Battery Reconditioning Ultimate Guide (Desulfation, Conditioner Charger)

Welcome to a Car Battery Geek deep-dive. This is an important topic, for sure, frankly it’s huge.

What is it? Well, it’s battery reconditioning. Or should we say battery conditioning? Desulfating? Pulse conditioning ? Pulse charging? A topic with a thousand names that all mean the same thing, really.

What they all mean is:

Fixing and rejuvenating batteries, particularly sulfated batteries (by far the most common problem). That means those batteries which have too much of this stuff called lead sulfate on their plates. Lead sulfate buildup is the cause of death for almost all lead-acid batteries.

This is a topic much discussed, seldom understood. Just take a look at some of the resources on the internet discussing sulfation, desulfating chargers and desulfators (which are two different things). It’s mostly either out of date or just plain wrong. 

Luckily, we’re here to shed the light. All the light shall be shed. 

We’ll discuss what sulfation is, what causes it and the best ways to fix it and maximise your battery lifespan. We’ll show you everything you need to know, as well as exactly how to recondition car batteries.

Let’s get to it, then!

Battery Reconditioning: An Introduction

In essence, this means reviving and rejuvenating your 12 volt vehicle battery.

How to do it? By reversing sulfation and acid stratification. These are the two major causes of battery decline and death.

Sulfation

Let’s firstly talk about sulfation (FYI, this can also be spelt sulphation).

What is sulfation?

All lead-acid batteries suffer from sulfation. It’s just chemistry. 

Lead-acid batteries contain lead plates and a free-flowing solution of sulphuric acid. One of the inevitable byproducts of the plates and acid coming into contact is that lead sulfate will accumulate on the lead plates of the battery. 

In fact, that contact is necessary the chemical reaction that cause a battery to be able to provide energy to your vehicle.

Sulfation occurs when the lead sulfate accumulates on the battery plates and stiffens, turning into crystals. Those crystals cannot easily be reconverted back into their original state. 

Therefore, they prevent some of the chemical reactions that cause the battery to deliver power and store charge.

What are the effects of sulfation?

Sulfation causes batteries to die much faster than they should. Many car batteries that have been junked are actually still full of the chemical energy required to power vehicles, it’s just that the sulfation is blocking this energy from being released.

Sulfation occurs when the lead sulfate turns to crystals and hardens. As a result, the battery cannot provide as much energy or store as much charge. Over time, as sulfation gets worse, it will eventually completely block the transfer of energy – then the battery is dead.

But sulfation can be cured and reversed, as long as you don’t leave it too late.

Why does sulfation happen?

Sulfation happens because of the way car batteries work, it’s the natural chemical process. The charge-discharge cycles and the chemicals involved produce lead sulfate on the battery plates.

To discover how sulfate forms, we need to understand how car batteries actually work…

How do car batteries work?

The main types of lead-acid battery are flooded (wet), AGM and gel.

Lead-acid batteries are made up of 6 cells. Each cell provides 2.13V and when fully charged the whole battery has a voltage of 12.72V.

Each cell has one positive plate and one negative plate.

The positive plate has as a lead dioxide (PbO2) coating. The Lead Dioxide is its active material, which means it can react chemically with the battery acid.

The negative plate has what’s called sponge Lead (Pb) as its active material.

A typical flooded (wet) battery (the most common types used in automotive vehicles) is filled with a free-flowing liquid within, called an electrolyte. The electrolyte in car batteries is a mixture of Sulphuric acid (H2SO4) and distilled water (H2O).

Discharging a lead-acid battery

Discharging refers to when a battery is in use, giving power to some device (though a battery will also discharge naturally even if it’s not used, known as self-discharge).

The sulphuric acid has a chemical reaction with the positive (Lead Dioxide) plate, which creates Oxygen and Hydrogen ions, which makes water; and it also creates lead sulfate on the plate.

The sulphuric acid also has a chemical reaction with the negative (Lead) plate, resulting in Lead sulfate (PbSO4) on the plate, and a free electron.

When the battery is fully charged, the negative plates have an excess of electrons (which are negatively charged). Since the positive plates don’t have any electrons, there is a difference in potential between the positive and negative plates.

This is what voltage is (a difference in potential between positive and negative). So the battery will have a voltage of around 12.7V at full charge.

How does the battery power devices and components?

When you connect a device to the battery, the negatively charged electrons move from the negative plate, through the device to the device’s positive side, hence giving power to the device (the movement of electrons is what electricity is).

This movement of electrons is called the flow of current, and is electricity in action. The battery has effectively transferred electrical energy from itself to the device.

Therefore, when the battery discharges it gets lead sulfate on the battery plates. 

And the acid becomes more diluted. That’s because there is: 1) less sulphuric acid (as the sulphate {SO4} has joined with the lead {Pb} to make the lead sulfate {PbSO4}; and 

2) because water is created in the chemical reaction.

Therefore, as you can see, lead sulfate gathers on the battery plates as part of the chemical process of a lead-acid battery.

In other words, discharging a battery creates sulfation.

Charging a lead-acid battery

Charging is the reverse process. A battery charger sends the negatively charged electrons to the negative battery plates which then flow through the battery to the positive plates.

The resulting chemical change again creates a difference in potential between the positive and negative plates, ie. a voltage. In this way, the battery has again become a store of energy.

The battery charger must put a higher voltage across the battery than the battery’s existing voltage. Higher voltages will charge the battery faster, but it can’t be too high a voltage or it will cause too much gassing of the battery acid.

During this charging process, the lead sulfate (PbSO4) is broken down and turns back into Lead (Pb) and the sulfate (the SO4 part of the PbSO4) returns to the sulphuric acid (H2SO4) in the electrolyte. In this way the acid returns to its former strength (ie. it becomes less diluted again).

Therefore, since charging a battery breaks down lead sulfate, we can say that charging a battery removes sulfation.

So do good charging practices prevent sulfation?

No, not entirely. But it does mean there’ll be less sulfation than if you have poor charging practices.

In an ideal world, a lead-acid battery will have lead sulfate accumulating each time it discharges, and then each time it discharges the lead sulfate will break apart, back into the electrolyte.

But, unfortunately, the reality is quite different.

For most people, they won’t be able to have perfect charge cycles – where a battery is charged fully, often and well, with the correct voltage at the correct stage, always discharged to 50% and no more, and never allowed to be left unused in a state of discharge.

Perfect charging cycles are just unrealistic, and actually, even if you managed it, you’ll still have sulfation. Over time, some sulfate will accumulate and harden, it won’t be broken down just by the ordinary charging process.

What Causes Sulfation To Grow?

• 1) Leaving the battery partially discharged.

If you ever leave your battery unused for any length of time, this will increase the sulfation on your battery. The longer you leave it, the worse the sulfation will be.

Charging the battery is what causes the lead sulfate to return to its original forms as lead and sulphuric acid. If you don’t do that, the chemistry of lead sulfate is such that it will form into crystals, stiffen and grow into clumps.

• 2) Undercharging the battery

It’s not just discharging that causes sulfation. It can be worsened if the battery doesn’t get a high enough charge voltage.

If the charge voltage is too low, it won’t provide enough power to the battery to break down the lead sulfate on the plates, and return it to the electrolyte.

The charge voltage, then, must always be higher than the current voltage of the battery.

If the battery doesn’t receive enough charge, lead sulfate gathers on the battery electrodes. The crystals formed will grow in size over time.

The lead sulfate becoming crystals, hardening and attaching more strongly to the plates means that the lead sulfate doesn’t return to the acid even when a charge is put through the battery.

In other words, there is less re-conversion of lead sulfate into the original Pb/PbO2 (lead/lead oxide, on the battery plates) and the SO4 part of the H2SO4 (sulphuric acid ie. the battery acid).

The PbSO4 is no longer fully breaking down into lead/lead oxide (Pb/PbO2) and sulphuric acid (H2SO4).

So there’s less lead/lead dioxide on the plates and the sulphuric acid is less concentrated.

As we discussed earlier, it’s the reaction between the lead/lead dioxide Pb/PbO2) on the plates and the sulphuric acid (H2SO4) in the electrolyte is what creates the power of the battery (since it creates the excess electrons ie. electricity).

So if there’s less lead/lead dioxide and less sulphuric acid, the battery power is weakened.

The effects of sulfation

 A sulfated battery will provide less power to the spark plug to start the engine, and less power to your on-board devices and components.  

Sulfation, then, is not just shortening the lifespan of the battery, it’s also reducing the power it provides your vehicle to start, and for its electronics.   

It also results in lower charge acceptance (again due to the reduction of the reactive chemicals within the battery cells). That means your battery will not charge fully, and will be slower to charge.

All this means that sulfation has reduced your battery’s capacity. It may still say 100Ah on the battery casing, but if sulfation has taken hold, your actual battery capacity could be 70Ah or even 60Ah.

As enough time passes, sulfation eventually leads to the battery no longer being able to deliver power or accept charge, and the battery is to all intents and purposes, dead.

If you’re exceptionally diligent with your charging, and you recharge after every use with a high-quality charger, and you use a maintenance charger (also called a trickle or float), you can certainly minimise sulfation and get a longer lifespan. But sulfation will still develop during discharge, and grow little by little over time.

It’s estimated that sulfation is the cause of death for 84% of all batteries, according to Battery Council International. Most car batteries, as a result of sulfation, don’t reach anywhere near the lifespan they would otherwise be capable of.

However, keep reading and you’ll see how, in many cases, sulfation can be removed, and the battery can be recovered and revived back to life.

Physical damage

If sulfation is allowed to grow without check, the lead sulfate crystals can become large enough and sharp enough to damage the separators between the plates, causing leakage. Or even create a short-circuit between the battery cells.

So what can be done about sulfation?

Self-discharge

As we mentioned earlier, batteries also lose charge when they’re left unused, and so not providing power to a device. This is called self-discharge, or internal discharge.

Most lead-acid batteries have some small percentage (often approx. 1-4%) of Antimony in their plates, making them a Lead-Antimony alloy. This is because Antimony stabilises the positive plate’s active material, providing more mechanical strength.

As a result of this, normal flooded lead-acid batteries can have high self-discharge rate, from 10-40% per month. So they’re very poorly equipped to deal with long spells out of use. This can be seen by the problems many people experience with with starting their vehicle even after as little as 2 weeks without using their car.

This was very common during the pandemic lockdown when millions of people had the unusual experience of not using their car for several weeks.

Gel and AGM batteries (AGM batteries and how to charge them), have lower self-discharge. Their plates don’t require this Antimony – their structure allows for sufficient mechanical strength as they are stabilised by the absorbed glass mat or gel material. This allows for lower self-discharge, it can be as little as 5-15% per month. 

Calcium (also known as silver-calcium) batteries also have much lower rates of discharge. The plates are lead, with a small percentage of calcium, which results in lower discharge.

Just as with discharge, sulfation occurs with self-discharge as well. And the greater the self-discharge, the more sulfation will occur. That’s one of the reasons why AGM, gel and Calcium batteries will last considerably longer than regular flooded batteries – as their self-discharge rate is much smaller.

Sulfation, then, increases in direct proportion to discharge. The more a battery is discharged, the more lead sulfate will develop on the plates.

The more time the lead sulfate spends on the plates without being removed, the more the sulfate will form crystals and harden into place on the plates. And therefore, the harder it becomes to remove.

On this topic, here’s why desulfating chargers and desulfators help car batteries last for longer without driving.

Charging a Sulfated Battery

After some of the lead sulfate on the battery plates has turned to crystals, the crystallized lead sulfate will no longer be broken down when you charge the battery.

Desulfation

Luckily, sulfation can be reversed and prevented. The lead sulfate that has hardened and crystallized, which can’t be removed by charging, can be removed by another process, called desulfation. This is the most important aspect of battery reconditioning.

Applying a very high voltage to the battery plates would be an effective way to remove the sulfate crystals from the battery plates. However, this voltage would need to be extremely high, which would damage the battery. So it’s not an option.

This technology was first developed for the US military, who used it to great success in making their vehicle batteries last longer.

It’s a long established scientific fact that a pulse voltage performs desulfation, improving lead acid battery capacity.

And also that this high frequency pulse results in better battery performance all round.

How does desulfation work?

In other words, how to recondition a sulfated battery?

There are 2 ways to recondition (desulfate) a battery: 1) using a conditioner charger / desulfating charger  (a battery charger with desulfation mode); and 2) using a desulfator (a standalone product that attaches to the battery). There’s a third desulfation method, but it’s not recommended.

Both work in the same way. Both have clamps/connectors that attach to the battery terminals and emit a high-frequency pulse across the battery.

The pulse of a desulfator / conditioner charger looks something like this:

The type of pulse used is the key to how it works.

We mentioned earlier that a high voltage charge can break down sulfation deposits on the battery plates.

However, if the energy put across the battery was a constant high voltage it would raise the whole battery’s temperature and potentially cause gassing. Both are highly dangerous and could even cause the battery to explode.

Fortunately, the pulse used in desulfating products (desulfators and desulfator-chargers) are entirely different.

Their pulses are extremely short blasts or pulses of quite high voltage, and high frequency. Since the pulses are so short, the overall power is low. So there is no danger of too much voltage or too much power causing the battery to overheat or cause gassing.

As a result of the pulse conditioning, the sulfation is broken down. That is, the hardened, crystallized form of lead sulfate has returned to its original state, as an active electrolyte that takes part in the battery’s energy-forming process.

How does the pulse actually work to break up the lead sulfate crystals?

The high-frequency pulses cause a resonance (a rhythmic beating) of the plates. The physical effect of this resonance introduced to the plates is what causes the lead sulfate crystals to break apart.

The effects of desulfating a battery 

The desulfation process means that the internal resistance of the battery cells has decreased. This is a very good thing, it means that the battery can hold more charge.

When your battery is suffering with sulfation, you may have noticed that it wasn’t taking on as much charge as it used, as well as delivering less power. It may have become harder to start, especially in cold weather.

Or you may have seen your electronics like lighting become dimmer and the your sound system less clear or lowered in volume.

So after the battery reconditioning, you’ll find that your car battery will take on more charge again. If your battery had been going flat often, you’ll find that won’t happen any more.

Since the battery can take on more charge, it can once again deliver more power. Starting the vehicle will become easier again, even in the cold. If lighting or sound had dimmed, that will become brighter and sharper again.

Desulfation, then, has rejuvenated your battery, and you’ll find you’ll get a much longer lifespan out of it. Often, it can be several years longer.

How to Prevent Battery Sulfation

As we said earlier, the 2 methods are to use a desulfator charger (battery conditioner charger) or a desulfator.

Conditioner charger

Also known as a desulfator charger or pulse charger.

A charger with a desulfator mode is a great way to combat sulfation. We’d go so far as to say, your next charger must be a desulfator-charger. And in fact, almost all chargers on the market now have a built-in desulfator function (though not all are equally effective).

One of the main reasons for desulfation is the battery not getting enough charge.

As we now know, it’s the discharging process that causes lead sulfate to develop on the battery’s positive and negative electrodes (plates).

If you always charged your battery immediately and fully after use (discharge), then this charge across the battery plates will be highly effective at breaking down the lead sulfate back into Lead/Lead dioxide and sulphuric acid (the electrolyte).

The longer the battery remains in a discharged state, the more the lead sulfate will become thicker and turn into crystals.

The fact is that for most people, they simply won’t be able to operate a perfect charge-discharge cycle – we won’t always fully charge the battery immediately after use

• We sometimes leave our cars unused (left in a partially discharged state) for a few days, and occasionally longer than that.
• Some of us only use our vehicles for short journeys (so the battery never gets a full charge)
• In the case of storage batteries and deep cycle/leisure batteries, we won’t always discharge to 50%, we’ll go beyond that to at least 60% or 70% sometimes. And sometimes, the battery will be left in a partially discharged state before we can charge it again.

Batteries want perfect charge-discharge cycles. We humans can’t give this to the batteries all the time, or perhaps any of the time.

The solution?

The desulfator charger.

Regular use of a desulfator charger solves this problem. Why?

1. It gives the battery a full charge
2. Its reconditioning mode (desulfation mode) removes the lead sulfate crystals that have developed during those times when the battery has been left in a discharged state

Which battery conditioner charger / desulfator charger should I get?

The best reconditioning chargers (desulfator chargers) are those by CTEK and NOCO.

Our list of the best car battery chargers goes into detail about the reconditioning and desulfating capabilities of each model.

As you’ll read in that article, only CTEK and NOCO’s chargers have desulfation technology that is capable of fully reviving and rejuvenating batteries back to life.

CTEK Battery Chargers

CTEK’s chargers have an 8 step charging process – Desulphation, Soft Start, Bulk, Absorption, Analyse, RECOND, Float, Pulse.

At Car Battery Geek, we’re big fans of this charging process, as battery geeks we feel this process is by far the best we’ve seen.

That’s because it takes into account the nuances of what batteries actually need at each stage of charging. That is the slow start, the big hit of high-power charge in the middle so that it charges quickly and to its full extent, the rounding out of the edges and the delicate final stages to make sure no overcharge occurs.

It’s fantastic technology, really.

CTEK say if you use their chargers, your battery can last as much as 3 times longer. Frankly, with our knowledge of batteries and the charge process, we we believe it. And we know professional users who say their batteries seem to be lasting much longer since they started using CTEK chargers.

Two out of the eight steps are devoted specifically to reconditioning the battery (though you could argue all the steps are doing so in synchrony).

CTEK’s first reconditioning step – Desulphation

The first step for every battery connected to a CTEK charger is Desulfation. It’s not even a mode to be selected, its done automatically at the beginning for all batteries. Why?

Because CTEK are experts. They know that if you want your battery to be capable of receiving a full charge, you MUST first remove the sulfation. Then the charge acceptance of all the battery cells will be increased and therefore the battery can be fully charged.

This sulfation happens in the same way we’ve described in this article. That is, short pulses of current and voltage (low current, high voltage), which breaks down the crystallized lead sulfate back into active material.

CTEK’s second reconditioning step – RECOND Mode

FYI, we’ve prepared a full analysis of CTEK RECOND Mode (the best battery reconditioning mode).

As long as you select RECOND Mode (and we recommend you always do except if its an AGM battery), the 5th step will be the RECOND Mode itself.

This step is specifically to fix acid stratification (acid layering) – when the electrolyte is not properly mixed and has settled into layers.

This means there is less electrolyte which is capable of reacting with the lead plates, and therefore the battery has less energy. So it cannot provide as much power and cannot be charged to its maximum potential voltage.

CTEK’s RECOND mode puts a high voltage across the battery, which causes a controlled gassing. As a result of the gassing, the sulphuric acid (battery acid) is mixed more effectively with the distilled water.

Then, there is an increased reaction surface area (more electrolyte which can react with the lead plates) so the battery now has more energy again.

The CTEK MXS 5.0 is the best battery charger for those who have a smaller to mid-sized car. It provides the full 8-step charging mode, with 5 Amp charging.

CTEK’s larger model, the MXS 10, is the best charger for mid-sized to larger cars, or those who want the most powerful, fastest charging.

Be warned, these chargers are not cheap. But bear in mind they can you a ton of money on new batteries in the long run. As long as you use them correctly.

And they significantly reduce your chances of ever having a battery-related breakdown (remember, battery problems are the No.1 cause of vehicle breakdowns), or trouble getting the engine started.

NOCO Battery Chargers

Noco’s Genius chargers also have an excellent multi-step charging process.

Though we feel it’s not quite as clever and multi-dimensional as CTEK’s 8-stage process, it’s very smart nonetheless.

It’s also fully automatic. It’ll analyse the voltage and chemistry of the battery and make the right choice at the right time – raising and lowering voltage and amperage according to that battery’s particular needs.

It too lowers the voltage at the beginning, has a fast and large voltage burst of charge in the middle, and a slower pace to round things off at the end.

Unlike CTEK’s MXS models, the NOCO Genius models do not automatically perform the Desulfation step each time they charge. Rather you can opt to select their reconditioning mode when needed.

As you may imagine, we recommend always using the Desulfator mode when you charge. And we do feel NOCO have missed a step by not including it automatically as part of their charging mode. It’s too important, and regular desulfation will significantly lengthen your battery lifespan. It’s really worth a little extra time to charge.

NOCO’s reconditioning mode – 12V Repair Mode

The 12V Repair Mode takes whatever action necessary to heal the battery. Old and discharged batteries can be recovered.

This mode operates both their desulfation step and their step to fix acid stratification.

Like CTEK’s chargers, the desulfation step involves a high-frequency pulse in short blasts to remove and break apart the lead sulfate that has hardened on the battery plates. And the mode to heal acid stratification also produces a high voltage to induce a gassing. The gassing mixes the battery acid, and it can again provide more energy.

In common with CTEK, NOCO have a 5A charger and a 10A charger.

The NOCO Genius 5 UK provides a 5 Amp charge, enough for smaller or medium-sized cars. And it has high quality charging and reconditioning modes. By the way, if you’re stuck, here’s how to choose between the NOCO and CTEK 5 Amp chargers.

The Genius 10 UK, as you’ve no doubt guessed, is NOCO’s 10 Amp battery charger. It also has a 12V Supply Mode.

If you want a monstrous amount of charge, check out our NOCO Genius 50 Pro Review. It’s a 50 Amp professional charger

You can also check out the UK’s best chargers, reviewed and compared.

Desulfator

As we mentioned earlier, discharging a battery means sulfation will develop. Fact. There’s nothing you can do about it. The more discharge, the more lead sulfate develops on the battery plates.

A desulfator charger is great because every time you charge your battery, the charger will remove the sulfation that’s gathered on the battery plates.

It does mean that whenever you’re not charging the battery and you’re driving the vehicle, sulfation is still allowed to develop in that time.

As you know, every moment a battery is discharging, it’s producing lead sulfate on the plates, and some of that lead sulfate will harden and turn into crystals.

However, if you have a desulfator permanently attached to the battery, it doesn’t allow sulfation to develop in the first place, even while discharging. As a battery reconditioning practice, this is the without question the most effective.

The high-frequency pulse of the desulfator is removing the sulfation every moment that you’re driving. It’s highly effective at preventing sulfation ever building up.

It’s always better to take pre-emptive action against something, than to react to it after it’s happened.

It’s like cleaning your bathroom. If you clean it regularly, the dirt and grim will wipe off with ease. If you don’t clean it regularly it’ll solidify, become more embedded to the bathroom surface and it’ll take a lot of elbow grease to remove it.

Which desulfator should I get?

The best desulfator we’ve found by far is called F-16 Pulse King (a review of F16 Pulse King). Its the one used by professionals, we know several fleet owners that were shocked by its ability to recover batteries that had been giving their drivers trouble.

And we know some who’ve said their battery costs are less than half what they were before, because their vehicle batteries are lasting longer and giving them less trouble.

We’ve done the math on this device. We checked CCA before during and after the F16 Pulse King was connected to batteries and seen significant increases.

CCA as a measure of battery health

CCA stands for Cold Cranking Amps. It’s a measure of the health of a battery.

It measures the ability of the battery to start a vehicle, from a cold start. Most specifically, it is the number of Amps a vehicle can deliver for 30 seconds at -18 degrees Celsius (0 degrees Fahrenheit) before the battery voltage falls to unusable levels (around 7.2V).

It reduces over time as the battery ages. However, it reduces faster if the battery is in poor condition, hasn’t been charged well and fully, and especially if it suffers from sulfation.

CCA, then, is a good way to see the health of a battery before and after sulfation is removed.

For example, if CCA was 600 when new, it may be 360CCA after the battery is sulfated. At this stage, it’ll be struggling to deliver power and accept charge. After 2/3 weeks with F16 Pulse King attached, CCA may rise to 550CCA – not quite as new but far better than before.

How long does it take to recondition a sulfated battery?

It depends on how badly sulfated the battery is. In our experience, we’ve seen people who’ve experienced the improvement in their battery starting power and the power of their in-car electronics (like their sound system) in a day or two.

But we’ve measured the battery capacity over time during sulfation. And we know that it takes 2 weeks, or up to 3 weeks, for the desulfator to fully recondition the battery ie. to remove all of the sulfation.

So you see, any time a battery is discharging, lead sulfate is accumulating on the battery plates ie. sulfation is happening. So it’s literally made by the natural chemical process of a battery doing its job of providing power.

Does desulfation ever not work?

Yes, there are times that desulfation cannot recover a battery to health. If the battery has been unused for several months, or years and is very severely discharged, then sulfation will have had time to develop to a highly advanced state.

That means the sulfate crystals will be extremely thick, hard and attached strongly to the battery plates. These crystals are very poor conductors so they won’t allow enough power to come through for the crystals to be broken down.

There is s a tipping point, then, beyond which, battery reconditioning methods like desulfation will not work. If there’s more crystals than there is active material that can conduct, then even the high-frequency pulse of a desulfator cannot penetrate and break down the hardened lead sulfate.

We have heard miracle stories of batteries that had lain in someone’s garage for years, and the desulfator was able to revive the battery, but don’t expect that to happen every time.

Acid stratification (or acid layering)

Sulfation is not the only issue that can afflict batteries. There is also acid stratification, which can also be called acid layering. A well-rounded and full battery reconditioning process will also take action to fix this problem.

If you remember, the electrolyte in a lead-acid battery is made from a mixture (or solution) of sulphuric acid and distilled water.

When a battery suffers from acid stratification, it means the sulphuric acid in the electrolyte has stratified because of poor mixing.

So acid layering is effectively like it sounds: the battery acid has settled into layers, instead of being properly mixed.

As a result of the poor mixing different parts of the liquid in the battery have different densities. There will be a section of the mixture with more sulphuric acid, which will be more dense, and so will settle at the bottom of the battery.

There will be a section which does have adequate mixing of the acid and water, which will be the middle section.

And there will be a section with more water, and very little sulphuric acid. This will be the least dense section, and it will be at the top of the battery.

Only the middle section can be used by the battery for charging and discharging. That’s because the reaction between the lead plates and the electrolyte requires the electrolyte to be a proper mixture of acid and water.

The result? Since less of the plate/electrolyte (Pb/PbO2 and H2SO4) chemical reaction can take place, the quantity of excess electrons produced is smaller. In other words, the battery cannot be fully charged, and cannot provide full power. The battery will deliver less power to the car or device.

What causes acid stratification?

Acid stratification is caused by:

         1) Undercharge

When the battery is charged with too low a voltage, or operates at too low a voltage.

The acid/distilled water mixture needs a full voltage applied across the battery to mix properly. If the voltage is consistently below around 80%, this mixing will not happen.

Why may the voltage be too low? This can happen if:

• you’re using a poorer quality battery charger that doesn’t provide a high enough voltage.
• you only use the car for short journeys, the alternator won’t have enough time to fully charge the battery.
• your car has electrical devices and accessories that consume too much power

        2) Overcharge

When the battery receives too high a voltage, it experiences overcharge. The excess voltage causes the distilled water (H2O) to split into Hydrogen and Oxygen.

       3) Leaving the battery unused for extended periods

This causes a problem for the same reason as undercharge – the battery doesn’t get the voltage it needs to cause the electrolyte to mix fully.

Not only that, over time simple gravity causes the sulphuric acid to sink to the bottom (due to its higher density).

Even though acid stratification is less common and severe a problem as desulfation, it’s still something that can cause battery issues. Therefore, a good battery reconditioning process will also fix it.

How to fix acid stratification?

A lead-acid battery acts as a store of power because of the reaction between the lead plates and the electrolyte.

The reason that both sulfation and acid stratification cause batteries to lose power and the ability to accept charge is because they both reduce the contact between the lead plates and the active electrolyte.

Therefore, the solution to the problem of acid layering it to mix up the electrolyte, so it is once again a proper mixture of sulphuric acid and distilled water.

How do battery conditioners do this? Well, they shake things up. They perform a process called equalization.

This involves putting a higher voltage across the battery than it would receive during normal charging. This higher voltage creates a controlled gassing in the battery, which mixes the battery acid. Tiny bubbles are formed, which stir up the acid that had settled at the bottom of the battery, resulting in it mixing better with the water.

It’s called equalization because it equalises the acid/water back to balance. As a result, there is once again better contact between the lead plates and the active electrolyte. Then, more chemical reactions can take place, so the battery capacity is restored.

Good quality battery chargers, such as CTEK’s MXS models and NOCO’s Genius models, have reconditioning modes that provide the exact level of charge needed. That is, the correct voltage and amperage that causes the bubbling/gassing, but not so much that it damages the battery.

Do all lead-acid batteries suffer from acid stratification?

No, AGM and Gel batteries do not. That’s because their electrolyte is not in free-flowing liquid form. So the sulphuric acid and water do not become separated into layers.

AGM batteries have the electrolyte absorbed in a glass mat, while Gel batteries have the electrolyte absorbed in silica (sand).

Why You Must Take Action On Sulfation

Around 50% of all breakdowns are due to battery failure. And as we said earlier, 84% of all battery failures are due to sulfation.

That means the main reason for cars breaking down is actually sulfation!

Sulfation is the most simple thing to take action on to prevent breakdowns.

The vast majority of the time, the vehicle battery is still good, still plentiful with the chemical energy require to provide power to your car. It’s just that the crystallized sulfate is blocking the transfer of energy between the battery plates and the electrolyte. Therefore, it prevents you from accessing the energy inside.

When this happens, people often buy a new battery. Here’s how to tell if you need to replace your car battery.

Some mechanics and garages will be aware of sulfation and can use a desulfator-charger to fix the problem and give your battery new life.

However, a new car battery is a good source of income for mechanics and garages. Some (not all) will prefer to sell you a new battery. They will test the battery and show you that the CCA value (a measure of battery health) is too low. And use that information to justify selling you the battery.

But there’s a reason the best battery chargers all have desulfation modes, it’s because battery conditioning works!

If a desulfation process is applied, the CCA value can be increased, sometimes it can return somewhere close to the original CCA value when the battery was new. The Car Battery Geek team has seen significant rise in CCA values after desulfation many times.

A leading German car manufacturer once checked 400 car batteries that had been returned under warranty. They found that 200 batteries were completely recoverable and in fine condition.

Any other solutions?

A temprary solution for poor battery condition is keeping a jump starter in your car. Check out the top 3000A jump starter on the market.

A Summary: Battery Reconditioning

Desulfation means fixing or reversing sulfation. In other words, removing hardened lead sulfate from the battery plates.

Sulfation is the most common cause of battery death but a conditioner charger (desulfator charger) or desulfator are highly effective at removing it.

When you use a desulfator to keep the battery plates clean, your battery will charge faster and deeper. This depth of charge means that the full power, the true power, of the battery is restored.

So the battery can release all of its stored energy. It will last longer before it needs recharging, it’ll have more power to start the engine, and your in-car electronics will work better.

Battery reconditioning then, is about releasing the true power of your battery.