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
Most if not all computers have a 2032 battery on the motherboard that supplies power to keep time and date accurate.
There is usually a small “coin” battery on the main board, which powers the computer just enough to keep the date and time. If it were to run out, or you were to take it out, then it would not keep the time.
Not all computers do this.
I’ve tinkered with a Raspberry Pi 3, and it absolutely always needed to stay powered on or use an Internet service to know the time.
The difference between computers that can keep the time and ones that can’t is a “realtime clock” (RTC) circuit or chip.
An RTC is typically powered by a little coin cell battery. On a PC, this battery is usually also used to retain some of the computer’s basic hardware settings in its BIOS or UEFI.
If you look inside your computer somewhere on the motherboard (the big main circuit board, can’t miss it) there’s a round little battery. The main purpose is to ensure that bios settings and the time and date are kept up to date. Eventually of course the battery will die and at this point when you power the computer on the date and time will reset to the default time.
There’s a small coin sized battery stuck onto the motherboard that powers a clock that keeps track of time.
The motherboard has a small battery about the size of a quarter called a CMOS battery, it’s responsible for keeping time. The MOBO keeps time, and other BIOS/UEFI settings. If the little battery fails, your computer will stop keeping track of those things accurately.
If you have a computer that you turn off and don’t use for months sell it and stick to the comforts of the analog contraptions that your boomer ass has been acustomed to.
There is a small button battery called a CMOS battery. They last for years but not forever. Your average consumer computer is replaced before the battery needs to be. But the do go bad and if the pc off and unplugged it will lose it’s time.
So, a desktop PC has that little battery. What about my phone? If my phone dies and I don’t charge it for 15 hours, how is the time correct when I finally do charge it and fire it up? Same idea? There’s also a little battery in there too?
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.
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