It’s fairly common knowledge that batteries have to be replaced eventually.

They lose their charge, they become less efficient and in some instances, the case can even bulge and cause major damage to the device or machine that they’re in.

However, this is actually only the case for disposable and low-quality batteries. In most cases, it’s actually possible to recondition batteries so that they become one hundred percent functional once again.

It’s a technique called reconditioning and it’s done with a number of different tricks and tips, and we’re going to spill all the beans for you in this article so that you too can learn how to recondition your batteries and get them fully functional again.

First, let’s start with the why; why should we recondition batteries?

As you may know, batteries can be very expensive to replace. Be it laptop batteries, car batteries or even non-replaceable batteries that are inside modern phones nowadays, they are incredibly expensive to repair and might not even go down in price as the device ages.

In some cases, old devices won’t even have replacement batteries available because they’re no longer in stock.

Reconditioning batteries allows you to preserve the function of your batteries and even refresh them so that they work the same as they used to, providing you ample charge and saving you a lot of money.

It’s also better for the environment because batteries themselves are very hard to recycle and they usually end up in trash bins, leaking chemicals to the environment and causing a huge impact to the well-being of the planet.

Lastly, reconditioning is just convenient. Imagine never having to buy a battery again for a major device because you can personally just recondition it.

You’ll save money, you’ll save time and it’s surely going to save you a lot of hassle in the future. There are virtually no disadvantages of reconditioning your batteries outside of putting in a bit of effort, and in this article, you’re going to find that it’s relatively easy to do so.

Are there any dangers When reconditioning batteries?

Batteries can be very dangerous if handled incorrectly, especially if you don’t have the right safety equipment on.

It’s vital that you wear glasses and gloves to ensure that the battery acid doesn’t leak out and burn your skin or anything else that it comes in contact with. Batteries can also explode under certain conditions, especially if they are mishandled and treated poorly.

If you start reconditioning a battery but realize that it’s cracked, leaking or damaged, it’s vital that you dispose of the battery as soon as possible. At that point, it’s an unsafe battery and you’re better off disposing it because you can no longer fix it in that state.

Finally, don’t recondition a battery more than three or four times. Reconditioning a battery can be a great way to prolong its life, but as time goes on it will eventually get worn out and you’ll experience diminishing returns each time you recondition it.

A reconditioned battery will last several years if you keep working on it, but it will eventually get worse and reconditioning will end up harming the battery more than helping it.

restore dead battery

How to recondition a car battery

Let’s explain how to recondition batteries with one of the most common types; a car battery. Car batteries are very simple to recondition because they’re large, the tools and materials are readily available, and it can actually prolong the life of it so that you don’t need to constantly replace it.

You can expect a reconditioned battery to have anywhere up to 80% of a brand new unit, so while it won’t be perfect, it will definitely work fine for several more years.

Equipment you will need:

  • Safety equipment such as goggles and chemical-resistant gloves
  • Extra clothes or an apron to protect yourself from spillages
  • A battery charger
  • Voltmeter
  • Basic tool kit with things like a screwdriver
  • Plastic funnel
  • Two large plastic buckets
  • A large amount of distilled water
  • 1 lb of Epsom salt
  • 1 lb Baking soda
  • Steel wool
  • Toothbrush
  • (Optional) Battery load tester

1. Preparing the battery

First, you’re going to want to clean the terminals of the battery. These are likely going to have a lot of corrosion built up on the battery posts and it’s recommended that you clean them before you recondition the battery. This source states that each type of car battery may have a slightly different size and set-up so be sure to familiarize yourself to the brand beforehand.

Simply use the steel wool mixed with some distilled water and baking soda. Mix the water and baking soda until it creates a runny paste and then apply it to the posts.

Use a toothbrush to scrub the posts or use a ball of steel wool to clean stubborn corrosion. If there’s a lot of corrosion, the mixture will react by foaming up. This is absolutely fine and you can continue cleaning it.

Once finished, you can then wash it down with a mixture of water and baking soda, then wipe it down and allow it to dry. Once it has been completely dried, you can move onto the next step.

2. Checking the battery voltage

Next, you’ll want to check the battery voltage with your voltmeter. These are very cheap to buy and they’re pretty self-explanatory in their use. Take your voltmeter and connect it to the terminals. If you see lower than 12.6v, then reconditioning will help improve your car battery.

However, if you see 0 volts, then it’s likely that your battery has suffered some kind of short circuit and will sadly need to be replaced.

3. Emptying the battery

Before we continue this step, make absolutely sure that you have goggles on and your extra set of clothes. Your gloves should be chemical resistant as well to ensure that you do not burn yourself from the battery acid.

Take your screwdriver and slide it under the caps of the battery. Give it a little push and you’ll take out the caps with ease. Once you’ve got them all, get your plastic bucket handy so that you’re ready to pour the acid in. Keep the caps safe nearby so that you don’t lose them.

Carefully tip the battery away from your body and pour the acid into the bucket. Go nice and slow so that you don’t spill any or get it on your body.

Once the battery cells are empty, you can stand the empty battery up normally. Pour around half a pound of baking soda into the bucket so that you neutralize the old battery acid. Don’t empty this bucket yet, you’ll need it for the next step.

4. Cleaning the cells

Now that the cells are empty, it’s time to mix around half a gallon of distilled water with half a pound of baking soda.

Once mixed, use the plastic funnel to pour it into each cell. Once they’re full, put that caps back onto the battery and then shake the battery to clean the insides. This will take around a minute or two of shaking and the battery might be quite heavy, so you can take it easy on this step.

Once finished, you can open the caps the same way and pour the cleaning fluid into the bucket. You now have a battery that’s ready for reconditioning and a bucket of waste liquids that you can safely dispose of.

5. Reconditioning the battery

Now that you have a cleaned car battery, it’s time to refill the cells. We’re going to use the distilled water and Epsom salt to create our own electrolyte. This will raise the voltage and increase the amps that the battery can give to your car, and will also stop sulphating on the plates that will slowly kill the battery.

To create the electrolyte, use half a pound of Epsom salt and half a gallon of boiling distilled water. Pour the boiling distilled water into the second plastic bucket. Gradually add the Epsom salt and stir it to combine the two.

Once the water is fully clear, you’ll have created your own electrolyte that is ready to fill the cells.

Use the funnel again (making sure it’s cleaned) and pour the electrolyte into each cell. Make sure each cell is filled to 100% and if you should have any left over, you can save it for the next time you recondition your battery.

Once the cells are full, put the caps back on and shake the battery for a few minutes. You’re now ready to charge it.

6. Charging the reconditioned battery

Before charging, make sure you take the caps off. This is to ensure that the electrolyte doesn’t heat up and overflow. The pressure inside the cells is going to create a lot of trouble and it’s the last thing you want to happen.

Take your battery charger and put it as far as possible from your battery. Now connect the positive lead to the positive battery terminal, and do the same for the negative side. Now you’ll want to slowly charge the battery and leave it for at least a day and a half.

Once you’ve waited that amount of time, you can then test your reconditioned battery.

7. Testing the battery

Take your voltmeter and test the battery. If you’re seeing 12.43v or more then the battery is good to go for a test. If you haven’t got more than 12.43v yet, don’t worry as you can continue charging it. If there was any electrolyte overflow, you’ll need to fill it back up with more of the solution and continue charging it. After another 12 hours, you should hopefully see 12v+.

If you have a battery load tester then it’s a fantastic way to test your batteries. If not, then you can test your newly conditioned battery by using your voltmeter. Put the caps back on and place the battery into your car. Connect it up and put on your high beams without starting your car.

This will put the battery under load. Give it a couple of minutes then take a reading from your voltmeter. The reading should be at 9.6v or more to be considered working. If it’s under 9.6v, then the battery isn’t fully reconditioned and you may need to repeat the steps to ensure you got everything done correctly.

The other option is to cycle the battery. If the battery fails the first load test and is below 9.6v, you’ll need to cycle it by discharging it and recharging it again.

To do this, you need to put your battery under load, and one of the quickest ways to drain the battery is to simply leave your high beams on for some time. Once the lights time, you can disconnect the battery and repeat the process.

You may need to repeat the cycle around 4-5 times before you get a reading of 9.6v under a load. However, once that’s finished, you’ll be left with a fully working and reconditioned battery.


Reconditioning your batteries will typically follow a similar pattern to this.

It may take some time to do (especially if you have to cycle your batteries) and it does take a bit of knowledge of the device (such as understanding the voltages of the battery you’re working on) but all of that information is freely available over the internet.

 For example, here is a great video explaining how to clean battery terminals:

Once you’ve managed to work out all of those specifics for each step above, you’ll be able to easily recondition any kind of battery that you require.

This article focused mainly on reconditioning a car battery, and it’s a good place to start because it’s large, it teaches you the fundamentals of how to recondition batteries and it’s also one of the more expensive batteries to replace.

If you’re simply looking to replace a smartphone battery or something small, then it’s best to take it to the manufacturer or purchase a replacement for convenience sake.

However, if it’s a larger battery like a car or laptop one, then reconditioning is the way to go if you want to save money and be more environmentally friendly.

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