system clock acting weird. 3820TG

I went and changed the CMOS battery for my 3820TG since the old batt was pretty much depleted. CR2032 3v.
Set the system clock to the correct time and it all was normal. However, when the system is shut off, it would fail to keep time. E.g. If the current time is 5:30 p.m., I shut the system down and power it up, say, 10 mins later, the clock will still show 5:30 p.m; as if time was frozen. (This is when it's plugged in and battery installed btw)

If there was something wrong with the battery, then it would automatically reset itself to 12:00 a.m. right? but the way it's acting is really weird.

Thoughts?

 

The BIOS may be corrupt.

Try reinstalling it from Acer's website. I had a similar issue with my 5710g a while ago. Reinstalled the BIOS update and it worked again.

 

BIOS can't be corrupt. It's no an OS.

If there is a problem with BIOS it can be fixed by reverting it to default settings.

As for the issue - what happens if the notebook is unplugged and the main battery is removed?

 

The time will reset itself to 12:00 a.m.!

I then set the time and shut down the machine. Now it seems it's keeping time throughout.

My question is shouldn't the CMOS battery keep time even when there isn't any external power?

 

Yes it should definitely that. But since it isn't, maybe the CMOS battery itself isn't all that fresh. I'd buy another one to test.