How to change cmos battery on a lenovo g560 laptop

I think of it as a glorified watch battery. The reason you still need a battery is very simple: no matter what happens to the computer, be it unplugged or turned off, the clock needs to keep running in order to keep track of the current time. In the past, back when the battery was actually powering “CMOS RAM” to retain those settings removing the CMOS battery would cause your BIOS to lose not only the date and time, but also any customizations you might have made to the BIOS configuration. Most of those settings are kept in a type of dedicated flash memory, not unlike the kind that might be inside a USB flash drive. Typically the CMOS battery no longer affects whether or not BIOS settings are remembered. If the battery dies or is removed, then when your computer boots it will have forgotten the current date and time. I think of it as a glorified watch battery.

The purpose of the CMOS battery most often today is simply to allow your computer to remember what time it is. While no longer the case, the term “CMOS” or CMOS battery lives on anyway. “CMOS” stands for “Complementary metal-oxide-semiconductor”, the original technology that was originally used in some of the circuitry that the battery was used to power. The good news is that, as you’ve seen, they typically last for years.

It serves an important function, even though it’s actually possible on most machines to run without Actually all PCs, desktop and laptop alike, have a battery like this, typically referred to as the “CMOS” battery.

How to change cmos battery on a lenovo g560 laptop