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CMOS battery-how long its life?

X200/X201/X220 (including equivalent tablet models) and X300/X301 series specific matters only.
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CMOS battery-how long its life?

#1 Post by Nasikh » Wed Jan 22, 2020 10:21 pm

I have been using my X220 since 2011 (9 years), at least 95% of the time in an Ultrabase 3 (i.e., on AC) with the battery in the machine. To this day, I have never seen any sign that the CMOS battery is not working. How long can I expect it to last, given that almost all the time I am working on AC? Should I put in a new one, preemptively, before the original one dies?

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Re: CMOS battery-how long its life?

#2 Post by RealBlackStuff » Thu Jan 23, 2020 4:16 am

The usual CMOS life expectancy is about 5 years, but can be a lot longer.
As long as the voltage is between ~2.95V and ~3.3V, you're good to go.
If/when you replace it, check that there is no password set in BIOS (or that you know it)!
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Re: CMOS battery-how long its life?

#3 Post by MikalE » Thu Jan 23, 2020 10:28 am

As far as I know the battery in my T520 has never been replaced either and it's still ticking along. That goes for my two T510's and T500 too.
A31p P-IV 2Ghz, 2MB, 2653-R6U
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T510 i5 4384-DV7
T510 i7 4349-A64
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Re: CMOS battery-how long its life?

#4 Post by w0qj » Thu Jan 23, 2020 1:07 pm

The CMOS battery in our T410 is ticking alive and well ;)

From our empirical observations, it is when you fully discharge your main battery, and then let your computer sit there unused (and unplugged) for months at a time.
ie: computer uses the CMOS battery to maintain itself.
That's when your CMOS battery is in danger. Just our two cents.
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Re: CMOS battery-how long its life?

#5 Post by kfzhu1229 » Thu Jan 23, 2020 3:23 pm

The CMOS battery of my T42 and T43/p's all died about 1-2 years ago. So about 12-13 years in my usage.
Dell Lat CP MMX-233 64mb 40gb W2k
600 PII-266 416mb 40gb WXP
T23 PIII 1.13ghz 1gb W7
Lat D830 X9000 8gb 128gb WSXGA+ Ultrasharp fp W10
T530i 15.6" i7 16gb fp W10
A30p PIII 1.2 1gb W7 (IDTech)
T43p 2.26 2gb fp W10 (Sharp)
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