Yeah that’s always good to know and you wouldn’t believe how many folks it has “tripped up” For some reason I must be living on borrowed time here. My old system is circa 2001 and strangely on the very rare occasion it ever shuts down It still keeps time but as its travelling days are over its plugged in all the time so that may have something to do with it. Its really more of an inconvenience should it fail and cant be changed (apparently some brands are “soldered” to the motherboard or buried in there in there deeply) So no need to run to the “Junk pile” just put up with its little idiosyncracies and leave it plugged in. If its a notebook and you and its travelling days aren’t quite over best to get saving alas 🙁

Hey Canadian Tech

woody wrote:

It is almost always the standard 2032 . This battery is recharged by your computer but has a life of about 5 to 8 years.

Pretty sure you may want to revise that statement!

Looking at the back of the package (Sony, CR2032 Lithium 3v) as I type–very small print–using a LED flashlight:

Caution: May explode or leak if inserted incorrectly, shorted, disassembled, heated, disposed of in a fire or recharged.

In a computer application setting, I think it simply has a life of about 5-8 years!

For safety reasons–do not attempt to *recharge* this battery!

NightOwl

1 user thanked author for this post.

AlanH

woody wrote:

“…. You need to enter the BIOS, which you do by pressing F2 in most systems to get to the place where the date and time is stored. Put in current time and date. Close this the way it tells you to save what you did. …”

I had, on a few occasions, made some changes to the BIOS settings on various computers. Some were simple, like changing the boot order, but some were a little more complicated and some others were actually changes made by the manufacturer. One thing I learned from a dying CMOS battery was to keep a record of all BIOS settings. The easiest way to do that is with a digital camera. So my suggestion is to go from one BIOS setting screen to the next and snap a photo of it. Then store the photos away somewhere you can access easily when the need arises. Just make sure you take the photos while your system is running well!

woody wrote:

“… For Notebook PCs it is likely going to be difficult to find the battery and will require a special part, requiring the services of a technician. …”

Another suggestion is for the tinkerers here (cheapskates, as well). Those CR2032 batteries cost about $10 for a pack of 8 at Costco here in the NY Metro area. The CMOS battery in one of my Dell laptops cost about $6 on Amazon and all it is is a CR2032 that is wrapped in plastic with a couple of wires to plug into a spot in the laptop. Now granted $6 is not a lot of money, even if you have to pay a few more bucks for shipping. It’s the principle of paying five times the amount (and more when you add in the shipping costs) for a silly coin cell with wires added. I stumbled across a webpage entitled “Make Your Own CMOS/RTC Battery” when the CMOS battery in my laptop started showing signs of dying. Using that web page as a starting point, I found if you carefully cut the plastic wrapping around the existing/dying/dead coin cell and carefully undo the soldered wiring, you could replace it with a new CR2032, reconnect the wires (I didn’t bother resoldering), rewrap the plastic coating, and add a small piece of tape to hold it snugly all together, it actually works. Again, only tinkerers and cheapskates need apply …

1 user thanked author for this post.

HiFlyer

Everything I see online indicates that the most commonly used battery, the CR2032, is NOT rechargeable.

The question has been raised above.  Can we resolve it?

Separate question: Do desktop computers typically relieve the CMOS battery of duty when (1) the computer is plugged in, whether powered-on or not, or (2) when powered-on?

If you are trying to keep a couple of stored Win7 machines ready for use, these questions matter.

The 2032 is a non-rechargeable coin type battery.
When the PC is powered off, the CMOS battery maintains the CMOS settings.
That is why, if the CMOS battery is dead, when the PC is powered on you find the time is incorrect, or it may request that you go through setup in the process of booting.

1 user thanked author for this post.

wdburt1

If your computer won’t power on no matter what you do, it could be something as simple as your CMOS battery being dead.

I have a Dell OptiPlex 3020M, and it was dead in the water. (It worked yesterday, but not today.) I tried every trick in the book to revive it, even switching power supplies (I had another one available) – nothing worked.

I happened to have a new CMOS battery handy, so I switched the battery, and like magic, the computer came back to life! All I needed to do was go into Setup and set the date and time.

If your computer seems dead, switch the CMOS battery before trying anything more expensive than that.

2 users thanked author for this post.

Washburn59, BobbyB

well woody, one of my relatives have an old HP pavilion a6050y computer using an ASUS P5LP-LE Leonite motherboard that seems to forget the bios settings and the date & time everytime I power off the computer and unplug it for a while and then replug & power on the computer again. the cause of that turned out to be a dead or worn out CR2032 lithium battery. Fortunately, I had a few spare & unused Energizer CR2032 batteries which I used to replace the dead CR2032 battery in the HP computer and now that HP computer remembers the date/time and the bios settings that I made.

CR 2032 batteries can be obtained at Dollar Tree – 2 | $1.

But there is contention whether they should be used for critical applications, like a computer’s CMOS board.