What is the density of the electrolyte should be in the

A battery is required to start the internal combustion engine. Its performance depends on how quickly and confidently the car starts at any time of the year and for any external factors. Serviced battery models are quite common, in which the car owner can independently adjust the physico-chemical parameters.

The main parameter affecting the operation of this device is the density of the electrolyte. Correctly changing its value, you can extend the service life of the appliance. However, the density of the electrolyte in the battery in winter and summer is different, because the external temperature conditions affect chemicals differently.


  • 1 Battery operation
  • 2 Chemical processes
  • 3 Instrumentation for surgery
  • 4 Preparatory operations
  • 5 Density change
  • 6 Full replacement solution
  • 7 Choosing the right battery
  • 8 Winter operation
  • 9 Conclusion

Battery operation

The Latin translation of the word “battery” means “accumulate”, since the device has the ability to collect and save electricity. Her battery is used to start the power plant of the car. The generator is also able to power the system with electricity, but it is not able to accumulate it, because after stopping the rotation of the rotor, the process of supplying current from the generator stops.

how is the density of electrolyte in the battery in winter and summer

In addition to starting the motor, the battery is charged with the function of maintaining the health of the alarm when the engine is off and emergency power supply if the generator for some reason refuses to work.

To ensure the performance of all functions, it is necessary to maintain a sufficient charge of the battery, as well as to know how to raise the density of the electrolyte in the battery, if necessary.

Chemical processes

Before you determine what the density of the electrolyte should be in the battery, you need to know what kind of substance and what it consists of. Due to the high-quality electrolyte, it is possible to hold the desired battery charge for a long time. The composition of this solution includes distilled water and sulfuric acid.

What should be the density of the electrolyte in the battery in winter and summer

Battery Composition

Density measurements in serviced batteries are carried out with a special device - a hydrometer. The procedure should be carried out under normal temperature conditions (from +22 to +25C), then the testimony will be as accurate as possible. It is undesirable to allow exceeding the permissible parameters of density, as this contributes to the strengthening of corrosion processes. However, excessively low density refers to negative factors, because during frosts the low-density electrolyte will simply turn into ice.

If the battery is low, it helps to reduce the density of the electrolytetherefore, the checking of the electrolyte density in the battery during the winter period should be carried out more often than in the warm season. It is also necessary to maintain a high level of charge in winter in order to ensure sufficient density.

You need to know that at low electrolyte density, recharging is first carried out using an external device.

You can provide the required amount of acid in the solution yourself at home. You need a certain set of tools and accuracy in the performance, as the acid is a dangerous and extremely active substance.

Toolkit for surgery

The current density value is determined using a hydrometer. The cost of a high-quality device is $ 2-5 at any online store or near auto shop. It is advisable to have a tared glass and a medium-sized medical pear. Consumables are distilled water and sulfuric acid.

See also: How to choose a car start-charger

what to do if the low density of the electrolyte in the battery

The algorithm is quite simple for those who do not know what to do if the low density of the electrolyte in the battery. In some cases, useful external charger, drill, baking soda and a soldering iron. Keep hands safe when working with acid help protective rubber gloves.

You need to know that household Chinese latex gloves for working with acid will not work, as they enter into a chemical reaction and lead to undesirable consequences.

Preparatory operations

If work with the battery is carried out in the winter, it will be necessary to bring it into the heated room and stand for several hours to equalize its temperature with the environment. After that, the battery can be charged. Pre-clean the contact surfaces with an emery paper of oxide film and measure the charge level with a multimeter. If necessary, carry out charging to the working value of 12.6 V.

how to check the density of electrolyte in the battery

When the battery is ready, we measure with a hydrometer. To do this, unscrew the lid, covering six cans of the battery. The areometer should be lowered into each of them alternately and wait until the float pops up to measure the density on the scale. You need to know that the winter values ​​of the density of the electrolyte should be higher than the summer readings.

Density change

Setting this parameter for your battery is necessary, given the seasonality and region of operation. The average density in a charged battery is usually 1.26-1.27 g / ml.

You need to know that the run-up of the electrolyte density values ​​between banks of more than 0.1 g / ml is not allowed.

how to increase the density of the electrolyte in the battery

Measurement of density with a hydrometer

The value can be taken from the table:

Region and seasonality The density of the poured electrolyte The density parameter of the battery
Summer 1,25 1,27
Winter 1,28 1,30
Northern region 1,28 1,30
South Region 1,24 1,26

For pumping fluid from each jar we use a medical pear. In the next step, we fill in a new diluted solution in the same volume that corresponds to the pumped out of each tank. After filling the cans, close them and slightly shake the battery.

Now once again you need to measure the data with a hydrometer. If the result does not correspond to the required one, then again we merge everything and level the readings with the help of distilled water.

what is the density of the electrolyte should be in the battery

When the density drops to critical values, below 1.20 g / ml, it is necessary to add acid, which is sold in specialized auto shops. Its density is 1.84 g / ml, and the process of topping up is carried out in the same way, using a pear and measuring container.

You need to know that when the acid gets on open skin, immediately rinse this place with running water to minimize the effects of a chemical burn.

Full replacement solution

Absolutely low electrolyte density, less than 1.1 g / ml, is not allowed, especially during the cold season. In this case, it must be completely replaced. Before this process, completely discharge the battery. Often for this purpose, an incandescent bulb of 12 V is connected to the terminals. You can see the degree of discharge by its filament level.

See also: How to find a leakage of current in a car with a multimeter

We pump out all the liquid from the cans and close the covers with sufficient pressure. Put the battery on its side and drill holes 3-4 mm in the bottom of each tank for downloading residues.

how to quickly raise the density of the electrolyte in the battery

Having added the distilled water

Using a distillate, we rinse the container from acid residues, and then solder the process openings. The patch is made with the help of acid-resistant plastic, which is taken from the old battery. After sealing, pour the prepared solution into all the jars.

You need to know that the solution is prepared by adding acid to water, and not vice versa!

Choosing the right battery

The service life of a classic battery is 3-5 years, depending on the manufacturer and operating conditions. It is important to take care of the battery during the approach of cold weather, to ensure its quality work.

Battery capacity is selected according to the recommendations of the automaker. It is advisable not to install a battery of excess capacity, as it will fail faster. This is due to its constant undercharging. Too weak in capacity will also be poorly effective when starting the engine, especially diesel. The average is 55-65 A * h.

How is the density of the electrolyte in the battery checked?

Serviced batteries require regular checking of the fluid level, which must be done at least twice a year. Distilled water is used for topping up, which you can carry with you in the car.

Frequent driving on poor-quality road leads to a shake-up, which is a negative factor for the battery. You will need to fix the battery securely so that the plates are not damaged.

Winter operation

The cold season is the most problematic period for battery density. At this time, its rate may be significantly underestimated, especially if the car is stored in a cold garage or in an open parking lot. Special devices help reduce the influence of external factors - thermoeusesthat wrap the entire battery. You can also use a universal blanket for the engine compartment.

What is the electrolyte density in the battery in winter and summer?

Thermobox for battery

Will help the operation of the battery in the winter and the use of more liquid motor oils, for example, synthetic or semi-synthetic brands. A reduced viscosity will provide less resistance, which is overcome by a battery-powered starter.

Temperature too low for the European region, for example, less than -20C should develop a habit for the driver not to start the engine immediately. At first for a few seconds the headlights are turned on in the high beam mode, to "run" chemical processes in banks. Under such conditions, a starter is not recommended to scroll for a long time, because more than 20-30 seconds is sometimes enough to completely discharge the battery.

If the car has long breaks during winter operation, then it is necessary to take the battery into the heated room and keep it charged. To do this, you will need to periodically monitor the charge level with a multimeter.


Even novice motorists are able to establish the required electrolyte density in the battery. The main thing to be careful and attentive while working with an acid solution. For long-term operation of the battery, it is necessary to follow the rules of operation, ensuring a normal and stable course of physical and chemical processes in the battery.