Ever wondered what happens if your CMOS battery fails? Most of us know that the CMOS settings are retained whenever the PC is powered, but what happens when you turn off the PC? Will those CMOS settings just go poof? Or will they remain intact as long as the power supply remains turned on? Believe it or not, no one knew for sure, so iModAMD decided to test a few motherboards and find out. Link : ED#98 : What Happens When The CMOS Battery Fails?
Did you leave the batterys out for the same ammount of time on each board, I was always told that all boards would loose their CMOS data after about 10-15 minutes of having no battery. Other then that Great article
Wow, that's a special review! Thanks! I still remember the most notorious CMOS battery ever - where they are SOLDERED onto the motherboard.
Nice pun, Mack Daddy, 386SUX processor... Personally I once HAD a 486DX-33 system with that barrel-shape battery SOLDERED onto the board. The most annoying part is, not more than 3 yrs after the purchase (purchased in 94) and the computer started having alzhiemer diesease, where it forgets and forgets and forgets the time, date and the other settings. And I have to everytime auto-detect the HDD, or else it won't enter Win95... hahah! I loved these coin-shaped batteries, they are obtainable even in convenience stores, 24/7.
I have an athlon xp system with that problem. But as long as it's connected to the power it won't lose settings. Leaving it off for long periods of time butchered the battery.
one thing i realized when the battery's dead is that the system won't boot. on my ASUS P5LD2 SE, there's the usual 1 beep, but that's it. the monitor receives no response at all.
Yeah, it should at least boot up to the main BIOS screen before informing you the BIOS settings are incorrect and you need to change them.
And there you have the follow up article. Which boards will BOOT with a dead CMOS battery. I can confirm there are lots of motherboards that will not boot with a dead battery. The worst of which give NO indication at all what is wrong. There are some boards where you get no beep, no video, nothing. I bet a ton of motherboards like that have been replaced because people thought the mobo died when all that it needed was a battery. I can remember my first experience with this was a long time ago back in the 486 days. In my case I was doing cable modem installations for the local cable company back then. I went to this house and the computer was sitting there running when I arrived and everything seemed fine. I had to turn it off to install a network card. Back in those days very few computers had built in network cards. So I unplug it, slap in the card and try to power it up and nothing, computer was dead. The customer was not happy, accused me of breaking the computer etc. So we had to take the computer in to have it repaired. Good thing we found a good computer tech who recognized that it just needed a battery and not an entirely new motherboard. Customer got the computer fixed for free even though the condition turned out to be pre-existing.
That would really suck. But even back when I had my 386, it would still boot up as the BIOS just resets to its defaults when the battery goes dead. I just have to keep adjusting the BIOS settings everytime I cold boot it.
Yearly battery changes I've had issues with some "Tomato" brand boards that I've had to change the battery yearly. Boards were ATX hooked to ATX PSUs which were always connected to AC. The systems were used 8-12 hours/day, 6days/week. The users just kept calling me that the system gives errors on start-up. The 1st time I had this problem, I updated BIOS setting and everything was ok...until the next morning. Only the 3rd morning I actually tried to change the battery, because I never expected a 1-year-old system to drain the battery.
Wow, that's a really short livespan. Usually the battery would last a few years since it's trickle charged as long as there is power to the PSU.