Signs that indicate the charge on the CMOS battery could be getting low include:

• The system time and date keep resetting to incorrect values, often defaulting to a past date like January 1, 2000, after the computer is powered off and restarted

• BIOS settings fail to save and revert to default values after reboot, requiring reconfiguration each time the computer powers on

• Error messages appear during boot, such as "CMOS Checksum Error," "BIOS Settings Reset to Default," or "System Battery Voltage Low"

• The computer experiences boot issues, including failure to POST, longer boot times, boot loops, or complete inability to boot

• Hardware detection problems arise, where the system fails to recognize or incorrectly configures connected devices

• Some motherboards emit frequent beeping sounds on startup, which can indicate a CMOS battery problem depending on the beep code

• The system may also exhibit unusual behavior such as self-awakening at the same time daily due to RTC malfunction caused by low battery

These symptoms reflect the CMOS battery's role in maintaining BIOS settings and the real-time clock when the computer is powered off. When the battery charge is low or depleted, these functions fail, causing the issues described above