What causes corrosion on battery terminals??
 

Simple question, right?

The reason I ask is that last night my '96 wouldn't start at the mall. Popped the hood, sure enough, corrosion on the positive terminal. Went back inside to Sears and bought a 5/16" wrench and coke and fixed the problem in about 5 minutes, but I don't understand why it was corroded in the first place. I just removed and cleanded the terminals about 4-6 weeks ago when I had my last starting problem (turned out to be the steering column that time).
The only thing I can think of is that it had been sitting in my garage for ~10 days while I was overseas last week, but I drove it to work everyday this week with no problem. And the terminal was very tight when I removed it last night.

Thoughts?

Jeff

Re: What causes corrosion on battery terminals?? (no_radio)
 

i coat my with die electric , helps contact and corrosion on the terminals...

Re: What causes corrosion on battery terminals?? (no_radio)
 

I think the technical term is called "electrolysis".

It's a chemical/electrical reaction with the air... and the metal on the terminal... you can get a spray that will stop it.

humidity will make it worse.

Re: What causes corrosion on battery terminals?? (no_radio)
 

We had a GREAT thread on this a year ago, wish I'd saved it - :mad

Maybe we can build it again, we'll see..............

Seems to me that acidic gas' or vapors are always escaping thru porus materials, and under certain weather, humidity, greasy, or loose fittings (conditions) will generate corrosion.

:lurk:

Re: What causes corrosion on battery terminals?? (bogus)
 

Plenty of that here in Houston...

Re: What causes corrosion on battery terminals?? (vinnies87)
 

you can get those little green and red felt pads to put under the terminals that seems to do a good job here in charlotte ,nc. most auto parts stores carry them.

Re: What causes corrosion on battery terminals?? (no_radio)
 

The sulfuric acid in the batteries electrolyte reacts with the copper in the cable lug to form copper sulfate (blue crud). A microscopic layer of this corrosion reduces the area contact of the cable lug to the battery terminal and the connection resistance gets large enough to limit the current the battery can deliver and the 100+ amps the starter motor requires will not be available. Periodic cleaning will prevent sticking you in the boondocks.

Re: What causes corrosion on battery terminals?? (jfb)
 

That's what pisses me off, I just cleaned both cables and terminals about 4-6 weeks ago...
I've never had a car where they corroded up so quickly.

Jeff

Re: What causes corrosion on battery terminals?? (no_radio)
 

I'm not sure about your '96, but on my '86 the battery corrosion had spread to the maf relays and connectors behind the battery. This caused some vey wierd intermittent problems that took a lot of time and wasted $$ to figure out. Just a heads up...

Re: What causes corrosion on battery terminals?? (no_radio)
 

With air being the initiating culprit, the simple fix is to put a small gob of vaseline or grease on top of the terminal post. You may need to add more in a year or two. THe engine compartment heat will melt the grease and distribute it where it needs to be. Using that one ever since grandpa mentioned it, many decades ago, too many!!

Re: What causes corrosion on battery terminals?? (Frank Zeman)
 

:iagree:

Keeping the terminals clean and corrosion free is good insurance.

Mark

Re: What causes corrosion on battery terminals?? (Mark-44)
 

My experience has been to keep both the terminals AND the top of the battery clean.....you will not see corrosion on the terminals. I think contamination on top of the battery conducts current and causes the green gunk! My two cents worth.

Re: What causes corrosion on battery terminals?? (no_radio)
 

I treat all lead and copper connections at the battery with silicon grease. It is good at high temps and doesn't breakdown like regular grease. No more problems. :cheers:

Re: What causes corrosion on battery terminals?? (no_radio)
 

Years ago the Society of Automotive Engineers did some testing and discovered that grease acts like an insulator when it gets hot and seeps between the post and cable clamp. Bad choice. Best use a product made for this purpose.

Re: What causes corrosion on battery terminals?? (jimtreber)
 

Friggin Engineers.... :D :D :D

Re: What causes corrosion on battery terminals?? (92corvette)
 

Check the condition of your positive cable.

I had this problem with my daily driver, which I used to have to clean 4-6 times per year. Eventually the corrosion and resistance got bad enough to kill an 84 month battery in 20 months. The cable had been slowly degrading and I never noticed it. I replaced the cable and haven't had any corrosion build up in over a year.

Re: What causes corrosion on battery terminals?? (sraft)
 

For those of you who have "battery crud sickness", here is the cure: take the battery out of the car (you will enjoy doing this), clean the top of the battery and terminals with 409 cleaner and a brush (I use my wifes toothbrush). Reinstall the battery (putting it in is more fun than taking in out) and wash off the top of the battery when you wash the car. Your battery crud problems will be in the past and you can thank Ole Sam!