# What happens when your PC’s CMOS battery dies?

- URL: https://talkfuse.com/story/what-happens-when-your-pcs-cmos-battery-dies/
- Published: 2026-10-26T12:15:00+00:00
- Updated: 2026-10-26T13:04:51+00:00
- Original publisher: Engadget
- Original article: https://www.engadget.com/2289047/what-happens-when-pc-cmos-battery-dies/
- Topics: Gadgets

## Key points

- A dead CMOS battery can reset a PC’s clock and hardware settings.
- Desktop coin cells often last years and are inexpensive to replace.
- You may need to restore BIOS or UEFI preferences afterwards.

## Summary

A failing CMOS battery can stop a desktop PC from retaining its time, date and basic BIOS or UEFI settings when it is unplugged. The problem can cause boot warnings and reset options such as boot order and fan settings, though it does not erase apps or files.

Most desktops use a CR2032 coin cell, which can last several years or up to a decade; CR2025 cells are less common. Replacing it usually takes only a few minutes: power off the PC, locate and gently release the battery, fit the replacement, then restore any preferred BIOS or UEFI settings. Many laptops use their main battery to keep the clock running, so the issue is more common in desktops.

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Summarised by TalkFuse (https://talkfuse.com/). Quote the original publisher for the reporting and link this page for the summary and discussion.