I put a new battery in about a year ago (Walmart's best, 9 yr warranty, 3 yr replacement ) but ever since, I have been getting an accumulation of powdery corrosion on the terminal (positive). I cleaned it and sprayed with a red terminal protector, but it is doing the same thing.

Any idea what's causing this and how to cure?

thx

 

It's sulfuric acid leaking around the terminals - seems to happen to most batteries, to a degree.

Being a Walmart battery, it might not be the highest quality, but like I said - seems to happen to all of them.

There's all sorts of tricks for keeping the corrosion away - a shot of WD40, vaseline, bearing grease, the list goes on.

I've honestly never had a corrosion problem, so I can't offer any suggestions. At NTB, we had this yellow spray stuff that didn't seem to do much for preventing corrosion.

If it's an excessively ridiculous amount, the battery's probably leaking pretty bad. I'd look into replacing it under warranty.

XXL

 

It may not be leaking at all.

The powdery corrossion is a normal chamical reaction.

Find a good quality coating to cover it. Vaseline or grease is a cheap alternative, too.

What kind of posts does it have? Top or side?

 

I have a top mount battery on another vehicle and had the same problem. I put on those treated felt washers under the cables and problem solved. Might want to try that.

BigMan69

 

Well, yeah, a little corrosion is a normal byproduct of the chemical reaction, but if you've got enough on there to routinely require your attention, then there's something wrong.

FWIW, I've had my Diehard SUV battery for some time now, and it hasn't corroded. My other (Ford) battery started corroding when it started dying. Maybe there was a leak?

XXL

 

my orig ford battery never corroded, ever. For some reason, this everlast has been problematic in that regard. It has three year free replacment and is only 15 months old. I will watch it for a few months and maybe take it back.

 

For lack of anything else,I put never-seize on the terminals (inside and out) and never have a problem. The corrosion is cause by the acid. As batteries vent during normal discharge/re-charge cycles a small amount of the acid is released into the air. If a battery is undersized, it will have a longer cycle time and more is released. That's why "cheap" batteries have more problems. any coation or acid nuetralizer will do the trick. I used to see people put pennies on batteries as sacrificial anodes to save the terminals but it really didn't work.

 

OK-battery terminals 101!!!!! Don't use vaseline or wd-40 or never seize or bearing grease for god's sake. You are "suppose" to use a di-electric type grease which prevents oxidation and allows conductivity. I use "No ox". But if you can't find it go to any good electrical store for some other product. Put it most on anything you have electrical connection wise especially electrical plugs under the hood etc. Some car parts stores might have some.

 

"A dielectric material is a substance that is a poor conductor of electricity" Why in the world would you want to do that? Dielectric greases are used to prevent arcing and prevent water from entering the plugs. Sort of a wipe on insulator/water displacer. (What the WD in WD40 stands for.) Your point about WD40, vaseline or bearing grease ( all dielectric materials) is well taken. It will work its way between the clamp and post and could cause problems. The idea is to prevent the acid from reaching the lead. But high nickel or copper anti sieze is an excellent conductor and actual acts as a sacrificial anode that you can simply wipe off if it does actual corrode. It will not act as an insulator.

 

Another thought. Coatings on the terminals are treating the symptoms, not the cause. The only battery corrosion I've ever had in a land or water vehicle was on a Jeep where the alernator was putting out too much current for too long, boiling the battery fluid, which caused excess venting of gases and fluid. Have your alternator checked for proper operation and then purchase some of those treated felt rings that go around the posts. They work very well for little money.

 

~~~~~~~~~~~Actually I said the dielectric grease will "allow" conductivity-yes, it is not conductive but I'm in the electrical trade and we all use it-here is some info~~~~~~~~All I can say, is I have been greasing my terminals for about 20 years,and
have yet to have a poor connection. If the battery terminal and the clamp are both smooth and shiny, and you mate them with a twisting motion and then tighten them properly, the dielectric grease will squeeze out of the metal-to-metal contact areas, but act as a seal to prevent moisture from getting in between the areas where contact is not so good.
Push-on terminals have a wiping action that similarly cleans the grease off where metal presses on metal. If you look at many newer cars, you will find some sort of grease on the bases of lamps, to keep out the moisture. The grease has the added benefit of keeping AIR out, too, which can help
prevent tarnish.
If you try the grease trick on already pitted and corroded contacts, you lose most of the benefit.

Getting the grease on the underside of the terminal is critical to keeping battery vapors out of there.Use the felt washers too.

Vaseline has one drawback over silicone greases made especially for this kind of duty - it tends to disappear in hot conditions, and if you put too much on, it runs down the wires, making a sticky mess. Be sparing.
There are proprietary contact treatments (very expensive) that do the same thing but also contain some sort of anti-oxidant / corrosion remover. Such treatments are used where thick copper bus bars are bolted together in places like electroplating shops. These are usually conductive, and would
short out something like a lamp socket