The CMOS is run off of a battery on the motherboard.
Chances are that the CMOS Battery on the motherboard is dead and needs to be replaced. Without this battery, the computer can not remember the CMOS settings when the power is turned off.
CMOS RAM is Powered by a trickle of electricity from a small battery located on the motherboard or computer case, usually close to the firmware chip, so that when the computer is off, CMOS RAM still retains it's data.
CMOS Battery holds power for storing infos.
Removing the CMOS battery will not prevent the computer from turning on, it will only cause the information in the CMOS RAM to be lost (while the computer is turned off). When you turn on the computer after the CMOS battery has been removed, while it will turn on it will most likely not boot the OS correctly but will stop in the BIOS and require you to completely setup the CMOS parameters again before you can tell it to continue..
CMOS battery
No, these types of batteries are not technically able to be recharged.
All AT computers (80286 processor) or later require a small battery on the system board that provides power to the Complementary Metal Oxide Semiconductor (CMOS) chip, even while the computer is turned off. This chip contains information about the system configuration (e.g., hard disk type, floppy drive types, date and time, and the order in which the computer will look for bootable disks). The CMOS battery allows the CMOS to preserve these settings.
Yes CMOS is available in modern computer. CMOS definition: Complementary metal-oxide semiconductor, or CMOS, typically refers to a battery-powered memory chip in your computer that stores startup information. Your computer's basic input/output system (BIOS) uses this information when starting your computer. CMOS-related error messages could be caused by a faulty or discharged battery. The battery can become discharged if your computer has been turned off for a very long time. To resolve CMOS-related errors, check the information that came with your computer or contact your computer manufacturer. Because your CMOS settings are specific to your computer's hardware, Microsoft can't provide specific instructions for changing them.
memory is not accessed when the computer is turned off. If the computer is in sleep mode, it retains power until resumed. If computer is in hibernate mode, contents of memory are written to disk first before power off, and reloaded on power on.
CMOS battery of your laptop maintains hard disk, time and date, and other drivers and configuration settings in a CMOS memory. You will see these tiny CMOS batteries connected directly to the laptop’s motherboard.
The complementary metal–oxide–semiconductor (CMOS) power comes from the CMOS battery located on the motherboard. This battery powers the Basic Input Output System (BIOS) and stores the start-up config for the computer.
CMOS battery of your laptop maintains hard disk, time and date, and other drivers and configuration settings in a CMOS memory. You will see these tiny CMOS batteries connected directly to the laptop’s motherboard.