes – you only need a screwdriver.

Technique for replacing the battery on the computer motherboard.

What is a battery on a computer motherboard for?

The only reason a battery is needed on the motherboard of a computer is to power the CMOS memory chip, which contains the BIOS settings, that is, the basic configuration settings of the computer. In addition, the built-in clock works thanks to the independent power supply. That is why they do not go astray when the system unit is disconnected from the network.

Signs of a dead BIOS battery

When the battery runs out, a variety of symptoms appear, sometimes subtle. The simplest symptom is a permanent reset of the system clock. This leads to other problems, for example:

  • The browser on different sites swears at outdated security certificates, since the system time can differ by several years, or even decades.
  • The anti-virus may report that its databases are out of date, and the license is invalid, and all due to a discrepancy between the date and the current one.
  • Another symptom is that some programs stop starting. Again due to a glitch in the calendar.

Usually, immediately when you turn on the computer, you can find signs of a dead battery – after the BIOS test, a message appears, and the system may not boot further. Often this inscription looks like “Press F1 to CMOS Setup”, and when you press the F1 key, you go to the settings. The fact is that they are reset to their default settings, and each time the configuration must be adjusted, since nothing is saved after shutdown. Although the computer usually starts up with the default settings, history repeats itself every time you turn it on.

Messages may be different, and all due to the BIOS battery. For example, there is an inscription “CMOS Battery Failed”, which clearly indicates a problem, or “System Battery State Low” – a warning about a low battery. If you remove the battery from the motherboard and check the voltage at its contacts, then it will indeed be noticeably lower than it should be.

Where is the battery and what it looks like

Finding this item is very easy. If you open the system unit, you can immediately see which battery is in the motherboard and where it is located. It’s hard not to notice this shiny round element. It sits in a simple round socket with a clip that can be positioned horizontally or vertically on the edge, depending on the design of the motherboard. The BIOS battery is located next to the microcircuit that powers it; it is easy to find an inscription on it. There is also a jumper for resetting settings nearby. Many people think that this is a battery that recharges while the computer is running, but in reality it is not. The battery in the motherboard is the most common – lithium manganese dioxide, 20 mm in diameter, with a voltage of about 3 volts. The same ones are used in wall clocks, electronic scales and other household appliances.

It is marked, for example, so CR2025 or CR2032. The first number 20 is the diameter in millimeters, and the second is the thickness. The most common is CR2032, most likely you will find such a battery in your system unit. It lasts for 3-5 years, after which its voltage drops to a level of about 2 Volts and problems begin, since this is not enough to power the CMOS microcircuit and replacement is required . Sometimes the batteries last for a longer period – some work for 7 years or even longer, but sooner or later they deplete their resource.

Where to buy a BIOS battery

It is not difficult to buy such batteries. They are sold, for example, in any consumer electronics or household goods store, as they are used in many appliances and even toys. Their cost is also low – 20-30 rubles.

How to properly replace the battery in a computer

Replacing the battery on the motherboard of your computer is a simple procedure. Let’s consider it in more detail:

  • Disconnect the computer from the mains, including the power supply switch on the back of the chassis.
  • Wait a few minutes.
  • Remove the cover of the system unit – left as viewed from the front.
  • Find the battery – it is inserted into a round plastic slot and can be placed flat on the board or on an edge.
  • Use a screwdriver or tweezers to pull back the latch while simultaneously squeezing the battery to the side. Then remove it.
  • Carefully install a new one, the latch should close.
  • Return the computer cover to its place.

Getting the battery out is the hardest part of this whole procedure, especially if it is placed vertically. You need to do everything carefully so as not to tear anything off, so it is convenient to use a small screwdriver or tweezers. After turning on, you need to go into the BIOS and reset the clock and date. Usually, you can enter the settings by pressing the Delete or F2 key immediately after switching on. You may need to change settings to improve computer performance or change boot devices. After all, the original ones were discarded when the old battery was still there.

Now you know how to remove the battery from the motherboard and what it is for. It is very simple to do this, but you need to be careful, because a computer is a rather sensitive and complex device, you can break it with an awkward movement, and even more so with brute force.


by Abdullah Sam
I’m a teacher, researcher and writer. I write about study subjects to improve the learning of college and university students. I write top Quality study notes Mostly, Tech, Games, Education, And Solutions/Tips and Tricks. I am a person who helps students to acquire knowledge, competence or virtue.

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