How to DeSulfate a car battery with a charger ford focus ctek

Car batteries typically only last 3-5 years. Sometimes shorter is they are in 4×4 vehicles getting jolted around on dirt tracks. Like all important pieces of equipment, batteries must be maintained to keep them in top working order.

For myself, I like to place each of my car and boat batteries on charge every 3 months to give them a top-up charge to 100%. This is the first step to getting extra like out of your vehicle battery.

Over time if the electrical charge in the battery falls below 10.5V your battery will start to fail due to a process called sulfation. This is the process of sulfate crystals growing on the lead electrode plates. Over time decrease the amount of charge or voltage that these plates can hold. A low electrolyte water level will also cause sulfation to happen rapidly with the exposure to air on the lead plates.

During a prolonged charge deprivation, the amorphous lead sulfate will convert to a stable sulfate crystal and deposit on the negative lead plates. These crystals will grow over time and removal will be very difficult. That’s why as soon as your car battery is low of voltage charge top it up immediately.

How to Desulfate a battery with charger.

topdon TB6000 pro vehicle charger 12v 6v How to Desulfate a battery with charger.
My Topdon TB600 charging the car battery.

Desulfation is the process of dissolving the crystals growing on the battery lead plates. There are a few quality on the market at the moment that has a special mode that can pulse a higher voltage of around 15-16 volts into your 12v battery to try and dissolve the sulfuric acid crystals.

This means each cell in a battery will be between 2.5v – 2.66v per cell once a full charge has been applied.

You will have to use a battery charger that is specifically made to desulfate batteries. There will be a setting to activate the pulse circuit to start the recondition or repair process. I use an older CTEK battery charger in desulfation mode.

Recently I purchased a Topdon TB600 charger. The cool thing is that I am able to connect it to my phone for more detailed results on the battery charging process. With 5 vehicles at my house no and a Jetski it was time to get another 12v charger.

This process may take a few days if the vehicle battery has very heavy sulfation. It also may not completely remove the sulfate crystals. This process only works for low-sulfated batteries. But there have been stories of people bringing back to life batteries that have been kept at a low state of charge for many months and brought back to life with this process.

What does a sulfated battery look like?

Here are 2 images of the same battery. The first image is new and you can see how shiny the lead and the spacers look. The second battery image is after 3 years of use.

how to desulfate a battery to bring it back to new condition inside a battery lead plates

As you can see above there is quite a distinction between the spacers and the lead. Every plate looks shiny and clean. This is a perfect working 12v deep cycle battery.

Now, this next image is of the battery that is beginning to show its age. The plates are beginning to be coated with sulfate crystals. Battery performance will drop and it will be due for replacement.

What does a sulfated battery look like. Inside a car 12v battery lead plates

With the CTEK charger in desulfation mode, we were able to clean up the sulfate and bring it back to a nearly new condition. If this battery is left in a low voltage condition longer it would be very hard to clean up the plates.

A battery kept at a low voltage will fail very quickly, it is the no1 reason why your car turns over but won’t start.

How long does it take to desulfate a battery?

The time to Desulfate a car battery will depend on the amount of sulfation and the size of the car battery. Smart chargers from CTEK and NoCo use a complex algorithm to determine the voltage and charging amp flow within the battery to destroy the sulfur crystals with pulses.

Some smart 12v chargers can desulfate an average battery in a few hours. If the sulfation is heavy it may take a day or two. It will also charge your battery at the same time. Just be sure to check the battery water level and top it up when it is low.

If you have a look at the video below you can see the voltages which drop down to around 6v and up to around 15 volts. These pulses are enough to shock the crystals to fall off or dissolve.

How to use a battery desulfator.

I have a Ctek battery charger and it has a desulfation setting called recondition.

  1. Remove your battery from the car when doing a desulfation as it will be easier to check on the water levels. Otherwise, if you are just doing a top up charge you can leave a 12v battery connected to your car’s electrical system.
  2. Check the vehicle battery water level and top up with distilled water only.
  3. Connect your desulfation charger to the battery and select the recon or repair mode.
  4. Monitor the battery for excessive heat, loss of battery fluids and any deformation of the battery. Stop the charge if you notice anything abnormal.
  5. Leave the charger on until the reconditioning process is complete.
  6. Check the water level once the charging process is complete and top up if required.
  7. Place the battery back into the car, truck or boat and tighten up the terminals.
  8. Place some Vaseline onto the terminals to stop corrosion.

The same process will apply to deep-cycle batteries as well as motorcycle batteries.

Uses for a dead car battery

The main use for a dead car battery is to extract the lead to be melted down for lead sinkers and diving weights. Some recycling centers will take these 12v batteries and you may get a few dollars for their trouble.

If you do want to extract the lead be aware that the battery is full of sulfuric acid and it must be disposed of correctly. Wear safety goggles, rubber apron, and rubber gloves when opening up any lead-acid battery.

Keeping a 12v battery can be a handy item to have even if it is not in tip-top condition. It will make for a handy portable jump starter with a set of jumper leads. They can even be used as an emergency 12v supply when you need to power up a 110v inverter for when the power goes out. Just remember to keep your batteries topped up and they will last for a very long time.


If you look after your car battery it will look after you. I get at least 5 years plus following general battery maintenance tips. This puts more money into my pocket and I have confidence the battery will start every time.

Battery sulfation is a fact of life we can’t stop the process but we sure can slow it down. If you do a desulfation repair process at least yearly you will have trouble-free driving. If you do a lot of stop-start driving your battery won’t get the full top-up charge it requires so its best to charge up your battery at least monthly.

Some new cars that turn off the engine at traffic lights give your starter motor and battery a real workout. I like to disable this feature as I think it will do more harm than good in the long run. Check out some of these other handy tips to quickly repair your car when it breaks down.

Ctek battery chargers are great. They are well made and are trusted by many 4×4 enthusiasts. I use a CTEK mux 5 smart charger, and I love its recon feature. It’s designed for motorbikes, cars, trucks, boats, ATVs, Jetskis, and many different types of vehicles.

If you do have a battery that is giving you some trouble try the desulfation repair hack and see if you can bring your 12v battery back to life. You may be pleasantly surprised, even if it is a gell battery you will get some benefit from reconditioning it.

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  1. That is a very good tip I got some more life out of my car battery until I can order a new one.
    Simple but very precise information… Many thanks
    for sharing this one.


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