Sooner or later, even the most expensive laptop needs repair. One of the faults is an incorrect date and time display of RTC (real-time clock). If you encounter this issue, it could indicate a CMOS battery discharge. In this article, we will describe in detail what a CMOS battery (round battery on the motherboard) is, the signs of its discharge, and how to properly replace it.

What is a CMOS battery?

A CMOS battery is designed to power a computer for a simple but very important task – timekeeping. Thanks to it, configuration settings, date, and time (Real-time clock RTC) on your PC do not get lost after each shutdown. The service life of the battery can vary greatly and is typically around 2-5 years. A battery’s life cycle depends on the operating conditions, temperature as well as manufacturer.

TOP 3 Signs You Need to Replace Your CMOS Battery

Recognizing that your CMOS battery needs to be replaced is fairly easy. Here are some signs that indicate failure:

1. Wrong date or time

If you notice that the time or date on your laptop has gone wrong. This indicates a problem and the need for replacement.

2. Alarm sound/error notification

The device can independently notify you about the discharge. You will see various CMOS-related errors. For example, CMOS Battery Failure. Also, the laptop may emit a characteristic sound signal or blinking LED lights.

3. Laptop stopped turning on/off normally

There are many reasons for this problem, but one of them could be a dead CMOS battery. If the laptop suddenly does not respond to the shutdown button, the problem could be related to the CMOS battery.

Where is the CMOS battery located?

Speaking of placement, the battery is attached to the motherboard and should be visible right away. It can also be wrapped in heat-shielding foil or tape of various colors. Some of the typical colors include black, yellow, green, and blue. The battery’s protection wrap is to protect the battery itself and nearby components from electrical shorts, heat, and direct contact.

In some cases, the battery is:

  • Soldered to the motherboard.
  • Placed in the RAM area. In this case, there is a separate housing used to mount the battery.
  • It is located near the motherboard, connected to the motherboard with wires, and is protected by heat-shielding elements.

What kind of battery is in the motherboard?

If you find that the battery is dead and needs to be replaced, you should purchase a replacement battery. Most often you can find products marked CR2032. Their diameter is 20 mm, thickness is 3.2 mm, and nominal voltage is 3v. You can find other devices on the market that are suitable for use but vary in battery size. Please keep in mind that their settings are different and not all of them are going to be compatible. For example, CR2016 has 1.6mm or CR2025 has 2.5mm thickness.

CMOS Battery Where Motherboard Laptop GP 2

When choosing a replacement product, be sure to pay attention to the size and voltage, as it must be compatible with your laptop. Also, if you have difficulties choosing one, it is better to consult with a specialist or a computer technician so they can help you buy the right product.

How to remove the CMOS battery on a laptop

Replacing the battery on a laptop is a more time-consuming process than on a desktop PC. This is due to the compactness of parts and the presence of more screws. It is better to turn to professionals if you are not comfortable taking computers apart and replacing parts.

However, if you still decide to do it yourself, we have prepared clear steps that will describe this process:

  1. Turn off the laptop, and make sure it is unplugged. close it and turn it over.
  2. Disconnect the main battery.
  3. Check for a door or easy-access compartment that some manufacturers provide.
  4. Remove all screws and take apart the housing. This is necessary in order for the internal components to become accessible.
  5. Find the motherboard, and then locate the CMOS battery.
  6. Remove it very carefully, paying attention to its placement and connector location.
  7. Install the new CMOS battery in the same place as the old one.
  8. Assemble the computer and housing in reverse.
  9. Replace the main battery.
  10. Turn on the device and make sure it works properly.


The CMOS battery is an important component of your laptop. Its proper functioning ensures that the current time (RTC) is displayed correctly even when the device is turned off or out of battery.

Finding out that the storage element is out of order is quite simple and if you encounter this situation, then an immediate replacement is required.

Despite the fact that extraction may seem simple at first glance, it is best to seek the help of a specialist or a technician. This will ensure correct installation and long service life.

On the Rome Tech Batteries you can find RTC Batteries for any laptop.

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