The PC you are using will probably have a large power supply unit (PSU) that takes power from the electrical outlet and converts it into direct current to power the internal components of the machine. Then why is there an extra button battery on the motherboard? We invite you to join GVN 360 to find out.
Origin of CMOS battery
Back in the day, the reason there was a battery there was to power a chip called CMOS (Complementary Metal-Oxide-Semiconductor). Basically, at that time, this was the chip used to save the BIOS (Basic Input/Output System) settings inside. The BIOS is what controls the low-level settings and starts up the hardware when you turn on the computer.
However, the CMOS chip that stores these settings is in the form of volatile memory, which means that all settings will disappear when the chip is no longer powered. And because not everyone lets their computer run 24/7, motherboard manufacturers have added button batteries on top of the mainboard to ensure that the settings are still saved when power is lost from the PSU.
Fast forward to the present time, motherboard manufacturers no longer use CMOS to save BIOS settings in it. Partly because these old CMOS chips could only store 128 bytes, while the system now needs to store a lot of BIOS data. So instead, they chose to use a chip with non-volatile RAM. Not only do they have a higher capacity, but they can also save data even when the motherboard loses power.
Purpose of CMOS batteries today
So what is the purpose of the battery on the motherboard now? It’s also simple guys, that’s because on the motherboard there is still… another CMOS chip on it. But instead of having to store BIOS data, this chip has almost the sole purpose of running the computer’s clock. Just like a watch, your PC will need a power source to keep the watch running on time even when you’ve unplugged it.
Interestingly, many servers are able to maintain the clock time accurately without the need for a CMOS battery, even during a power outage. In this case, instead of using the CMOS battery to store the time locally, the server will usually connect to the NTP (Network Time Protocol) server on startup. NTP is a protocol used to connect to another server via the Internet to get the most accurate time information.
This method isn’t very popular with mainstream PC users, so the CMOS battery on your motherboard is still important. In fact, if you remove this battery from the motherboard, there is a high chance that your BIOS settings will also be erased, just like the day before. The reason is because we have been in the habit of removing the CMOS battery to reset the BIOS for many years, so most PC manufacturers still keep this function to clear the BIOS settings for convenience. However, some motherboard manufacturers still equip a clear BIOS setting button (Clear CMOS) on the mainboard or on the rear I/O side, creating convenience for users.
You don’t have to worry too much about this battery
The good news is that you don’t need to worry too much about this CMOS battery. They can run for many years before needing to be replaced, and when the battery runs out, buying a new one is quite easy. But be careful, you should still have a backup of your BIOS settings located somewhere else, in case you lose everything, you can still restore it.
Hope the above information will help you discover new things about the world of technology. If you have any suggestions or additions, please share them with us in the comments section below. Thank you for your interest in this article.
Source Techquickie compiled GVN360