car battery maintenance

Car Battery Reconditioning – How to do it?

In Electric by Magnus SellénLeave a Comment

car battery maintenanceIt can be frustrating if your car battery is not holding a charge for long.

This can lead to problems starting the car in the morning. Most car batteries are lead and acid.

They use chemical reactions between the acid to generate a charge. The downside is that with time sulfur will accumulate at the terminals hindering the safe working of the battery.

Car battery reconditioning is recommended to do a maximum of five to six times. Batteries do get worn and need to be replaced after some years.

Check the voltage

The voltage reading on your battery will determine whether your battery can be reconditioned. Charge your battery with a car battery charger and let it sit for some days. If it’s okay you should read a voltage of 12-13 volts. However, the easiest way to check the battery is with a car battery tester or a car battery load tester. 

Cleaning the terminals

As stated above, the accumulation of sulfur at the lead plates interferes with your battery ability to deliver charge. Removing this corrosion is the first step in reconditioning. You can make your own cleaning solution by making a mixture of 2 parts baking soda and one part water. Mix the solution to a paste and use a toothbrush to rub the terminals as you pour the solution on them.

You should do this while wearing gloves as the acid is still reactive. For situations where you notice excessive corrosion, you can use steel wool or 300-grain sandpaper to clean off the sulfur on the posts.

Replacing the old acid

A good battery should have a reading of around 12.6 volts. Readings of between 10 and 12 volts mean you can recondition the battery but below 10 volts you are wasting your time. You need to remove the old acid from the battery and replace it so that you can have readings of 12.6 volts. Use a flat-head screwdriver to remove the battery caps.

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A lot of newer batteries does not have caps for refilling! If the acid is low, you have to replace the battery!

Have a bucket near you where you can pour the contents of the battery on. Most of the batteries will have between two to six caps. Place the caps in a secure place so that you do not lose any one of them. Take precaution that the acid does not come into contact with your clothes or hand. If you accidentally spill some, then use your baking soda to neutralize its effects.


car battery

car battery

The crucial step is reconditioning your battery is to use electrolytes to refill your empty battery cells. This electrolyte is a combination of distilled water and Epsom salt. Pour the contents onto your battery cells and but do not close them with the caps. This is to allow the electrolyte to overflow while charging.

When you are using Epsom salt as an electrolyte you need to mix it in the ratio of one part Epsom and one part distilled water. Another alternative is copper Sulphate.

Recharging battery

This is the last step and the longest. To fully charge the battery expect to spend 24 to 36 hours depending on the charging speed of the charger. This is dependent on battery chargers operating at between 2 and 12 amp. When charging ensure that the negative terminal is connected to the black wire of the battery charger. You will know that the battery has been fully charged by checking the voltage readings. This should be around 12.42 volts, depending on the charger.

Tips to keep your battery in good working condition

Annual maintenance

Always keep your car battery charged. A battery with low voltage will damage it in colder temperatures. Use a maintenance charger once in a month to make sure that your car battery is always charged.

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You do not need to wait until your car battery is completely dead for you to recondition it. As the sulfate crystals form around the battery terminals it hinders its ability to operate efficiently. This is because the lead sulfate will hinder the electric resistance of the battery terminals.

The more you continue using your battery with this sulfate on, the more it deteriorates. Having a battery regenerator will prevent this from happening. You can also clean out the battery terminals with some coke or baking soda solution.

Battery water level

If you have an older battery with filling caps, it is advisable to check the battery water level after every five to six months. In the case of the wet-cell batteries, the water levels in the cells should almost touch the bottom of the refill hole. If the levels are low use a funnel to pour in some distilled water until it is full. Avoid overfilling a cell.

Cleaning battery terminals every 6 to 8 months

The battery terminals may become pour conductors when they get filled with lead sulfate. To clean them, carefully remove the battery terminals. Mix a solution of distilled water and baking soda. Use a toothbrush to remove any corrosion. Clean the area with some distilled water. After cleaning the terminals coat them with some grease to prevent further corrosion or rust.

Inspect the battery voltage

It is imperative that you conduct regular battery voltage tests every time you take your car for servicing. This can also happen sooner when you notice that your battery is not as powerful as before. A typical battery should have a voltage of between 12.4 to 12.6 volts.

Inspect the insulator

Not all cars have battery insulators. These are there in order to protect the battery against high temperatures under the car hood which may dry out the battery fast. Check for any damage of the insulator and replace worn-out one immediately.

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Take your battery for regular maintenance

After every 6,000 miles or 6 months, it is vital that you take your battery to a certified mechanic for inspection. While you can do this at home, most auto shops have equipment that is not readily available to ordinary car owners.


The battery is a vital component in running of electrical devices in the car. Since most of the batteries are lead-acid types, they do lose charge with time. The terminals can become poor conductors of charge as sulfate builds up. To recondition your battery you will need to use

Epsom salt and distilled water solution to refill your battery cells. The battery terminals can be cleaned by a solution of baking soda and distilled water. Use a toothbrush to clean out the terminals. Check your battery voltage regularly for any signs of malfunction.

Hello I'm Magnus, the owner and the writer of this website. I have been working with cars since I was 16 and I'm specialized with in-depth Automotive diagnostics. Also been driving drifting for the last 6 years. I'm here to give you answers to all your automotive questions and I hope that you enjoy our content.

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