Who has experience with a desulfator for deep discharging lead acid batteries

Honestly, here in Minnesota, once a battery won't charge; the risk of it freezing is just so high; we'd rather fail them on all our equipment than try. So batteries here live a pass/fail life.

I am interested in your work, but it would be unprofessional to comment much if at all. I have 5 batteries in boats, 7 batteries in mowers, and 4 in cars. My wife has more batteries in a Tesla. I used to have a charger that reported sulfication, but I always giggled and said, 'what am I to do then'? The charger did not seem to charge; just report the error state.

with my conservative estimate of 16 batteries, four more are getting added this spring on my boat build and at 20 batteries with an average cost of say $100 each; the investment and lifetimes are important...

Today, I am pulling the last tractor batteries as we are dipping below zero Monday...

 

Thank you Fallguy, Yes cold weather is another problem. The gassing voltage for a lead acid battery will then increase from 13,8 Volt at 25 degrees Celsius to over the 15 Volt for minus 40 degrees Celsius. I thought that your wife's Tesla has lithium batteries and that need a different way to charge. Normally maximum 5 times the C rating of the battery cells. i.e. a 3,3 Volt 20 Amphour cell you can with an older type go for maximum 100 Ampere. (constant current preferable) Except that now with new modern fast charging Lithium batteries, it is much more and could be as much as 10 x C, i.e. 200 Ampere per cell. My lithium batteries are not showing any signs of degradation after 8 years.
The following problems I noticed of those 3 cheap suffocation units is that the frequency is not between 2 and 3 Mhz and that worries me. The reconditioning of an elderly battery is a well known fact. But my cut feeling is that each different lead acid battery type will need a different frequency. The cheap one has a very fast and steep spike, which is good, but I calculated that the higher harmonics does not reach the 2 to 3 Mhz resonance frequency or it is maybe too small in energy. My cut feeling is that I wasted my money and unless the manufacturers will give their secrets away at what frequency their model is in resonances. we can only experiment and that will take weeks. Bert p.s. that the gassing voltage is increasing by cold weather is not that bad, as you will by voltages for over 14 Volt not loose liquid due to exceeding of the gassing voltage
.

 

At the beginning, 4 days ago I was very skeptical and accepted that I was wasting my money, but now after 4 days, I am pleasantly surprised that 1 battery is holding its charge at 12,5 Volt for so far for 5 minutes. I knew that one cell was not right and now it seems to hold its charge. I will still keep the desulfating unit on the battery for another 96 hours and see what the final result is.

(sagm = Sealed Lead Acid AGM deep charging battery)

5/12/2019 08h00 7 Ah/12 Volt slab battery | 24 Ah /12 Volt sagm | 24Ah/12 Volt also sagm | 5 Ah/12 Volt dead battery | 5 Ah/12 Volt dead battery
5/12/2019 17h20 12,64 Volt ..........................|.........10,18 Volt .........| ..................11,27 Volt..........| ......... 4,8 Volt ....................| ................3,56 Volt ...........
6/12/2019 21h47 12,78 Volt ..........................|..........10,44 Volt.........|...................11,87Volt...........|...........7,34 Volt ..................| ................3,60 Volt...........
7/12/2019 18h02 13 Volt I stopped charging|...........11,12 Volt..........|...................12,34 Volt ........|...........8,06 Volt no charge currents of the 2 above I stopped.
8/12/2019 09h08 xxxxxxxxxxxxxxxxxxxxxxx| ..........11,72 Volt.........|.....................12,38 Volt.......| xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
8/12/2019 13h48 xxxxxxxxxxxxxxxxxxxxxxx|.......still charging ........|.....................12,5 Volt holding 12,5 Volt for 5 minutes , will still carry on for 96 hours.

I am careful optimistic. If I was the designer, I would have made the frequency sweeping from 1 to 3 Megaherz, hereby ensuring for whatever type lead acid battery I would hit the resonance frequency. Bert

 

I just found an interesting quote via my old friend Mr google: At the resonant frequency, the sulphate crystals will have the weakest bond among them, so by applying pulse current at their resonant frequency, it is easier to break them and to dissolve them in the electrolyte.

From many sources on the internet, it seems that the frequency range is from 2 to 6 MHz.

Fallguy, it means that indeed one should try to obtain the resonance frequency for a particular type and model battery. Thus the idea to make it sweeping could be not really a bad idea. But those cheap desulfators have in my view a too low frequency selected. But I still carry on with my testing, I could be badly wrong in thinking that it is rubbish and a scam sale via amazon . Bert

 

The desulficator would get pretty complex if there is that much variation.

You would not just run up and down; you'd need to cycle and test and cycle and test. For example, 1x and no result, 2x and some improvement, 3x is best improvement; run system at 3x. Forgive me, I was in an electrical engineering program and it was not my cup of tea. I had a hard time fathoming spending weeks and months of my life chasing hertz. And I mean zero disrespect. My failure was more complex than that. And I wish for you success.

Imagine if say; 10% of batteries could be resurrected, so to speak, if your method was good enough; you could test all cores for sulfication and restore them. Of course, government would almost need to mandate. I know little about battery recycling, but I imagine it is done on a large scale somewhere and you'd need to step into the chain.

And perhaps commercialization is of no interest. But one does wonder how many batteries are failed for this reason.

 

Hi Fallguy, I am sorry to hear that electronics is not your kettle of fish.
First at all the bad news. Over night, the one battery I thought was recovered, did not keep the charge in the faulty cell and the voltage dropped again from 12,5 Volt to 11,3 Volt. This means that the desulfator misses the correct resonant frequency to loosen the crystals. That is my conclusion.
I think differently. If I sweep not too fast then it will reaches the correct resonant frequency every second once. This is better to reach it once per second then not at all. All what it means is that it would take indeed longer to get rid of the crystals formed on the battery cell plate. I will try it it, with a 20 or 40 Mhz PIC18F2431, my favorite microprocessor and see what that could do for me. I don't want to loose 800 to 1000 E pounds of batteries (+/- 1200 Dollar). Let me think whether it will work when I start to sweep between 2 and 3 Mhz and in steps of 100 Herz per Mhz. Let me think about it, in how to do it. It depends on the speed of recovery of the Mosfets. And also how sharp should the resonance frequency actual be. Let me ask my dear friend Mr Google what he has to say. Bert

 

Fallguy, I have a problem with getting information how sharp the resonance frequency has to be. I mean it has to be on the dot in the middle of the resonance frequency or can it be a few or lots of Hertz out, Mr. Google has not been able to help me. Do you have any suggestion in where I could find that information. The PIC microprocessor is able to do the job with 20 outputs, of which each could trigger a MOSFET to get a sharp spike with 2nd, 3rd etc harmonics. To step from the one to the next output can be up to 10 Hertz or any Hertz later also with time inter-falls to give the spike to do its work. Maybe you have some suggestions I did not think of it. I tried to get answers from the How to Restore Lead-acid Batteries https://batteryuniversity.com/learn/article/how_to_restore_and_prolong_lead_acid_batteries/comment ,but struggle to get my question loaded.
Bert

 

Hi Fallguy, It appears that I was right and that we will have to do some sweeping of the frequency to get proper result. refer Mr Google :
Pulse conditioning products
It appears that BatteryMINDer was one of the first companies to produce a pulse conditioning desulfator and they have "patented frequency sweep technology" which may be superior to some other products.[8]

Please correct me it you think I made a mistake somewhere on the line. I can take criticism.

Well it means we have to go the PIC 18F2431 way. But must it be in steps of 1 Hz, 10 Hz, 100 Hz. and should the stepping stages be 10 seconds at a oscillation frequency. The PIC18F2431 takes 1 step at 0.05 uSec if I have a 20 Mhz oscillator and 0,025 uS at 40 Mhz. I will get a 40 Mhz crystal from the local shop next week, in the meantime lets try it at at 20 Mhz. It means that if I do it in steps of 100 Hz from 2 Mhz to 6 Mhz, it means 20.000 steps x 4 ( from 2 to 4 Mhz) = 80.000 steps. with a 20 Mhz PIC 18 crystal = if each steps stops and oscillates at that frequency, for 10 seconds to give it time to oscillate at that frequency, it will take some 80.000 x 10 seconds = 800.000 seconds /3600 = 222 hours to have the whole spectrum covered. Thus I am going for 80.000 steps but only 10 millisecond at that particular oscillation frequency and not 10 seconds. That would mean 0,2 hours for covering the whole frequency band. I am going to try that. If anybody can help me to find out how the relationship between the size of a battery and the resonance crystal oscillation frequency is for that size battery, it would cut quite some time. Bert

 

Hi Fallguy, I have really bad news for myself. I measured the pulses from those 4 desulfation products and I cannot believe that pulses with a 20 mV spike with a base of 1 mV and repeated every 5 mS, that they have enough energy and will sulfate my deep charging batteries. I had a Crystal XI 200oVA charger/invertor on which I dropped a 12 Kg battery accidental. Needless to say that it took me days and days to have it repaired without a circuit diagram and with chip resistors and capacitors which are 1 mm by 0,5 mm in size. To make a block diagram and circuit diagram was a nightmare. I had to replace one 130 Amp/75 Volt MOSfet which was shortened because the chip resistor was crushed by the shock or whatever the heavy battery did and blew that MOSfet when I was testing it. I even had to make a little spanner of 5,5 mm hex screws to loosen 7 screws to replace 1 Mosfet. Who has a 5,5 mm spanner in his toolbox. Not me, yes 4 ,5 , 6 mm etc but not 5,5 mm. The fan was crushed and with super glue I had the casing and one wing glued back again. I am pleased to state that it is all working again. So now I had a chance to get deeper into this desulfation problem. How more I read about it, how more I am convinced that some units indeed are able to improve the life span of a deep charging lead acid battery. But definitely not those cheap Amazon units I bought.

Here are my questions I need to find answers on.
1) What energy is needed to get the crystals to come into resonance.
2) What center frequency is right for a small 12 Volt battery and what is the center frequency for a larger battery.
3) Are all answers applicable to a Lead Battery Acid cell or also to a complete 12 or 24 Volt battery.
3) How long should the resonance oscillation frequency have to stop at that point to loosen the crystals, 1 Micro second? 1 Milli second? 1 Second or longer?
4) What makes the frequency shifting from between 2 to 6 Mhz, why not all at one particular frequency?.

If I can get answers on all of the above, it would be possible to make a sweeping pulse oscillator which would really work. My apology Fallguy, this is going to take Months and Months. Maybe I will never get it right, but who knows.
I will keep everybody updated in the Months to come.
Bert


On April 9, 2012 at 1:58pm
John Fetter wrote:
Chris C. - Lead-acid chemistry is most definitely well understood. There is plenty of excellent literature, Handbook of Batteries by David Linden; Lead-Acid Batteries by Hans Bode; Electrochemical Power Sources by Monty Barak and, of course, Storage Batteries by George Wood Vinal and so on.

There is an abundance of information on so-called pulse desulfation at the United States Patent & Trademark Office, uspto.gov/patents/process/search. Use their boolean search facility. Start with “lead acid” in field 1 and run through “sulfate”, “sulfation”, “pulse”, “pulsing”, etc. in field 2. A picture soon emerges. The patents are all written by inventors who describe their own version as correct and all previous versions as flawed. You will find at least 70 patents if you look long enough. There is not one explanation that holds water.

Lead-acid battery manufacturers are fully aware of the problems with low maintenance and maintenance free batteries. They all make the same type and therefore the consumer cannot avoid the problems. Two out of every three batteries sold are replacement batteries. The industry relies for its very existence on the replacement market. A bright young engineer in a battery factory would be ill advised to go to his boss with a new idea on how to make batteries that last longer. Not a career enhancing thing to do.

Pulsing must provide at least some benefit, otherwise there would not be thousands of desulfation pulse merchants making a living around the world.

The positive active material is lead-dioxide. Lead-dioxide is a semi-conducting material. When it is housed in a lead-antimony grid, the antimony and dioxide remain firmly in contact. When housed in a lead-calcium grid, an ultra thin oxide layer of a different kind builds up over time between the grid metal and the lead-dioxide, which takes just long enough for the battery to survive a couple of years. Manufacturers add a little tin to try and prevent this problem but it is not very effective.

The term sulfation is overused. No one bothers to check whether it actually describes what has really happened inside the battery. Most of the people who work on pulse equipment are electronics oriented. Do not really understand batteries very well. They assume the other guy knows what he is talking about. It is not unusual to have millions of people convinced they know what is going on and then one day to discover they were all wrong.

I am a lone voice in the wilderness. I am perfectly content to be so. John Fetter.


Fallguy lets see what the future brings. Maybe the lithium batteries will be replaced by a simple new type of battery, who knows. Maybe I am wasting my time. Bert

 

I had some time to do some research and have some idea's which may bring 2 batteries back, which I cannot use as they are in anyway below 12,5 Volt. First lets have a look at all those cheap units I was so stupid to buy 4 of them. My personal view is that they are frauds. The pulse is 20 mV peak and the base frequency is about 100 Khz. That means that if we look at my attached Boatdesign-sketch that the 3rd or 4th even harmonic frequency is about a few Micro Volt. There is no way that those few micro Volts can bring the crystals in resonance and have them removed from the anode of a battery. I tried those cheap so called desulfation units on a 9 Volt miniature Lead acid battery and there was absolute no improvements. I will sent them back to Amazone.uk and request a refund for their in my view fraudulent selling product. But the fact is, a lead acid battery could be recovered by a resonance frequency between 2 and 6 Mhz. That is a proven fact. But nobody can tell me a) the resonance frequency per battery size, b) the intensity. Thus if we make a system whereby the even harmonics are between 2 and 6 Mhz. I am planning to sacrifice those 2 expensive batteries, which has dropped to 10 Volt.

How am I planning to do it? Well I take a 24 Volt power source and as per sketch, discharge a capacitor via a MOSfet and by taking different capacitors, I will generate different frequencies in the hope I will hit the right note and have the crystals dropping from the anode. This reminds me when I was driving my sports car when I was young and drove over gravel road for a few hunderd kilometer and suddenly all kinds of products like my window handles started to disintegrate and dropped on the ground. Lucky it did not affected my vital components like my engine. Those broken products just came into resonance.

To explain the circuit. The PIC18F2431 microprocessor has at least 10 outputs. each output drive a MOSFET which charges the capacitor and a MOSFET which discharges the Capacitor into the "BAD battery" By having 5 or 6 capacitors supplying a second and all further even frequencies between 2 and 6 Mhz some of them should bring the crystals in resonance. So lets hope so. But Fallguy it will take months and weeks before we may see some result. Bear with me. Bert

 

I am so sorry Bert, but I am not smart enough to help.

I would probably go about it differently and try to pin down the frequencies better, so that you are not wasting time on useless bands.

But how?

I am only able to be a google expert and this link says frequency shopping is bad.

https://batteryuniversity.com/index.php/learn/article/sulfation_and_how_to_prevent_it

 

Hi Fallguy. No, you are of a great help. Certainly you are smart enough. I am a strange fellow, I don't like to talk to the wall, but love to have somebody who listen and motivate me. I am of a different opinion. Having also searched the internet, I did read that article and subsequent later articles which are contradicting the fact what was written in the BU-804b article. First at all. It is a fact that crystals formed on the anode could be broken away by the right frequency bringing those crystals in self oscillation resonance, like what happened to my pewter door handles from my sports car when driving over a gravel road at fast speed. Like tonight when I dropped 5 eating plates accidentally and one disintegrated to 3 pieces, while it was regarded as impossible to break this type of material. Unfortunately my wife is already sleeping, but tomorrow I will get the name from her. The drop had to do with a very short vibration of the right frequency.

Secondly it is a fact that the frequency has to be between 2 and 6 Mhz. Most likely because of size, shape and kind of anode construction, the right frequency will be somewhere there between 2 and 6 Mhz for my batteries.

I believe that those other eating plates also were subject to a vibration, but at a different frequency,and therefore did not explode. Thus I believe, that having multiple frequencies at the same time bombarding the anodes of a battery going bad, will not damage the anode. And if the right frequency is found and applied to the crystals they will come lose. Provided the energy does not heat the battery up, but brings the crystals in self resonance.

By having chatted to you, I started to formulate my idea what could work. I have applied for lots of provisional patents and sold quite a few thereof and only 1 patent in my name, but the Large International Electrical company I worked for, decided not to extend that patent after 7 years because the mining engineers, not only were most of them old in age, but did not understand electronics. Today a number of mining companies are using this patent free of charge as it is not extended.

There are two provisional patents I really liked from all the ones I registered. I hated to have a BMW pushing 2 meters behind my Mercedes as the BMW want to have me driving faster. Thus I made a compressed air cylinder with a rolled up trunk, which rolled out when pressing a button and at the end I had a big fist stating" keep distance". Those guys always had the fright of their life. Needles to say that the large International company was not willing to put money in that project. ( The director himself had a BMW) The other one was, when Philips Holland came out with a small 12 Volt radar component, I made an electronic system whereby this radar unit let my car go slower when I was too close to the car in front of me. It got the speed from a wheel sensor and I had a table with safe distances. The large International company also told me, too dangerous. Today, some 35 years later Mercedes has it build into their cars. You must understand, when I joined this company, I had to sign that all my ideas were their property. Every time they did not wanted to put money in an idea, I had to beg them for permission to sell the provisional patent.

So enough bragged, now let see whether we can make something what may work for my gone bad batteries in the hope that I hit the right idea and hope that you will motivate me, by sometimes telling me I am an idiot etc. while I will struggle in the months to come, as I don't think it will be an easy task.

Is that a fair deal? Bert

 

With my remarks to the previous thread. The name of the material of those eating plates is Melamine. Bert

 

Marry Christmas to you all. Trust that you all have a piece and pleasant Christmas.
Fallguy, I have now a great problem. Lets say I am able to make it work for my batteries and that I have been able to find the right resonance frequency for my type of battery. That does not mean that this will also work for your battery. The plates are different, the size maybe different. That is going to make me the same sort of fraud person as all those out there claiming that their units work.

But I do appreciate if you sometimes give your opinion. I am 79 and can take a knock.

This is what I like to do:
Select a capacitor which base frequency is at 1,5 Mhz, therefore the first even harmonic is 3 Mhz, the 2nd even harmonic is at 6 Mhz . I will let that run for 1 day and measure the battery. Then I will add a small capacitor and the frequency changes to 1,49 Mhz ( it slows down by adding a small capacitor}. therefore the first even is 2,98 Mhz the second even is 5,96 Mhz and I repeat the check. Than again I add a small capacitor it will be 1,48 Mhz , 2,96 Mhz, 5,94 Mhz. From my experience if the resonance is close, it normally pulls the product into resonance.
Well have a lovely Christmas and let see what will happen.
Bert

 

Christmas has been good for me, as my daughter gave me a different de-sulfator as a Christmas present. Sadly she probably wasted her money. The pulsating pulses are totally different then those cheap ones, previously tested. Although this one is also not expensive. No literature with it, no proof why it works, thus we have put it on the batteries. This is a total different Oscilloscope screen then those cheap ones previous tested. This one, the base frequency is 10 KHz (also too low in my view) and has a lot of "white frequencies which could cover the 2 to 6 Mhz spectrum. Bert