Computer clock?

[Stella]

The clock on my computer keeps gaining time and is now 10 minutes fast. I keep having to adjust it. Anyone know how to slow it down please?

[Guest]

thats odd Stella I just looked at mine and seems there is a Internet time ?? too is yours set right ?

[Stella]

Val, I have reset mine right twice, but it is wrong again - seems to be gaining time. It is now saying 1430!

[Guest]

have you googled

[Stella]

Yes, have Googled Val, but not much help there - too complicated. Thanks.

[col48]

The internet references seem to say that this is most likely due to a dying computer battery. This link is to a set of instructions for changing it, but if opening up the case makes you nervous, then get a friend who knows what they are doing to replace it for you. I suggest you back everything up first.

http://www.ehow.com/how_2324129_fix-computer-clock-problems.html

Some of the references seem to imply that a loss or gain of a few minutes a month is normal, but I've never noticed any myself.

By the way, I THINK that if the battery dies completely all you will see is that the time will revert to some default initial time every time you switch on. I'm open to correction on this but I believe the battery is there just to keep the clock going when the computer is switched off.

[Stella]

Thanks for that col. I think I will leave it well alone then as it isn't really bothering me, just wondered why it was happening.

[rivington]

I believe that the small battery usually mounted on the motherboard supplies a chip known as RTC(real time clock) this powers the clock. If the clock is running slow this battery requires to be replaced. Not only does this chip provide the time on screen it supplies some information for the Bios. Not being very tech I cannot explain it any more than this. I have always been advised to change this battery once the clock starts to run slow. Someone with more tech knowledge may see this and give you more information. The battery should last for at least 5 years.
Rivington.

[Stella]

Thanks Rivington, my clock on the computer is running fast though.

[col48]

My reading suggests that a dying battery can cause the clock to go either slow or fast.

As to what the battery does, I think it keeps the clock (RTC) "correct" while the computer is powered off. When the computer is booted up, the BIOS reads the current time from the RTC and then maintains the time from then on using mains power. Which ought to mean that if the machine time is an hour fast when you switch on it should stay an hour fast until you switch off or reboot. If it is changing while the machine is on, then it could be that either (1) the CMOS battery is maintaining the clock by itself or (2) it is being used to allow for mains variations, for example.

Some applications might rely on the clock, so I think it would be as well to change the battery. These would obviously include anything which tells the time such as email (when was it sent?), 'action' games, incremental backups (which rely on knowing for each document whether it has been changed since the last backup) and no doubt others I haven't thought of. Backups could be the most serious.

NB we are all talking about the little CMOS battery which looks like a small coin on the motherboard. A laptop will have a separate battery which powers the disk and the monitor and so on.

[Stella]

Thanks col48, will sort that out then - will get my pc-whizz friend to change the battery for me. Thanks.