Export thread

Perhaps a desulfator used from the beginning will prevent sulfate buildup on cell plates, but after weeks of testing a desulfator / charger on the two weak 75 ah cells taken out of my Ryobi 480e (replaced all cells with 100 ah) there was zero improvement. I have purchased a lab power supply, and a 12V to 120V inverter to try a different cell refurbishment method. Anyone interested stand by for results over the next few weeks

Keith

PS: Anyone know the CCA rating of new 75 ah Ryobi batteries? My quick test for results is a CCA check (long test is a controlled discharge with the 12V to 120V inverter at a set discharge rate), but I don't know what "good" results would be... I "think" it is in the 300 CCA range but real information would be welcome.

Fourdoor said:

Perhaps a desulfator used from the beginning will prevent sulfate buildup on cell plates, but after weeks of testing a desulfator / charger on the two weak 75 ah cells taken out of my Ryobi 480e (replaced all cells with 100 ah) there was zero improvement. I have purchased a lab power supply, and a 12V to 120V inverter to try a different cell refurbishment method. Anyone interested stand by for results over the next few weeks

Keith

PS: Anyone know the CCA rating of new 75 ah Ryobi batteries? My quick test for results is a CCA check (long test is a controlled discharge with the 12V to 120V inverter at a set discharge rate), but I don't know what "good" results would be... I "think" it is in the 300 CCA range but real information would be welcome.

Click to expand...

Desulphating will only work if the battery has sulphated
Sulphating happens when the battery has been run down dead flat and let to stand that way for extended time .

When you use a desulphater you generate explosions of gas on the plate surface with knocks the old deactivated paste off allowing the active paste underneath to get reverted to charge the battery
Every time you run one you loose paste thickness and active paste thickness is what determines the Ah of the battery
The thicker the paste the longer it will run, past grain sizes being equal .

Now the caveat to this is PVR SLA AGM batteries.
In these batteries the space between the paste surfaces is occupied by a fiberglass mat .
The purpose of the matt is to support the plate and make it more vibration fatigue resistant because the grids now days are very very thin, typically around 0.75mm to 0.5mm .
in the old days they were 3mm to 2 mm thick which is what made them so heavy, If you are over 40 then you will remember the old days of the 13 plate car bateries that took 2 big beefy blokes to pick up .
Now days the proverbial 40 lb weakling can carry one in each hand without breaking into a sweat.

Now the you-beaut fancy charger can not blow away the sulphated surface of the paste because that sealed battery is pressure valve regulated ( PVR ) to prevent the gassing at the plate that your charger is trying to make happen .

Once a modern battery is dead, then it is dead .
A dumb charger can revive a dead flat battery but not a totally used up deceased battery
Auto chargers can not tell the difference between a dead flat battery & a fully charged battery which is why you need an old fashioned dumb charger and in particular one that uses a stepped transformer where you can adjust both the voltage ( in 2 volt steps ) and amperage .
Expept to pay over $ 1000 for one of them and buy a pocket timmer because they are not called battery cookers for nothing .

And do not bother looking at any "how to regenerate your battery" videos on your tube.
They are all total BS
Some solutions like EDTA or DMG can be use to complex used paste then cause it to precipate down the bottom of the cell , from where it can be washed out, from OPEN CELL batteries not sealed batteries .
The best thing to do is open your wallet & buy a spiral cell battery of which Optima are the most commonly known brand
They are head & shoulders better than flat plate batteries because they have more surface area than a rectangular plate battery and the plates are continious so you get far less internal resistance between the grid & the busbars that take to power to the terminals .

However like everything that is substantially better, they are substantially more expensive

plates also buckle and the pieces and detritus that falls off them eventually short the cells out. Average life of a car battery in the USA is about 4 years. Some more, some less. If it dies at 4 years, replace it. I remember one for a boat I spent weeks on trying to revive it. Got the voltage, got the correct reading in a hydrometer. Died after about the 3th or 4th second of cranking. Since then it is quicker to replace than screw with one.

bertsmobile1 said:

Desulphating will only work if the battery has sulphated
Sulphating happens when the battery has been run down dead flat and let to stand that way for extended time .

When you use a desulphater you generate explosions of gas on the plate surface with knocks the old deactivated paste off allowing the active paste underneath to get reverted to charge the battery
Every time you run one you loose paste thickness and active paste thickness is what determines the Ah of the battery
The thicker the paste the longer it will run, past grain sizes being equal .

Now the caveat to this is PVR SLA AGM batteries.
In these batteries the space between the paste surfaces is occupied by a fiberglass mat .
The purpose of the matt is to support the plate and make it more vibration fatigue resistant because the grids now days are very very thin, typically around 0.75mm to 0.5mm .
in the old days they were 3mm to 2 mm thick which is what made them so heavy, If you are over 40 then you will remember the old days of the 13 plate car bateries that took 2 big beefy blokes to pick up .
Now days the proverbial 40 lb weakling can carry one in each hand without breaking into a sweat.

Now the you-beaut fancy charger can not blow away the sulphated surface of the paste because that sealed battery is pressure valve regulated ( PVR ) to prevent the gassing at the plate that your charger is trying to make happen .

Once a modern battery is dead, then it is dead .
A dumb charger can revive a dead flat battery but not a totally used up deceased battery
Auto chargers can not tell the difference between a dead flat battery & a fully charged battery which is why you need an old fashioned dumb charger and in particular one that uses a stepped transformer where you can adjust both the voltage ( in 2 volt steps ) and amperage .
Expept to pay over $ 1000 for one of them and buy a pocket timmer because they are not called battery cookers for nothing .

And do not bother looking at any "how to regenerate your battery" videos on your tube.
They are all total BS
Some solutions like EDTA or DMG can be use to complex used paste then cause it to precipate down the bottom of the cell , from where it can be washed out, from OPEN CELL batteries not sealed batteries .
The best thing to do is open your wallet & buy a spiral cell battery of which Optima are the most commonly known brand
They are head & shoulders better than flat plate batteries because they have more surface area than a rectangular plate battery and the plates are continious so you get far less internal resistance between the grid & the busbars that take to power to the terminals .

However like everything that is substantially better, they are substantially more expensive

Click to expand...

Most batteries are not worth the effort of trying to revive. A thousand dollar battery pack with one good unit, one OK unit, and two bad units is worth the attempt. A desk top DC power supply with variable voltage / variable current capability and a built in voltage ramping capability to ramp down voltage to maintain your desired current input (no need to stand there with a timer) is a hell of a lot more useful than an old school dumb battery charger, and cost less than $100. Now, doing the discharge load test will require me to spend some time watching (and timing) to see when the battery reaches the low limit so I can calculate capacity.

Will the revival attempt work? Beats me. Is it worth attempting? It is to me. If you don't care to see the results, no need to follow this thread. If you want to know the results keep watching.

Keith

As far as I know there is no magical cure for dead batteries. Yes some can be recovered. I use a 60 watt solar panel that brings several back from the graveyard. I make the mistake of buying one so called smart chargers. It preforms very poorly when compared to the 1970 charger I have here. It sits more in the cabinet than in use. It is so dumb that if the 12v batteries are below 6v it will only charge them to six volts. I have to bump charge with the solar panel to get the smart charger to recognize the 12v battery as a 12v battery.

For me most the dead batteries coming into my shop have internal mechanical damage usually from freezing during the winter months which makes any attempts to recover nearly impossible.

My first job as a qualified metallurgist was with SimsMetal,
While their main business was recycling they had thousands of other companys because scrap prices are very volatile so after Albert G Simms ( a man who never went to high school ) had finished doing a full vertical intergration including owning the ships he used to export scrap, he diversified .
Sims owned about 20 or so battery making & repairing businesses and introduced the first sealed battery making plant into Australia.
As such I am very conversant with lead acid batteries from the 5 ton ones used in ships to the open top ones used in phone exchanges to the standard ones used in cars .

Modern lead acid batteries usually fail mechanically unless they have been left flat or dry for extended periods of time .
As I tried to explain if a battery is not sulphated then desulphating he plates will not revive it and after desulphating the Ah will be reduced because the depth of the paste is reduced
Discharge rate is all about surface area of the plates & the effiency of the busbar connecting the plates
Capacity is all about the grain size & thickness of the paste .

To self discharge. failing things like a build up of sludge on the bottom of the case or warped plates touching each other , the battery has to be able to generate H+ and these H+ ions need to join together to form H2 gas molecules.
Now there is a controling phenomnia called partial pressures and it is by the way how oxygen gets into your blood and why beer , champers or soft drink remains fizzy in the bottle or can till you open it up because the pressure of the gas above the liquid prevents any more of the gas coming out of solution.
So with a battery if you pressurise the air space above the electrolyte then the electrolyte can only gas a tiny amount till the partial pressure prevent any more gas generation so the battery does not self discharge as quickly as an open top battery .
So desulphating will not work on a PVR battery and all that happens is the paste crumbles and falls to the bottom of the cells thus drastically reducing the capacity of the battery because the paste thickness is reduced so you end up with a surface charged battery that shows full voltage but goes flat in a few minutes .

On a standard car battery the plates are held on by a single tab in one side of the plate thus at best it is a cantilevered support.
The + plates have their tabs at one end & the - plates have their tab at the opposite end
Inside there are 2 busbars, one on each side of the battery + on one side and - on the other.
Typically the - plate tears near the tab and it falls down either creating a short with the + plates either side or dropping to the bottom where it breaks up contaminating the electrolyte with the libberated paste or shorting out the entire cell .

Over time little bits of the paste break away and these will pass from one plate to another rather than the paste changing valenance so again the battery capacity is reduced .
Complexing this paste with the EDTA or DMG solutions then rinsing it out can revive a dead battery but at reduced capacity .

This is fine for a starting battery as most have enough capacity to crank the engine for near an hour in total ( not of course in one hit ) so ill recharge happily between starts.
However for a motion battery it is different and just one bad plate in a typically 13 plate cell will drastically reduce the run time of the battery .

And yes I predate modern solid state lab power supply units which are a lot cheaper than a multi wind stepped transformer , although like modern chargers rely on quite frail power transistors . I used one to do electro deposition analysis of precious metals & the occasion ore assay where a cyanide reduction was not appropriate .

Enquireing minds need to be fed so please carry on with your investigations the only damage it will do is lighten your wallet and espose you to the potential of acid burns or hydrogen gas explosions both of which are easily manageable dangers.

Just don't expect to find a simple solution.
Weather you can economically recover a battery will very much depend upon why it has failed in the first place .

BAck in the old days of rubber cased batteries the "restorers" would heat the cases , remove the top completer with all of the plates
The entire cell at the negative end would be replaced if they were an honest person
The dishonest ones just cut off the dead plates and refitted the top then when through a charging cycle, starting with 1/2 strength acid with spectator ions ( ususlly phos ) to keep it going .Then that solution gets replaced with another partially charged strength solution.
This is done a few times before the battery gets up to full voltage when it get fresh acid
The old solutions get processed and reused over & over again.

A similar rejuvination process was done with open cell plastic cased batteries without taking the top off & removing or replacing dead plates .
Not as good but could give you another year or two out of the battery, back in the days when batteries were actually expensive .

Once fully automatic battery assembly lines went into production, battery prices crashed , or rather just failed to rise which made rejuvination of batteries uneconomic .
WhenI started work w used to supply thousands of bare grids, busbars, terminals and pots of pastes.
In the space of 5 years that trade just about ceased except for special batteries shaped to fit in a specific place like a fork lift or tow motor plus the railway & telephone plates where the batteries were open ( no tops _ so single plates could be replaced as they failed .

Interesting, my OE Chevy Panel truck battery lasted 11 years. Although it is located in back under the load floor, away from engine heat.
And since it sees little use I do use a Battery MINDer on it occasionally.. I load tested it about every 2 years... Was still testing decent, but I replaced it anyhow..

I don't have high expectations for this attempt at restoration, I just figure "why not try"? If I can restore the weaker cells and use them as a home backup in case of power outage (rare here, but they do happen) it is better than just junking them. The batteries don't self discharge, and they are not useless... just not of the same capacity as they used to be. When they were in the pack wired up in series, the weak batteries dragged down the capacity of the pack as a whole. Even in the likely event that the restoration doesn't work, I should be able to use them as a home backup supply to run the fridge and freezer wired up in parallel and using a 12V DC to 120V AC inverter. I understand that if I still have unbalanced capacities I shouldn't charge the system as a parallel wired pack, I would be better off charging each battery individually to avoid over heating / over charging of the lower capacity cells. This wouldn't be a "daily use" pack like you would use in a solar array, only used on rare occasions.

Keith

where I live a normal car battery is old after 3 years. Yes, some make it to 5+, had that happen once, in 50 years of car ownership.

in case of power outage

Click to expand...

relying on a dead battery in an emergency. I'd think that one thru again. "Got this old worn out parachute that I thought I'd keep around just in case I need one... ."