Pc Clock

[torroray]

My pc is more than 3 years old. Last year I change the battery. The Clock is not accurate and have to be set every time when I need to use it. Sometime I forget to set it.

Do I need to put in another battery?

[RJGoodhouse]

The MotherBoard has it's own Battery about the size of a 50 Cent Piece. In A LapTop that are often much hard to replace and it is best to take it to a shop. They are 3 volt Batteries often the Number is CR2032 and they tend to last 3-5 years. The Batteries are often like a Dollar. so it'

s the labor to install it Correctly that will cost you.

[David H. Lipman]

No. You only need to change a battery when you boot the PC and it indicates a CMOS battery failure.

People do not realize that while computers are accurate in many aspects it is not as accurate as a watch or clock in that regard.

Therefore computers use the Network Time Protocol (NTP) to synchronize the time to..

NIST Internet Time Servers

Go to; Control Panel --> Date and Time --> Internet time --> Change settings

Enter a server from the above NIST list and click on "Update Now"

EDIT:

I left out that it is best to choose a server which is closest to you.

[torroray]

No. You only need to change a battery when you boot the PC and it indicates a CMOS battery failure.

People do not realize that while computers are accurate in many aspects it is not as accurate as a watch or clock in that regard.

Therefore computers use the Network Time Protocol (NTP) to synchronize the time to..

NIST Internet Time Servers

Go to; Control Panel --> Date and Time --> Internet time --> Change settings

Enter a server from the above NIST list and click on "Update Now"

EDIT:

I left out that it is best to choose a server which is closest to you.

It works.

Thanks

[David H. Lipman]

[torroray]

I thought since the motherboard is old replacing a new battery wont solve the problem.

[David H. Lipman]

Here is how this works...

In what's called Read Only Memory (ROM) is a set of Basic Input/Output System (BIOS) routines. When you turn on a computer it runs those routines. The BIOS acts as "middleware" between the computer's Operating System (OS) and the hardware. There is a software front-end to the BIOS that allows the user to configure various parameters. Additionally the BIOS will auto-set some of those parameters. All these "configuration settings" would be lost if the system is turned off. Therefore there is an area of memory that stores these parameters as well as the time and they are saved by a battery. The memory is a type of Random Access Memory (RAM) built on Complementary Metal–Oxide–Semiconductor (CMOS) technology. This memory is deemed volatile because the contents are destroyed when there is no power. Thus we have come to call this RAM the CMOS memory and accordingly the battery that keeps this memory intact the CMOS battery.

If one keeps the computer "on" 24x7x365 then the CMOS battery is not needed. However, in most cases, that's not true therefore there is the CMOS battery. There are two types of CMOS batteries. Storage Batteries and Rechargeable batteries. Storage batteries such as the CR2032 are often used and they don't last forever. Therefore, eventually, they will have to be replaced. You would know this when the computer is cold booted and a CMOS Battery Failure message is shown on the screen. On the other hand, rechargeable batteries are trickle charged when the computer is in the "on" state so they will tend to outlive the life of the actual computer.

[CWB]

RJG : "The MotherBoard has it's own Battery about the size of a 50 Cent Piece."

you might want to use your dial calipers and double check that .

in addition to what david mentioned ...

BIOS = Basic Input/Output System : http://en.wikipedia.org/wiki/BIOS

basically speaking , there is a section on the motherboard called the "RTC" (real time clock) . this bit of circuitry is designed to provide time keeping pulses (think oscillator in a digital wristwatch) . it runs 24/7 and gets power to keep running from the bios backup cell/battery when the computer is powered down . this is what keeps the "time keeping" function of the bios and MB "up to date" .

there are two basic types of "rtc" . one type (most commonly implemented) is not very accurate over the long haul . take the average computer and turn it off for a week or thereabout and look at the time displayed after it is fired up ... it may be off by several minutes depending on when in the boot sequence the rtc checks against (or is updated via software command) a time server .

the second type (not commonly used in joe consumer computers) is a very accurate sub assembly that plugs/hooks into the MB . these type can be very expensive but if accurate time is required to be kept during computer power down the price is justified . these types can be "stand alone" or synchronized against a time server .

many years ago joe consumer comps (and some stereo equipment !) used NiCd cell/battery assemblies for "back up" ... these were trickle charged while the comp was running/powered up .

these types of cells/batteries had a short cyclic lifespan and would often fail before the end-of-life cycle of the computer/equipment .

the replacement of these was really no worse than the more modern bios cell (CR-2032 , about the size of a u.s. nickel/5 cent piece) ...

damage to the MB/circuitry sometimes occurred from electrolyte leakage .