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Windows 7: Replacing CMOS battery

18 Jan 2013   #1

Windows 7 Professional 64 Bit
Replacing CMOS battery

How often should the CMOS battery be replaced in a laptop.Have a Toshiba Satellite Pro L300-1FK which was three years old last August and is working fine.I contacted Toshiba to ask what type of cmos battery was installed but they were unhelpful and refused to give me make and model of battery,just referring me to their service engineers for them to do the work.

My System SpecsSystem Spec
18 Jan 2013   #2

Microsoft Community Contributor Award Recipient

Windows 7 64 Bit Home Premium SP1

"If it ain't broke, don't fix it"

The life of the battery will depend on how you use the laptop (or any PC). If the unit sits unused and unplugged for day or weeks at a time (the battery removed from a laptop would be equivalent) then the 3v battery will run down much faster than a PC that is always plugged in and/or the laptop battery is always in and charged.
I have 10 year old PCs here with the original batteries and they are still reading 3v+.

Many laptops use the same 3v battery that desktop motherboards do, but some use a proprietary design. If you can find a "Service Manual" online for your laptop you could find out quickly which you have.

But here is the fast test for your laptop:
  • Shut it down.
  • Remove the laptop battery.
  • Let it sit overnight.
  • Put the battery back in, turn it on and go into the BIOS settings. If the time is still correct the 3v battery is working. If not, then it is time to replace it.
My System SpecsSystem Spec
18 Jan 2013   #3
Lady Fitzgerald

Win 7 Ultimate 64 bit

I had a Gateway desktop go for seven years without replacing the CMOS battery. I've always believed in, "If it ain't broke, don't fix it."
My System SpecsSystem Spec

18 Jan 2013   #4

Windows 7 Professional 64 Bit

Thanks for the tip on how to test the battery,will give that a go.I agree that if it ain't broke don't fix it,otherwise known as leave well alone but though I was never a boy scout I do like to be prepared.Thanks to you both.
My System SpecsSystem Spec
18 Jan 2013   #5

Windows 7 Ultimate x64 SP1

How often? The same frequency you change a light bulb...when it dies. The way you normally can tell when a CMOS battery has died is that you have to set your BIOS options everytime you power on a system. I can't say I've ever had to change one in a laptop, even during the last 15 years I've been in corporate IT. I also wouldn't bother buying one to have handy, because you may never need it, and if you do eventually need one, it would be better to have a new, fresh one.
My System SpecsSystem Spec
18 Jan 2013   #6
Lady Fitzgerald

Win 7 Ultimate 64 bit

Quote   Quote: Originally Posted by DeaconFrost View Post
...I also wouldn't bother buying (a battery) to have handy, because you may never need it, and if you do eventually need one, it would be better to have a new, fresh one.
X2. Although long, batteries do have a shelf life and a spare purchased now may not be much better than the old one by the time the old one finally dies.
My System SpecsSystem Spec

 Replacing CMOS battery

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