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Old 13-09-2010, 16:32   #1

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Epsom Salt Treatment for Battery Renewal

Anybody using epsom salt to desulfate batteries? Im giving it a try with 2 ,3year old golf cart batteries. drain acid, add in place 8 oz epsom salt to 1 qt distilled water, charge discharge 3 times over 3 week span. I noticed the batteries boiled for a week after the first charge, dissolving sulfate? Advice experiences and tips appreciated

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Old 16-09-2010, 18:53   #2

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Hmm taking it that this technique is not too widely known. I first heard of the "secret" in the book All for a Bottle of Whiskey. Its sold on the internet and Ebay, also available for free on . The epsom salt chemically reacts with the sulfate to form new electrolyte and convert the sulfate back to sulfuric acid.Im working on half my battery bank (4 6v) and am going to compare the battery capacity to the untreated 4 to see the difference. will post back once tests are done with the results.

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Old 16-09-2010, 19:07   #3
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Well I will confess. 30 years of mechanicin' and I never heard of epsom salt rejuvenation.

You did say you were already doing it. I guess many of us are awaiting your results!
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Old 16-09-2010, 19:14   #4
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There is a youtube video on it.

I tried it....didn't work
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Old 17-09-2010, 05:07   #5
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Let us know how you make out.

The “experts” don’t generally recommend the use of additives.

In 1925, NBS published a technical news bulletin stating that battery additives do not work. The NBS conducted additional tests over the next few years mostly for the Federal Trade Commission and the Post Office. The tests supported earlier conclusions about the ineffectiveness of battery additives. In 1931 after receiving more inquiries concerning battery additives, the Bureau published Letter Circular No. 302, Battery Compounds and Solutions. While not mentioning any specific brand names, the circular confirmed NBS's previous conclusions.

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AD-X2 Battery Additive - National Institute of Standards and Technology Virtual Museum

Frank Wentzel of Brooksville, Florida writes:

"I spent over 20 years in the battery industry, starting at the Exide battery research center in Yardley Pennsylvania. Battery additives and rejuvenators have been a hot item as long as batteries have been in existence.

Sulfation is the most often mentioned failure mode that these additives are supposed to correct. The problem is that the formation of lead sulfate is the normal manner in which a battery delivers its energy. The active materials in a charged battery are PbO2 (lead dioxide), with a valence of +4, in the positive plate and a porous form of lead called sponge lead, with a valence of 0, in the negative. On discharge the active material of both plates becomes lead sulfate (PbSO4) with a valence of +2. On charging the lead sulfate is converted back into the respective active material. Both the PbO2 and Pb on the plates are conductive, the lead sulfate discharge product is essentially non-conductive. As long as the crystals of lead sulfate formed during discharge are very small, their proximity to conductive portions of the plate permits them to be converted back to active forms. Destructive sulfation occurs when the PbSO4 crystals become larger and more difficult or impossible to be converted back into active material.

This occurs through a phenomenon called Ostwald Ripening. OR causes crystals to become larger over time. The best way you can see this would be to take a small jar of water and add sugar till no more will dissolve and then add another spoonful or two. At first when you stir it the powder in the bottom will swirl around easily. By the end of the day a crust will form on top of the sugar so the powder will no longer swirl. In a few days you will see crystals growing. Over time they may get to be a quarter inch or more in size. In your battery the PbSO4 crystals will be quite a bit smaller, but if you were to take apart a sulfated battery and dry the plates you would see them "sparkle" as light bounced of the crystal faces.

This sulfation is essentially irreversible. Battery manufacturers have tried to combat it since the beginning of the last century. Besides tying up active material the, sulfation also consumes the sulfuric acid electrolyte. As the battery degrades the acid concentration drops and the internal resistance of the battery goes up. This rise in internal resistance further limits the power output needed to start your vehicle. Most battery additives act to decrease the internal resistance which means that, for a limited time, you can more efficiently access the remaining power in the battery. Depending on the application (initial condition of the battery, power requirements, temperature, etc.) you may get anywhere from a week to several months of additional use out of your weakened battery.

One of my first jobs when I joined Exide in 1969, was to analyze a new battery additive called "POW'R". When I complete the analysis I discussed the results with one of the "Old Timers" who had been designing batteries for over 40 years. The major ingredient was magnesium sulfate (MgSO4) otherwise known as epsom salt. He said epsom salt was the old standby for additive charlatans. It gave a quick reduction in internal resistance but could do nothing to renew an ailing battery. There was enough cobalt (Co) in the additive to give it a blue color. My
friend said that cobalt would reduce the voltage required to charge the battery which might help if the car's charging system was weak. The downside was cobalt also causes the battery to self-discharge more rapidly and accelerates corrosion of the positive grid. There was nothing else of any value (?) in the stuff. At the time it sold for $7 a bottle (maybe $30 adjusted for today's inflation).
At that time I told him that a lot of people thought it was possible to make a really long life battery but that the battery companies didn't do it because they wanted to keep sales up. He said there were 5 major companies. The company that could find a way to make a demonstrably better battery (for a price) could blow the others out of the market. If you could dominate the market why would you sit on the idea? He said that he could make me a 15-year car battery The only problem was it would cost five times as much as current batteries and weight 250 pounds.

As to EDTA in batteries, it will increase conductivity of the electrolyte, which may give you a brief reprieve as noted above. In addition, it may increase battery capacity for a time. As a salt of an organic acid EDTA will again become an organic acid when placed in the battery. Organic acids readily attack the metallic lead of the positive grid structure. A small amount of organic acid can consume a large amount of lead grid because the reaction "recycles" the acid back to its original form to continue the attack. The corroded grid material will be able to withstand a few charge-discharge cycles but will fail fairly quickly. Over time (dependent on depth of discharge, frequency of use and temperature) the positive grid will corrode through and the battery will fail.

In other words, a battery that is close to failure might be brought back for a limited amount of time. That will give the battery a chance to finally fail just when you need it most! If the battery is known to be weak, it is best to replace it as soon as possible rather than hoping you won't be in the middle of a serious situation when it does fail. The only valid use I can see for battery additives would be to have some epsom salt in your tool kit so that you can try to get one last start out of a bad battery when caught unaware.

/// Frank ///


Frank Wentzel of Brooksville, Florida writes:

"Shortly after the introduction of pulse-chargers for nickel-cadmium batteries, we (at the Exide lab) tried the same thing with lead-acid batteries. It turns out that the lead acid battery, or even just bare lead grids suspended in acid, acts like a giant capacitor. A car battery may have an equivalent capacitance of several Farads! Therefore any pulse or spike that we attempted to introduce was absorbed by the capacitance effect and had no effect on the battery. The purpose of the experiments was to try to find a way to charge electric vehicle batteries rapidly. A starry-eyed researcher I knew was hoping for a 5 to 10 minute charge! One difficulty would be the amount of power required by the charging station. Considering that an EV battery could have a capacity of 200 amp/hours at 120 volts, in order to charge it in 10 minutes the charging system would have to supply over 1,200 amps at about 150 volts. That's 180,000 watts! A single charging station, with maybe 8 bays, would require as much power as a small town! In any case, we never found a way to rapid-charge a battery without killing it after a few cycles.

As to these battery conditioners, with their claims to rejuvenate the battery by applying as little as 2 watts at high frequency, I class those in the same category as the battery saving "elixirs". Any of you who have played around with elementary electronics are familiar with the DC isolation capacitor used in simple amplifier circuits. A capacitor of 10 microfarads or less is put in series with the input of the ampilfier. This stops the passage of DC but the AC voltage of the audio frequencies goes right through the capacitor. These guys are talking about frequencies 10 to 100 times higher than audio frequencies. At these frequencies a capacitor is essentially a short circuit. The capacitance of the internal conductors of the battery alone would shunt the AC signal from these devices let alone the multiple Farad capacitance of the battery plates.

As I said before, any battery company that could gain a significant advantage over the competition would be able to dominate the market. Batteries are a mature product - everyone knows how to make them. As a result the profit margins are miniscule. A technical advantage would give the company that possessed it a commanding position. Sulfation and corrosion are the two principle failure modes of lead-acid batteries and the battery manufacturers have left no stone unturned in trying to combat them.

The rebuilding of batteries was once a thriving business. Before battery construction was automated (in the late sixties and seventies) batteries cost much more than they do now (after inflation corrections). The old hard-rubber cases and over-the-top cell connections also facilitated disassembly of the battery. In many cases the active material that sloughed off the plates caused short circuits. By disassembling the battery and dumping out the "sludge" a battery could often give considerable additional life. In addition the modular construction facilitated replacement of the negative plates which used to have a problem with "densification". Modern "unibloc" construction techniques and through-the-wall cell connections make rebuilding much more difficult. In addition, the positive plates are now put into microporous plastic 'envelopes" which greatly reduce the incidence of short formation. It is no longer economically viable to rebuild these newer battery designs.

A final comment: the pulse charging that was supposed to permit the fast charging of nickel-cadmium batteries turned out to be a case of wishful thinking. Fast charging of NiCd batteries is not assisted by any pulse technique. All you need to do to safely fast-charge a NiCd battery is watch the temperature and cut the charger off as the battery gets hot. The link below goes into this in some detail.

Red Scolefield worked as a battery engineer for GE in Gainesville, Florida for quite a few years and knows whereof he speaks. Once again, if a technology works it can only improve your market position. There is no reason to bury it as some insist industry does - i.e., buy up the patents and keep the item off the market. If something is patented you can't hide it by purchasing the patent. Doing so would only alert your competitors to the potential of the discovery and it would generally be no problem to use the information from the patent to find a "loophole" in the patent.

This reminds me of an "urban legend" I heard repeated quite often, years ago. Many people believed that years before someone invented a light-bulb that would never burn out. The story goes that the company went bankrupt because they flooded the market and then they could sell no more light-bulbs because no one needed to replace them. My response - was where are your "eternal light-bulbs". I always got a blank look. Then I said if they sold these bulbs until there was no more market then that is what we must all be using now - so where are yours?

It's the same for all these "magic" devices. If they really worked all manufacturers would be using them because they couldn't be competitive otherwise. One telling feature for all these items is the high cost. (A two watt electronic device should sell for $25 or less). Whether it's a battery "rejuvenator", a magnetic water-softener, or a magic "fuel energizer" for your car - the price will be high because the advertising and promotional expenses needed to push the product are high and they know the product will have a short "lifetime" as customers find out they were "had".

/// Frank ///
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"

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