How To Make Distilled Water For A Car Battery

explaining how easy it is to prepare distilled water.

One of the simplest and easiest DIY things to do is how to make distilled water for a car battery. Honestly, it doesn’t take rocket science to prepare distilled water for your battery. All it needs is a little ingenuity and patience. Let me show you how.

How do you need to make distilled water? Making distilled water is easy. All you need to do is boil water, catch the condensation formed by the boiling water and then let the condensation cool to become water again. This time, the cooled condensation is free of salt, minerals and other impurities.

Actually, there are many ways of preparing distilled water that can be used for a car battery. What I described is the most effortless and uncomplicated. All you need are a shallow pot with a glass lid, a small cup or dish, and a stove.

Here’s how to do it:

Step 1

Put water on the shallow pot. Fill it at least halfway full.

Step 2

Place the cup or dish at the center of the pot. Don’t allow the water to inundate the dish.

Step 3

Turn the lid upside down and cover the pot with it.

Step 4

Put water on top of the inverted lid. The water on the lid will make condensation faster since it will cool down the lid.

Step 5

Boil the water. As the water boils, steam will rise up the lid and become condensed water. The inverted lid will direct the condensation to the center of the pot and down to the dish/bowl.

This condensed water is free of salt, minerals and other impurities normally found on tap water. This is the distilled water you can use to replace the liquid in the electrolyte of your battery.

Why Use Distilled Water For Car Batteries

The most commonly used battery for a car is a lead-acid deep cycle rechargeable battery. And usually it’s a wet or flooded lead-acid battery since it is the least expensive, but not necessarily cheap. A battery is a form of investment that needs to be taken care of to prolong its life so that you get the most out of your investment.

And lead-acid battery has four major components; a positive plate, a negative plate, a separator, and the electrolyte. The electrolyte is a solution made up of a mixture of sulphuric acid and water, normally, distilled water.

One problem or issue with a wet or flooded lead-acid battery is regular maintenance. The water in the electrolyte solution needs to be topped off periodically. When a chemical reaction is generated in the electrolyte to produce electrons, the water in the electrolyte solution evaporates and the water level is diminished.

To ensure that the battery is in good form and will last longer, you need to replace or top off the water in the solution periodically. If you don’t do this regular maintenance, the plates, which are supposed to be submerged in the solution, will be exposed and will become warp or distorted, causing an irreparable damage to the battery.

So why distilled water? Distilled water is free of impurities such as salt and minerals found in tap water. These minerals and other impurities clog the pores and create a layer of scum on the battery plates. This affects the normal chemical reaction that takes place in the generation of electricity and could shorten the life of the battery.

On the other hand, using distilled water on a battery will help prolong the life of your battery since it is already free of the salt, minerals and other impurities found on tap water. It does not only prolong the life of your battery, but it also improves the battery’s efficiency and performance.

How To Top Off A Battery With Distilled Water

In adding distilled water to the electrolyte solution, there are some precautions that need to be followed. Keep in mind that you are dealing with a hazardous substance, sulphuric acid. Any misstep could cause injury and even a serious accident such as an explosion or fire. Learning the right and safe way to add water to the battery is important in caring for your battery.

First, you have to protect yourself by wearing goggles, rubber gloves, and protective old clothes such as a long sleeve shirt, long pants, and shoes with closed toes.

Second, prepare the work area by seeing to it that it is clear, with no open fire or anything that could cause combustion. Prepare a pale of water close by to douse off any spark and clean off spills.

Third, prepare the following tools and materials; a screwdriver or wrench, window cleaner, clean rags, a clean funnel or a turkey baster, water and baking soda solution, and a stout wire brush.

Now that you have everything ready, let me give you a detailed instruction on how to replace water in your battery:

Step By Step Procedure Of Topping Off A Battery

Step 1. Find out where the battery is located. In most cars, the battery is located under the hood. But there are cars with batteries located under the engine compartment, behind the wheel well, or at the back of the bumper. Find out exactly where it is located so that you’ll know how to access it.

Step 2. Inspect and clean the batteries. Once you have found the battery, give it a good inspection and do a thorough cleaning. Remove the debris, scum, and dirt on top of, and surrounding the battery terminals.

This is an important step in the process since no foreign material should enter the battery cells.

Apply a water and baking soda solution on terminals and the surrounding area and brush off the corrosion and grime using a stout wire brush. Wipe the area clean once you have removed the debris.

Step 3. Remove the port covers. These are the plastic covers that are used to seal the battery cell port. Loosen the covers using a screwdriver or a wrench then lift them out.

Step 4. Resume cleaning if necessary. Once the ports are open and you see more grime and dirt, wipe it with a rag soaked in window cleaner. Don’t use the baking soda and water solution for this procedure, and make sure that no grime, dirt or any debris enter the port.

Step 5. Check the electrolyte level in each cell. This is done by simply looking down the ports. The cells should be equally covered by the solution. It is important to note that the electrolyte levels on the cells are of equal amount. An unequal level could mean a crack or a leak which is a serious matter that could even need the battery to be replaced.

If the water level is equal, then check if the water level is the correct level, meaning, it is ½ cm above the top of the terminals and does not need topping off. If it is below the correct level then topping off is required.

Electrolyte level is too low when the top of the plates are showing and are exposed to air. If this is the case, your battery will not be able to operate efficiently. Exposed plates could easily warp or get ruined in a matter of days.

If the electrolyte is only half an inch lower than the top of the plates, simply adding enough of the distilled water to reach the required level could bring the battery back to operation, with its capacity a little bit diminished.

To avoid such a situation, make it a habit to do this topping off operation at least once every three months.

Step 6. Add the distilled water to the electrolyte. In doing so, you can use a funnel or a turkey baster so that you can control the flow of the water. Make sure that whatever it is you are using is clean.

Fill the battery only up to the maximum safe level, which is a half inch above the top of the plates, or touching the ends of the filler tubes.

Some words of caution: If you are adding distilled water to a dead battery, don’t fill it up to the maximum safe level. Just add water enough to cover the plates. There should be ample space for the electrolyte level to rise once the battery is charged.

Step 7. Clean up and close the ports. Once you have finished topping the battery off, wipe any spill or excess moisture on the surface of the battery, replace the covers and securely close the ports.


Distilled water is available almost everywhere, but I’m sure it will give you greater satisfaction if you know how to make distilled water for a car battery and you can top off your battery on your own. You don’t only learn a skill, it also means savings that could be put to better use.