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#1
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Bad CMOS Battery
After buying a couple of 2032 cmos batteries last year to replace the
one in my 5-year old build. I sprung for a new build including an ASUS Z97Pro series motherboard. Put that together in August 2014. recently, the new build began losing time, ie the time would continue to display the time that the system was last turned off. After resetting it a few times and playing with the choice of Internet Time servers displayed in Win7, I finally replaced the alledgedly 4 month old CMOS battery. Life is good and now time marches on. ONLY 4 MONTHS ON A CMOS BATTERY?? T2 |
#2
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Bad CMOS Battery
On 12/19/2014 10:58 PM, MrTsquare wrote:
After buying a couple of 2032 cmos batteries last year to replace the one in my 5-year old build. I sprung for a new build including an ASUS Z97Pro series motherboard. Put that together in August 2014. recently, the new build began losing time, ie the time would continue to display the time that the system was last turned off. After resetting it a few times and playing with the choice of Internet Time servers displayed in Win7, I finally replaced the alledgedly 4 month old CMOS battery. Life is good and now time marches on. ONLY 4 MONTHS ON A CMOS BATTERY?? T2 I have been having the same problem with the ones I use at work. I have them installed in electronic measuring devices and they just don't last as long as they use to. http://www.amazon.com/Panther-Power-.../dp/B002T8Q5EQ |
#3
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Bad CMOS Battery
MrTsquare wrote:
After buying a couple of 2032 cmos batteries last year to replace the one in my 5-year old build. I sprung for a new build including an ASUS Z97Pro series motherboard. Put that together in August 2014. recently, the new build began losing time, ie the time would continue to display the time that the system was last turned off. After resetting it a few times and playing with the choice of Internet Time servers displayed in Win7, I finally replaced the alledgedly 4 month old CMOS battery. Life is good and now time marches on. ONLY 4 MONTHS ON A CMOS BATTERY?? T2 The important thing, is to keep track of how long the new ones last. Long term, you may decide the motherboard has a problem. ******* The battery should last a little less than 3 years, if the PC is kept unplugged all the time (24 hours a day). If you run the PC 16 hours a day, and unplug each day for 8 hours, then you'd expect 9 years (or getting closer to the 10 year shelf life). If the PC has +5VSB (motherboard green LED lit all the time, whether sleep/hibernate/run), then there is no excuse for less than ten years from the battery. In other words, if you don't switch off at the back or unplug each day, the +5VSB provides the clock current and not the battery. The Asus motherboard box has a "Serial number" on the outside sticker. The first two characters of the serial number are the manufacturer date. My last purchase was "E4..........", which would be 2014 May or so. So I know my CMOS battery, even if the PC is left unplugged, the battery should last another two years minimum. These numbers are only approximate. They assume the Southbridge CMOS well draws maybe 10 microamps or so. The CMOS battery is only used, if the +5VSB is not running (the +5VSB runs that green LED on the Asus motherboard surface and is proof the supervisory circuits have power). If you place the "Clear CMOS" jumper in the wrong position, that could drain the battery. But you would figure that out, based on how that messed up the settings. If the motherboard has an electrical fault in that section of the design, and draws more than 10 microamps, that too could flatten the battery. There have been some defective motherboards, where they drained one battery after another, in short order. And it's some sort of motherboard problem. And that's why this is a "wait and see" situation. If each and every battery only lasts four months, then you'd suspect excessive current draw from that battery. You cannot draw more than 3000 microamps from the battery at any one time. There is a 1K ohm series resistor to the battery, which limits current flow. And that seems to be there for some sort of safety reason, is all I can figure. So at least you know the drain rate cannot exceed more than 300x the normal rate :-) The battery should last at least one day, even with the worst of luck. Paul |
#4
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Bad CMOS Battery
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#6
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Bad CMOS Battery
In article , says...
MrTsquare wrote: In article , says... MrTsquare wrote: After buying a couple of 2032 cmos batteries last year to replace the one in my 5-year old build. I sprung for a new build including an ASUS Z97Pro series motherboard. Put that together in August 2014. recently, the new build began losing time, ie the time would continue to display the time that the system was last turned off. After resetting it a few times and playing with the choice of Internet Time servers displayed in Win7, I finally replaced the alledgedly 4 month old CMOS battery. Life is good and now time marches on. ONLY 4 MONTHS ON A CMOS BATTERY?? T2 The important thing, is to keep track of how long the new ones last. Long term, you may decide the motherboard has a problem. ******* The battery should last a little less than 3 years, if the PC is kept unplugged all the time (24 hours a day). If you run the PC 16 hours a day, and unplug each day for 8 hours, then you'd expect 9 years (or getting closer to the 10 year shelf life). If the PC has +5VSB (motherboard green LED lit all the time, whether sleep/hibernate/run), then there is no excuse for less than ten years from the battery. In other words, if you don't switch off at the back or unplug each day, the +5VSB provides the clock current and not the battery. The Asus motherboard box has a "Serial number" on the outside sticker. The first two characters of the serial number are the manufacturer date. My last purchase was "E4..........", which would be 2014 May or so. So I know my CMOS battery, even if the PC is left unplugged, the battery should last another two years minimum. These numbers are only approximate. They assume the Southbridge CMOS well draws maybe 10 microamps or so. The CMOS battery is only used, if the +5VSB is not running (the +5VSB runs that green LED on the Asus motherboard surface and is proof the supervisory circuits have power). If you place the "Clear CMOS" jumper in the wrong position, that could drain the battery. But you would figure that out, based on how that messed up the settings. If the motherboard has an electrical fault in that section of the design, and draws more than 10 microamps, that too could flatten the battery. There have been some defective motherboards, where they drained one battery after another, in short order. Well at least its nice to have a "canary" like the time display to tell you its time to replace. Concerning the green light... After reading the right section of the book and powering down to verify, the Z97pro has a little "Power On" red light/push button right below the CMOS battery that performs the safety feature you discribed as well as the ability to "kitchen table" turn on test the MB. T2 |
#7
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Bad CMOS Battery
MrTsquare wrote:
In article , says... MrTsquare wrote: In article , says... MrTsquare wrote: After buying a couple of 2032 cmos batteries last year to replace the one in my 5-year old build. I sprung for a new build including an ASUS Z97Pro series motherboard. Put that together in August 2014. recently, the new build began losing time, ie the time would continue to display the time that the system was last turned off. After resetting it a few times and playing with the choice of Internet Time servers displayed in Win7, I finally replaced the alledgedly 4 month old CMOS battery. Life is good and now time marches on. ONLY 4 MONTHS ON A CMOS BATTERY?? T2 The important thing, is to keep track of how long the new ones last. Long term, you may decide the motherboard has a problem. ******* The battery should last a little less than 3 years, if the PC is kept unplugged all the time (24 hours a day). If you run the PC 16 hours a day, and unplug each day for 8 hours, then you'd expect 9 years (or getting closer to the 10 year shelf life). If the PC has +5VSB (motherboard green LED lit all the time, whether sleep/hibernate/run), then there is no excuse for less than ten years from the battery. In other words, if you don't switch off at the back or unplug each day, the +5VSB provides the clock current and not the battery. The Asus motherboard box has a "Serial number" on the outside sticker. The first two characters of the serial number are the manufacturer date. My last purchase was "E4..........", which would be 2014 May or so. So I know my CMOS battery, even if the PC is left unplugged, the battery should last another two years minimum. These numbers are only approximate. They assume the Southbridge CMOS well draws maybe 10 microamps or so. The CMOS battery is only used, if the +5VSB is not running (the +5VSB runs that green LED on the Asus motherboard surface and is proof the supervisory circuits have power). If you place the "Clear CMOS" jumper in the wrong position, that could drain the battery. But you would figure that out, based on how that messed up the settings. If the motherboard has an electrical fault in that section of the design, and draws more than 10 microamps, that too could flatten the battery. There have been some defective motherboards, where they drained one battery after another, in short order. Well at least its nice to have a "canary" like the time display to tell you its time to replace. Concerning the green light... After reading the right section of the book and powering down to verify, the Z97pro has a little "Power On" red light/push button right below the CMOS battery that performs the safety feature you discribed as well as the ability to "kitchen table" turn on test the MB. T2 Interesting. So the ole Green LED got the boot :-) It used to be a T-1 3/4 sized LED, which is a bit out of style now. The surface mount LEDs would be more popular with the staff on the soldering equipment (reflow machine). I downloaded the manual, but missed the illuminated switch detail. I was scanning for a "LED" feature. Paul |
#8
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Bad CMOS Battery
I have built and bought dozens of PCs over the last 20 years.
I have had at least 3 PCs with this problem, they were LGA775 or LGA1156 boards, but different makes. The battery would go flat after a few months. So eventually it would boot up and say I have lost my settings, hit FX to load failsafe defaults and continue or something like that. I replaced with known new good batteries and they expired too. Yet these same boards had no other flaws at all. So I am puzzled what sort of fault causes this. |
#9
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Bad CMOS Battery
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#10
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Bad CMOS Battery
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