Looking for a CMOS Battery for old DOS computer

Myronazz

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Sep 5, 2016
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Hello,

My old DOS computer has a dead CMOS battery, i have no idea where to find one
Here is what it looks like

s4Hk2hN.jpg


Can i find this anywhere, or am i stuck with no CMOS battery?
 
Solution
Many year's ago I worked on a desktop PC that used a proprietary battery like the picture showed. I did not feel like tracking down the same kind of battery for the computer. So I made a quick trip to RadioShack and ended up buying a battery holder and bought a 3.5v battery for it as well.

At that point I got the connector off the old battery. Then I soldered the connector on to the new battery holder and connected it to the motherboard like it was before. It worked like a charm without any problems at all.

Myronazz

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Sep 5, 2016
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Are you saying that i can open up that little box and replace the battery it has inside with a 18650 cell?
If so that will be so real convenient
 

HamBown81

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Aug 3, 2017
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The voltage is nearly the same but it may not be that straightforward.

Why not just order one (or more) of the direct replacements from Amazon?
 

InvalidError

Titan
Moderator

The wires are most likely soldered to the cell, you'll have to cobble up your own wire attachment method.

Voltage-wise, use a multimeter to measure the voltage at the RTC when power is on. That will usually be 5V (from 5VSB on ATX motherboards) diode-OR'd with the battery so you get 2.5-3.5V at the RTC when it is on the battery depending on remaining battery charge and 4.5V when power is on.
 

Myronazz

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Sep 5, 2016
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Hey guys, sorry for the extremely late reply
can i rig a Mn O2-Li cell to it? or does it have to be a 18650 cell

i can't order any of the replacements above due to them being from the U.S
And its usually expensive to import items from the U.S to Greece
 

iantigone

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Sep 11, 2017
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Many year's ago I worked on a desktop PC that used a proprietary battery like the picture showed. I did not feel like tracking down the same kind of battery for the computer. So I made a quick trip to RadioShack and ended up buying a battery holder and bought a 3.5v battery for it as well.

At that point I got the connector off the old battery. Then I soldered the connector on to the new battery holder and connected it to the motherboard like it was before. It worked like a charm without any problems at all.
 
Solution

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