...lead/acid batteries do that.

quick search result purdy much explains why...
https://answers.yahoo.com/question/index?qid=1006020306083

I'd suspect your battery could be leaking...
or someone spilled electrolyte on the terminals.

how to eliminate that issue !?
^ besides the little tricks that can help when using a lead/acid battery.

Get a gel cell battery and terminal corrosion/build up will no more.
and there are no tricks required.

My Optima YT looks and functions as good as it did
15 years ago.

And I've never had to do any terminal maintenance, ever.

 

This happened on my 2011 with 20k.. and another family members with 50k. Keep it clean and it will be fine.. try putting a felt ring at the base of the post as well.

 

indeed.

 

Thanks for the responses. I got the little felt rings last week and put them on after cleaning it off thoroughly. I talked to the service writer earlier in the week and he said it was fairly common even at lower mileage from what he's seen. I guess between my old GTI and my wife's old Corolla (that didn't develop it until much later as well) I just wasn't expecting it this soon. But I'll check it every couple months from now on.

 

I've used the felt. It does not solve the cause. You should clean regularly according to others' instructions to neutralize the acid. If leaking maybe change new battery as soon as possible.

 

Thanks. I've been keeping an eye on it. I don't really buy the service writer's explanation. My wife's RAV4 is at 20k and is still clean as new. I've got one more service prior to the expiration of warranty in July and plan to push the issue with them then to replace it.

 

Your battery's positive terminal is not properly sealed in the casing, and some electrolyte is leaking... When electrically charged, the copper clamps react with sulphuric acid to produce copper sulphate (CuSO4), along with water and sulphur dioxide gas. Anhydrous copper sulphate changes to blue colour when water is added to it. The bluish substance which you see around corroded copper terminals or copper clamps is hydrated copper sulphate.

You just need a good new battery.

http://www.interstatebatteries.com/...utomotive-truck/mtp-35-toyota-corolla-2012-standard-battery-oem-cca-360-l4-1-8l

http://www.sears.com/diehard-gold-automotive-battery-group-size-35-price/p-02851835000P

 

It has nothing to do with your car, or any car for that matter. It's only the battery that is causing this as some do it more because of a small leak. It's not really a huge deal as you can keep it clean & you will be fine. It only takes a few minutes every 6-12 months. When you get a new battery you can buy a gel cell battery like an Optima and never have those issues again.

 

you definitely want to keep it clean as much as you can if you stick with the same battery. you don't want the corrosion to affect the terminal cable because that's a PIA to replace.

or like others have mentioned you can drop in a fresh, new battery

 

Last time I had a severe corrosion problem on my battery post was due to a crack near one of it's post that was leaking fume and added corrosion sulfure dust near it's post.


Upon a real close inspection found the crack had spread almost to a half moon circle around the affected post.


I got rid of it and bought a really nice used one and problem was solved for good.


Maybe you should have a real closeup check around both of them, who knows.