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Car Battery Reconditioning (A Step-By-Step Guide)

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What if we told you that there was a way to get your dead battery back up running

Instead of replacing it with a new battery each time it died, you could get your car battery reconditioned. While this may not be possible for damaged or extremely old batteries, battery reconditioning is a common way to extend the lifespan of a battery

With that said, what exactly is battery reconditioning?
And how is it done

In this article, we’ll answer both of those questions to help you with your lead acid battery. We’ll also go through some FAQs on battery reconditioning for added information.

This Article Contains

Let’s begin.

What Is Battery Reconditioning?

Battery reconditioning is the process of returning dead battery cells to full health and charging capacity. 

But why is reconditioning even needed in the first place?
The lead acid battery generates electrical energy through a chemical reaction between its electrolyte fluid (consisting of sulfuric acid and water) and lead plates. 

Each time a battery discharges, lead sulfate crystals form on the battery plates. When the lead acid battery is recharged, the lead sulfate disperses. 

However, not all of it goes away

With time, the lead sulfate crystals build up, affecting the charging and discharging capacity of the battery. This condition is called sulfation

Sulfation causes the battery to undergo longer charging times, have less charge capacity, and become less efficient until it eventually can’t hold a charge. 

Here’s where battery reconditioning steps in. 

The battery reconditioning process helps clean off the excess lead sulfate crystals in each battery cell and replenish its electrolyte solution, allowing the battery to function almost like new. 

So, how is battery reconditioning done?

Lead Acid Battery Reconditioning (Step-By-Step Guide)

Battery reconditioning can be done on both a flooded lead acid or sealed battery

It involves these seven steps: 

  1. Mix the cleaning solution
  2. Clean the battery of corrosion
  3. Empty the battery cells
  4. Clean the battery cells
  5. Replace the battery electrolyte
  6. Recharge the battery
  7. Test battery voltage and loading

Before you begin, there are a couple of things you need to get ready ahead of time.

Required Items 

Here’s what you’ll need to have on hand. 



Safety Measures

To start, suit up with your protective gear. Battery electrolyte contains sulfuric acid, and you don’t want any on your skin or clothing. Make sure you work in a well-ventilated area in case of splashes, spills, or released fumes.

Check your car battery for any kind of damage — cracks, bloating, leaking. Don’t bother reconditioning a physically compromised battery. Get a new battery. 

Check The Battery Voltage

Checking the battery voltage will tell you if the battery is viable for reconditioning. 

The standard 12V car battery has six cells. Each battery cell generates a cell voltage of 2.1V, so a healthy battery reading will be around 12.6V. 

Touch the voltmeter or multimeter (that’s set to read voltage) to the battery terminals — the red cable to the battery’s positive terminal and the black cable to the negative terminal. 

The battery may be reconditioned for a voltage reading between 10V-12.6V. If it’s less than 10V, you have a completely dead battery and should replace it. 

If all is fine, you’re ready to proceed with the reconditioning process:

Here’s how:

1. Mix The Cleaning Solution

Mix the baking soda with distilled water to create a watery paste. The ratio should be 2:1 or 1:1 of baking soda to distilled water. Don’t use any other type of water (like tap water) as these may contain unsuitable trace minerals.

This solution will act as the battery cleaner and also to neutralize any acid spills.

2. Clean The Battery Of Corrosion

Detach the battery cables — negative (-) battery terminal first, then the positive (+) terminal. 

Apply the cleaning solution to any corroded battery terminal, then use the toothbrush or steel wool to scrub. Corrosion impedes the transfer of electrical energy, so it’s important to remove it from the terminals and cable connectors.

Alternatively, a dedicated battery terminal cleaner would also work here. 

3. Empty The Battery Cells 

Remove each battery cap and place them in a temporary container, so you don’t lose them. If it’s a sealed battery, use the flathead screwdriver to pry off the battery cover and battery cell caps underneath. 

Carefully empty the battery acid from each cell into the bucket. 

Add around 500gm of baking soda to the bucket to neutralize the battery acid, so it’s safe for disposal at a recycling center. 

If there are any spills, pour the baking soda cleaning solution to neutralize this too. 

4. Clean The Battery Cells

With a funnel, fill each battery cell with the cleaning solution. Replace the battery caps and shake the battery between 30 seconds to 1 minute. 

Open the battery caps again and empty the cleaning solution into the bucket.

5. Replace The Battery Electrolyte

Dissolve 120gm of Epsom salt in 1 liter of distilled water (this creates an electrolyte of 1 molar concentration). You can warm up the water to help dissolve the Epsom salt. Mix it well until there aren’t any solids left. 

Fill each battery cell and close the battery caps. Shake to distribute the salt evenly.

6. Recharge The Battery

Set the battery in a safe and secure area. 

Remove the battery caps again as an additional precaution — the electrolyte solution will heat up and may overflow during charging. 

Connect the battery charger to the battery terminal — the red wire to the positive terminal and black wire to the negative terminal. 

Keep the charger as far away from the battery as possible, then set it to charge a very low current of 12V / 2 Amps. Charging at a low current allows the Epsom salt to break down the lead sulfate crystals on the battery plates. 

Let the battery charger run for 24-36 hours. 

7. Test Battery Voltage And Loading

Disconnect the battery charger and check the battery voltage with the voltmeter. The readings should be around 12.42V. If lower, reconnect the battery charger and charge up for another 12 hours. 

If all is well, perform a rudimentary load test: 

A voltmeter reading of 9.6V means the battery is good. 
Alternatively, you could use a dedicated battery load tester for this if you have one on hand.

Now that you know what battery reconditioning is and how to do it, let’s go over some FAQs. 

7 Battery Reconditioning FAQs

Here are the answers to some common questions on battery reconditioning:

1. What’s The Difference Between Reconditioning And Recharging?

Battery recharging is simply charging up the battery for a period of time.

Battery reconditioning, however, means restoring a battery to full functioning capacity. It’s not the same as battery conditioning when you charge a new device battery before using it. 

While battery reconditioning can be done with materials found at home, there are also services that use a dedicated battery regenerator (or battery reconditioner). The battery regenerator uses high-powered pulses to break down sulfation on battery plates. 

2. Why Would I Want To Recondition My Car Battery? 

There are several advantages to reconditioning batteries. 

Car battery reconditioning can: 

3. When Shouldn’t I Recondition A Battery?

There are a couple of situations where you shouldn’t recondition a battery. 

These include:

4. How Long Do Reconditioned Batteries Last?

A reconditioned battery can typically last around one year, so you can theoretically extend its life by at least three years if you repeat the process a few times. 

5. When Should I Recondition A Car Battery?

Battery reconditioning is typically performed when it has lost around 30-40% of its original capacity. However, if it’s lost part of its plates from sulfation or is severely corroded, it might not be recoverable. 

Note that desulfation using a battery regenerator (battery reconditioner) can be done at any time. It can help improve batteries that are even as young as 1-2 years old.

6. Can Other Types Of Batteries Be Reconditioned?

Lead acid batteries aren’t the only ones that can be reconditioned. 

For example, a laptop battery is well-suited for reconditioning. 
This is typically a lithium ion battery, NiMH, or NiCad battery. 

Hybrid battery reconditioning is also an option for the relatively expensive hybrid vehicle battery. 
Just know that each battery type has its own reconditioning methodology due to differences in chemistry.

7. What Is The EZ Battery Reconditioning Program?

EZ Battery Reconditioning is an online program for battery fixing, recharging, and reusing. 

The EZ Battery Reconditioning guide covers different types of batteries, including the:

Closing Thoughts

Battery reconditioning has several neat benefits, including extending your battery life — and it isn’t just for the standard lead acid battery. The hybrid battery in your hybrid car can be reconditioned too! 

However, every battery reaches the end of its age eventually. When that happens, getting a new battery really is the only option. 

But don’t worry, even if you find yourself stranded with a dead battery on the roadside. 
Get hold of a mobile mechanic like AutoNation Mobile Service!

AutoNation Mobile Service is a convenient mobile auto repair and maintenance solution, offering easy online booking and a 12,000 month | 12,000-mile warranty. Just contact them for any car issue, and their ASE-certified technicians will drop by to help you in no time!