Galvanic Corrosion on battery posts. Best preventative?

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Randy88FJ62

Randy88FJ62

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Installed a second marine battery in my cruiser and did all the battery cables myself with a hydraulic crimper. The terminal for the 1/0 AWG winch cable is copper and the 2 AWG wires for the dual battery system are tin plated copper.

I am already noticing small amounts of white oxide due to the different materials and galvanic corrosion. A quick google search looking at different sites say to use the felt washers and/or vasoline.

Any other comments on keeping battery terminals clean and free of corrosion?

Never had this problem on my main battery.
 
Its primarily being caused by acid fumes eeking out of the vent caps while the battery is getting overcharged while driving.

If you've got removable battery caps, remove them and rinse them out real well with water. Shake them dry. Really dry. Do this regularly. When the battery is getting (overcharged) while driving, the electrolyte acid bubbles and fizzes acid mist up into the caps. When the caps collect enough of it, they eek some acid vapor (mist) along with the hydrogen gas & tiny bits of it spew out & deposit on whatever is nearby. The terminal posts & cables.

Acid + electricity = corrosion.

Clean up the battery & cable ends with some baking soda & water to neutralize the acid that's there.
 
Thanks output. This would explain why it's happening on just the marine battery.
 
Also, many people fill a wet battery until the 'eye' forms in the water well. For charging systems that tend to fling acid past the battery caps, I was told to run the water a bit lower (just cover the plates and then a bit more) and watch it more closely. There are some vehicles and batteries that really spew the acid, and some that are nearly dry. Generally, newer vehicles (in my experience) don't push as much acid past the caps as older ones. My '58 Massey tractor and '83 GMC 2500 tend to spew acid and corrode cables regularly no matter what I do.

I had never heard of rinsing the caps, but it seems like sound advice.
 
Dielectric grease +1 - simple and 1 coat will last 5 years
 
Terminal wax on exposed parts, noalox on conductor to terminal connections and shrink over the joints.
 
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