Dear Tom and Ray:
I live near the ocean, and my less-than-a-year-old battery died this week. My neighbor, who jumped the battery with his cables, said that my connections should be disconnected and cleaned with a wire brush due to corrosion. My other neighbor said that she poured a can of Coke on her battery and it cleaned off all of the corrosion. Before I start pouring Coke on my car battery, may I have your opinion on her fantastic remedy? — Martha
We prefer Dr. Pepper, Martha.
If you do have a lot of corrosion between the posts and the terminal ends of the battery, it can prevent the battery from being charged completely, or discharged when you need the power.
But you shouldn’t have that kind of corrosion on a year-old battery — even if your next-door neighbors are Mr. and Mrs. Sea Cucumber.
: Corrosion like that usually is caused by “out-gassing,” which means the acid in your battery is escaping from its container in gaseous form.
That can be caused by either a faulty battery — in which case yours should be covered by warranty — or a charging system that’s “overcharging” the battery and causing it to emit gas.
So you’ll want to take your car to a good mechanic, and ask him to test your battery and charging system.
If all’s well, the corrosion may be a red herring. Especially since we know herring live near you in the ocean. Your battery may have died due to human error: You may have left a dome light on, or simply left the car sitting for a few weeks without driving it.
If there IS a problem with the charging system, then you need to fix that before you blow through any more good batteries.
And Coke — with its carbonic and phosphoric acids — will help remove corrosion from battery terminals, as will any carbonated beverage (they all contain carbonic acid). Although a nice sparkling water, without the sugary syrup, would be an even better choice. Add lime or a twist if you want your terminals to feel particularly refreshed.
Or even better, and cheaper, mix a little baking soda with water to make a runny paste. Remove the battery’s terminal ends, smear your mixture on the battery posts and terminals, give them each a little scrub with a wire brush, and rinse it all off with a garden hose.
You can listen to Tom and Ray Magliozzi’s “Car Talk” program at 10 a.m. Saturdays on National Public Radio station WUSF, 89.7 FM.
Got a question about cars? E-mail Click and Clack by visiting the Car Talk website at www.cartalk.com. They can’t answer your letter personally but will run the best letters in the column.