Metal finishing Q&As since 1989

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Coin cell batteries rust in refrigerated service

2005

Hello all,

I have three questions all related to some coin cell batteries (type CR2032 from China) that have been reported to us as rusting. They are being used in a refrigerated environment.

First, I was told by a supplier in China that the battery contacts were made from "Stainless Steel plated copper". Has anyone heard of such a plating process? If so where can I find some information (Google is not helping). I imagine that they meant nickel plate, or maybe chrome plate. I suspect that the contacts are actually nickel or zinc plated steel.

Second, I have been investigating the finish used on the battery cases. It is my understanding that these are made from nickel plated stainless steel (Nickel plate apparently improves solderability and lubricity. Must be why the little suckers are so slippery). Does anyone have any information to the contrary? Is it possible that Chinese batteries use different materials versus say Japanese batteries?

Third, the rust is described as typical red rust. It is my understanding that this is possible only with the presence of iron (thus creating iron oxides, rust). Does nickel plate rust? I just can't understand the presence of rust unless something is made from carbon steel.

Actually, I have a fourth question. Where can one buy a small quantity of Nitric Acid? I would like to test the parts I have to verify they are stainless steel.

Thanks in advance for any insight you may be able to offer.

David Seebauer
- Watertown, Connecticut

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David It is likely , with red rust as an indicator, one could consider mild steel plated with nickel as a possible direction. Find a lab nearby to qualify this point. Copper is plated over mild steel before Nickel. Thats a common technique. Regards Asif Nurie [deceased] - New Delhi, India With deep regret we sadly advise that Asif passed away on Jan 24, 2016 Hello Mr David, I was intrigued and tested some Chinese pencil batteries here. The caps were made of mild steel and were nickel plated. Indian battery manufacturers use this steel and nickel combo too. Some use Brass and Nickel. Some just Tin plated steel as well. Khozem Vahaanwala Saify Ind Bengaluru, Karnataka, India