Stopping Corrosion on Battery Terminals

[29 Tudor]

I suspect this will start a controversy and that is definitely NOT my purpose. I post this because I KNOW it works from personal experience as well as the experience of many others that have done it ... starting with Thomas Edison.

Years ago, the storage batteries that were placed along the railroad tracks to power the signals had "Edison Oil" floating on the top of the acid to provide a blanket that prevented evaporation. In fact, you used to be able to find "Edison Oil Bottles" scattered in the woods near where battery operated signals used to be installed. I have a couple myself. I researched this some years ago for use in the 6 volt deep cycle batteries used for house power in my motorhome and found the oil was in fact, heavy mineral oil.

At that time, I went to a chemist that worked in our company and asked him if there would be any reaction between mineral oil and sulfuric acid. He smiled and quickly said, "No, why do you ask?" When I explained what I was considering he said as a young man, he had worked in his dad's shop and virtually all the trucks they worked on had mineral oil in the battery on top of the acid. He said there was no corrosion and rarely had to add water.

For a number of years, there was a company called "Thermoil" that sold lead acid batteries with the oil installed as delivered. Now, they no longer sell batteries but still sell the oil and in fact, on their webpage, make a case against using mineral oil "if you discharge the batteries below 50%". I'm not quite sure why that makes a difference but I will say that for years, I have used it in my 6 volt house batteries on my motorhome and I have NO corrosion and only add a small amount of water maybe once a year.

With the oil blanket on top of the acid, when the battery is charged, there is no violent bubbling in the cells but rather, bubbles that slowly rise through the oil blanket and gently break at the surface. I believe the acid carried in the bubbles slowly condenses to the bottom of the bubble and, since the oil is lighter than the acid, it settles back into the acid below.

If you are having to deal with corrosion under the floor boards of your "A", it might be worth a look.

Steve

[MikeK]

The oil to prevent evaporation and micro acid spatter from the bubbles breaking works well in stationary batteries but presents a problem in mobile batteries with an inch or less of electrolyte over the plates.

One of the battery plates is Lead Oxide (PbO) which is very spongy and a covalent compound that easily 'wets' or binds via Van-der-Waals attractions (don't ask!!) and adhesion to long-chain HC's (oil). If the battery is constantly in motion from driving over bumps and making turns, it is like shaking a jar of water with oil on top. The oil touches the plates, specifically the PbO plate, and the oil soaks in and adheres to it even after things settle down. The now oil insulated plates are electrically dead, forever.

Think of an oil soaked rag. You can throw it in a bucket of water, but a week later it is still an oily rag. If it self-separated we wouldn't need soap or detergent. In a stationary battery the oil floating on top effectively stops evaporation and is OK provided it is never shaken to touch the plates.

[29 Tudor]

I'm sure you're right but I (and a lot of others) have been doing it for years in the deep cycle batteries that are used for house power in my motorhome. I have well over 100,000 miles on the motorhome and do a lot of dry camping with the batteries in question. The last load test I did a few months ago showed NO degradation from new specification and those batteries definitely get moved and shaken. I'm certainly not saying you are wrong. Perhaps the difference is the depth of the acid on top of the plates.

[H. L. Chauvin]

FWIW:

As far as stopping corrosion on Battery Terminals for life of the battery, or even any & all Model A wiring terminals, one totally maintenance free solution is "Kopr-shield" by Thomas-Betts.

Years ago, Eastwood used to sell either a 1/2 ounce or 1 ounce bottles for just a few bucks which could last a Model A owner an entire lifetime.

Now the smallest bottle one can find is about 8 ounces which costs about $19.00 per bottle -- it could be bought by a club & divided to provide once in a lifetime corrosion free connections -- or Ebay has deals now & then.

Great for Model A headlight connections & Model A (+) grounded connections -- never experienced a connection failure after using same.

My oldest son is in the wireless telephone & wireless computer tower building business for years where even in a heavy salt water coastal environment, one wants to climb a new "high & slim" tower "once" to make wire connections & never have to go up again.

They use Kopr-Shield & never climb again.

Have it on my riding lawn mower batteries, vintage tractor batteries & Model A batteries for years -- clean terminals, apply Kopr-Shield generously , & you are done.

[mshmodela]

Very interesting reading, thanks for sharing... I do not like the idea of a battery that close to wood... i hope to put metal between the two.

[marc hildebrant]

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My father would use Vaseline smeared on the battery terminals prior to clamping on the cables to keep the terminals corrosion free.

Marc

[Rocketsled]

The corrosion is caused by gas leaking up around the battery posts.
The cure is to apply a silicone paste, or "Dielectric Grease" around the base of each post.
Bearing grease, or Vaseline applied to the connections will eventually seep down
and interfere with the electrical connection. Silicone paste will not migrate, if so applied.

[modeleh]

Interesting thread 29 Tudor. I enjoy hearing about the ideas of the early inventors like Edison, Tesla and others that were once commonplace but now are largely forgotten.
Along the lines of what HLChauvin wrote about the Kopr coat, I have found that a simple coat of copper never seize on battery terminals is sufficient to combat corroded connections. I have used the standard grey anti seize with the same results, but I do believe the copper based product would be a better choice.
When using stake on or crimp type electrical connectors, if I am feeling lazy and don't solder the terminal, I will dip the end of the wire in never sieze before inserting into the crimp terminal, then crimp. IMO this does a great job of preventing corrosion within the wire, where often you will see the copper wire turn green, the never seize seems to stop this effect and provides many years of "good connections".

[29 Tudor]

Never thought of anti seize on crimped connections but that sounds like a good idea.

Thanks!

Steve

[Willie Krash]

When I was a sweep and power supply tech for cable television we used Karo syrup. Hey it was cheap.

[darrylkmc]

Originally Posted by Willie Krash

When I was a sweep and power supply tech for cable television we used Karo syrup. Hey it was cheap.

Dark or Light Karo?

Darryl in Fairbanks

[Willie Krash]

Dark. Does create problems with ants.
29 Tudors post is quite interesting.
We had very stable supplies and sealing the oxygen out was simple. The syrup simply hardens. Grease et. al works but messy. The red stuff is expensive.

[noboD]

I've used regular never-sieze for decades.

[Ray64]

Doesent mineral oil create P. C. B,s when electrified as in the old transformers?

[29 Tudor]

Nope, different stuff.