Has anyone actually successfully desulfated a battery?

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I've been messing around with trying to bring new life to batteries which still work, but are clearly aged. For example, I have some AGM and maintenance free batteries that will only hold 12.2 - 12.5V. I was doing some testing such as hooking them up to a cheap eBay pulsing desulfator, or briefly overcharge them @ 16V to see if it would help. None of that seemed to do anything.

So I'm just curious if you guys could share your experiences with desulfating batteries? Do any of the electronic means or strategies to "knock off" some of the sulfation on the lead plates actually do anything? Do any of the chargers that claim to have a desulfate feature actually work any better?
 
Get an intelligent charger like C-Tek and don't go cheap, it will pay dividends especially if you have several batteries.
 
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I've used a Battery Tender Jr. on a few weak ones-it takes a while,but eventually there is some testing improvement (as shown by my cheap HF impedance type battery tester). Nothing makes them like brand new, though.
 
Originally Posted by Pelican
Get an intelligent charger like C-Tek and don't go cheap, it will pay dividends especially if you have several batteries.

I agree. Take a look at the CTEK Multi US 3300 - https://bit.ly/2IQTE4R

Ed
 
The Battery Minder has a good chance of helping. It can take a week to a month according to the manufacturer. I am guessing but assume some batteries are good candidates and some are not. I am not sure if you can look into the cell and tell. And I am not sure what I should be looking for. Will it just knock off the sulfur crystals or put them back into solution.

I put the Battery Minder (I think I have 5 now) on batteries not used in the winter and hope/assume it helps some.
 
I use a small old 6 amp charger and just charge the battery for a few days. If you can look into each cell, eventually every second plate will go from grey to black. This is what you want to see. Keep an eye on the charge rate, you don't want it to start climbing. It should stay under 1 amp for the last day or two. This will recover a battery to some extent but there is nothing like a new battery. If you put a 12v light bulb in series with a charger you can lower the charge rate which is a good thing. This applies to the old buzz box chargers, not the newer electronic gizmos.
 
The marine guys who can perform actual capacity tests, meaning they load the battery with a precise amperage load for 20 hours keeping the battery at 77f in a water bath, have tried all sorts of 'pulse' Desulfating chargers and none of the results have ever come back any higher than what a normal extended time held at higher voltage would achieve.

A true capacity test of a 100Amp hour flooded battery would require the battery be held at precisely 77F, and the load held at a constant 5 amps for 20 hours, which is not easy to achieve as as battery voltage drops the loads amperage will likely also change.

I believe in some narrow cases the pulses might be beneficial, but by and large, the general view that a pulse desulfation is effective, merely shows how effective marketing is, rather than actual verifiable results using actual measuring tools and collecting data, performing before and after experiments controlling the variables in order to make any relevant conclusion..

If you want to try and revive a battery, after it is 'fully' charged, load it with 10 to 15 amps of load per 100Ah of capacity until the voltage falls below 10.5v under that load. Take note of how long this took, for later comparison using the same discharging loads. Immediately apply no less than 20 amps of charging current per 100Ah of capacity (Odyssey AGM says no less than 40 amps per 100Ah of capacity) and hopefully this charging source will hold that amperage until mid to high 14 volts is achieved at the battery terminals. One there, it should be held until amperage tapers to very low numbers for AGM and less than 1.5 amps per 100Ah of capacity for flooded. This time span after achieving 14.4+ at the battery terminals, is no less than 3.5 hours and might take 10 times that depending on the condition of the battery.

While this method is way outside the 'trickle charge it is always best', grandpa's advice which was wrong both then and now, the higher amperage causes heating of the hardened sulfate, and stands the best chance of driving it bck into the electrolyte solution, in my opinion.

Keep voltage at 77f battery temperature from exceeding 15, until amperage tapers to very low levels. hotter batteries, lesser voltage, colder batteries higher voltage.

Dot not allow battery to exceed 120f but it will rise very quickly from 105f to 120f, so be on the look out for quick increases of battery temperature, and do not try these hail mary recharges in hot ambient temperatures. unless very closely monitored.

Flooded batteries will offgass a lot, ventilate the area properly, and use eye protection when getting near the battery and wear clothes you do not care about. Baking soda dissolved in water is good to have on hand to neutralize battery acid.

AGMs can have the valves release some pressure. Many people think this is instant death of the AGM. They are wrong. They are not one time vents and a single release it not going to cause them to 'dry out' as you will read about on forums such as these. The vents also do not open easier on subsequent monitored overcharges.

True equalization charges of flooded batteries requires upto 16.2 volts (At 77*F/25*C)and a battery will require 5 to 6.5 amps of current per 100Ah of capacity to get voltage up that high initially. These should only be initiated after the battery has spent many hours held at 14.5 to 14.9v. One should not attempt without a hydrometer, compensating for rising electrolyte temperature, no longer shows any gains in electrolyte density. One specific gravity stops rising there is no point in continuing. AGMS require an accurate ammeter since one cannot take electrolyte readings. Amperage will bottom out at some point at a constant 14.x volts, and will likely stay there on healthy batteries, and start rising again at some point on less healthy batteries. This might be the beginnings of thermal runaway, which is to be avoided.

Concorde AGM, who make Mil-Spec AGM batteries have a conditioning procedure as well as a deep discharge recovery procedure one can read about here:

http://lifelinebatteries.com/wp-content/uploads/2015/12/6-0101-Rev-E-Lifeline-Technical-Manual.pdf

Odyssey's reconditioning procedure is here:

https://www.odysseybattery.com/documents/ODYSSEY_Battery_Reconditioning_Charge_Procedure.pdf

Note that the procedures are not able to be achieved with just any off the shelf charger, they require higher amperage capability and the ability to both seek and hold higher voltages for longer durations than any 'smart' charger will allow, as they are basically intentional overcharges. Smart chargers are all about NOT overcharging, and as such they are basically automatic smart 'underchargers' which will compromise longevity compared to a charger capable of reaching a true 100% state of charge each time.

Somebody with a garage charger has no chance of performing true recovery procedures. Even stopped and restarted multiple times a 'smart' charger has little chance of recovering lost capacity. The desulfating charger holding the battery at 13.6v for weeks on end, will likely have no different results than a NON 'pulse 'desulfating charger holding the battery at the same voltage for the same amount of time.

Rolls Surrette is pretty much the top dog in the deep cycle flooded battery department, their literature is also well written

http://rollsbattery.com/public/docs/user_manual/Rolls_Battery_Manual.pdf

The person who reads and comprehends the Concorde and Rolls user manuals will have a better understanding of lead acid batteries than 99.99% of the people who respond about batteries on the internet. The rest just want to believe marketing and the wiseness of the purchase whose product marketing they fell for.

Trojan also has well written documentation on the proper care and feeding of lead acid batteries:

https://www.trojanbattery.com/pdf/TrojanBattery_UsersGuide.pdf

https://www.trojanbattery.com/tech-support/battery-maintenance/



Batteries are just rented, their contract length is determined by how they are treated. They always want to be kept cool, and fully charged and todays starting batteries are made as cheaply as possible. Where deep cycle manufacturers cant get away with such shenanigans.

Hail mary attempts at returning capacity to sulfated batteries is by and large futile for most of the battery using population, as it requires special equipment and knowledge more costly than a new battery.

Seeing this, the marketers have fastened onto 'pulse desulfation' as their latest goto for max profit.

Unless the charger is taking the battery up into the 15.5v+ range after a normal 'full' charge, any restoration of capacity or performance is extremely doubtful, and it is my opinion a quick 100% depletion of the battery, followed by a higher amp recharge until amperage tapers to very low numbers at voltages in the 14.4 to 14.9v range, stands the best chance at being effective. After this high amp recharge to low amperages in the high 14's, then higher voltages can be initiated, but the battery must be monitored for heat build up and possible thermal runaway.

Overcharging does degrade the battery if done excessively. The perfect recharging regiument would stop once the battery is inded fully charged, but this is a moving target. No product can achieve this every charge cycle on each and every battery, and the ones which can come the closest, automatically, are in teh 350$+ dollar range and still require being programmed for the specific batteries in a specific usage by a human capable of determining and testing the efficacy of those settings.

Starting batteries are at the mercy of the vehicle's voltage regulation and underhood temperatures. Wiser battery 'owners' will seek to return the battery to as close to 100% charged as their equipment will allow, on a regular basis.

Those cycling lead acid batteries better be able to afford to simply replace them when they have lost too much capacity for the intended usage, or they figure out how to properly and promptly recharge them to full as often as possible to get the most total KWH delivery from them, over their lifespans. the equipment which allows one to approach ideal chrging, can cost as much as many sets of new batteries, so accepting lesser longevity using less than ideal charging sources, is a valid strategy, for some.
 
I had a Sears Diehard (maintenance free....lol) at 3 yrs old that was extremely low on water and heavily sulfated. The car wouldn't even start at that point. It was putting out around 10-11 v. At that point I used my fixed marine battery charger (0-10 amps). I just charged the cr@% out of it over several days. The very first equalizer charge took like 8-12 hours to get a green 'charged' light on the unit. After about a week it was holding a charge decently. Must have added 1-2 pints of DI water to get it back to normal. Much of the sulfation went away....and there had a been a lot of it nearly blocking all the cells. From that point on I would still charge it every week for 15 minutes at a fixed 0-2 amps. The next time the car wouldn't start (3 yrs later) that was it. Time for a new battery.
 
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I use a DC power supply to charge each battery at least monthly at 14.4VDC (temperature-corrected) for ~ 24 hrs.

A few times per year, I'll supply an equalizing charge voltage of 15VDC for several hours.
Note: I once forgot and left our Legacy's battery at equalizing voltages for something like 6 hours and there was definitely some electrolyte loss. Adding Some CRC battery cleaner to the top of the battery resulted in a lot of RED color change, too, indicating the presence of acids.
So, be careful. If you don't have the ability to pay attention to these things, then just buy a smart charger.

This is all I ever intend to do to keep my batteries healthy.

//

I've used dumb chargers, on the lowest 1A setting and seen higher than 16VDC before! These things are NOT meant to be left on for any longer than to fully charge the battery. When the ammeter drops to near-zero, turn that freaking thing off!

//

Sulfation is a chemical reaction with the plate material. Removing it removes some of the plate material. Higher voltages will also corrode the plate material, which is why charge voltages (14.4VDC) and especially float voltages (15VDC+) need to be limited. While higher voltages are required to ensure all cells are fully charged, they need to be limited due to corrosion and off-gassing concerns.
 
It should be noted (as an old EV head) that capacity loss due to aging is rarely recoverable via desulphator unless that battery (even if sealed) needs water.

Most car batteries have thin plates that shed then short out which also is not recoverable

The situations where a desulphator works are limited but it also costs very little to try so no harm no foul but it likely won't work unless it's a newer battery that was overdischarged suffering infant mortality

Good Luck
 
Originally Posted by Rmay635703


Most car batteries have thin plates that shed then short out which also is not recoverable



What about AGM batteries where the plates are held in place by a permeable separator?
 
AGM shouldn't sulphate (that's the point) but they can dry out and break separators.

Turning them upside down occasionally helps, or if they are marginalized drill and add water or acid

Usually if they fail their junk
 
Originally Posted by wrcsixeight
The marine guys who can perform actual capacity tests, meaning they load the battery with a precise amperage load for 20 hours keeping the battery at 77f in a water bath, have tried all sorts of 'pulse' Desulfating chargers and none of the results have ever come back any higher than what a normal extended time held at higher voltage would achieve.

A true capacity test of a 100Amp hour flooded battery would require the battery be held at precisely 77F, and the load held at a constant 5 amps for 20 hours, which is not easy to achieve as as battery voltage drops the loads amperage will likely also change.

I believe in some narrow cases the pulses might be beneficial, but by and large, the general view that a pulse desulfation is effective, merely shows how effective marketing is, rather than actual verifiable results using actual measuring tools and collecting data, performing before and after experiments controlling the variables in order to make any relevant conclusion..

If you want to try and revive a battery, after it is 'fully' charged, load it with 10 to 15 amps of load per 100Ah of capacity until the voltage falls below 10.5v under that load. Take note of how long this took, for later comparison using the same discharging loads. Immediately apply no less than 20 amps of charging current per 100Ah of capacity (Odyssey AGM says no less than 40 amps per 100Ah of capacity) and hopefully this charging source will hold that amperage until mid to high 14 volts is achieved at the battery terminals. One there, it should be held until amperage tapers to very low numbers for AGM and less than 1.5 amps per 100Ah of capacity for flooded. This time span after achieving 14.4+ at the battery terminals, is no less than 3.5 hours and might take 10 times that depending on the condition of the battery.

While this method is way outside the 'trickle charge it is always best', grandpa's advice which was wrong both then and now, the higher amperage causes heating of the hardened sulfate, and stands the best chance of driving it bck into the electrolyte solution, in my opinion.

Keep voltage at 77f battery temperature from exceeding 15, until amperage tapers to very low levels. hotter batteries, lesser voltage, colder batteries higher voltage.

Dot not allow battery to exceed 120f but it will rise very quickly from 105f to 120f, so be on the look out for quick increases of battery temperature, and do not try these hail mary recharges in hot ambient temperatures. unless very closely monitored.

Flooded batteries will offgass a lot, ventilate the area properly, and use eye protection when getting near the battery and wear clothes you do not care about. Baking soda dissolved in water is good to have on hand to neutralize battery acid.

AGMs can have the valves release some pressure. Many people think this is instant death of the AGM. They are wrong. They are not one time vents and a single release it not going to cause them to 'dry out' as you will read about on forums such as these. The vents also do not open easier on subsequent monitored overcharges.

True equalization charges of flooded batteries requires upto 16.2 volts (At 77*F/25*C)and a battery will require 5 to 6.5 amps of current per 100Ah of capacity to get voltage up that high initially. These should only be initiated after the battery has spent many hours held at 14.5 to 14.9v. One should not attempt without a hydrometer, compensating for rising electrolyte temperature, no longer shows any gains in electrolyte density. One specific gravity stops rising there is no point in continuing. AGMS require an accurate ammeter since one cannot take electrolyte readings. Amperage will bottom out at some point at a constant 14.x volts, and will likely stay there on healthy batteries, and start rising again at some point on less healthy batteries. This might be the beginnings of thermal runaway, which is to be avoided.

Concorde AGM, who make Mil-Spec AGM batteries have a conditioning procedure as well as a deep discharge recovery procedure one can read about here:

http://lifelinebatteries.com/wp-content/uploads/2015/12/6-0101-Rev-E-Lifeline-Technical-Manual.pdf

Odyssey's reconditioning procedure is here:

https://www.odysseybattery.com/documents/ODYSSEY_Battery_Reconditioning_Charge_Procedure.pdf

Note that the procedures are not able to be achieved with just any off the shelf charger, they require higher amperage capability and the ability to both seek and hold higher voltages for longer durations than any 'smart' charger will allow, as they are basically intentional overcharges. Smart chargers are all about NOT overcharging, and as such they are basically automatic smart 'underchargers' which will compromise longevity compared to a charger capable of reaching a true 100% state of charge each time.

Somebody with a garage charger has no chance of performing true recovery procedures. Even stopped and restarted multiple times a 'smart' charger has little chance of recovering lost capacity. The desulfating charger holding the battery at 13.6v for weeks on end, will likely have no different results than a NON 'pulse 'desulfating charger holding the battery at the same voltage for the same amount of time.

Rolls Surrette is pretty much the top dog in the deep cycle flooded battery department, their literature is also well written

http://rollsbattery.com/public/docs/user_manual/Rolls_Battery_Manual.pdf

The person who reads and comprehends the Concorde and Rolls user manuals will have a better understanding of lead acid batteries than 99.99% of the people who respond about batteries on the internet. The rest just want to believe marketing and the wiseness of the purchase whose product marketing they fell for.

Trojan also has well written documentation on the proper care and feeding of lead acid batteries:

https://www.trojanbattery.com/pdf/TrojanBattery_UsersGuide.pdf

https://www.trojanbattery.com/tech-support/battery-maintenance/



Batteries are just rented, their contract length is determined by how they are treated. They always want to be kept cool, and fully charged and todays starting batteries are made as cheaply as possible. Where deep cycle manufacturers cant get away with such shenanigans.

Hail mary attempts at returning capacity to sulfated batteries is by and large futile for most of the battery using population, as it requires special equipment and knowledge more costly than a new battery.

Seeing this, the marketers have fastened onto 'pulse desulfation' as their latest goto for max profit.

Unless the charger is taking the battery up into the 15.5v+ range after a normal 'full' charge, any restoration of capacity or performance is extremely doubtful, and it is my opinion a quick 100% depletion of the battery, followed by a higher amp recharge until amperage tapers to very low numbers at voltages in the 14.4 to 14.9v range, stands the best chance at being effective. After this high amp recharge to low amperages in the high 14's, then higher voltages can be initiated, but the battery must be monitored for heat build up and possible thermal runaway.

Overcharging does degrade the battery if done excessively. The perfect recharging regiument would stop once the battery is inded fully charged, but this is a moving target. No product can achieve this every charge cycle on each and every battery, and the ones which can come the closest, automatically, are in teh 350$+ dollar range and still require being programmed for the specific batteries in a specific usage by a human capable of determining and testing the efficacy of those settings.

Starting batteries are at the mercy of the vehicle's voltage regulation and underhood temperatures. Wiser battery 'owners' will seek to return the battery to as close to 100% charged as their equipment will allow, on a regular basis.

Those cycling lead acid batteries better be able to afford to simply replace them when they have lost too much capacity for the intended usage, or they figure out how to properly and promptly recharge them to full as often as possible to get the most total KWH delivery from them, over their lifespans. the equipment which allows one to approach ideal chrging, can cost as much as many sets of new batteries, so accepting lesser longevity using less than ideal charging sources, is a valid strategy, for some.





And this, dear reader, explains why battery electric cars will NEVER replace internal combustion cars...
 
I have no clue really. Have I extended the useful life of my batteries by occasionally using low amp maintainer to bring the voltage back up? I'd have to say most definitely.
 
Originally Posted by A_Harman


And this, dear reader, explains why lead acid battery electric cars will NEVER replace internal combustion cars...


Fixed it for you,


Your conclusion is about 20 years out of date, lead acid isn't used for EVs anymore
 
Not sure how you rate success exactly. I bought a Stanley Smart Charger from Walmart around $50. It has a regenerate cycle on it that will usually run several days.
I have had 2 mid grade Walmart batteries rated for 2 years that I bought in 2012. Just replaced 1 and the other had some struggles in real cold weather if not driven daily. It sat for a week a month ago and started fine. I was expecting to jump start it but no need. I hit every battery a few times a year with it and it makes a huge difference. Before this charger I would get 1.5 to 3 years out of the same type of Walmart battery.
 
Originally Posted by Rmay635703
Originally Posted by A_Harman


And this, dear reader, explains why lead acid battery electric cars will NEVER replace internal combustion cars...


Fixed it for you,


Your conclusion is about 20 years out of date, lead acid isn't used for EVs anymore



Only when electric vehicles are used in a relatively short radius and in a large metropolitan area is where they make sense. Which is fine by me... Nothing wrong with that.

Still have to wonder where the initial power is generated from... And I'm sorry but all these people who love "green" energy... Don't truly believe in it... Because they might actually have to live like a true "off the grid person"... Which 99 percent of those people do not want to live like that.... Just like that world Champion owning two extremely large houses separted by 2k plus miles... Think that guy lives like a off grid person?? Highly highly doubt it.






The "magic rainbow" powered batteries you want to believe in... Don't exist either....

The math is quite complex.... But for a magical rainbow powered battery you want so desperately to believe in would have 0 chance of moving a larger vehicle that most people in this country actually want to drive... That battery would weigh almost has much has the vehicle. And no range... Like what a regular powered vehicle does have...
 
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As a battery sulfates particles of lead fall to the bottom of the battery. As the battery loses lead it at the same time loses capacity, thats why it does`nt take as long to charge a sulfated battery. Engines that start quickly will usually show no problem until it completely fails. Since the lead is resting at the bottom of the battery there is no possibility of saving those batterys.
 
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