How to Recondition a Car Battery at Home

How to Save Your BatteriesA car battery is essential as it performs the function of powering up your car. A car battery should be kept in perfect condition to avoid hindrances. For this reason, after about five years, it is important to recondition your battery in order to extend its lifespan.

To recondition a car battery, one must take the necessary precautions. Reconditioning a car battery will save you some money and protect the environment as well. Also, with this knowledge, you can open up a car reconditioning business at your place.

You can recondition your old batteries for up to three times. Batteries are essential as most electronic devices around us are battery operated. There are several batteries in the market from NiCad, Lithium-ion, NiMH rechargeable batteries to Lead-acid batteries used in vehicles.

People give up on their car batteries right away. This is mostly because they have no idea on how to recondition them. Battery reconditioning is the way to go once your battery is no longer efficient and is not considered damaged.

Advantages of reconditioning batteries include:

One advantage is that you will use your battery for longer. The average lifespan for batteries is around five years. By reconditioning your battery, you can use your batteries for approximately six or seven years, making good use of your money.

Another advantage is that you will save about 25 to 50 percent of the retail cost of a brand new car battery. By doing so, you can save some money.

Thirdly, you will be reducing pollution by reducing the number of pollutants thrown into the environment. Lead-acid vehicle batteries have an acid electrolyte consisting of sulfuric acid. These batteries also include lead content. Lead and most of its compounds have hazardous effects on Mother Nature.

Lastly, a car reconditioning business will make good returns if taken seriously in the long run.

Reconditioning a car battery at home is not hard at all. However, extra care should be taken as the electrolyte contains lead and acid as well.
You will need the following materials:

  • Baking soda
  • A working battery charger
  • Battery terminal cleaner
  • Toothbrush
  • Apron or another set of clothes to catch spills
  • Voltmeter
  • Plastic funnel
  • Two buckets made of plastic
  • One gallon of distilled water
  • A funnel
  • A regular toolkit that consists of a flathead screwdriver
  • Goggles
  • A mask
  • Disposable rubber gloves
  • Some Epsom salt
  • Steel wool or wire sponge
  • A battery load tester(not required)


Protective precautions

Wear your protective gear before beginning this procedure. Make sure you have your gloves, mask, apron, and goggles with you. Prepare a weak baking soda and water solution in case you need to neutralize any sudden splashes and spills.

Reconditioning groundwork (Clean out the car battery)

The second step is to remove the corrosion in the battery terminal. You do this by preparing a paste-like solution of water and baking soda in a ratio of 1:2. Dip your toothbrush in the paste-like solution and then rub it against the battery terminal to remove any corrosion. If the corrosion is hard, use a sandpaper grit or steel wool to rub against it.

Also, as you do your cleaning, try to know every part of the unit. Various brands have cells of different sizes. When preparing your mixture, add your ingredients until it forms a drippy paste. Remember to use a steel wool for tough stains. Don’t forget to clean the moisture and leave out the unit to dry.

Verify battery voltage

The third step is to measure a volt reading of the battery using a voltmeter. Before doing so, make sure that the cable is connected correctly to the battery terminal. Your battery is excellent and does not need reconditioning if the voltage reading is 12.6 volts or higher. However, if it is between 10 volts to 12.6 volts, then it needs reconditioning.

Make sure that you know how to use a voltmeter and how to operate it correctly. Your voltmeter will confirm the voltage supplied by the battery of your vehicle. You can get a voltmeter at an affordable cost at your local hardware store.

Take out battery acid

Fourth, remove the battery caps using your flathead screwdriver by placing it under the caps. After placing your battery caps in a temporary container, pour the old electrolyte into the bucket slowly. Then, neutralize the acid by pouring 500 grams of baking powder into the bucket.

The battery caps usually vary from two to six. At this stage of reconditioning your car battery, remember to be extra careful and to use protective clothing and goggles. Don’t forget to use your safety gloves as well as they will protect you from hazardous spills. Acid spills can damage your skin. The baking soda may be used in case of spillage.

Remove Dirt from the cells

Fifth, make a baking powder and water solution in a 1:1 or 2:1 ratio. Mix and fill each battery cell with a baking soda solution. Then, lock back the cells with the caps and gently shake it for about 30 seconds to 1 minute. Afterward, unlock the lids and pour out the solution into the bucket.

Remember to use a plastic funnel to toss in the solution.
Put back the battery into working order.

Sixth, replace the old battery electrolyte solution with one molar concentration of Epsom salt or by dissolving 120 grams of the salt in one liter of distilled water. Mix it well until no solids are left behind without dissolving. After that, refill each cell and cover them with their caps. Failure to pry out the caps of the battery is dangerous as the battery liquid might heat up and spill out of the unit. Moreover, the resulting pressure may lead to severe accidents.

Charge the cleaned battery

The seventh step is to slow charge the conditioned battery at 12/2 amps for around 24 to 36 hours. Then, read the voltage of the battery using a voltmeter. If it reads around 12.42 volts to 12.6 volts, then your battery is already in good condition.

Remember to place the charger on the furthest possible distance from the battery. Afterwards, attach the positive lead of the charger to the positive terminal. Repeat the process with a negative point and battery terminal.

Test the Reconditioned battery

Finally, grab your load tester and subject your reconditioned car battery to a load test. Your battery must maintain 9.6 volts for 15 seconds at half the CCA rating for it to pass the load test. If this is not the case, drain off charge and let it recharge for 24 to 36 hours, then subject it to the load test.

In addition, add some electrolyte and charge the battery for an extra 12 hours if the unit has spilled. It is also possible to use a voltmeter to test your reconditioned battery. If you prefer this option, screw in the caps of the battery and connect it to the car. Don’t start the vehicle. However, you can turn on the fog lamps. Use a voltmeter to take a reading after you leave the lights on for a few minutes. If you take a reading of less than 9.6 volts, it means that you will have to work on the battery again.

Furthermore, you can also opt to do cycling for the treatment of your battery. Cycling involves placing the unit under load while doing activities such as switching on the fog lights for a moment. This treatment is used when the battery offers a voltage reading of 9.6 volts or fails the test. However, you have to recharge and discharge energy repeatedly.

You might have to cycle the battery for at least four times in order to get a favorable meter reading of 9.6 volts, under load for the most part. On completion of this process the unit will perform efficiently. With this in mind, it is very possible to recondition a car battery near you.

Tips and warnings when reconditioning a car battery

Don’t store your battery as it gradually loses charge allowing the lead sulfate to form on the lead plates. Instead, put it on a trickle charger to avoid loss of performance.


Avoid using tap water as it may contain chemicals that will harm your battery. Also, remember to wear your rubber gloves and safety goggles. In the event that you accidentally splash acid on your skin, flood it with water straight away. Sulfuric acid is dangerous.

Do not rush the charging process. Most experts affirm that you should allow the unit to rest for 36 hours. After waiting for this period, you can then decide to test the battery. Always work in a well-ventilated area with no open flames nearby.

Alternatives to Epsom Salt Battery Conditioning.
Other alternatives to Epsom salt include copper sulfate and aluminum sulfate.

Copper sulfate
Copper sulfate is not as effective as Epsom salt, but it can be used to recondition your car battery.

Aluminum sulfate

Mix one pound of Aluminum sulfate with a gallon of distilled water. Then, stir this mixture until it becomes as clear as possible. Afterward, fill your cells with this solution and charge your battery. The battery is supposed to charge faster because of the aluminum sulfate electrolyte.

Points to note

‘Dead’ batteries can be fully recovered. Many people think that car batteries die like ordinary dry cell batteries. The correct term to use for a car battery that is not functioning is ‘discharged.’

A battery loses its ability to power the vehicle after years of use. Failure to change it will result it to become swollen and could harm the engine itself.

When verifying the battery voltage, the readings should be about 12.6 volts. If the reading is less than 10 volts, don’t waste your time to recondition it. Moreover, if you see zero readings, there might be chances that your battery has undergone a short circuit. In this case, contact your mechanic right away.

As you clean out your car battery, you might notice excess foam caused by specific chemical reactions. Don’t worry if you have this issue as the situation is perfectly harmless.

Different ways to test a car battery

There are different ways in which a car battery can be tested. A car battery can be tested with a digital multi-meter, an alternator, a hydrometer and a power probe.

How to test a car battery (In a nutshell)

The first step of course is to find the battery. Regularly, the battery is usually located behind the hood of the vehicle. Some vehicles however have batteries located in hard to find spots like the trunk or the back seat of your vehicle.

Secondly, gather the required equipment for testing. Switch off the ignition and the lights of your vehicle. Find your multi meter and place the red point on the positive wire of the cell. Likewise, take the black lead and place in on the negative cable of the battery. Then, switch on the device to DC Volt setting.

The third step is to automatically look at the results on the display. A 66 volt reading means that your battery is fully charged. On the other hand, an 89 volt reading means that your battery is zero percent charged.

Fourth, understand the readings. If the car battery reads more than 12.45 volts, it means that your battery has a proper charge. The essence of a charge test is not to ascertain whether or not your battery is in good condition but to signify the present condition of the charge.

The fifth step is to recharge your car battery if your battery is presented with a low charge, then make sure to repeat the test.

Finally, test the car battery and use any method to check for charge in a cell.


If you own a vehicle, you should consider changing your battery after years of use, particularly after five years. However, if you use an excellent battery you might consider reconditioning it.

Getting the skills to recondition a car battery is not rocket science. Yet, it might take some hours as it could involve cycle treatment. Luckily, there are You Tube videos on how to recondition a car battery giving you more insight on the procedure.

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