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Simple plating cell for a science fair project

 

I am trying to help a neighbor kid with his science fair project and I thought some of you plating experts may be able to help me out with this one.

He wants to determine which brand of battery (brand names vs. generic) provide the longest life. The problem is designing an experiment that tests each battery type under consistent conditions and does not require 24/7 monitoring to determine when the battery dies.

My thought is to set up a small copper plating cell and power it with the DC battery. We can weigh the cathode before the process and then connect the cell for X hours or days and then reweigh to determine the weight gain.

We could monitor cathode weight vs. time and when the weight gain levels off declare the battery "dead". The battery that produces the greatest weight gain would be the "longest lasting" battery.

Any comments from the plating gallery before I run off and test the design? Will the cathode start to "de-plate" once the battery dies? I would use a copper or more noble cathode to prevent immersion plating.

Any comments would be appreciated. A simple battery test could plant the seeds that grow the next great metal finisher.

Thanks,

Scott Campbell
automated chemicals - Tempe, Arizona

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Sounds like a good experiment, and assuming your electrolyte is a mild acid, I would expect no measurable de-plating.

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

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Less graphic and less cost and less risk and a lot quicker is to load a battery in a clip from radio shack, hook a bulb of your choice as a load and cut in a voltmeter. Use a given voltage like 1.00 volts as a "dead" battery. Grandson ranked batteries by type and brand using elapsed time. A neat science variation was a cold battery, one out of the fridge and one out of the freezer. Can be kept cool with a baggie of ice water or salted ice water.

James Watts
- Navarre, Florida

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It is far more easy, to hook up a load to the battery, for instance a bulb, and a voltage meter connected to an recorder. In this way you don't have to wait until the battery is "dead", but just read it from the recorded line.

You need to know the capacity of the battery, as the time the battery last depends on the capacity of the battery and the current. Also the given capacity on batteries is sometimes measured on different circumstances by the different manufacturers. There are a lot of factors playing a role in discharging a battery and their lifetime.

H.Woortmeijer B.Sc.
- Apeldoorn, The Netherlands

Why not use a motor attached to a bicycle wheel with a small bicycle odometer attached and check the distance. OK there is no plating involved but why complicate matters.

Ciaron Murphy
- Great Britain