It does not happen often but every once in awhile we get a question that just plain stumps us. Recently, a Customer called late on a Friday, just before closing, with a question that left us scratching our heads. Apparently, he was doing his monthly water service maintenance on his batteries and he accidently grabbed the “Distilled Vinegar” jug instead of the “Distilled Water” one. Oops! He used his battery water fill system and poured about ½ cup of vinegar into the batteries before he caught his mistake. He knew it was wrong and stopped immediately but wanted to know how much damage he may have done to his batteries. So he called us.
When we answered, he explained his situation and we answered with, “Huh?” He explained some more and again we responded, “Huh?” At the end of the story, we summarized our answer with, “Huh, we never heard that one before.” So we called our Battery Supplier and got the exact same responses. So he called the Battery Manufacturer and got pretty much the same “shoulder shrugs”. Fortunately, the Engineers were still at work that evening and were able to come up with an answer after a bit of thought and analysis.
Bottom line … Vinegar is bad for the battery. It shortens the life expectancy, decreases performance and endurance, and voids any applicable warranties. DON’T DO IT!
If you like Chemistry, here’s a little bit of the “why” to explain the situation. Battery Water is an electrolyte made up from Sulfuric Acid and Distilled Water. It is the “engine” that drives the process of transferring and storing electrons onto the Lead Plates within the battery when electrical current is applied during the charging process. When batteries are being discharged, such as while driving or turning on lights, fans, radios, etc., the Lead Plates will discharge electrons and absorb the electrolyte as they lose electrons. Basically, the Lead Plates act like sponges. This is not a perfect analogy but hopefully you get the idea. If there are contaminates in the Electrolyte, such as Vinegar, then the ability of the Lead Plates to absorb the Electrolyte is decreased. Essentially, the Acetic Acid (Vinegar is mostly water with about 5% Acetic Acid) corrodes and damages the Lead Plates (Acetic Acid is very corrosive to metals). This decreases the available volume of lead to absorb Electrons during the Charging process. Charging the batteries reverses the process and pushes Electrolyte out of the Lead Plates and back into the battery casing while allowing electrons to again migrate onto the Lead Plates. But the damage to the Lead Plates from the Acetic Acid remains and the damage will increase over the remaining Charge/Discharge Cycle life of the batteries.
The other question our Customer had was, “What do I do about it?” Another great question which we deferred to our Subject Matter Experts.
Just in case you were thinking that all you would have to do to fix the problem is to dump out the contaminated battery acid and start fresh. In a word … DON’T. Sulfuric Acid is dangerous to work with even while paying attention to proper safe handling, storage, and disposal procedures. Mixing the Acid and Water to the correct ratio is also a specific science. And you must be very careful even just servicing your batteries. We do not have the facilities to store or dispose of Sulfuric Acid safely so we refer any such issues to our Supplier. Once you use the batteries, even just once, the damage is already done.
The recommendation we received was to go ahead and use the batteries normally and try to get as much life out of them as possible. Since the warranty is already voided, it does not make a lot of economic sense to just dispose of them and start over. Some of the Acetic Acid will “boil off” along with the water during normal Charge and Discharge Cycles and should lessen additional damage (but not reverse) over time. When you decide that Performance and Endurance are no longer satisfactory, then that will be the time to change out your batteries.
In summary, what does this all mean to you, the Driver? Fewer electrons stored on the batteries, means shorter run times. Restricted flow of electrons due to contamination means slower speeds. Corrosion of the Lead Plates means a shorter life expectancy.
GOOD : Only use Distilled (contaminate free) Water
BETTER: Service at least once a month so that the batteries have the proper mixture of Distilled Water and Sulfuric Acid that completely covers the Lead Plates
BEST: Remember that Distilled Water will “boil off” during normal usage (Charging and Discharging) and you may need to check your water levels more frequently depending on usage
NOTE: We used this story with our Customer’s permission. We sincerely appreciate his candor and honesty. We all learned something, including our “Experts”.