One thing I was taught about button batteries (and halogen lamps, too), is that they should never be handled without some kind of skin protection, (gloves, tissue paper, etc.), because skin acids can have an adverse reaction with them, shortening their lives, and causing corrosion, possibly even leading to electrolyte leakage. This applies to all types of button batteries, regardless of their intended application, whether it's a CMOS, a digital or an analogue camera, or something else. Also, I don't know about the UK, but here in Australia, we can buy genuine Mallory CR-2032 batteries or their Eveready equivalent at most supermarkets usually in packs of 4, which will last you for years, and much cheaper than those Amazon and eBay burglars are charging (plus shipping costs).
Noice! need to get this out to the masses. See a lot of "fix my rig" where they omit checking the 3.3V Button cell on old budget builds. Bit-rot can cause so many issues that it should be the first replacement you do servicing an old mobo. Shared! 👍
Better YET = A Windows / IOS / Google / any OS Update Checksum = However = Weak Battery Causes This To Fail Causing a Blue Screne = your First IS The Worst =- AND YES = Even a Brand New Battery Can Be Defunctant = the pc = While just merely having an excess psu = Should Not Requiire the battery Til its Required = This is a Motherboard Miss-qued Advantage of Process Awareness as well as having a Monitoringg Directly In Bios To prevent Data Loss = some SAY they Do = But Really Dont due to iit Takes Up So Much ROOM and anymore they would have to stop using jpeg or something =idk = but i should have the ability to open it up in wondow/s and see the percentage life of product as It can be measured Through A Manual Stress test on the unit each request for data on subject = you Could Literally Have End User ONly access to monitor this as well = And In Fact = DATA SHOWS = It Would Pay To Design Such = maybe a Software = BUT OMG = That 3rd Party Direct Access to MY OS = H__L NO it must be by those products you use alone = NO MORE 3rd Parties !!!!! either directly from creator or manufacture , no more through this or that may have went on a tangent there , MY BADD
This video is extremely useful and important , thank you for making it. Many, many people, think that a worn out or faulty CMOS battery will simply set the BIOS values and date/time to their default, and that you can get away with it if you enter the correct values each time you turn on your PC. This , unfortunately, is simply NOT true.... I 've been building PC rigs for more than 20 years for friends and relatives and here's maybe the funniest story that i have to share : i once put together a retro gaming xp pc for myself. Brand new hdd, RAM, good quality PSU, all other hardware known to work PERFECTLY, and just to have everything in top shape, i decided to install a BRAND-NEW CMOS battery, from a very reputable and well-known company i might add...well, to cut a long story short, the pc kept crashing at the same exact point when it was loading windows XP, with me banging my head on the desk trying to figure out what was wrong....after swapping every hardware i could , from all the obvious ones to all cables, and even trying to loosen up the motherboard screws (!), i was ready to give up, when it occured to me to swap the brand new CMOS battery that i had installed with an old battered one i had laying around...and , lo and behold, the PC booted up perfectly!!! the funniest thing is , that the same "faulty" new CMOS battery worked just fine in another motherboard.....!! Now i 've seen a lot of weird stuff, but never an...incompatibility of a certain motherboard with a specific CMOS battery! Life as a PC tech never ceases to amaze me ....
@@pibbles-a-plenty1105 no I didn't , i didn't get access to any such equipment unfortunately. But like I said, the battery that gave me all that trouble was brand new...and also worked fine on another pc
Have you considered the possibility that there could have been dirt or a loose connection or something, maybe the battery wasn't fully seated in or something and the voltage being slightly off caused corrupt data in either the BIOS or the system RAM?
There's a number of strange behaviors that can occur when the batteries are dying. Usually the most obvious is the time/date problem. It's usually a CR2032 battery which you can often find at the dollar store.
' It's usually a CR2032 battery which you can often find at the dollar store.' Much better to spend the $5 and get a real name brand in this application, they'll tend to last 5 or 10 years. The cheap ones tend to only last a year or two at most, and you'll spend half the money in total on the next several batteries anyway during the same time.
@@anthonyg9739 Which dollar stores are you talking about? Dollar Tree doesn't even list a 2032. There are tons of cheap versions, and even the main companies put out their own cheaper versions. You have to look to make sure you're getting the full version that isn't cost reduced and half empty.
I've seen some systems that will refuse to power on with a dead CMOS battery primarily the Prebuilt ones like the old Compaq Presarios from around the Windows ME era are one example if the CMOS battery dies it won't turn on. Carey Holzman had one as soon as he put a new battery in the thing sprang to life without even having to hit the power button
@@electrocat9 it depends on the system like my example was a Compaq they dont exist anymore HP bought them I have seen other motherboards with dead or dying CMOS batteries they will turn on but they will give various errors at least now the system can detect the hard drives etc automatically back in the 80s and early 90s if your CMOS battery died and you didn't know wat settings to put in the bios for the hard drive etc you were dead in the water
Great video, thanks Brian. I've just changed the CMOS battery on my brothers old XP dual core Pentium 4 PC. There the dying CMOS battery first manifested via errors with delayed writes to the D: drive, then boot errors, but BIOS and time settings were still remembered, so it took a while before I started to suspect the battery.
Thank you. About a week before your video my Intel motherboard wouldn’t boot or power on. Replaced the CMOS battery and it worked then failed again. I forgot to clean the metal contacts. Cleaned and fixed. Also did a deep cleaning of dust and dog fur from my fans and motherboard. Great 👍 video
I've had my machine running for 5 years and my CMOS battery still runs sweet as a nut. Battery came free when I bought my motherboard too which was a nice touch.
When the CMOS battery is ending it's life it will still show close to 3 volts by itself. But in the motherboard the voltage will be much lower due to current drain. Best to measure the CMOS battery in the motherboard first before taking it out of it's holder. Measure between the + side on top of the battery in its holder and the board ground at a metal connector shield at the back side of the board. If the battery is at 3 volts or more it has a lot of life left. If it's down to 2.7 volts replace it for good measure before trouble starts.
What I always found annoying is that there's no way to replace the CMOS battery, even when it isn't dead, with a new battery without having to re-configure all your settings. So, you either make a habit of replacing it every few years or so and, consequently, re-configure your BIOS, or you just wait for it to die when you didn't plan and be forced to replace within the next days less. I suppose you could leave the computer plugged in as you replace the battery, but it's a risky move.
I don't even know where did you get that information. I used to clean my motherboard and disassembling everything including took off the battery. When I installed new CMOS battery, BIOS settings are still the same from the last time I made changes to it. However the clock seem to be out of sync but it doesn't matter.
I can only assume there are older models or a picky maker you speak of. I just changed my battery on a Dell Inspiron 3860. After starting it up, a blue screen said windows didn't restart properly. And a button icon that you click to restart. Fired right up. Only issue after that was that the clock had to be re-synced. No biggie, the clock right clicks to that option.
Since 1993 I've only ever had that happen once. It was on a PC my brother had for several years before he gave it to me. I haven't had any others long enough for that to become an issue. If you're constantly upgrading and buying new parts you may never run across this.
I've had to replace CMOS batteries several times in my life, but yeah, it's rare. Sometimes the battery the motherboard came with just wasn't the newest one and so it only lasts a few years. Personally, I replace my desktop PC every 7-10 years and so, just recently, I had to replace the CMOS battery.
I've gone down to my dollar tree store and purchased a CR2032 for only a buck! Last few times they've had the Panasonic brand!!! I figure if I'm gonna crack my case open for a good blow-out, I might as well check the CMOS battery!!! When I was doing tech work, I'd go to a location and see customers with their tower PC on the floor. WORST place to put a PC....sucks in dust and whatnot!!! Then, if it was a lawyer's office, they'd have crap piled everywhere!!!...pretty much suffocating the airflow to the PC!!! Several times, the pc's contained sooo much dust that the user would complain that the PC was running slow!!! And I'd say...your computer is running slow because the heatsinks are clogged with dust and your processor is throttling down to keep from burning itself out due to lack of free airflow. I would usually get a blank stare in return. 😏
On some laptops, certainly ones I've used, nothing happens. That's because once the CMOS battery dies any power needed is automatically redirected from the laptop's battery. In that case you only discover the CMOS battery is dead once the laptop battery is removed and you run it off mains power only. But even in that niche case, nothing happens except system date and time needs resetting and any custom BIOS settings are lost.
Thanks. On a refurbished Dell laptop I have it constantly go into "sleep" mode which I suspect is not a CMOS setting but something with the Dell locked BIOS. But maybe it's a CMOS battery? I also thought the CMOS battery was rechargeable but no. BTW the PC I am posting this on has an original CMOS battery that's 14 years old and doing just fine. (Wikipedia): CMOS This battery type, unlike the Lithium-ion battery, is not rechargeable and trying to do so may result in an explosion. Today's UEFI motherboards use NVRAM to store configuration data (NVRAM is a part of the UEFI flash ROM), but by many OEMs' design, the UEFI settings are still lost if the CMOS battery fails.[4][5]
@@raylopez99 How do you mean the laptop constantly goes to sleep? You mean just randomly? That's definitely not a CMOS battery issue. I deal almost exclusively with refurbished Dell laptops as that's my area of interest. Does your laptop have a locked BIOS? You know it's possible to unlock it without the user password. I don't see why any issues would be related to a locked BIOS as all that means is that you can't access it without a password and doesn't itself dictate any power settings. It's certainly a bizarre design decision for settings to still be lost when the CMOS battery dies even though stored on NVRAM.
@@FlyboyHelosim You are saying something very relevant to my ears. Please elaborate if you have time. Yes my Dell E6520 (i5-2520M chip) goes to sleep 'randomly' with the battery in, and with the battery out, it does less so (but on occasion) so I leave the battery in since it's easier to awake it from sleep rather than reboot. Tell me how to unlock the BIOS without the password please, but keep in mind I've heard that if you do it with a "hardware reset" some Dells have it set up so, for security purposes, it trashes the EEPROM (?), urban legend but maybe true so I don't want a hardware reset. Also you last sentence implies that if the CMOS battery dies, since the BIOS is locked, your laptop might die even if you put in a fresh CMOS? Is that true? I did look at the user manual and know where the CMOS is stored, it's behind the WiFi antenna. My philosophy, given shortages in laptops these days, is "if it aint' broke, don't fix it". I use this laptop for storing business data and tho I backup I don't want the PC to die by messing with the CMOS. Any thoughts appreciated. Bye.
My father always measures both votage and milliamps on these batteries because voltage may be right (3v) but if you can also have low milliamps and this causes malfunction too.
Funny enough I was looking at my 2032 batteries yesterday thinking how many things actually use them these days including the CMOS haha. Good info as always
Why oh why doesn't CMOS do a battery check before loading & detecting all of the computer hardware components? And why doesn't CMOS tell you that the battery life is low and you need to change it soon or the battery has discharged too much and you need to replace it ASAP or you will have problems booting your computer properly? We have all kinds of sensors like SMART for hard drives that can tell you the status of them, fan speed detection, CPU & GPU temps, memory testing at CMOS, etc. But we have nothing going on for a simple battery check? Why this oversight still continues to this day is beyond me and totally inexcusable. For shame, for shame on the engineers of motherboards.
Usually, unless the BIOS chip is coded really wonky, the computer will know when something isn't right upon boot-up and it will just give you a "CMOS Checksum Error" which basically means data got corrupt in CMOS, and the data (settings) do not match the checksum, thus popping the error message. The #1 reason why this happens is quite simply, a dying battery. I've had this happen in plenty of my PCs, and this is always what has happened, 100% of the time. I've never seen a computer do anything else other than pop the checksum error. Maybe if you're running really cheap motherboards that don't have a CMOS Checksum? That technology has been around since at least the 90s, or maybe even earlier than that, I've had 486 computers that had CMOS Checksums and they all did the same thing when the battery died. Also, how long a battery lasts also depends on whether or not you use the PC regularly. A PC that is in regular use will last far longer than one that is only booted up once in a month, for two reasons: One, Li-Ion batteries last longer if they aren't discharged as much, and Two, if you keep it charged with constant use, it will never have a chance to discharge and it only needs to keep the CMOS running for a few hours. Lastly, if you leave the surge protector your PC is plugged into on, and you leave your PSU on, your PC is not even using the CMOS Battery at all; the PSU is supplying power to the mainboard even while the computer is not actively running. You may wish to turn the PSU off for about 10 seconds and turn it back on before you boot the computer to make sure you have a fresh cold boot, though.
A modern machine with UEFI will never actually show you a "CMOS Checksum Error" from a failing battery, since UEFI stores its configuration data not in CMOS RAM, but instead in a dedicated part of the BIOS flash chip called the variable store; the battery only runs the real-time clock. Gamer motherboards often will clear the variable store if an RTC reset is detected (to ensure that the old technique of "clearing CMOS" by removing the battery still work, even though it has no reason to work anymore), but a dying battery won't corrupt your variable store.
I worked at a company that had a PC based piece of medical equipment. Whenever we got a unit in from the field, we automatically changed out the battery. And we carried batteries in the field.
Is it possible for the battery to fall out just by a shaky desk? And Is there a way (without using electrical tape or something) to make sure it stays in place?
I was always wondered why don't motherboards use the internet to set time and date in the bios. So when u turn on the pc it asks to connect to the internet and sets the bios and date time and eliminate the battery fully.
Neglecting CMOS warnings by choosing Continue can cause your Antivurus to block access to certain sites like banking, because the date and time is not correct. A pc that is connected 24/7 to mains power is less likely to have issues. I use a standard lifecycle of three years to replace the battery anyway.
My mum's computer after a reboot resets the BIOS settings and if I change and save them, it doesn't boot at all, but continue with default ones helps. Old PC but had its battery replaced during maintenance, maybe the battery itself is bad or needs a replacement again?
Mine is beeping 5 times then the fan starts spinning faster and faster but 5he screen remains black. I've only done very few CMOS battery replacements in the past and I'm not quite sure what I've got going on here?
I just clicked on this out of curiosity because I didn’t know what a cmos battery was and realized that it’s the likely culprit for my repeated boot errors on my ten year old system. I’d just assumed it was my hard drives conflicting at startup but ironically I get the exact issues listed every time I restart it and I’ve just been going through the bios and exiting out just to bypass it lol.
Can dying CMOS Batteries also cause BIOS settings not being changed/saved? On my previous PC that I used from August 2015 to January 2020 the mainboard started to have issues persisting settings the last year (2019) or so, although booting up wasn't a problem. It once reset to default values after OC instability and then I wasn't able to reconfigure my settings. Only every now and then when taking the battery out for a bit I could set some things IIRC. Unfortunately I didn't get to searching and buying a new CMOS battery and don't remember having checked the voltage (although I was able to), I just worked around this by installing a program for CPU OC from Windows and letting the RAM run at default 1333 MHz instead of the 1866 MHz XMP profile. And then I built a new PC and sold the previous one, so didn't do further troubleshooting. Could it have been a dying CMOS battery or was it something else going wrong with the mainboard? If so, what could it have been?
Had a power surge recently and my computer wasn't turning on, but the motherboard lights were on (PC was plugged in the power outlet). From the get-go I already knew it wasn't the power supply module, so I started thinking the motherboard had been damaged somewhere. If you're having the same symptoms, I'll save you some precious hours of anxiety: try reseating the CMOS battery, because it worked for me.
I came here wondering if this might explain why my pc recently started spontaneously restarting (as in as if the reset switch had been pressed), seemingly at random in the last few days, until eventually while I was trying different possible solutions it stopped displaying the motherboard splashscreen at all and is now completely unresponsive. No beeps either, but it never did beep on startup. Clearly based on this it's not the CMOS battery, but since I'm here I thought I would ask for advice anyway. While it was restarting I tried various power setting suggestions in windows, and also disconnected the power and reset switches in case they were responsible. Then when it no longer booted up at all I tried unplugging all non-essential usb devices, reseating the memory and graphics card, and even resetting CMOS. The next thing I will do is get hold of an adaptor to allow me to view my main hard disc from my laptop and at least recover the last few days' worth of work that I did between this failure and my last backup, but before I resort to buying a new motherboard and/or anything else, I would welcome any suggestions. Thanks!
Did you figure it out? I had PC restart due to overheating I think... lowering PSU load on graphics card let it work without rebooting itself. Like in MSI afterburner lowered power use from 110% to 70.
i've noticed mostly on msi motherboards that it gets glitchy during POST or does not POST entirely. also, after replacing the cmos batter and the issue persist, usually its the clock crystal that needs replacement.
I'm pretty good with computers and I've always thought that a failing CMOS battery would just show the error messages shown in this video. I learned that it isn't true even for fairly recent mobos because a dying CMOS battery caused my PC from turning on in the first place. The mobo is an Asus ROG Maximus VIII with an i7-6700K and is around 7 years old or so. First error that occurred was double booting (PC turns on for several seconds, shuts down, then turns on again during POST) while on XMP. I encountered this problem ages ago and the Asus forums always claim that this is "normal" as part of memory training but I managed to solve this by fiddling with some obscure BIOS setting. I was surprised that the problem returned, but noticed that if I didn't turn off the power to the system completely the double boot didn't occur. After a while, there were times when the system refused to power on and it progressed to the point it wouldn't power on at all no matter how many times I pressed the power button. I tried doing a BIOS flashback twice and it didn't solve the problem. I thought it was a motherboard problem so I started using my laptop instead while searching for a second-hand mobo. After around a week I had decided to try turning on the PC and I was surprised that it did, although it didn't last and refused to turn on again later. At this point I realized that the errors that occurred in the beginning might be from a failing CMOS battery. I removed the battery and tested the voltage with my multimeter which showed a reading below 1 volt. After replaced the 2032 battery all the problems disappeared. To make the long story short, if there's anything weird happening at the POST level always consider the CMOS battery. It took me a long time to figure it out because I always had the notion that PCs should be able to boot even without a CMOS battery, you'd just have to enter the correct BIOS setting every time. Unfortunately this isn't true; it's just surprising that the dead battery = no power on would happen in an upper-tier mobo that isn't very old.
@@Vasant8300 Maybe it's solar powered 🌞. Kidding aside, you should first check if the laptop has a CMOS battery to begin with. Some don't, especially models that have non-removable batteries.
@@Vasant8300 That seems like a hardware issue since it's occurring very early, specifically during POST (power on self-test). If I had to guess, it's likely a failing motherboard. Since it's a very old model (the CPU is an Intel 3rd generation processor) I doubt replacement motherboards are still available. I suggest you just invest in a new laptop and migrate all your data from the old laptop to the new one. If buying a new laptop isn't an option then last resort would be board-level component repair.
today again i placed my back of laptop in sunlight for warm it , and it turn on normally ,please can u hrlp me why it happen. and when i turn it off for night it then in morning no display comr
Great video Brian, quick question. Recently when I boot up my pc it goes to boot then the power goes off and comes back on a few seconds later and it says the pc was not turned off correctly and have to go into my bios to boot my pc up. Is this a CMOS battery problem in your opinion? Cheers Lee.
Without Evan Watching the video. Your clock starts to show the wrong time . For one calendar gets wonky. Stuff starts to slow down or you have issues with accessing the drives kits an allover breakdown of your main board systems . Thank God most of the 2032 battery's are replaceable. Some you have to desolder. Oh your random access memory is linked to the cmos battery. That's if I rember it correctly I grafuated IT school in 03 been a while lol
Hi Brian, I have an old computer which I haven't started for about 2 years old. Should I change the CMOS battery before I boot it up since it hasn't been powered on in 2 years?
My PC was turning off out of nowhere all of a sudden and one day the PC would refuse to boot. The PC would turn on and the case fans were spinning but the CPU, GPU, and exhaust fans werent. Replaced the CMOS battery and it rebooted a couple times then worked like a charm. Never knew these things could die on you. Been using the same motherboard for about 5 years.
Can a dead battery cause the entire pc to not turn on? (I got a old toshiba laptop that i never got bother to try change the battery to see if it would turn back on)
Hello, please I've been having the same issue and inserted a new CMOS battery but it does not work and my computer always bootup by it self when I switch on the power socket on the wall. Pls I need help.
I had a Packard Bell system bought in Portugal 10 years ago. Recently built a new system but the PB was working fine since new. Battery lasted through all the moves etc. Came back to UK 5 years ago.
Ok, great topic Brian. But I'm curious that after all these years and with technology advanced, why are we still using stupid batteries? I mean the bios and system settings are stored correct? We use ssd's, flash drives etc. So again why are we still relying on a battery to hold that information in? Just curious. 🤔
i have a problem where my pc sometimes boots normally and sometimes it beeps and show the no memory detected what can i do to fix it pls help me and I'm sure it's not the ram i tested it
So I have a question I updated my bios and on my monitor it said it got my bios settings to default and I was supposed to change customised it back. Next every time I push to start the pc , it starts then goes off and again on by itself. What issue is that ? Cmos or something else?
My parent's computer show a "cmos checksum error or cmos battery loss, default bios config loaded" message after EVERY power outage (then i press F1 to continue and all is dandy), could it be that this battery needs a changing?
dear sir. I forget to put my CMOS battery back. but my desktop PC running very well. do I need to put it back or is its o.k PC running without a CMOS battery? thank you. have a good one.
Depends on your OEM and design. Wikipedia-- This battery type, unlike the Lithium-ion battery, is not rechargeable and trying to do so may result in an explosion. Today's UEFI motherboards use NVRAM to store configuration data (NVRAM is a part of the UEFI flash ROM), but by many OEMs' design, the UEFI settings are still lost if the CMOS battery fails.[4][5]
@@quintusupalifullhdgaming450 I'm no expert but if you use your PC everyday perhaps the static ram, which is what the CMOS battery prevents from discharging, will not discharge as it will get energy from the main power supply when the PC is on. Just a guess. Good luck and always backup your data.
My motherboard sudden started to boot up slowly the other day. It went from starting up right away, and now it takes like a minute for it to boot up and then go right into loading windows. Would a dying battery do this?
My serverboard boots up all the way to the windows startup you could hear the windows startup sound but no display output...could that also be due to CMOS battery?
What happens is a lot of people think as long as the computer is plugged in that it should be OK and that the battery is just their for when the computer is unplugged.
didnt even know tthis was a thing!! thanks alot!, do the battery have to be a specific size. or all they all the right size to fit into any motherboad.. my motherbaord is a AsRock B450 Pro4
hi . can i change the battery with the computer running ? that way the bios won't need to be reset? or is there any other way around resetting the bios with computer off? cheers
I have an old computer, it's 18 years old now. The original battery was completely dead when I got it 7 years ago. It didn't even detected the SATA HDD at this state, when it was plugged in it said "hardware initialization failure". It worked with an IDE disk, however. I've replaced the battery, the computer was in everyday use for about 2 years, then it got unplugged for 4 years before I turned it to a retro gaming PC as my modern PC can't run my old favorites. I measured 2.7 Volts on the battery but it still works, the clock was only about 10 minutes behind after 4 years without power and it recognize the SATA HDD as well. Maybe time to replace? I started to have issues with another PC when the battery measured 1.1 Volt. It's always plugged in now so it should't drain too fast.
My 2013 alienware laptop keeps shutting down from "low battery charge" even if the battery level is charged at 90%. Do you think the CMOS battery is the culprit or the main battery just toasted?
I plugged in a 970 evo into my hdd cable on my PC (dumb move i know) and now the pc wont even boot bios, could the ssd have somehow shorted my cmos battery?
My PC doesn't starts, although it has power in it. CPU fan case fan, nothing starts. I tried everything, like jumpstart, removing and reinstalling the CMOS battery etc. But it still doesn't work. Actually my pc wasn't been used for a month, and this problem happened. Than I turned on the pc by reinstalling the CMOS battery, and it worked. I used to do that almost every day for almost a month, whenever I face this problem. But today that trick isn't working. Now what should I do? Should I buy another CMOS battery, or it's not the problem of CMOS battery?
My pc acts strange. i can run my os, but when it comes to restart, it doesn't turn back on unless i power off psu for a bit . Now, if i try and save and exit in bios, it shuts off, but something does go back on, so i turn off psu for a bit, turn back on, bios, and nothing saved
I have an old windows XP computer that can't detect the hard drive or the disk drive in the bios and thus wont boot to windows; is this caused by the cmos battery being dead?
I didn't know that, would the same happen with laptops too? Cause my omen 17 was only 1 day old technically when I first started using it and it refuse to start up after battery running very low
What i think i experienced with pc's i had (cant recall if it was with cmos battery dying, but i think so) is that its important to set the time correct, am i totally out biking on this or kinda right?
When i pull the plug out of the wall (after turning the switch off), i get an error each time on bootup next time i start the pc (after plugging things in again.) I want to be able to unplug it from wall because of power surges ive tried and there will be more in the future. So will changing the CMOS battery help avoid this error? Or am i just wasting my time and taking EDS risks with changing it?
It's just a simple voltage reading so any multimeter (even a cheap analog one) will do. There are tons of options from online platforms or you can buy from your hardware store.
@@Shiv.141 By the way I forgot to mention just go for a cheap digital one because they're easier to read rather than analog ones with a dial. The CMOS battery of my PC recently died (lasted ~7 years) and I confirmed it with a voltage reading of less than 1 volt (I think it was just 0.7 V or so). It's not absolutely necessary though to confirm a dead battery with a multimeter since you can just pop in a new CR 2032 which is very cheap. I just happened to have one because I occasionally work with electronics.
I broke my Cmos socket on build im in process of doing one end come off the one opposite the one opposite the plus sign. Just waiting for ram to be delivered but worried pc will not post because of cmos battery holder being damaged?
My prev cmos battery showing above 3V but my pc freezing when playing game,and boot to bios and not showing my SSD M.2,after i replace ne battery,i hv no longer experience with pc freezing and blue screen,my conclusions is,just replace the battery,even its looks still "okay"
Brother could you please help. I have an error in my system. My pc turns on and even boots into windows 10. But after a couple of hrs approx 1 or even 1 and a half hours of usage and even idle my pc's display goes no signal. But all other components in my pc are running the hdd the processor the rams the GPU the keyboard the mouse etc. What might be the problem with my pc. I am not able to find which component of my pc is dying or should be replaced
when i turn on my PC its taking too long on the motherboard's loading screen like 7-10mins before booting up the windows OS, is this also a cause of battery failure??
Sir I have a similar problem coming again " Time of the day not set - pleas run the program" this happens when I start after shut down. Dell G3 1790 core I 7 9th Gen. May I change my CMOS
I recently had an issue where I tried to install a dual boot OS (Linux on Windows) but I had an issue with it during installation and when trying to fix it my PC seemed to have just stopped working. I was able to fix it by removing some RAM but do you think it's the CMOS? I've noticed since I've fixed it my PC still doesn't boot properly. Sometimes it powers up, then off, then up, then off etc. Other times I get rapid beeping and no boot Other times I get power up and some little ticks. I suppose it could be the CMOS?
After 2 years of my using my new gaming PC. Mother board Asus Darkhero VIII . I got error message when booting: Please enter setup to recover BIOS settings. Press F1 to run Setup. I have replaced the CMOS battery with new one still get this problem. If I leave my computer unplugged for 4 weeks I loose the system date and time after changing the batttery is this normal? How can I fix this issue?
This video should help you resolve a lot of computer problems. Drop us a LIKE 👍
Thank You :)
One thing I was taught about button batteries (and halogen lamps, too), is that they should never be handled without some kind of skin protection, (gloves, tissue paper, etc.), because skin acids can have an adverse reaction with them, shortening their lives, and causing corrosion, possibly even leading to electrolyte leakage.
This applies to all types of button batteries, regardless of their intended application, whether it's a CMOS, a digital or an analogue camera, or something else.
Also, I don't know about the UK, but here in Australia, we can buy genuine Mallory CR-2032 batteries or their Eveready equivalent at most supermarkets usually in packs of 4, which will last you for years, and much cheaper than those Amazon and eBay burglars are charging (plus shipping costs).
Noice! need to get this out to the masses. See a lot of "fix my rig" where they omit checking the 3.3V Button cell on old budget builds. Bit-rot can cause so many issues that it should be the first replacement you do servicing an old mobo.
Shared! 👍
Before the memory errors, the clock time will run fast.
Never thought of it. Cheers buddy!!
I'm surprised motherboard manufacturers haven't come up with a design that detects low voltage on the battery and gives a meaningful warning.
Especially if you can't see. It would be nice to have some audible feedback like a beep code of some sort.
Yes all other voltages are displayed in bios, surely it wouldve been easy to monitor the cmos aswell :-)
EXACTLY! Even my kitchen scale tells me the battery should be replaced, but my zillion dollar PC just wont boot up.
Better YET = A Windows / IOS / Google / any OS Update Checksum = However = Weak Battery Causes This To Fail Causing a Blue Screne = your First IS The Worst =- AND YES = Even a Brand New Battery Can Be Defunctant = the pc = While just merely having an excess psu = Should Not Requiire the battery Til its Required = This is a Motherboard Miss-qued Advantage of Process Awareness as well as having a Monitoringg Directly In Bios To prevent Data Loss = some SAY they Do = But Really Dont due to iit Takes Up So Much ROOM and anymore they would have to stop using jpeg or something =idk = but i should have the ability to open it up in wondow/s and see the percentage life of product as It can be measured Through A Manual Stress test on the unit each request for data on subject = you Could Literally Have End User ONly access to monitor this as well = And In Fact = DATA SHOWS = It Would Pay To Design Such = maybe a Software = BUT OMG = That 3rd Party Direct Access to MY OS = H__L NO it must be by those products you use alone = NO MORE 3rd Parties !!!!! either directly from creator or manufacture , no more through this or that
may have went on a tangent there , MY BADD
Like on a phone and other electronic stuff
CR2032 stands for:
C - type of battery: lithium , voltage 3V
R - shape: round
20 - diameter: 20mm
32 - height: 3.2mm
Thanks, I've always wondered about that.
@Arne Ragnarsson batteries don’t hold the information. just powers the module that stored the information
****** THE MORE YOU KNOW *****
@Arne Ragnarsson
Umm why you stated the obvious?
Your comment has awesome information! I never knew that about the meaning of the battery name. Thank you very much
This video is extremely useful and important , thank you for making it. Many, many people, think that a worn out or faulty CMOS battery will simply set the BIOS values and date/time to their default, and that you can get away with it if you enter the correct values each time you turn on your PC. This , unfortunately, is simply NOT true....
I 've been building PC rigs for more than 20 years for friends and relatives and here's maybe the funniest story that i have to share : i once put together a retro gaming xp pc for myself. Brand new hdd, RAM, good quality PSU, all other hardware known to work PERFECTLY, and just to have everything in top shape, i decided to install a BRAND-NEW CMOS battery, from a very reputable and well-known company i might add...well, to cut a long story short, the pc kept crashing at the same exact point when it was loading windows XP, with me banging my head on the desk trying to figure out what was wrong....after swapping every hardware i could , from all the obvious ones to all cables, and even trying to loosen up the motherboard screws (!), i was ready to give up, when it occured to me to swap the brand new CMOS battery that i had installed with an old battered one i had laying around...and , lo and behold, the PC booted up perfectly!!! the funniest thing is , that the same "faulty" new CMOS battery worked just fine in another motherboard.....!! Now i 've seen a lot of weird stuff, but never an...incompatibility of a certain motherboard with a specific CMOS battery! Life as a PC tech never ceases to amaze me ....
Ever use a volt meter to check voltages when working on PC's? Like the CMOS battery voltage?
@@pibbles-a-plenty1105 no I didn't , i didn't get access to any such equipment unfortunately. But like I said, the battery that gave me all that trouble was brand new...and also worked fine on another pc
Dude, this just confirms to me all computer tech runs on Black Magic and Voodoo! 🤣
@@hurdygurdyguy1 Well Black Magic makes custom wire sleeves and the Voodoo gpu was once a big thing.
Have you considered the possibility that there could have been dirt or a loose connection or something, maybe the battery wasn't fully seated in or something and the voltage being slightly off caused corrupt data in either the BIOS or the system RAM?
I was about to buy a new PSU because my PC keeps on shutting down and this video saved me a ton of money! Thank you so much!
There's a number of strange behaviors that can occur when the batteries are dying. Usually the most obvious is the time/date problem. It's usually a CR2032 battery which you can often find at the dollar store.
Yeah, the pc will act real funny on a dying cmos battery
' It's usually a CR2032 battery which you can often find at the dollar store.' Much better to spend the $5 and get a real name brand in this application, they'll tend to last 5 or 10 years. The cheap ones tend to only last a year or two at most, and you'll spend half the money in total on the next several batteries anyway during the same time.
@@ModelLights Dollar stores sell name brand. In fact, I've never seen an off brand CR 2032. They are all energizers or duracells.
@@anthonyg9739 Which dollar stores are you talking about? Dollar Tree doesn't even list a 2032.
There are tons of cheap versions, and even the main companies put out their own cheaper versions. You have to look to make sure you're getting the full version that isn't cost reduced and half empty.
@@ModelLights Seen them at Dollar General and Family Dollar. Energizers and Duracells.
I've seen some systems that will refuse to power on with a dead CMOS battery primarily the Prebuilt ones like the old Compaq Presarios from around the Windows ME era are one example if the CMOS battery dies it won't turn on. Carey Holzman had one as soon as he put a new battery in the thing sprang to life without even having to hit the power button
Yeah, CMOS battery is very important
I know it starts without battery on defaults. Am i wrong?
@@electrocat9 it depends on the system like my example was a Compaq they dont exist anymore HP bought them I have seen other motherboards with dead or dying CMOS batteries they will turn on but they will give various errors at least now the system can detect the hard drives etc automatically back in the 80s and early 90s if your CMOS battery died and you didn't know wat settings to put in the bios for the hard drive etc you were dead in the water
Yeah lol
Also, a lot of newer laptops will not power on with a weak CMOS battery.
Great video, thanks Brian. I've just changed the CMOS battery on my brothers old XP dual core Pentium 4 PC. There the dying CMOS battery first manifested via errors with delayed writes to the D: drive, then boot errors, but BIOS and time settings were still remembered, so it took a while before I started to suspect the battery.
Mine was manifested by having blue screens every now and then.
Thank you. About a week before your video my Intel motherboard wouldn’t boot or power on. Replaced the CMOS battery and it worked then failed again. I forgot to clean the metal contacts. Cleaned and fixed. Also did a deep cleaning of dust and dog fur from my fans and motherboard. Great 👍 video
EXCELLENT VIDEO REMINDER TO THOSE WHO OVERLOOK THEIR CMOS BATTERY, AND USE THEIR PC AND LAPTOP ON SUCH A REGULAR BASIS.
I've had my machine running for 5 years and my CMOS battery still runs sweet as a nut. Battery came free when I bought my motherboard too which was a nice touch.
You mean u ran it for 5 years straight? Without ever shutting it off?
@@samir9735 The first 4 years I always shut it down when I wasnt using it but for the last year I've been mining.
i7 4770k Asus Z87 Maximus VI Hero from 2013 on factory CMOS battery going on 9 years still working perfect.
I had mine running for 13 years and now it seems to be dying on me...hmm. :)
Sweet as a nut? 😄
When the CMOS battery is ending it's life it will still show close to 3 volts by itself. But in the motherboard the voltage will be much lower due to current drain. Best to measure the CMOS battery in the motherboard first before taking it out of it's holder. Measure between the + side on top of the battery in its holder and the board ground at a metal connector shield at the back side of the board. If the battery is at 3 volts or more it has a lot of life left. If it's down to 2.7 volts replace it for good measure before trouble starts.
What I always found annoying is that there's no way to replace the CMOS battery, even when it isn't dead, with a new battery without having to re-configure all your settings. So, you either make a habit of replacing it every few years or so and, consequently, re-configure your BIOS, or you just wait for it to die when you didn't plan and be forced to replace within the next days less. I suppose you could leave the computer plugged in as you replace the battery, but it's a risky move.
if you replace with 5 seconds you dont need to do anythinh.
I don't even know where did you get that information.
I used to clean my motherboard and disassembling everything including took off the battery. When I installed new CMOS battery, BIOS settings are still the same from the last time I made changes to it. However the clock seem to be out of sync but it doesn't matter.
I can only assume there are older models or a picky maker you speak of. I just changed my battery on a Dell Inspiron 3860. After starting it up, a blue screen said windows didn't restart properly. And a button icon that you click to restart. Fired right up. Only issue after that was that the clock had to be re-synced. No biggie, the clock right clicks to that option.
Since 1993 I've only ever had that happen once. It was on a PC my brother had for several years before he gave it to me. I haven't had any others long enough for that to become an issue. If you're constantly upgrading and buying new parts you may never run across this.
Exactly. In my 24 years of computer ownership I've never replaced a CMOS battery.
I've had to replace CMOS batteries several times in my life, but yeah, it's rare. Sometimes the battery the motherboard came with just wasn't the newest one and so it only lasts a few years. Personally, I replace my desktop PC every 7-10 years and so, just recently, I had to replace the CMOS battery.
I've gone down to my dollar tree store and purchased a CR2032 for only a buck! Last few times they've had the Panasonic brand!!! I figure if I'm gonna crack my case open for a good blow-out, I might as well check the CMOS battery!!! When I was doing tech work, I'd go to a location and see customers with their tower PC on the floor. WORST place to put a PC....sucks in dust and whatnot!!! Then, if it was a lawyer's office, they'd have crap piled everywhere!!!...pretty much suffocating the airflow to the PC!!! Several times, the pc's contained sooo much dust that the user would complain that the PC was running slow!!! And I'd say...your computer is running slow because the heatsinks are clogged with dust and your processor is throttling down to keep from burning itself out due to lack of free airflow. I would usually get a blank stare in return. 😏
Thanks for sharing
Good info as usual Brain ,keep up the good work.
On some laptops, certainly ones I've used, nothing happens. That's because once the CMOS battery dies any power needed is automatically redirected from the laptop's battery. In that case you only discover the CMOS battery is dead once the laptop battery is removed and you run it off mains power only. But even in that niche case, nothing happens except system date and time needs resetting and any custom BIOS settings are lost.
Thanks. On a refurbished Dell laptop I have it constantly go into "sleep" mode which I suspect is not a CMOS setting but something with the Dell locked BIOS. But maybe it's a CMOS battery? I also thought the CMOS battery was rechargeable but no. BTW the PC I am posting this on has an original CMOS battery that's 14 years old and doing just fine. (Wikipedia): CMOS This battery type, unlike the Lithium-ion battery, is not rechargeable and trying to do so may result in an explosion. Today's UEFI motherboards use NVRAM to store configuration data (NVRAM is a part of the UEFI flash ROM), but by many OEMs' design, the UEFI settings are still lost if the CMOS battery fails.[4][5]
@@raylopez99 How do you mean the laptop constantly goes to sleep? You mean just randomly? That's definitely not a CMOS battery issue. I deal almost exclusively with refurbished Dell laptops as that's my area of interest. Does your laptop have a locked BIOS? You know it's possible to unlock it without the user password. I don't see why any issues would be related to a locked BIOS as all that means is that you can't access it without a password and doesn't itself dictate any power settings. It's certainly a bizarre design decision for settings to still be lost when the CMOS battery dies even though stored on NVRAM.
@@FlyboyHelosim You are saying something very relevant to my ears. Please elaborate if you have time. Yes my Dell E6520 (i5-2520M chip) goes to sleep 'randomly' with the battery in, and with the battery out, it does less so (but on occasion) so I leave the battery in since it's easier to awake it from sleep rather than reboot. Tell me how to unlock the BIOS without the password please, but keep in mind I've heard that if you do it with a "hardware reset" some Dells have it set up so, for security purposes, it trashes the EEPROM (?), urban legend but maybe true so I don't want a hardware reset. Also you last sentence implies that if the CMOS battery dies, since the BIOS is locked, your laptop might die even if you put in a fresh CMOS? Is that true? I did look at the user manual and know where the CMOS is stored, it's behind the WiFi antenna. My philosophy, given shortages in laptops these days, is "if it aint' broke, don't fix it". I use this laptop for storing business data and tho I backup I don't want the PC to die by messing with the CMOS. Any thoughts appreciated. Bye.
Wow 😲this is the video that I exactly want. Nice one mate.
Glad you liked it
My father always measures both votage and milliamps on these batteries because voltage may be right (3v) but if you can also have low milliamps and this causes malfunction too.
It's funny you just now made a video on this topic, as i not more than an week ago had to change my battery. 😁👍
Cool 👍
Funny enough I was looking at my 2032 batteries yesterday thinking how many things actually use them these days including the CMOS haha.
Good info as always
My scales use them as well
my blood glucose meter uses them.
Well done, Brian. Brilliant as always.
Computer BIBLE. A good PC life begin with "CR 2032". Have a nice smooth boot to all.
Thank you kindly!
Why oh why doesn't CMOS do a battery check before loading & detecting all of the computer hardware components? And why doesn't CMOS tell you that the battery life is low and you need to change it soon or the battery has discharged too much and you need to replace it ASAP or you will have problems booting your computer properly? We have all kinds of sensors like SMART for hard drives that can tell you the status of them, fan speed detection, CPU & GPU temps, memory testing at CMOS, etc. But we have nothing going on for a simple battery check? Why this oversight still continues to this day is beyond me and totally inexcusable. For shame, for shame on the engineers of motherboards.
Planned obsolescence?
@@raylopez99 They never planned on implementing this feature.
Usually, unless the BIOS chip is coded really wonky, the computer will know when something isn't right upon boot-up and it will just give you a "CMOS Checksum Error" which basically means data got corrupt in CMOS, and the data (settings) do not match the checksum, thus popping the error message. The #1 reason why this happens is quite simply, a dying battery. I've had this happen in plenty of my PCs, and this is always what has happened, 100% of the time. I've never seen a computer do anything else other than pop the checksum error. Maybe if you're running really cheap motherboards that don't have a CMOS Checksum? That technology has been around since at least the 90s, or maybe even earlier than that, I've had 486 computers that had CMOS Checksums and they all did the same thing when the battery died. Also, how long a battery lasts also depends on whether or not you use the PC regularly. A PC that is in regular use will last far longer than one that is only booted up once in a month, for two reasons: One, Li-Ion batteries last longer if they aren't discharged as much, and Two, if you keep it charged with constant use, it will never have a chance to discharge and it only needs to keep the CMOS running for a few hours. Lastly, if you leave the surge protector your PC is plugged into on, and you leave your PSU on, your PC is not even using the CMOS Battery at all; the PSU is supplying power to the mainboard even while the computer is not actively running. You may wish to turn the PSU off for about 10 seconds and turn it back on before you boot the computer to make sure you have a fresh cold boot, though.
A modern machine with UEFI will never actually show you a "CMOS Checksum Error" from a failing battery, since UEFI stores its configuration data not in CMOS RAM, but instead in a dedicated part of the BIOS flash chip called the variable store; the battery only runs the real-time clock. Gamer motherboards often will clear the variable store if an RTC reset is detected (to ensure that the old technique of "clearing CMOS" by removing the battery still work, even though it has no reason to work anymore), but a dying battery won't corrupt your variable store.
Does a dead /dying CMOS battery cause the mouse and keyboard to suddenly stop working ?
I worked at a company that had a PC based piece of medical equipment.
Whenever we got a unit in from the field, we automatically changed out the battery.
And we carried batteries in the field.
Is it possible for the battery to fall out just by a shaky desk? And Is there a way (without using electrical tape or something) to make sure it stays in place?
Good to know this probably was an issue a few years back that old pc reviving had problems booting - always a spare handy
I was always wondered why don't motherboards use the internet to set time and date in the bios. So when u turn on the pc it asks to connect to the internet and sets the bios and date time and eliminate the battery fully.
Neglecting CMOS warnings by choosing Continue can cause your Antivurus to block access to certain sites like banking, because the date and time is not correct. A pc that is connected 24/7 to mains power is less likely to have issues. I use a standard lifecycle of three years to replace the battery anyway.
Yeah, some batteries don't last long
My mum's computer after a reboot resets the BIOS settings and if I change and save them, it doesn't boot at all, but continue with default ones helps. Old PC but had its battery replaced during maintenance, maybe the battery itself is bad or needs a replacement again?
Thank you very much! A very important and useful video indeed!
Mine is beeping 5 times then the fan starts spinning faster and faster but 5he screen remains black. I've only done very few CMOS battery replacements in the past and I'm not quite sure what I've got going on here?
I just clicked on this out of curiosity because I didn’t know what a cmos battery was and realized that it’s the likely culprit for my repeated boot errors on my ten year old system. I’d just assumed it was my hard drives conflicting at startup but ironically I get the exact issues listed every time I restart it and I’ve just been going through the bios and exiting out just to bypass it lol.
Can dying CMOS Batteries also cause BIOS settings not being changed/saved?
On my previous PC that I used from August 2015 to January 2020 the mainboard started to have issues persisting settings the last year (2019) or so, although booting up wasn't a problem. It once reset to default values after OC instability and then I wasn't able to reconfigure my settings. Only every now and then when taking the battery out for a bit I could set some things IIRC. Unfortunately I didn't get to searching and buying a new CMOS battery and don't remember having checked the voltage (although I was able to), I just worked around this by installing a program for CPU OC from Windows and letting the RAM run at default 1333 MHz instead of the 1866 MHz XMP profile. And then I built a new PC and sold the previous one, so didn't do further troubleshooting.
Could it have been a dying CMOS battery or was it something else going wrong with the mainboard? If so, what could it have been?
Had a power surge recently and my computer wasn't turning on, but the motherboard lights were on (PC was plugged in the power outlet). From the get-go I already knew it wasn't the power supply module, so I started thinking the motherboard had been damaged somewhere. If you're having the same symptoms, I'll save you some precious hours of anxiety: try reseating the CMOS battery, because it worked for me.
worth to mention that a new motherboard can also have q dying cmos battery like mine did and i couldnt figure it out till i stumbled on your video
You don't have to remove the battery to test. The + is on the top so touch red lead to top and black lead to metal chassis
I came here wondering if this might explain why my pc recently started spontaneously restarting (as in as if the reset switch had been pressed), seemingly at random in the last few days, until eventually while I was trying different possible solutions it stopped displaying the motherboard splashscreen at all and is now completely unresponsive. No beeps either, but it never did beep on startup.
Clearly based on this it's not the CMOS battery, but since I'm here I thought I would ask for advice anyway.
While it was restarting I tried various power setting suggestions in windows, and also disconnected the power and reset switches in case they were responsible. Then when it no longer booted up at all I tried unplugging all non-essential usb devices, reseating the memory and graphics card, and even resetting CMOS.
The next thing I will do is get hold of an adaptor to allow me to view my main hard disc from my laptop and at least recover the last few days' worth of work that I did between this failure and my last backup, but before I resort to buying a new motherboard and/or anything else, I would welcome any suggestions. Thanks!
Did you figure it out? I had PC restart due to overheating I think... lowering PSU load on graphics card let it work without rebooting itself. Like in MSI afterburner lowered power use from 110% to 70.
Thank you for the clarity, showing 2.84v on my multimeter and the system won't boot at all so I'm away to the shops 😂❤
i've noticed mostly on msi motherboards that it gets glitchy during POST or does not POST entirely. also, after replacing the cmos batter and the issue persist, usually its the clock crystal that needs replacement.
I'm pretty good with computers and I've always thought that a failing CMOS battery would just show the error messages shown in this video. I learned that it isn't true even for fairly recent mobos because a dying CMOS battery caused my PC from turning on in the first place. The mobo is an Asus ROG Maximus VIII with an i7-6700K and is around 7 years old or so.
First error that occurred was double booting (PC turns on for several seconds, shuts down, then turns on again during POST) while on XMP. I encountered this problem ages ago and the Asus forums always claim that this is "normal" as part of memory training but I managed to solve this by fiddling with some obscure BIOS setting. I was surprised that the problem returned, but noticed that if I didn't turn off the power to the system completely the double boot didn't occur. After a while, there were times when the system refused to power on and it progressed to the point it wouldn't power on at all no matter how many times I pressed the power button. I tried doing a BIOS flashback twice and it didn't solve the problem. I thought it was a motherboard problem so I started using my laptop instead while searching for a second-hand mobo. After around a week I had decided to try turning on the PC and I was surprised that it did, although it didn't last and refused to turn on again later. At this point I realized that the errors that occurred in the beginning might be from a failing CMOS battery. I removed the battery and tested the voltage with my multimeter which showed a reading below 1 volt. After replaced the 2032 battery all the problems disappeared.
To make the long story short, if there's anything weird happening at the POST level always consider the CMOS battery. It took me a long time to figure it out because I always had the notion that PCs should be able to boot even without a CMOS battery, you'd just have to enter the correct BIOS setting every time. Unfortunately this isn't true; it's just surprising that the dead battery = no power on would happen in an upper-tier mobo that isn't very old.
i have lenovo g500s , 8years old. its only turn on when i put it on sunlight for 4hours . i thing my cmos bettery is dying
@@Vasant8300 Maybe it's solar powered 🌞. Kidding aside, you should first check if the laptop has a CMOS battery to begin with. Some don't, especially models that have non-removable batteries.
when i press power , logo come for 2 sec and then black screen , laptop both led glowing harddisk running, but no display
@@Vasant8300 That seems like a hardware issue since it's occurring very early, specifically during POST (power on self-test). If I had to guess, it's likely a failing motherboard. Since it's a very old model (the CPU is an Intel 3rd generation processor) I doubt replacement motherboards are still available. I suggest you just invest in a new laptop and migrate all your data from the old laptop to the new one. If buying a new laptop isn't an option then last resort would be board-level component repair.
today again i placed my back of laptop in sunlight for warm it , and it turn on normally ,please can u hrlp me why it happen. and when i turn it off for night it then in morning no display comr
Great video Brian, quick question. Recently when I boot up my pc it goes to boot then the power goes off and comes back on a few seconds later and it says the pc was not turned off correctly and have to go into my bios to boot my pc up. Is this a CMOS battery problem in your opinion?
Cheers
Lee.
Yes. Exactly the same symptoms on my PC. Resolved by installing a new battery.
@@deere3350 Yeah I fixed it with a new battery as well.
Without Evan Watching the video. Your clock starts to show the wrong time . For one calendar gets wonky. Stuff starts to slow down or you have issues with accessing the drives kits an allover breakdown of your main board systems . Thank God most of the 2032 battery's are replaceable. Some you have to desolder. Oh your random access memory is linked to the cmos battery. That's if I rember it correctly I grafuated IT school in 03 been a while lol
Hi Brian,
I have an old computer which I haven't started for about 2 years old. Should I change the CMOS battery before I boot it up since it hasn't been powered on in 2 years?
Thanks to this video I was able to diagnose a cmos battery that was causing the processor to beep
My PC was turning off out of nowhere all of a sudden and one day the PC would refuse to boot. The PC would turn on and the case fans were spinning but the CPU, GPU, and exhaust fans werent. Replaced the CMOS battery and it rebooted a couple times then worked like a charm. Never knew these things could die on you. Been using the same motherboard for about 5 years.
Can a dead battery cause the entire pc to not turn on? (I got a old toshiba laptop that i never got bother to try change the battery to see if it would turn back on)
Hello, please I've been having the same issue and inserted a new CMOS battery but it does not work and my computer always bootup by it self when I switch on the power socket on the wall. Pls I need help.
I have the same problem haven't changed the cmas battery yet but it boot itself everytime!
Even if CMOS dies (or we take it off), we don't lose the Windows 10 activation license, right?
No you don't
Britec my pc is showing its loading but doesn't do anything its just loading can resetting cmos fix it?
Another question, does the battery stay charged or receive a charge when PC is on?
The battery is not rechargeable
I had a Packard Bell system bought in Portugal 10 years ago. Recently built a new system but the PB was working fine since new. Battery lasted through all the moves etc. Came back to UK 5 years ago.
Ok, great topic Brian. But I'm curious that after all these years and with technology advanced, why are we still using stupid batteries? I mean the bios and system settings are stored correct?
We use ssd's, flash drives etc. So again why are we still relying on a battery to hold that information in?
Just curious. 🤔
Ok, RTC "real time clock" so essentially it's like watch.
This is too much info for me, but thanks for reminding me to change batteries in both mine and my mum's computer!
i have a problem where my pc sometimes boots normally and sometimes it beeps and show the no memory detected what can i do to fix it pls help me and I'm sure it's not the ram i tested it
So I have a question I updated my bios and on my monitor it said it got my bios settings to default and I was supposed to change customised it back. Next every time I push to start the pc , it starts then goes off and again on by itself. What issue is that ? Cmos or something else?
Hi once you reset the Bios by removing the cmos battery do you then have to update the bios again?
My parent's computer show a "cmos checksum error or cmos battery loss, default bios config loaded" message after EVERY power outage (then i press F1 to continue and all is dandy), could it be that this battery needs a changing?
dear sir. I forget to put my CMOS battery back. but my desktop PC running very well. do I need to put it back or is its o.k PC running without a CMOS battery? thank you. have a good one.
Depends on your OEM and design. Wikipedia-- This battery type, unlike the Lithium-ion battery, is not rechargeable and trying to do so may result in an explosion. Today's UEFI motherboards use NVRAM to store configuration data (NVRAM is a part of the UEFI flash ROM), but by many OEMs' design, the UEFI settings are still lost if the CMOS battery fails.[4][5]
thank you sir.
@@quintusupalifullhdgaming450 I'm no expert but if you use your PC everyday perhaps the static ram, which is what the CMOS battery prevents from discharging, will not discharge as it will get energy from the main power supply when the PC is on. Just a guess. Good luck and always backup your data.
thank you sir.
Excellent. Thank you. Cheers, Harry.
My motherboard sudden started to boot up slowly the other day. It went from starting up right away, and now it takes like a minute for it to boot up and then go right into loading windows. Would a dying battery do this?
thank you so much for this video, king. i think this is whats causing me trouble
What if when you press F2 or Del the screen turns black and stays that way? Would the battery dying cause that?
My serverboard boots up all the way to the windows startup you could hear the windows startup sound but no display output...could that also be due to CMOS battery?
What happens is a lot of people think as long as the computer is plugged in that it should be OK and that the battery is just their for when the computer is unplugged.
Well, that's what I thought! I was today years old when I learned what it was for!!
Hi..I can't access my bios in startup is there anything to do with my CMOS battery?I think my CMOS battery is dead I not replace it yet.
didnt even know tthis was a thing!! thanks alot!, do the battery have to be a specific size. or all they all the right size to fit into any motherboad.. my motherbaord is a AsRock B450 Pro4
They all have the same size.
hi . can i change the battery with the computer running ? that way the bios won't need to be reset? or is there any other way around resetting the bios with computer off? cheers
What if it's just the disks, fan header? Time and bios settings are the same.
I have an old computer, it's 18 years old now. The original battery was completely dead when I got it 7 years ago. It didn't even detected the SATA HDD at this state, when it was plugged in it said "hardware initialization failure". It worked with an IDE disk, however. I've replaced the battery, the computer was in everyday use for about 2 years, then it got unplugged for 4 years before I turned it to a retro gaming PC as my modern PC can't run my old favorites. I measured 2.7 Volts on the battery but it still works, the clock was only about 10 minutes behind after 4 years without power and it recognize the SATA HDD as well. Maybe time to replace? I started to have issues with another PC when the battery measured 1.1 Volt. It's always plugged in now so it should't drain too fast.
What CPU air cooler model is Britec09 using in this video?
Is there a way to backup your bios settings? I heard that if you change it within 5 seconds you won't lose the settings. Is that true?
My 2013 alienware laptop keeps shutting down from "low battery charge" even if the battery level is charged at 90%. Do you think the CMOS battery is the culprit or the main battery just toasted?
I plugged in a 970 evo into my hdd cable on my PC (dumb move i know) and now the pc wont even boot bios, could the ssd have somehow shorted my cmos battery?
My PC doesn't starts, although it has power in it. CPU fan case fan, nothing starts. I tried everything, like jumpstart, removing and reinstalling the CMOS battery etc. But it still doesn't work. Actually my pc wasn't been used for a month, and this problem happened. Than I turned on the pc by reinstalling the CMOS battery, and it worked. I used to do that almost every day for almost a month, whenever I face this problem. But today that trick isn't working. Now what should I do? Should I buy another CMOS battery, or it's not the problem of CMOS battery?
would it shut my laptop off from seemingly nowhere when gaming in a major game like maybe beamng drive?
My pc acts strange. i can run my os, but when it comes to restart, it doesn't turn back on unless i power off psu for a bit . Now, if i try and save and exit in bios, it shuts off, but something does go back on, so i turn off psu for a bit, turn back on, bios, and nothing saved
Cmos battery can cause your computer to turn on but screen stays black
I have an old windows XP computer that can't detect the hard drive or the disk drive in the bios and thus wont boot to windows; is this caused by the cmos battery being dead?
Can a dead CMOS also make it so your PC wants to restart like its going through a Windows update, just no update?
with out removing the battery on HWinfo on VBAT is the same ? to read the battery ?
I didn't know that, would the same happen with laptops too? Cause my omen 17 was only 1 day old technically when I first started using it and it refuse to start up after battery running very low
What about laptops? Do they show similar or smh else?
Laptops often don't show any signs of a dead or dying CMOS battery because they can draw the needed power from the actual laptop battery.
What i think i experienced with pc's i had (cant recall if it was with cmos battery dying, but i think so) is that its important to set the time correct,
am i totally out biking on this or kinda right?
Does the cmos battery need to be replace while the power on or off?
When i pull the plug out of the wall (after turning the switch off), i get an error each time on bootup next time i start the pc (after plugging things in again.) I want to be able to unplug it from wall because of power surges ive tried and there will be more in the future. So will changing the CMOS battery help avoid this error? Or am i just wasting my time and taking EDS risks with changing it?
Britec09 can you leave a link to the tester you used in the video or recommend at tester please.
It's just a simple voltage reading so any multimeter (even a cheap analog one) will do. There are tons of options from online platforms or you can buy from your hardware store.
@@Vendemiair ok thanks
@@Shiv.141 By the way I forgot to mention just go for a cheap digital one because they're easier to read rather than analog ones with a dial. The CMOS battery of my PC recently died (lasted ~7 years) and I confirmed it with a voltage reading of less than 1 volt (I think it was just 0.7 V or so). It's not absolutely necessary though to confirm a dead battery with a multimeter since you can just pop in a new CR 2032 which is very cheap. I just happened to have one because I occasionally work with electronics.
@@Vendemiair yes I want to get one it a helpful tool.
I broke my Cmos socket on build im in process of doing one end come off the one opposite the one opposite the plus sign. Just waiting for ram to be delivered but worried pc will not post because of cmos battery holder being damaged?
Is panasonic 2032 good enough
Good informative video!
Great topic. 👌
Glad you think so!
My prev cmos battery showing above 3V but my pc freezing when playing game,and boot to bios and not showing my SSD M.2,after i replace ne battery,i hv no longer experience with pc freezing and blue screen,my conclusions is,just replace the battery,even its looks still "okay"
Same Problem I Will Try
Thx 🌹
Love From India 💯🙌🏾
Brother could you please help. I have an error in my system. My pc turns on and even boots into windows 10. But after a couple of hrs approx 1 or even 1 and a half hours of usage and even idle my pc's display goes no signal. But all other components in my pc are running the hdd the processor the rams the GPU the keyboard the mouse etc. What might be the problem with my pc. I am not able to find which component of my pc is dying or should be replaced
Shouldn't you have reset the CMOS while the battery was out?
No point if the battery is out the data is wiped anyway
when i turn on my PC its taking too long on the motherboard's loading screen like 7-10mins before booting up the windows OS, is this also a cause of battery failure??
i have a problem with no display but my pc is turning on, also no lights on keyboard and mouse. Is it possible that the cmos battery is at fault?
Sir I have a similar problem coming again " Time of the day not set - pleas run the program" this happens when I start after shut down. Dell G3 1790 core I 7 9th Gen. May I change my CMOS
I recently had an issue where I tried to install a dual boot OS (Linux on Windows) but I had an issue with it during installation and when trying to fix it my PC seemed to have just stopped working. I was able to fix it by removing some RAM but do you think it's the CMOS?
I've noticed since I've fixed it my PC still doesn't boot properly. Sometimes it powers up, then off, then up, then off etc.
Other times I get rapid beeping and no boot
Other times I get power up and some little ticks. I suppose it could be the CMOS?
After 2 years of my using my new gaming PC. Mother board Asus Darkhero VIII . I got error message when booting: Please enter setup to recover BIOS settings. Press F1 to run Setup. I have replaced the CMOS battery with new one still get this problem. If I leave my computer unplugged for 4 weeks I loose the system date and time after changing the batttery is this normal? How can I fix this issue?
For some reason sometimes my pc wont turn on
so i mash the turn on button and flick on and off the psu switch
what is that about ?