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Need advice from experts for an oscilloscope cmos battery replacement

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mohkam

New Member
My MTX 3352 digital oscilloscope cmos battery got low and need replacement.

Original battery specs : varta brand Li-Manganese dioxide With PCB solder tags
1/2 AA 3V-950mah, non-rechargeable battery.

Found available on the market : NX brand Lithium-thionyl chloride ER14250 1/2 AA 3.6V 1.2Ah PP (Ref : PCL9005) without solder tags.

Question : Is it risky to use the 3.6V 1.2Ah battery instead of the 3V-950mah ?
If so, do I need to use a diode to drop the +0.7V excess and then what about the +250mah ?
Or is there any simpler and more efficient circuit to fit the 3.6V without risk for my oscilloscope.

Thanks
 

dknguyen

Well-Known Member
Most Helpful Member
10% difference. I would assume that's okay. I certainly wouldn't worry about it if it was any other kind of circuit but there might be something about CMOS battery backups that I am unaware of.

Wow. The discharge curves for Lithium-thionyl chloride chemistry look amazing. Most people would have trouble hand-drawing a rectangle better than the graph is.
 

mohkam

New Member
10% difference. I would assume that's okay. I certainly wouldn't worry about it if it was any other kind of circuit but there might be something about CMOS battery backups that I am unaware of.

Wow. The discharge curves for Lithium-thionyl chloride chemistry look amazing. Most people would have trouble hand-drawing a rectangle better than the graph is.
Thanks for your quick reply.
Please note that difference is 20% 3.6V instead of 3v !
 

audioguru

Well-Known Member
Most Helpful Member
The voltage curves and rated capacity for those new batteries are for very low currents.
They are crazy to make AAA, AA, C and D normal sizes for these high voltage batteries. The 18650 Lithium high voltage battery will not fit in an AA battery holder to prevent overvoltage to a product.
 

ChrisP58

Well-Known Member
Most Helpful Member
What you want is a CR14250. Which is a 3 Volt Lithium Manganese battery, 1/2 AA package.
 

gophert

Well-Known Member
Most Helpful Member
10% difference. I would assume that's okay. I certainly wouldn't worry about it if it was any other kind of circuit but there might be something about CMOS battery backups that I am unaware of.

Wow. The discharge curves for Lithium-thionyl chloride chemistry look amazing. Most people would have trouble hand-drawing a rectangle better than the graph is.
I calculate 3.6V to be 20% more than 3V.

My MTX 3352 digital oscilloscope cmos battery got low and need replacement.

Original battery specs : varta brand Li-Manganese dioxide With PCB solder tags
1/2 AA 3V-950mah, non-rechargeable battery.

Found available on the market : NX brand Lithium-thionyl chloride ER14250 1/2 AA 3.6V 1.2Ah PP (Ref : PCL9005) without solder tags.

Question : Is it risky to use the 3.6V 1.2Ah battery instead of the 3V-950mah ?
If so, do I need to use a diode to drop the +0.7V excess and then what about the +250mah ?
Or is there any simpler and more efficient circuit to fit the 3.6V without risk for my oscilloscope.

Thanks
The Lithium thionyl chloride have exceptionally long shelf life. They are to intended for any significant current and overheating one can cause a problem you don't want to deal with. The thionyl chloride is a liquid that is reactive with humidity that forms HCl gas and SO2 gas as the reaction products. I know the guys at the biggest manacturer of these batteries and they claim they are safe when used in appropriate applications. In other words, make damn sure you know what appropriate means.
 

audioguru

Well-Known Member
Most Helpful Member
The spec's I found were for a cheap Chinese ER14250 battery that did not say its length is 1/2 an ordinary AA size, it simply said "AA".
Nobody has found one with solder tags.
 

mohkam

New Member
I wish to thank every contributor.

Problem was solved by soldering a 3V Li-Manganese dioxide battery 1200A instead of the 3V-950mah with PCB solder tags, and gluing the battery to the mobo for better security.

Please note that the initial issue was my oscilloscope refused to turn on : it always went to sleep mode, when switched on. Replacing the cmos battery solved the issue. This might help others having same problem.
 

large_ghostman

Well-Known Member
Most Helpful Member
Dont care what people say, Lithium-thionyl chloride int something i would trust in my house. Nuclear reactors are a good power source but again not in my backyard thx. Seriouly though, Thats some combination of chemicals to have in a battery!
 
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