They were wrong about the dilution, the added water is just replacing water lost to evaporation and electrolysis during charging. But there is a tiny shred of truth that replacing the battery acid might give a failing battery a bit of a boost, but not much of one, and not for long.
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If you can run the battery all the way dead and then put a 1 amp charge on it for a few days, maybe a week then you can sometimes desulfate the plates and bring the battery back to life… My newer battery charger has a smart desulfate function, but I can’t make it do it on demand, but I just took a car that hasn’t been started in 5 years and the battery was pulled out of another vehicle before that, and put it on the charger (multiple times), it wasn’t holden a charge, but the battery charger finally went into desulfate mode and battery has been holding a charge for a few weeks now… time will tell… lol
From what I understand the acid doesn’t leave the battery unless spilled out, but it was the water evaporating from the battery that made it low…
I know years ago, we used to hook up a small bulb (194/168 size) to a battery and run it dead for a week, then check and top off the battery water level and then put a one amp charge on it, brought a lot of older battery’s back that way… Good luck finding a 1amp charger now a days, but hopefully this newer smart battery charger will do the trick if I can ever figure out how to, if able to, desulfate on demand… lol
Not volts, specific gravity. How would I measure the voltage of individual cells?
The one I bought yesterday has them.
Yes. I keep a bottle of distilled water for just that purpose.
That was the only hypothesis I could come up with. It seems a large difference though. Does a cell that starts out weaker degrade more quickly?
A steady one amp charge over a long period of time will not desulfate a lead/acid battery.
Tester
When the battery is new the lead plates inside are uniformly coated with the chemical needed for the chemical reaction used in the battery’s charging & current delivering functions. When the battery discharges that chemical moves into the battery solution, then when it recharges it goes back onto the plates. Unfortunately it doesn’t go back on as uniformly as when it was new. No way to control the process, where it goes onto the plates is the luck of the draw, random. The plates, cell to cell, are also differently configured, which could also affect how the chemical reattaches to the their cells plates during charging.
I add distilled water to both my Corolla and truck batteries as part of routine maintenance. They don’t have the old style individual caps, they use the top-plate method as shown above. Corolla’s battery is relatively new, from Walmart. Truck’s is 8 years old, from Costco.
I have epsom salts; take a ½ tsp daily.
Not neccesarily, no.
Where does it say you can not desulfate a battery by draining the life out of it and then doing a slow 1 amp charge on it… It does say in a few places that It’s true that there are different methods to perform it, and some may be easier than the rest. and
Below, we have explained the two best ways to desulfate a battery. and There are different methods to desulfate a battery. While some are advanced and others old,
But it doesn’t say that the 2 methods they explain are the only two methods that work…
The gentleman that taught me this 27 ears ago is 75 and been doing it most of his life… I also seem to remember hearing this from my automotive technology teacher back over 30 years ago, but I may be remembering the teacher part wrong…
So, I know what ever it is doing it has worked many times in the past, not every time, but most of the times… I also remember U-Haul’s service manager at the time, charging 10-20 battery’s at the same time with one regular battery charger for a week at a time when I was an engine specialist for them, this was back in around 2000…
Now granted, most were interstate battery’s (U-Haul was whatever battery, don’t remember brands)…
Now, if I’m calling this the wrong name then please inform me as to what we were doing is called, and I will stand corrected…
When one of my vehicle’s battery is very discharged, I can usually get it working again with an overnight 2 amp-rate charge. At least enough to start the engine, then the alternator finishes thejob. But sometimes charging it at the two-amp rate won’t bring it back to life no matter how long i keep it on the charger. When that occurs I’ll remove it from the charger for a day or two, let it rest, then charge it at the 6 amp rate for a few hours, then complete the job at the 2 amp rate. Sometimes that does the trick.
Had to so something similar with completely discharged NiCad batteries, AA size, for portable electronics. Sometimes the battery charger could never revive them. But if I connected them to an alkaline battery briefly, just a few seconds, somehow that would shock them into accepting a charge from the battery charger.
Safety note: Good idea to wear eye protection whenever working with batteries, especially stubborn ones.
I remember several mechanics years ago saying they were able to revive a dead battery by putting it on a steady low charge over a long period of time, but the revival was never long term.
I only recall what one said for how long it would last, saying “a week later, it was dead again.”
Well? That new smart battery charger either has this technology to desulfate a battery.
or it came with a bag of epsom salts?
Tester
I’d like to know how much capacity the battery has now compared to the original capacity? If it is only restored to 25% capacity, it can still be used, but specific gravity is still low even at full charge and the battery won’t be protected from freezing.
That or oxygen and hydrogen bubbles from the water being broken down.
I thought the proper method was very high charging current, like from a DC welder. I’ve heard this before. I’m skeptical that it works though. Maybe it only works for mild sulfation.
At 2000 Amps charge current, I was only able to bring a battery back up to about 40 Amp hours.
I think so. It starts to discharges a little more than the others on its own. Then if periodic equalization charges are skipped, it doesn’t charge back up all the way. Then it sulfates, and the self discharge rate gets worse. Then it sulfates more because of that, and the self discharge rate gets even worse.
For batteries? Those salts will fix a sulfated battery, but then after a year it is ruined for good I hear.
Some chargers won’t turn on if the batteries are completely dead. That’s rare for a NiCd charger though. NiCd can develop internal shorts. Connecting one to a higher Voltage briefly can blow away the short inside and it will work for a little while longer.
A healthy battery should stay at 13.1 Volts for several hours after it is taken off the charger. If it is sulfated, it’ll drop down to 12.7 or such fairly soon off the charger.
I didn’t know about the high frequency feature of the Black+Decker battery charger.
Charging at 2000 amps? Sulfated batteries dropping to 12.7V? Are you making this stuff up as you go?
What’s the issue with the 12.7 Volt claim?
Like I said, I may be calling it the wrong name, but I know it worked a lot of the times, I can NOT prove it now due to not having an old 1amp charger… You can either take my word for it or not, your choice… lol
And my newer charger has an auto desulfation mode on it…
Fully Automatic Battery Charger, Engine Starter, Boost Maintainer and Auto Desulfator with Advanced Diagnostic Testing
A surface charge of 13.1V after charging that drops to 12.7V indicates the battery accepted a 100% charge. There’s nothing to indicate it’s sulfated. Sulfated batteries generally will not charge that high.
That’s what I mean. If it’s still sitting at 13.1V the next day, the battery is in good condition. If it falls down to 12.7 fairly soon after the charge, it is probably somewhat sulfated.
12.7V is a 100% fully charged battery. It’s not unusual for a battery to read 13V+ (surface charge) after charging and then drop to 12.7V (resting charge) within a few hours. Nothing odd about that.
Tester