How Long Does CMOS Battery Last? CMOS Battery Life

Most components on a computer, like the CMOS battery, can only last for so long until you have to change into a new one. Changing the required parts at the right time will make your computer last longer and be in perfect condition.

However, you should note that some of these components are not user-replaceable. When these non-replaceable components encounter problems, you’ll have to spend hugely on a repair.

Luckily, you can replace the CMOS battery with a new one when it starts to fail. In this article, you’ll find out exactly how long CMOS batteries last and get valuable insights on how to change them.

What Is CMOS Battery?

It’s essential to understand your computer BIOS if you want to know what is a CMOS battery. BIOS stands for Basic Input and Output System, and it helps manage vital functions in your computer system. Basic input and output commands help control your computer, and your BIOS helps regulate these commands.

A CMOS (Complementary Metal Oxide Simulator) battery helps power your device BIOS, allowing your computer to process commands even when powered off. The battery can also help manage other things on your computer, like the time and date, disk drives, etc.

cmos battery

How Long Does CMOS Battery Last? CMOS Battery Life

A CMOS battery lasts around 2 to 10 years after the manufactured date. Realistically, you might never need to worry about changing your CMOS battery on your computer. The CMOS battery will start charging when you plug in your laptop and stop when you unplug it, and it typically stays charged perpetually.

What Is CMOS Battery Failure?

CMOS battery failure is when the battery stops working because it has exceeded its lifespan or for any other reason. When the battery fails, you’ll start noticing some abnormalities in the computer. Some problems you may experience include inconsistent timing, difficulty booting and connecting to the internet, etc.

CMOS Battery Failure Symptoms

Earlier, This article hinted that your computer would show symptoms after a CMOS battery breakdown. Most of them are performance issues that won’t allow you to use the device enjoyably, but what are these symptoms exactly?

CMOS Battery Failure Symptoms

You May Not Be Able To Connect To The Internet

One of the most apparent signs of a CMOS battery failure is difficulty connecting to the internet. Without an internet connection, the computer is useless. If this happens, the only way to restore your computer’s connectivity is to replace the CMOS battery.

Your Computer May Be Too Slow

Your computer may experience lags and bugs that make it run too slowly to perform basic tasks. Please check the CMOS battery status if you notice slow performance in your system. However, it is only sometimes that your computer experiences a slowdown due to CMOS battery failure.

Constant Beeping Sound When Working With Your PC

It might sound unrealistic, but your computer may experience constant beeping sounds from the motherboard if the CMOS battery fails. However, the motherboard may only make the sound if the CMOS battery stops working sometimes. So you should pay attention to other signs.

The Date And Time Have Been Reset

Reset date and time is one of the most notable signs of a faulty CMOS battery. Your BIOS, aided by the CMOS, helps to ensure that your date and time are up-to-date even if you shut down your system. When the CMOS battery fails, the BIOS can’t keep track of the time. Therefore, your date and time will reset to a very long time in the past.

Some Of The Drivers May Be Missing Or May Not Work Properly

Manually installed drivers might disappear suddenly if the CMOS battery fails. Some of them may be present but won’t work more appropriately. Since faulty drivers directly impact your system’s functionality, you should reinstall them to make them work well again. After reinstallation, you can then proceed to change the failed CMOS battery.

Hardware Drivers Have Disappeared

Hardware drivers are specific driver types that allow your computer to communicate effectively with hardware components in your computer system. This hardware includes the keyboard, mouse, GPU, motherboard, monitor, etc. If you have recurring issues with these hardware drivers, check the CMOS battery for failure.

Causing Booting Problems

Booting issues are the most evident signs of a failed CMOS battery. BIOS is hugely responsible for how your computer startup and booting issues might mean a problem somewhere. Dissemble your system and replace the battery to make it work well.

How Often Do You Replace A CMOS Battery?

Realistically, you won’t need to replace your CMOS battery sometimes. You might never need to replace the CMOS battery for all the systems you’ll ever use, mainly because the CMOS battery on the most modern device can last for as long as ten years, and most people only use a few computers for that long.

How Do I Know If My CMOS Battery Is Dying?

The best way to know if your CMOS battery is dying is to pay attention to the symptoms mentioned earlier in the article. Sometimes, these signs may not indicate that your CMOS battery is past its lifetime. To be safer, approach a qualified technician to help you check the system if you notice any or a combination of the abovementioned symptoms.

What Happens If CMOS Battery Dies?

You’ll experience many performance-related issues that may make the computer hard to use. The system will also forget all its hardware settings and reset the date and time.

Can A PC Run Without CMOS Battery?

Your PC will run even without a CMOS battery because the CMOS battery isn’t crucial to the computer’s functionality. As I explained earlier in the article, only the date and time will be off because that is the only part of the computer that the CMOS battery controls. Although it might take your computer a long time to start, it will.

How Long Does A CR2032 CMOS Battery Last?

Most CMOS batteries on modern computers are CR2032 lithium coin cells with an estimated uncharged lifespan of around three years. If you use them as recommended on your system, you can get up to 5 years of usage or more on these little batteries.

Can A Dead CMOS Battery Cause No Display? 

Although your computer can display a blank screen as an indicator that something’s wrong with the CMOS battery, it’s unlikely. Your system might interrupt the booting process and tell you to set a new date and time after the battery failure, but it will still boot normally. If you experience display issues, understand it’s mostly not because of a faulty CMOS battery.

How Long Does A CMOS Battery Last Without Power?

A CMOS battery will last for around three to four years without power. Note that this estimate is for new systems in which the battery is in perfect shape. If you buy a used system with a CMOS battery that has yet to see a lot of charges, it may be quicker to the end of its lifespan than you think.


Does A CMOS Battery Recharge?

CMOS batteries will charge when you plug in your computer and stop charging when you unplug it. The batteries last longer in desktop computers because they are plugged in most of the time and will always charge no matter what. If the battery fails, no amount of charging will revive it until you replace it.

How Much Does A CMOS Battery Cost?

Changing the CMOS battery on your computer is generally inexpensive. It costs around 1-10 dollars to purchase the battery, no matter the store or the type of computer that you use. Replacing it is equally inexpensive as you can unscrew the back cover, locate the motherboard, and replace it.

Are All CMOS Battery The Same?

Most systems use the CR2032 CMOS battery. However, some manufacturers might use another CMOS battery type on their computers. No matter the battery type your computer uses, it’s essential to confirm it before you buy a new one to avoid mistakes.

What Is CMOS Battery Voltage?

Depending on the battery type and computer model, most CMOS batteries can be around 3-6 volts. These batteries can either be NiCad batteries or AA Alkaline batteries. The 3-volt lithium battery is the most popular among manufacturers because it’s changeable and available at almost every store. 


That sums up all you may need to know about the lifespan of your computer’s CMOS battery. Changing your CMOS battery is easy if you know how to take your laptop apart, and all you have to do is remove the back cover until you see the computer motherboard, locate the CMOS battery, remove it, and replace it with a new one.

Although the process sounds easy, it might be difficult if you need to learn how to do it or how to locate the CMOS battery. The CMOS battery is usually distinct as it will be a small, shiny, coin-shaped entity on the motherboard. Be extremely careful while dealing with the computer to avoid making complex mistakes. If you need to learn how to replace the battery, take the device to a technician to do it for you.

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