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Vinegar in battery

Okay, I’ve been nominated for Dumb___ of the year. I accidentally grabbed distilled vinegar instead of water to top off the 6 month old battery in my car. I topped off 3 of the 6 battery cells before realizing it. I have read that distilled vinegar is actually 95% water, so I am wondering just how much battery damage to expect. If a shorter battery life is the only real result, then I can live with that. Thanks!

Vinegar’s a weak acid, so it might not have hurt anything. I’d just wait and see.

that is a first for me , please keep us informed if anything happens with the battery.

I’m puzzled why a 6 month old battery needs topping up at all. Was the water/acid level that low? What kind of battery is this?

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A blunder, but surely harmless. You are correct that vinegar is 95% distilled water and 5% acetic acid. Acid in the battery is OK. Vinegar is not recommended but don’t expect anything bad to happen.

The battery came from Advance Auto. Believe it was not totally full when purchased

Robsp- I’m curious, what is your idea of “full”?
Just asking because it shouldn’t be full as in full to the top. There has to be room for expansion and for the gas to escape. How low was the battery?

@TwinTurbo Correct, manuals say that the plates have to be convered. Most batteries used to have a star shaped opening to which level you should fill the water. Batteries also heat up and room for expansion is also necessary.

Do NOT use vinegar in a car battery. It is acetic acid and will react with the sulfuric acid in the battery and the lead terminals to form lead acetate. Not good. Only use distilled water for small amounts. Otherwise, buy battery acid tabs from an auto supply shop. To clean the outside electrodes, baking soda with just enough vinegar to form a paste can be used to clean them. I usually use sand-paper to clean those.

what’s the chemical reaction to form lead acetate with a (very?) small amount of acetic acid in excess sulfuric acid?

Car or automotive battery acid is 30-50% sulfuric acid (H2SO4) in water. Usually, the acid has a mole fraction of 29%-32% sulfuric acid, a density of 1.25–1.28 kg/L and concentration of 4.2–5 mol/L. Battery acid has a pH of approximately 0.8.​

OTOH, Distilled white vinegar usually measures around pH 2.4, with a strength of 5%.

The real trouble comes when you add baking soda to the battery…

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OP if you are still there, tell us if the vinegar seemed to have done anything good or bad for your battery. I’m guessing it had little to no effect. This would have been a great question for the radio show … Tom: “Doesn’t anyone screen these calls???” … lol …


Wet batteries should not be topped off. This bottle is made to properly fill a wet battery