Replacing the CMOS battery

Hello OCAU,

I am wondering if it is possible to replace the CMOS battery on a Socket 1156 Gigabyte motherboard (Most likely a UD3R or 4)? I also wonder how it is done because I've never actually had to do it?

 

Its pretty straightforward - just need to buy a CR-2032 battery - even woolworths / coles has them in the battery section.

Pop out the old battery with a screw driver, guitar pick / flat bladed implement pop the new one in.

Thats it.


BTW - you sure you need to do it? Your mobo sounds pretty new

 

Try and get a silver oxide CR2032, you can buy them from ebay quite cheaply.

^ This. It is easy to use a flat head screw driver to pop it out. It can be done with your fingernail too, they are spring loaded so they pop out easily. I also wouldn't think that your battery should be flat yet being a s1156.

 

If you're wondering why I need to replace the CMOS battery on the mobo, it must be said that the motherboard is over 5 years old and it's an old socket. Might not be 1156, could be closer to 1366. It's a Intel i5 860 CPU

 

That is a LGA1156 socket, the CPU was released in 2009

http://ark.intel.com/products/41316/intel-core-i7-860-processor-8m-cache-2_80-ghz

 

I still have Pentium 4 and Pentium 3 rigs on their original battery here.

 

^^ Likewise. CMOS batteries last a looooong time generally speaking. One of my machines has a 16 year old battery in it.

What makes you think its the battery? Are you needing to set up the BIOS again every time you boot?

 

Yes, pretty much. For some odd reason, the computer 'forgets' what boot settings I put on it. It also blue screens periodically, saying that boot device (my SSD) cannot be found even though I point it to it.

 

OK. Certainly sounds like the CMOS battery, and like everything, sometimes you can get a dud. It may not be the problem, but its a dirt cheap first step to try.

Do the time/date settings in the BIOS also change? That would totally confirm a dead battery.

Just pop out the battery if you are unsure of what to buy, go to the battery section in Woolies and you will find one to match easily. If you don't, try a camera shop, or Jaycar or pretty much anyone that sells a reasonable range of batteries. My local IGA has them... 5 bucks should get you the battery and some change.

To remove it, look at the battery on the mobo. The battery will be sitting in a recess on the board, circular apart from one small flat clip on an edge. Just push on the side of that clip with anything, a small flat screwdriver or even a key will do it, and the battery will just pop out. Install the new one by pushing the battery into the clip side first, and then down, it will go in as easily as it came out.

Sometimes (not often) the battery might be mounted vertically instead of horizontally, impossible to say without knowing what board it is, but removal and replacement will be a similar procedure, just look at it and it should be obvious.

The SSD will be forgotten as the boot device with a dead battery, and when you 'save and reset' it as the boot device, it could be forgetting that choice when it reboots, as of course without a working battery it will forget what it saved.

The battery is certainly the first port of call, because its so cheap and easy and has a strong chance of being the problem.

Once its up and running though, its unlikely that the battery is causing it to blue screen and lose the drive. You may have a separate issue there. The battery plays no part in anything once the machine has booted successfully.

 

I have a motherboard which is unable to remember what bios settings have been set. I have replaced the battery with a known working one with no change. The interesting thing with my board is that it will remember the time and date that you set but nothing else. I have an identical motherboard without this problem, must be some slight physical problem with it.

This doesn't really help your situation but if nothing else is interesting.

 

Reflash the BIOS.

As for CMOS batteries in general - theoretically they last a long time. But the first point of call for me with odd BIOS issues is to automatically change the CMOS battery in any motherboard - I don't care how old it is. "Not too old" battery != "good" battery. This procedure seems to clear most issues.

 

I've never ever had to replace the CMOS battery hmm

 

It's pretty unusual for the battery to actually get used. As long as the power supply is supplying standby power (ie normal situation when the PC is "off") the battery doesn't do anything at all. It's only when the PC really loses power that the battery being flat becomes obvious.

In any case, when you can get ten CR2032 batteries for a dollar on eBay (including shipping) you might as well keep some spares handy.

 

Hmm, I was quietly wondering if the CMOS battery is continuously used by the clock or if there was a "relay" circuit of sorts that bypassed it when 5VSB is present. It's also slightly errornous to say that the battery will get "used" as all batteries self-discharge over time, even if this equates to many, many years, it still happens.

That said, while I know that CR2032 cells are not rechargable, laptops some seem to use another type of battery (smaller cell) that is rechargeable, this would make sense given that loss of power (removal of main battery) is a lot more likely. Of course, like phones, this doesn't apply to any laptop that has an internal battery (MacBooks, Ultrabooks etc) as they will always take power from the main battery to keep the clock going, even if "flat", they will have some reserve for this purpose, and also to prolong the life of the cells - if lithium cells discharge far enough, they become unstable and are much more prone to outright explosion if a charge is applied to them.

Ever wondered how your phone keeps time even if the battery goes flat? That reserve power is why.

 

Hey guys, just reporting in to say that I have found out my issue. The CMOS battery WAS part of the issue but I found out that the SSD of my sister's computer was malfunctioning. It doesn't appear on BIOS consistently.

 

Good to hear you've sorted it out, an SSD dropping out will screw up the boot order, even if it reconnects later.

Just out of sheer curiosity, what SSD is it?

 

This was an OCZ Vertex 4.

 

That explains a lot.