If you still have an older Pokemon game, typically from the third generation or earlier, you may have encountered a problem where the internal battery runs out and makes your game unplayable (the save files for 2nd generation games cannot be kept in this situation; the 3rd generation games simply don’t use clock capabilities). For second-generation games, the tiny lithium battery inside the game cartridge powers the clock and the save state.
The clock only draws a tiny amount of power, thus the batteries can last for a long period. Similarly A lithium battery is used to power your computer’s real-time clock instead of the standard power supply.
A “real-time clock,” which is a specialized piece of hardware (on the motherboard of computers, for instance, a quartz crystal) that precisely keeps track of the time, is a feature found on the majority of computers. The computer’s internal clock uses an oscillator, which vibrates at a set frequency, to determine the passage of time. The clock then keeps track of time by counting the number of vibrations.
Your computer keeps running even after you unplug it from the power source. At the absolute least, the battery should last a few weeks, if not longer. Because of this, even after you turn the computer off, it might continue to retain time. There is no electricity waste due to the minimal power consumption of real-time clocks.
If the clock battery is removed along with the main battery and power cable, the computer will lose track of time, and you will need to enter the time and date when you resume the machine. When you connect your device to the Internet, the operating systems of many computers look for a time server on the network and request the time.
Content for this question contributed by Fiona Wilhelm, resident of Santa Cruz, Santa Cruz County, California, USA