The battery acid taste test.

Dear Car Talk

Dear Car Talk | Sep 01, 1993

Dear Tom and Ray:

I just had to replace the two year old battery in my 1982 Dodge Rampage. I've had the car a year and a half, and the papers that came with it indicate that the battery was installed in 1991. Whenever I opened the hood, it would appear that fluid had been running down the side of the battery. I would add water to it quite often. Now, with the new battery, I also notice a slight amount of fluid on the top. I have been chicken to taste it to see if it might be acid. Could it be?

RAY: I wouldn't advise tasting it, Roy. Here's the real "acid test:" Buy a $45 dress shirt, preferably medium blue with a button down collar. Get some of the fluid on your fingers and smear it all over the shirt. Then throw it in the wash. If the shirt comes out in one piece (or, if you can still leave fingerprints), then it's probably not acid.

TOM: But it probably IS acid, Roy, and there are two possible reasons why it's there. The first is that you've been overfilling these batteries. You're only supposed to add water till it reaches the rings at the bottom of the fill tubes. If you overfill them, water and acid could spill out, and that would shorten the life of the battery.

RAY: If you're sure you're not overfilling them, the other possibility is that your battery is getting overcharged. That would cause it to boil over and spill, which would also shorten it's life.

TOM: So have your charging system thoroughly checked out to be sure it's putting out the correct number of amps and volts. And next time you need a new battery, get one that's maintenance-free.

RAY: And then keep your grubby hands off it, Roy!

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