A CPU battery, more accurately known as a CMOS (Complementary Metal Oxide Semiconductor) battery or coin-cell battery, isn't directly related to the CPU's power. Instead, it's a small battery on the motherboard that provides power to the BIOS/UEFI chip when the computer is turned off. It is often referred to as a CPU battery because of its location on the motherboard near the CPU.
Here's a breakdown of its purpose and function:
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Purpose: The CMOS battery allows the BIOS or UEFI to store hardware configuration settings and maintain the system's date and time, even when the main power is off.
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Function: It provides a small amount of power to the CMOS chip, which is a type of memory that stores essential system information. Without it, the computer would lose its settings every time it's powered down.
Key Functions Supported by the CMOS Battery
| Function | Description |
|---|---|
| Storing Hardware Settings | The CMOS battery allows the BIOS/UEFI to retain critical hardware configurations, such as boot order, hard drive settings, and other system parameters. |
| Maintaining Date and Time | It ensures the computer's internal clock continues to run, so the date and time are accurate when the system is powered on. Without it, the system will revert to a default date. |
Consequences of a Dead CMOS Battery
- Incorrect Date and Time: The computer's date and time will reset to a default value each time it's powered on.
- BIOS/UEFI Reset: Custom BIOS/UEFI settings will be lost, potentially affecting boot order or other system configurations.
- Boot Issues: In some cases, a dead CMOS battery can prevent the computer from booting properly.
Replacing the CMOS Battery
Replacing the CMOS battery is a relatively simple process.
- Locate the Battery: The CMOS battery is typically a small, silver, coin-shaped battery located on the motherboard.
- Remove the Old Battery: Gently pry the battery out of its holder.
- Install the New Battery: Insert the new battery into the holder, ensuring the correct polarity.
