Car Battery Reconditioning

The car battery reconditioning is easier than you might have think of. It needs a little bit of patience and work but it pays off. Although some precautions should be taken, because you’ll be dealing with an acidic solution that is present in the car battery.

If you learn to recondition a car battery, you’ll obviously, save some bucks as well as you’ll protect the environment from thrown battery waste. If you have any entrepreneurial qualities, you can start a business of reconditioned car batteries.

Check how to recondition batteries if you have other types of batteries as well.

In this guide you’ll learn

What is Reconditioned Car Batteries

Reconditioned car batteries are those batteries that have been revived/repaired after being dead. You can call it repaired batteries or refurbished batteries. These batteries have almost the same charge storing capacity as a new one, but slightly less lifespan. But these are way cheaper than brand new batteries.

People that do business in reconditioned car batteries, buy old dead batteries. Then repair these or replace their damaged cells and sell them as refurbished batteries OR some even using their own label/brand name.

You can also do the same if you want to start refurbished car batteries business.

How to Recondition a Car Battery at Home

Before you start working on your car battery reconditioning, you should take some basic precautions. Because you’ll be dealing with acidic solutions. So protecting your skin, your eyes, and your breath as well, are necessary. Except this, the process is straight simple, which anyone can do easily.

Needed tools and materials

  • Rubber gloves, mask, goggles, and apron
  • Flathead screwdriver
  • Battery Charger
  • A Funnel and a bucket
  • Voltmeter (or better multimeter)
  • Battery terminal cleaner, toothbrush (used or new)
  • Distilled water (1 gallon)
  • Baking soda (powder)


Safety first, because you’ll be dealing with an acidic solution. So

  • Wear your goggles, gloves, mask, and apron to avoid any contact with your eyes, skin, or even breathing.
  • You should work in a well-ventilated area.


measuring car battery voltage with a multimeter

How to Recondition a Car Battery at Home

Total TIme (without charging) 2 hours and 300 minutes

Clean the battery terminals

Cleaning Battery Terminals

The first thing that you need to do, is to clean the battery terminals from corrosion. For this, you need to prepare a paste-like baking soda solution with a ratio of 2:1. Then dip a toothbrush or steel wool in the baking soda paste and rub the battery terminals with it.

You can use sandpaper grit if the corrosion is very hard. A foaming reaction means the solution is working.

Take measurement

measuring car battery voltage with a multimeter

Take the measurement of your battery voltage. Normally, when the battery is fully charged, it shows 12.6 to 12.9 volts, and if it is less charged, then you’ll see it about 12 volts. So depending on the charge that you have given, take the measurement.

If you have charged the battery, then it should show 12.6 volts, or your battery has issues.

Also note, that the voltage is not the only thing that indicates your battery health. So, it is better to load test it and see if the voltage is dropping rapidly or not.

If you are sure about your battery’s low health, follow the next steps.

Clean your battery internal plates

Flooded battery caps opening closing

For this, you need to prepare a baking soda and water solution with a ratio of 1:1 to prepare a running paste.

Next, remove the battery caps, and pour the old electrolyte into a container. It should be neutralized before throwing away by putting about 1/2 KG baking soda in it.

Now fill the battery cells with the baking soda solution that you have made and close the battery caps. You need to stir the battery for a minute to ensure the solution reaches every part of the battery cells. Then pour off the solution in the same container where the old electrolyte is.

This will clean your battery plates from any acidic solution in them. Now, you can use your new electrolyte.

Refill the battery cells with a new electrolyte

filling epsom salt distilled water in flooded battery

Prepare the Epsom salt + distilled water solution. For this mix 4 cups of water with 4 ounces of Epsom salt. Then stir the water until it clears. You can heat up the water to fasten the mixing process. All the solid mass should be dissolved.

Now, fill all the battery cells with the new Epsom salt + distilled water solution. It’ll work as a new electrolyte for your battery.

Recharge with a low Amp settings

Car battery charging jumpstarting

Before charging, make sure you have not put the caps on the battery cells. Because, during charge, the electrolyte will heat up and some gases will be produced. So remove the caps to avoid any unexpected situations.

Set your battery charger at a low amp settings, i.e. 12 Volts / 2 Amps, and recharge your new reconditioned car battery for about 24 to 36 hours.

Re-test your reconditioned car battery

After 24 to 36 hours, measure your reconditioned battery voltage and test it. It should now show 12.5+ volts.

Besides the voltage, subject it to a load tester. The battery voltage should not drop below 9.6V for about 15 seconds of load testing at half the CCA rating.

If you don’t have any load tester, try putting it directly in your car and check it there.

EZ Battery Reconditioning explaining Video
EZ Battery Reconditioning Video

Reasons why you should learn Reconditioning batteries

After your car battery goes down, you’ll have two options, i.e. buy a new one, or recondition your old one. If you have a lot of extra money, you can buy a new one, and properly dispose of the old one. But if you are like most people and always manage your finance, you should pick the 2nd option. I.e. repairing your dead car battery.

Here are some of the benefits of reviving your dead car battery.

  • The first reason is obvious, i.e. saving some bucks. Because a new car battery can cost about $75 to $120 depending on your car model. But reconditioning your old one can save you this amount.
  • An average car battery lasts for about 5 years. After that, if nothing crazy damaged in it, you can recondition your car battery, and get another usable year or 2. So technically, you get up to 7 years of usable lifespan for the initial investment.
  • You can help save the planet by reducing non-disposable waste thrown into it. I.e. Lead-acid batteries contain acidic electrolytes which are harmful to be thrown without neutralizing. Lead particles are also hazardous to our nature. If you throw them, it’ll poison our groundwater and soil and food is grown from it. So always avoid when possible.
  • You can start a business for reconditioning car batteries. It’ll help you and your family financially as well as saving mother nature.

Why People Throw their Car Batteries Right Away

Mostly, they don’t want the hassle and trouble of using batteries that are no longer efficient. Some people may not even know if it is possible to recondition a car battery.

Frequently Asked Questions (FAQs)

Here are some of the frequently asked questions about how to recondition a car battery.

Is it good to throw car batteries into ocean

While Google says yes, stating that it helps electric eel and some other creatures. But I’d definitely avoid it, due to the fact as it is non-dissolvable and there are also other creatures than those specific ones. SO A BIG NO.

Are there some alternatives to the Epsom Salt solution as Battery Electrolyte?

Yes, you can use the following alternatives as battery electrolyte solutions if you do not have Epsom salt nearby.
♦ Copper Sulfate: It is a good alternative, and it dissolves easily in water.
♦ Aluminum Sulfate: It is also a good alternative, and some even prefer this one over Epsom salt. Its ratio can be 1:1.

What is the typical reading for a fully charged 12V car battery?​

When a car battery is fully charged, it’ll produce about 12.6 to 12.8 volts. If your voltmeter is showing a voltage anywhere between 12.4 and 12.8, that means your battery is in good shape. Any voltage above 12.9 volts is a good indicator that your battery has excessive voltage.

Is it alright to overcharge my car battery?

No, you should not overcharge your car battery, otherwise, you are reducing its lifespan. Although, other lead-acid batteries can be overcharged. But it should be only done when you need to equalize the battery cells voltage. It heats the electrolyte in it.

At what voltage is a car battery dead?

A fully charged battery should register at 12.7 volts or more. If the voltage falls below this number, the battery should be recharged. A battery is only charged by one quarter at just 12 volts. Once it drops to 11.9 volts or less, your battery is considered dead.

Does reconditioning a car battery work?

Yes, it works, and you’ll get another year or 2 above the typical 5 years car battery lifespan. So technically, you get up to 7 years of efficient battery lifespan on the initial investment. It saves your money and it is also fun to recondition car batteries.

How long will a reconditioned car battery last?

Usually it lasts for up to 3 years beyond its typical 5 years lifespan when it is new. But proper maintenance and care are necessary.

When should I recondition a battery?

When your battery shows signs of becoming dead. I.e. Producing less than 12 Volts OR its lifespan has ended and its terminals are corroded. Then you should recondition your battery.

What does battery recondition mode do?

The way the recondition mode in modern charger works is that it raises the voltage inside the battery to over 15 volts thereby causing the water/electrolytes to Bubble so that it remixes them.

Final Words

Battery reconditioning does work especially when your battery is not substantially damaged. If you need to learn more about battery reconditioning, you should check out the following course. It teaches you to step by step to repair your dead battery of any type. You can even start your own battery reconditioning business with it.

ez battery reconditioning course
ez battery reconditioning course

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