Battery Water


Our daily lives depend heavily on batteries because they run everything from our phones to our cars. But there are a lot of myths regarding the necessity of water when it comes to battery care. Does your car's battery really need to be filled with purified water? Is it okay to do that? What are the distinctions between distilled and deionized water, and how will they impact the performance of your car? Continue reading to learn more about the facts you need to know to keep your automobile running smoothly and safely.


Distilled water is an essential component of a car's battery, ensuring its longevity and performance.

  • It helps to keep the battery cells cool and prevents corrosion.
  • It should be checked regularly to ensure it is at the correct level.
  • It should be replaced every two years or when it becomes discolored.

By taking care of your car's battery water, you can extend the life of your car's battery and keep it running smoothly!

We've all been there: STUCK the middle of the highway, with nothing but dashed hopes and a dead battery.

Have you heard about an ol' battery water trick from mechanics and technicians about bringing a dead car battery (and even large lead batteries) back to life again... with WHAT? Distilled water?

You wouldn’t have imagined how well these two things work together. Although this doesn’t fully revive the battery, you can certainly count on this giving your car a second wind that just might get the job done.

On the other hand, if you want to learn more about how distilled water can affect your car battery then you're definitely in the right place. Read on below.

The Deal with Batteries & Battery Water

Using distilled water for battery units lengthens the battery life and improves performance and efficiency. One interesting thing to note is that using regular tap water does little to help your battery. At most, it even contributes to damaging your battery and decreasing its life span.

The reason behind this trick lies in the way batteries operate. In order to understand the mechanics of the distilled water trick, it’s important to understand how a battery works, and this will give us a clue as to how your battery's water plays an important role.

A battery, when broken down will yield three major portions from which it draws out electrical currents. These are:

  • separator
  • electrodes
  • electrolyte

These three components work together to create a chemical reaction that releases an electric current from the battery.

Different car batteries can use a variety of chemical combinations to generate this electric current. One of the most common combinations is lead dioxide and lead.

Why Do We Need Battery Water? Here’s what happens inside a battery:

  • When the battery is connected to your car and you attempt to start it, the lead dioxide and the lead sponge in the battery react to form a new compound known as lead sulfate.
  • During this process of creating the new chemical, electrons are released from the two initial substances. When the car is started, the electrons flow through the electrodes of the battery and into the electrical system of the car, providing the necessary voltage to get things going.
  • Water plays an important part in this chemical process. When the initial chemical reaction takes place within the battery, the newly-created electrons would need a medium in which to travel from the inside of the battery to the electrodes which will carry the current into the car.
  • This is where battery water comes in. The battery water will serve as the medium for the electrons and ensures that all of the stored electrons in the battery get used properly. Thank heavens for battery water!

It is important to note, though, that as the water in the battery helps conduct the electrical current away from the inside of the battery, the water is also subjected to the chemical process that creates the electrons in the first place.

This causes the water to go through changes as well. Usually, this change causes the water to evaporate, depleting the amount of water in the battery. With less water in the battery to carry the electric current, the battery doesn’t perform as well as it should.

This is the reason why car owners would usually replenish the amount of water in their batteries by using tap water.

The Problem with Tap Water for Battery Water Use

Although tap water replenishes the battery and keeps it up and running, it also contributes to its wear and tear. Certain substances in the water affect the chemical processes that are already running inside the battery.

Water that comes from faucets and other home sources is laden with minerals. These could be minerals coming from the home plumbing system as well as the local water treatment facility in the area. This kind of water can slow down your car battery’s performance over time.

This is because the minerals in the water get left behind after it evaporates from inside the battery.

Using Regular Water As Your Battery's Water Will Harm Your Battery

When the water evaporates, mineral traces such as iron and calcium don’t evaporate with the water. They get left inside the car battery.

When this happens, these minerals attract the free-flowing electrons that should have been used by the car. What happens is that these electrons attach themselves to the minerals and create a different compound which has no place inside the battery.

This, in turn, will cause the battery to lose out on efficiency because of a lack of electrons. It also shortens the lifespan of the battery because of the mineral build-up that takes place inside the car.

Enter Distilled Water for Battery Water

On the other hand, distilled water doesn’t carry the same problem as tap water. This is because distilled water doesn’t carry enough substances to affect the battery. It’s pure enough and does not affect the chemical processes that need to take place inside the car.

When you use distilled water for your battery's water, it doesn’t leave anything behind when it evaporates. Every other contaminant in the water evaporates as well, leaving nothing significant but water vapor. That means there won’t be any minerals to affect the chemical processes inside the battery.

What you get is an efficient battery with battery water that will start your car without fail. You’re also left with a healthy battery that doesn’t deteriorate as much as a battery that’s topped off with tap water.

Distilled Water As Your Battery's Water Is Good For Batteries In Other Ways Too

  • Another reason that distilled water is better for battery water and car batteries is because it’s acidic. You might be wondering why something as harmless as water could be classified as acidic. This is because of the distillation process.

When water is distilled, it turns into water vapor then is condensed back into a liquid state. During this process, carbon dioxide from the immediate area gets dissolved in the water. This creates a very weak carbon acid solution.

Is Using Distilled Water For Battery Water Acidic and Dangerous?

This is because the level of acidity within distilled water is very low. To answer the question “Is distilled water acidic or alkaline?”, you need to measure its acidity through a pH scale.

Distilled water comes around a level of 6, which is very close to the neutral level of 7 on the pH scale. This scale goes from 1 to 14, where any value below 7 is acidic and any level above 7 is considered as alkaline.

When drinking distilled water, our bodies counteract the acidity of the water by having our stomach produce more stomach acids to deal with the water. As long as you keep a healthy stomach, you’ll be able to handle drinking distilled water on a regular basis.

"Acidic" Battery Water Is The Best Kind Of Water For Batteries

  • Because our car batteries operate due to a chemical process, distilled water as battery water helps this process happen because of its slightly acidic properties.

It helps break down the lead components better which makes for a more conducive area for these chemical processes. This makes distilled water a great alternative to tap water for your car battery.

Where to Buy Distilled Water for Battery Water Use?

Although it’s slightly more costly than tap water, distilled water can be bought at supermarkets and grocery stores. They are usually sold in bottles and come in different brands. Having a few bottles at hand in the glove compartment is a good idea just in case your car has problems starting up.

You can buy bottled distilled water in groceries.

Little do people know that a car needs about 12 volts in order to get started once you turn the key. After that initial charge, a steady current has to be kept in order to keep the electrical systems of the car running smoothly.

That means the battery needs a constant supply of water in order to operate properly. Interestingly, this is also the reason why a dead battery is also called a “dry battery.” This isn’t because the battery has run out of electrons. It’s because the battery has run out of water.

Don't use the wrong water type for your battery's water!

  • Just be careful to read the labels on your bottles before purchasing them for use with your battery. There’s a large chance that your grocery store sells distilled water right next to their mineral water selections as well, and that won't work as well as battery water.

As you’ve already learned, foreign minerals inside your car battery aren’t a good idea. Make sure that you’re not buying mineral water.

How to Make Distilled Water: DIY Battery Water?

On another note, you can also create your own distilled water through the process of distillation. In a nutshell, distillation simply entails the usage of a heating system to get the water to evaporate at different temperatures.

When the water evaporates, it turns into water vapor. Since heavy metals and other minerals cannot evaporate with water, they get left behind by the water vapor. What you get at that point is distilled water vapor.

After heating the water and turning it into vapor, it’s simply a matter of condensation or cooling. Putting the water vapor through lowered temperatures will bring the vapor back to a liquid form, leaving all the heavy contaminants behind.

You can either create a DIY water distillation system (for creating your battery's water) on your own with special materials as well as a heating system like a stove. There are plenty guides on the internet that will show you how to set up a working system for your personal use.

Be warned that an amateur may find it difficult to set up a distillation system. In fact, it can become quite dangerous. Be sure to ask someone for help and exercise every precaution. You undertake this project at your own risk.

Interestingly, you can also buy a water distillation system from many manufacturers. These can be installed into your home water system to ensure that the water that you use around the house is free of heavy minerals and other contaminants.

Anyone Need A Battery Water Expert?

For the more practical readers, you may think that this is too much trouble. But when power is out and you have an emergency, this distilled water-battery system may be exactly what you need. Don’t discount science at all.

You may never know, but if the zombie apocalypse comes true, this is one of the most important information you could have, right?

Additional Research:

5 Tips for Maintaining Battery Water Levels

  1. Check the water levels in your battery regularly. This should be done at least once a month, or more often if you use your vehicle frequently.
  2. Make sure to use distilled water when filling up the battery. Tap water can contain minerals that can damage the battery.
  3. Be careful not to overfill the battery with water. Too much water can cause corrosion and other problems.
  4. If you notice any signs of corrosion on the terminals, clean them off immediately with a wire brush and baking soda solution.
  5. Always wear protective gear such as gloves and safety glasses when handling battery acid or working around batteries.

ALSO: Consider investing in a hydrometer to measure the specific gravity of your battery's electrolyte solution!</p

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About The Author

Joseph Bartley
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Joseph Bartley, also known as the WaterFilterFanatic, is a seasoned content writer who specializes in water filtration and water quality topics. On AllAboutWaterFilters, he has written a range of water filtration system reviews, water health and quality articles, swimming pool, hot tub and aquarium filtration guides, DIY methods to assist people clean their drinking water, and much more. Joseph enjoys spending his time working with the #AllAboutWaterFilters Editorial Team to provide some of the best quality water filtration content available on the web.

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