If I completely shut down a computer and not use it for months, how can it still tell the time accurately? (given that it isn’t immediately connected to the internet)

Question

If I completely shut down a computer and not use it for months, how can it still tell the time accurately? (given that it isn’t immediately connected to the internet)

In: Technology

Answer 1

There is something called a CMOS battery inside the computer on the motherboard. Its basically a very small car remote type battery, you know the flattened CR2032 like ones. Like flattened watch batteries. Anyhow, this battery keeps a timer awake. And it draws very less power to do that. Once this battery is dead, your computer wont be able to tell the time. This battery stays functional even when you switch off your computer.