Is it possible, how much and how to add water to the battery. We will also look at the maintenance-free option

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I often receive messages on my blog about battery maintenance, in particular, is it necessary (and is it possible) to add distilled water inside? How much is needed? Why is this done, and will it cause any harm? I have already written several articles on this subject, but I have not examined this issue in detail. Today I want to close this gap, as usual there will be a video version at the end. Separately, I will focus on the maintenance-free battery. So read and look, it’s definitely useful information...

The water in the battery is everything to us! Without it, it will not work normally, all because it is part of an electrochemical fluid, simply an electrolyte. However, under the influence of temperature, it can evaporate from there.

Electrolyte

As you and I know, the electrolyte (inside the battery) consists of two main components:

This is sulfuric acid. Its approximately 35% of the total volume
Distilled water. Its approximately 65%

When these two substances are mixed, the electrolyte needed for work is obtained, with a density of 1.27 g/cm3. It is not recommended to add more than 35% acid; if you raise the density to 1.3 - 1.4 g/cm3, then at this concentration the lead plates will suffer and may collapse prematurely.

However, it is also not recommended to pour less acid; a reduced density of 1.2 - 1.23 g/cm3 can contribute to the freezing of the electrolyte at extremely negative temperatures (-25, -35 degrees).

That is, this density has been verified by many experiments and is a reference; it is worth noting that in the north up to 1.29 g/cm3 is allowed

Determination of electrolytic fluid in a battery

There are two types of energy sources commonly used in the automotive industry today:

Maintenance-free devices are enclosed in a sealed housing that completely prevents access from the outside. They, as a rule, exhaust their resource and must be replaced. You cannot restore their functionality on your own. The only thing the owner of such a battery can do is charge it as needed.
Maintained - require constant attention and monitoring. It is necessary to regularly monitor the level of the electrolyte solution, as well as its density and the condition of the plates.

How to find out the electrolyte level

Electrolytic liquid can change its volume as it is stored and used. How can you check the electrolyte level in a battery? There are several options, each of which can be used in a specific situation:

According to special marks applied to the body. Some energy sources have two horizontal lines parallel to each other on the outer surface of the housing in its upper part. The bottom one is marked “min” - shows the minimum possible level of the electrolyte solution. The top one has the inscription “max” - the maximum permissible limit of the liquid medium.
By visual inspection. It allows you to determine the approximate amount of liquid content. In the absence of tags and other available means, it is enough to simply unscrew the plugs on the top cover of the case, while installing the device on a flat horizontal surface. Looking inside, especially if there is good lighting, you can understand by the following criteria whether the solution is enough or not:
the electrodes are visible (they are level or above the surface of the liquid) – topping up is required.
By performing simple measurements. The electrolyte level in the battery can be checked using:
Available means: a transparent juice tube or the same body of a ballpoint pen. We lower the tube into the hole in place of the unscrewed cap until it rests against the top edge of the jar. We pinch the end remaining on the surface with a finger, thus blocking the flow of air into it. Holding your finger, remove the tube and measure the height of the column of liquid trapped inside it. At a normal electrolyte level, its value should be in the range from 11 to 15 mm.

Low battery electrolyte level

How can you tell if your battery has low electrolyte levels? This is very eloquently evidenced by:

significant increase in density;
the appearance of plates above the surface of the liquid medium.

There may be several reasons for this:

Evaporation of distilled water is the most common factor in volume reduction in the summer. As is known, too high outdoor temperatures provoke evaporation processes. And when using the battery during this period, it is very hot under the hood.
Liquid boiling over due to a malfunction of the temperature relay-regulator.
As a result of battery discharge, some of the acid is consumed for electrochemical reactions.

A decrease in the electrolyte level below normal in the battery leads to very serious consequences:

firstly, a solution of increased concentration promotes accelerated destruction of the plate material;
secondly, that part of the electrode surface that is located above the liquid boundary undergoes sulfation.

In both cases, the outcome is the same: rapid loss of capacity and premature failure of the energy source. This means it will need to be replaced. Where is the guarantee that the new battery will not lose its functionality just as quickly?

Option one is to learn how to properly operate and maintain the battery, and first of all, maintain the liquid component at normal levels.

What should be the electrolyte level in the battery? The norm is when the electrolyte solution is 1–1.5 centimeters above the electrode plates, completely covering them when the car is moving.

Moreover, the electrolyte level must be the same in each jar - this is very important for reliable battery operation.

Water inside the battery

How we figured out water AJ - 65%! But it is not simple (from the tap) , but distilled without any impurities (this is necessary for many reasons, if only because the resistance inside decreases, there is no sediment on the plates, etc.).

But its level is not constant. As is known from high temperatures in the engine compartment, from charging the generator (sometimes overcharging ), water can evaporate from the cans, and the electrolyte level drops.

Sulfuric acid does not evaporate, and therefore its concentration begins to increase; this is bad for the battery in several ways:

High density negatively affects the plates, destroying them
The level drops, which means the plates are exposed, thereby reducing the battery capacity and it is not able to start your car.
At high acid concentrations, sulfation of the plates

To avoid this, you must replenish it - add water inside the battery to the required minimum.

What cannot be replaced?

Neither ordinary tap water nor tap water purified with a simple filter can be used as battery fill. Also, you should not replace the distillate with unfiltered rainfall and melt water.

Rainfall collected in a city where industrial enterprises operate is not suitable. The reasons for the impossibility of using these types of water lie in the following:

tap water contains many salts that are harmful to batteries;
tap water passed through a filter contains fewer impurities, but the concentration of dissolved salts is still high;
In unfiltered rainfall and urban melted snow there are many chemical compounds that got there from the atmosphere polluted by industry.

Any unpurified solutions contain chemical components that can cause car batteries to fail prematurely.

Reference. Do not mix boiled water with electrolyte. Although this composition becomes less rigid, a salt precipitate is formed in it. Boiled liquid produces even more impurities that negatively affect the operation of the battery.

How to add water to the battery?

First, let's look at the serviceable option - when there are plugs on top of the battery. Everything is elementary here:

First , you need to buy distilled water in a store or make it yourself at home .

Second , just unscrew the plugs on top and look at the plates. If they are bare, the electrolyte level is lower, you need to add so that the water covers them. I’ll tell you how much to pour below.

Third , after adding it, put it on charge; you can use automatic chargers

As you can see, everything is elementary - there are no problems.

Is this water suitable for drinking?

In conclusion, it would not be amiss to answer a question that interests many, which is not directly related to our topic: is it possible to drink distilled water?

Since this is purified water, it does not pose any danger to drinking. Moreover, it was always drunk for gastrointestinal disorders. With proper storage, it does not lose its properties for a long time and can be used as drinking water.

There is no need to waste time preparing it at home. There is always the opportunity to purchase it in specialized stores for motorists. It is often produced in convenient plastic canisters. You can carry them with you in the trunk if there is enough space.

Thus, we learned not only about how much distilled water should be poured into the battery, but also how to do it correctly - so as not to harm the battery.

How to properly add distilled water to a battery When using batteries, the electrolyte level in the banks inevitably decreases. With maintenance-free batteries, the fluid level in the compartments remains virtually unchanged for 5-6 years. As for serviced batteries, owners constantly have to monitor the electrolyte level and take timely measures. In the article we will tell you how to add distilled water to the battery, how much of it is needed and whether it can be replaced with something. Where to get distilled water for the battery About 20 years ago, motorists had no questions about purchasing distilled water; it was sold in almost every pharmacy. Now the situation has changed. The fact is that this liquid is suitable for use for medical purposes for three days, so you can only get it at a pharmacy that has its own distiller.

Modern alternative options: auto parts stores, gas stations with a retail outlet; hardware stores (distilled water is used in irons and steamers). Another option is to search for water in online stores. It is suitable for those who want to stock up for future use. The delivery time, depending on the region, can be several weeks; this method is not suitable for emergency topping up of fluid in the battery. Some motorists do not want to waste time visiting stores and wonder whether it is possible to fill the battery with plain or boiled water. The first option is absolutely not suitable. There are foreign substances in tap water: chlorine, magnesium, phosphorus, etc. When charging the battery, they will settle on the lead plates. At best, this will lead to a decrease in battery capacity, at worst, to a short circuit and failure of the battery. As for boiled water, it cannot fully replace distilled water; it contains metal salts, albeit in small quantities. This option is suitable if you urgently need to bring the battery into combat readiness, but then you will have to rinse each jar and fill in new electrolyte.

An attempt to replace distilled water with boiled or some other water can lead to a decrease in battery capacity, destruction of lead plates and other unpleasant consequences. How to add distilled water to a car battery correctly If the density of the electrolyte in your battery has increased or you notice that it does not produce the required voltage, most likely the reason is a decrease in the amount of distilled water. Normally it should be 65% to 35% sulfuric acid. Sequence of work when adding distillate to the battery. To correctly add liquid to the jars, use the instructions. Remove dirt and dust from the top of the battery, especially around the plugs. Wipe the area around the necks with a rag soaked in soda solution to neutralize any sulfuric acid that may have splashed out during charging. Carefully unscrew the plugs and protect your hands from exposure to electrolyte. Take a medical syringe, syringe or hydrometer and fill with distilled water. Pour liquid into jars with insufficient electrolyte levels. Tighten the plugs. After 2-3 hours, check the density of the electrolyte with a hydrometer (normal value in the table below). If everything is done correctly, put the battery on charge.

Adding distilled water to the battery should be done on a horizontal surface. Otherwise, the level of liquid in the jars will be different, so you will either overfill or not add water. The recommended battery electrolyte density depends on the climatic conditions of your region. Climatic zone Electrolyte density (g/cm3) 1.25 Middle zone 1.27 North 1.29 To ensure accurate results when measuring the electrolyte density, hold the hydrometer vertically and do not allow the float to touch its walls. Having collected the electrolyte into the flask, gradually reduce the pressure so that the float floats freely. If you were able to achieve this, pay attention to the place where the liquid comes into contact with the scale. This will be the density of the electrolyte in the battery. Check the density of the electrolyte after adding distilled water to the battery.

How much distilled water to add to the battery In a modern battery, it is easiest to understand how much distilled water to add. Its body is made of transparent plastic with a scale printed on it. It is enough to ensure that the level recommended by the manufacturer is not exceeded. If you have a different type of battery, use the following tips. Some batteries have a metal or plastic tongue located just below the neck of the can. The electrolyte level should be 5 mm above the tongue. If there are no marks in the jar, add distilled water so that the electrolyte level is 10-15 mm higher than the lead plates. If you cannot visually determine how much electrolyte is in the jar, take a glass tube, lower it into the compartment, pinch the top with your finger and carefully remove it. The amount of liquid in it will be equal to the distance from the lead plates to the surface of the electrolyte. Try to follow the pouring rules to achieve the correct ratio of hydrochloric acid to distilled water. If there is more acid, it will destroy the lead parts of the battery; if there is less acid, the battery will defrost at negative temperatures. How to get distilled water at home Some car enthusiasts prefer not to buy distilled water, but to make it themselves. Usually these are people of the older generation, accustomed to times of scarcity and who do not want to change. But residents of remote villages where there are no shops have to adapt in a similar way. Let us immediately note that it is impossible to obtain high-quality distilled water at home. To do this, you need a distiller, the cost of which is not comparable to the price of a bottle of water. As an alternative, you can use a moonshine still if you remove the coil from it. But the yield of distilled water with this method is insignificant, about a glass in 3-4 hours. Distilled water has the formula H2O, that is, it does not contain foreign impurities. No matter how hard you try, it is almost impossible to get a similar result at home; a small part of the metal salts will remain in the water.

If you urgently need to top up the battery with water, put it in a plastic bottle and put it in the refrigerator for 2-3 hours. Then pour the unfrozen water into the sink, melt the ice and use it to pour into jars. In this case, the damage to the battery will be minimal. You can collect rainwater in a plastic container, then carefully filter it and use it for its intended purpose. It is important that the water does not come into contact with metals. For example, the one that drips from tin roofs is not suitable for filling the battery. Let's summarize Now you know how to add distilled water without damaging the battery. We recommend purchasing a hydrometer to monitor the density of the electrolyte in the jars. Without this device, it is impossible to achieve the required density, and changing it can damage your battery.

Maintenance free battery

But if you take a maintenance-free battery (for example, BOSCH, VARTA, MUTLU and many others), then you won’t be able to add it here so easily. The design does not provide for adding water inside, that is, you will have to “chemically” it.

To be fair, it is worth noting that often maintenance-free batteries are made using calcium technology and their water loss is very small. However, after 4–5 years the level still drops and it is advisable to bring it to normal

BY THE WAY - many of these batteries are handed over to specialized stores when they no longer start the car and they buy new ones. BUT NOT MANY people know that you just need to add water there and then performance will be restored.

HOW TO ADD, STEP-BY-STEP INSTRUCTIONS:

First, determine the electrolyte level. Lightly shake the battery left and right, if there is a minimum level, then you should add water. If there is a feeling that there is enough of it there, then perhaps water will not help you (maybe you have shedding or sulfation)
We determine where your plates are located (at what height). If the battery is transparent (has a white casing, like BOSCH's), you can illuminate it with a flashlight. But if the body is black, then it won’t work out that easily, you have to figure it out “by eye”
We retreat from the plates approximately 1.5 - 2 cm upward. We take a 2-3 mm drill and drill small holes.

Take distilled water and a syringe with a needle. Fill the syringe and pour it into the battery through the holes

It is worth adding before liquid begins to ooze through the holes.
Then we put the battery on its side and solder the holes with a regular soldering iron.
Then we just charge

You have to “collective farm”, there is no other way. Some people drill holes from the top, but this way it is impossible to control the level (and you also cannot overfill).

What can you do instead of distillate?

To fill the battery, instead of distilled water, it is permissible to use undistilled water.
But the composition used must be purified.

The distillate contains no salts with other impurities. This composition does not adversely affect the condition of the battery.
Important. Replacing distillate as a battery fluid is acceptable, but only if it is as free of salts as possible.
It is allowed to pour into the electrolyte a purified mixture whose composition is as close as possible to distilled water.

How much water should I add to the jars?

Another important condition. Some batteries have a special level (usually on the side of the case) to which you should add water (you cannot overfill).

However, a large number of batteries do not have this level, so how much should you pour?

ONE very simple rule. The plates must be covered with electrolyte by 1 - 1.5 cm (measured with special measuring tubes). At this level, a density of 1.27 g/cm3 is obtained

You shouldn’t pour more, otherwise the density will drop to 1.20 - 1.24 g/cm3 and there is a high probability that the battery may freeze in winter.

Now let's watch a small but useful video.

This is where I end, I think my article was useful to you. Sincerely yours, AUTOBLOGGER

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What to do if the electrolyte solution level is low or high

Currently, two types of batteries are most widespread: serviced and maintenance-free. In maintenance-free models, there is no way to check the electrolyte level; therefore, there is no need to add fluid. In serviced batteries, the plugs will be unscrewed, and many models have a special window for checking the fluid level.

Car battery maintenance, including checking the electrolyte level, should be performed at least once a year.

Checking the electrolyte level in the battery is carried out as follows:

The battery cover is unscrewed.
A special measuring transparent tube with a diameter of 5 millimeters is lowered into the liquid to the very bottom.
Pinch the outer hole of the meter with your finger.
The tube is removed from the battery.
Compare the electrolyte level with the corresponding scale.

For most battery models, the electrolyte level should be 10-15 mm above the level of the lead plates.

The easiest way to measure the electrolyte level is in batteries that have transparent plastic windows or the battery case is made of transparent plastic. In this case, there is no need to unscrew the cap and use special transparent tubes.

When servicing a battery, a car owner may encounter a situation where the acid level is higher or lower than normal. It will be necessary to decide whether it is possible to add electrolyte to the battery. If the fluid in the battery is more than normal, you will need a syringe or rubber bulb to remove excess solution.

If the electrolyte level in the battery is low, distilled water should be added to the solution. The distillate can be purchased at gas stations or in specialized stores. It is not recommended to use ordinary clean tap water for this, since the salts contained in tap water can react with acid, which will lead to sedimentation and subsequent difficulties in the operation of the battery.

Many car owners think about what to add to the battery - water or electrolyte. In most cases, it is water that evaporates from the electrolyte, therefore, to ensure the correct density of the liquid, distilled water should be added.

To know exactly whether to add water or hydrochloric acid to the battery, you should measure the density of the solution. You can do this yourself using a simple hydrometer. Such a device looks like a float that is immersed in a liquid, and the density of a particular solution can be determined by the depth of immersion.

Standard density indicators for hydrochloric acid are 1.25−1.3 g/cm 3. If the density indicator deviates upward or downward, then it is necessary to fill in distilled water or hydrochloric acid, respectively.

When adding water to the battery, you should remember that the density indicators should not be lower than the established values. Otherwise, the process of lead precipitation from the plates will begin in the diluted electrolyte, the battery will accumulate energy poorly, and problems will arise with starting the engine. That is why, when servicing a battery, you should check the density of the liquid, performing this test on a fully charged battery.

To understand why an electrolyte is needed, you need to know how a car battery generally works. There are 6 cans inside the plastic battery case. Each can contains 2 plates of different polarity:

anode (positive electrode);
cathode (negative electrode).

The plates are connected to current-carrying grids on which the following substances are applied:

lead dioxide - on the anode;
lead powder is on the cathode.

In order to ensure the cycle of charge, discharge and release of electrical energy to vehicle consumers, the following chemical reactions must be performed.

These reactions occur when the battery is discharged, that is, when it releases energy. In case of charge, reactions proceed in the opposite direction.

And it is precisely in order to ensure their flow that electrolytic fluid is needed.

if, according to the results of measurement using a plastic tube (see above), the level turns out to be higher than normal, then you should pump out the excess (using a rubber bulb, for example), then measure again using the tube, and if everything is normal, then measure the density and then “level” it exactly (how to do this, see below);
if, according to the measurement results, the level, on the contrary, is below the norm, then you need to immediately determine the density - this will determine what needs to be poured.

Is it necessary at all or not?

Topping up the device is always necessary when the hydrometer detects an increase in the density of the composition. If this is not done, the battery will overheat greatly. All this will eventually lead to failure.

If you do not systematically add distillate to the battery when the acid saturation inside it increases, then the battery life will be reduced several times.

Attention! The purified aqueous composition must be added to the device to prevent exposure of the lead plates. If you don't do this, they will quickly collapse. The result will be the failure of the entire mechanism.

Why add?

Periodically, clean water must be added to the device. This is done for the following purposes:

replenishment of previously boiled away water mass;
preventing overheating of the battery mechanism;
reducing the concentration of sulfuric acid in the mixture;
improving the process of accumulating a mixture of electrical charges necessary for battery operation.

Reference. The distillate is added to the battery to preserve the battery plates. Sulfuric acid melts them because they are made of lead. The purified aqueous composition slows down the process of destruction and mitigates the negative impact of the aggressive internal environment on them.