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Electrical resistance of chrome plating

February 15, 2008

We have designed some battery contacts in gold plated brass but have a customer who wishes to have a chrome (bright silver) finish for cosmetic purposes.

Will chrome plating have an adverse effect on the electrical resistance? It is very important that the resistance is kept as low as possible to guarantee good electrical contact and maximise current flow.

If chrome will significantly increase the resistance are there any durable finishes of similar appearance that are suitable.

Geoff Goldsmith
product designer - Milford Haven, Pembrokeshire, UK

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Chrome is probably not a good finish for this but electroless nickel probably is, and it has a nice bright finish. You'll see electroless nickel on battery charging terminals on cordless phones, the battery terminals on watches, etc. Remember, however, that only precious metals are immune to tarnish; so, for critical very low voltage signal contacts, gold or rhodium would be required.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
February 15, 2008

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February 27, 2008

Hey Ted,
We both know that chrome plating on battery cable ends have a greater resistance than copper or nickel. However recently I nickel chrome plated the battery cable ends and a lot of the electrical connectors on a customers car. Everything seems fine. Car starts, cables stay cool. From an electrical engineers perspective copper or nickel would be better. From a show car guys perspective chrome does the job and looks better.
It all depends on the load

Frank DeGuire
- St. Louis, Missouri, USA

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Thanks, Frank. I pictured a watch battery with spring loaded make-and-break contacts, you pictured a car battery with tightening lugs.

Either one of us may be right :-)

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
March 31, 2012