How to determine battery health

Checking the car battery - when else can you fix it?

When the key is turned in the ignition, it is the battery that provides the impulse to start the engine. If the battery is completely discharged, the car is unlikely to move. It is for this reason that it is important to check the car battery in a timely manner (with a multimeter, for example), because problems noticed in time will not only allow you to avoid searching for someone to light a cigarette, but will also save you from much larger problems. Checking a car battery should be comprehensive and thorough and include both an external inspection and a check of the “inner world”, as well as electrical indicators.

Visual inspection

First of all, carefully inspect the battery: normally it is dry, clean and without signs of damage. It's bad when:

the surface of the battery is heavily contaminated;
terminals are oxidized;
the battery case is damaged;
There are traces of electrolyte.

Any of the items listed will lead to rapid discharge of the battery, and therefore increase the risk of getting into unpleasant situations. What to do?

The same solution will help deal with terminal oxidation - apply the mixture to contaminated areas, wait a couple of minutes and thoroughly clean with a brush (not a metal one!). After the procedure, rinse the cleaned surfaces with distilled water.

If the oxidation is extensive, then the first step is to resort to mechanical cleaning, the main thing is not to damage the wires.

Exploring the inner world

The battery check should continue with electrolyte measurements. It is he who is responsible for most of what happens to the car. The electrolyte is checked according to the following parameters: density and level.

To check the level you will need a glass graduated tube. Unscrew the washers covering the so-called banks - sections in the battery. Lower one end of the tube all the way down and close the upper end with your finger. Pick up the tube.

It is optimal if the solution covers the upper edge of the plates by 10–15 mm. The total liquid content should be 30–40 mm. So check each section.

The next step is to check the density of the electrolyte using a hydrometer. The normal value is 1.26–1.28 g/cc. see at above-zero temperatures. The indicator will be lower if measurements are taken at zero temperature, but this indicates a low battery charge.

If the density of the electrolyte is higher than the required values, and its level is lower, then it is worth adding distilled water. It is important that it is not any other water, since only the distillate does not contain impurities of salts and metals that can damage the battery.

If the density is slightly lower (1.24–1.25 g/cc), then the electrolyte is added. You can either make it yourself or purchase it in specialized stores. Excess liquid is removed using a “pear”. Any leaks of electrolyte must be removed from the housing!

Making electrolyte at home

For this recipe you will need a well-ventilated area, personal protective equipment (at least gloves), non-metallic utensils, distilled water and 360 ml battery (sulfuric) acid.

First, water is poured into the container, then acid is poured in small portions and carefully. The mixture is thoroughly mixed at all stages. Then the resulting mixture is left to stand for several hours, and the electrolyte is considered ready.

After the completed manipulations, but before repeated measurements, the battery must be charged using a low current. This is the moment when longer is better. After charging, the measurements are repeated.

If during measurements the readings differ in only one section, this indicates damage to the plates. Maintaining life in such a battery will cost much more than purchasing a new one.

Using a Multimeter

A common question is: “How to test a car battery for performance with a multimeter?” First, it’s worth understanding what is measured using this device:

Even the simplest multimeters will help in measuring air temperature and other indicators. Hence the name: “multi” translated as “many”, which means that the device can measure a lot of things. However, when it comes to the battery, it is the first three indicators that will tell you about its health. Let's take a closer look.

Voltage check

This manipulation will allow you to assess the current state of battery charge. To carry out the measurement, the multimeter is switched to the voltage measurement mode at around 20 units. Connect the red wire of the device (also known as “plus”) to the positive terminal of the battery, and the black (sometimes blue) wire to the negative terminal.

If the car is not started, then the optimal indicators will be numbers in the range from 12.4 to 13 V. In this case, a higher value indicates a 100% charge, and a lower value indicates an incomplete charge. It is better to carry out such a check when the car has been parked for a long time (at least several hours), in which case the measurement will be the most informative.

If the numbers are slightly less than 12, then the situation is bad - the battery is close to natural death. There is a chance to try charging it with a low current. Numbers close to 11 mean the death of the battery, and it is better to take care of purchasing a new one.

When checking with the car running, the readings will be different: from 13.5 to 14 V, the readings are good. If the figure is greater than 14.2 V, then we can judge that the battery is being recharged by the generator. However, if measurements are taken in winter, you should wait 15 minutes and repeat the procedure - perhaps the generator was intensively recharging the dead battery.

Capacity check

The battery capacity is usually indicated on the accompanying sheet. Another thing is that over time the capacity decreases, and it is important to keep track of this point. In this case, checking the car battery with a multimeter will be a good help.

To check, you will need:

disconnect the car battery from the generator;
connect an energy consumer with fixed consumption to the circuit (for example, a 12 V light bulb);
The operation of the circuit is observed for several minutes (here it is important to see whether the light of the light bulb becomes noticeably dimmer, whether there are any interruptions in its operation, etc.);
the consumer is switched off, battery readings are measured in voltage mode.

If the measurement result is 12.4, then this indicates that the battery is fully operational. If the readings are in the range from 12 to 12.3 V, then soon the battery may “forget how to work”.

Another method is the control discharge method. The steps are similar to the previous method, however, before starting the test, charge the battery to 100%, then connect a light bulb to the circuit, noting the exact time of switching on, and, under the control of an ammeter, wait until the battery charge is reduced by exactly half.

Next is the question of calculations: the time spent discharging the battery is multiplied by the current in the circuit. The result should be the same as in the technical passport or close to it. If this does not happen, then the battery capacity has already suffered greatly.

Resistance check

To understand what is happening, you can also check the internal resistance of the battery. To do this, you will need the same 12 V light bulb. It is connected to the battery terminals, and the voltage at the terminals is immediately measured. After the measurement, the light turns off and the measurement is repeated. If the difference in measurements is within 0.05 V, then the battery is working. If the difference is greater, then the battery has problems.

Checking with a load fork

To obtain the most accurate measurement results, a load fork is used. Of course, this equipment is rarely seen in private hands, much more often in professional workshops or at technical diagnostic stations. However, if it does exist, then why not use it.

The load plug is a device that, like a multimeter, is connected to the battery terminals. It then supplies a short circuit current to the battery, which simulates the operation of the starter. As you know, without load the readings are about 13 V.

At the moment of turning the ignition key, which is simulated by the load fork, the readings normally “drop” down. The maximum normal drop can be up to 9 V and return to the initial reading after the voltage is removed. In this case, the battery can be considered serviceable.

If the readings drop below 9 V, then even if they return to their original state, such a battery is unlikely to start the car. It is important to remember that testing with a load fork should be carried out only in the warm season (optimally at a temperature of +20... +25 degrees), otherwise it is possible to drain the battery charge during testing.

A little theoretical knowledge

Knowledge of how to test a car battery should also be combined with knowledge of normal values and readings and why they change.

The density of the electrolyte can change due to temperature fluctuations - overheating or hypothermia. In this case, in case of overheating, the electrolyte may boil, in which case the distilled water will partially boil away, and the electrolyte will become more dense.

In the case of cold, the electrolyte, on the contrary, often begins to have a reduced density. In both cases, the conductivity becomes worse, and therefore there are problems with the establishment, rapid “landing” and work on its last legs.

But why is any liquid so important? The thing is that the battery only looks like a small box. In fact, it consists of many parts, the main of which are conductive plates, positive and negative, which make up 6 elements connected in series. They are in contact with the electrolyte, so the electrical impulses move with the necessary force.

For what other reasons could a battery suddenly stop working? For example, just from time to time. On average, batteries work stably for 3–4 years. Of course, many work longer, but their capacity and ability to hold a charge still decreases.

Another reason is frequent battery overcharging, undercharging, or complete discharge. It is very important for a car battery to maintain some kind of average state, without strong changes.

The next reason is hidden in the generator, or rather, in its breakdown. In this case, it may either constantly recharge the battery, giving too much current, or, conversely, may not even be able to maintain the existing charge. Both options indicate the need for urgent replacement of the generator.

The last on the list of unpleasant situations is current leakage: something in the car consumes too much energy even when the car is turned off and parked. This can be determined using the same multimeter. To do this, you will need to turn off the car and remove the negative terminal of the car from the battery. Turn the multimeter into current measurement mode, set the switch to 10 or 20 units. Connect one wire to the negative terminal of the car, and the other to the negative terminal of the battery.

Conclusion

Simple car diagnostics are available to any car owner. Careful attention to the battery will save a lot of effort and nerves, especially on long trips, in winter or at low temperatures.

The simplest thing that anyone can do is remember to inspect the battery every time you lift the hood. Quickly inspect the integrity of the case, wipe it with a rag to remove dirt, make sure that the terminals fit tightly and there are no signs of oxidation.

Once a month it is a good idea to check the level and density of the electrolyte, this is especially true in winter, during severe cold or long trips.
If suddenly the car begins to behave strangely when starting up, the starter turns sluggishly, and the engine does not start the first time, serious problems are not far off, and you need to check both the battery and the car’s alternator in the near future. To do this, you will need a multimeter, which can be purchased at almost any auto store for a fairly modest amount. Timely attention to detail often helps to avoid serious troubles.

How to check your car battery for performance

One of the important elements of a car that requires checking is the battery, or battery. The serviceability of the battery and its performance are very important, since it is thanks to the battery that the car starts, and all systems of the car are powered by it: low and high beam headlights, media system and much more.

Content

If you have already met with the seller and want to be sure that if you buy a car, the first thing you will have to do is run headlong to the store for a new battery, which usually costs more than 10 thousand rubles, then you have several ways to check the battery by car:

Inspect the battery externally;
Measure the voltage on the battery with a multimeter;
Check the battery with a load fork;
Check the electrolyte level in the battery.

We will consider each question in detail, but we immediately note that the fourth option, with checking the electrolyte level, is only available for serviceable batteries. But one way or another, there are a number of methods for checking a car battery for performance, and in this article we will look at them.

External inspection of the battery

You met the seller and have already walked around the car, seeing how clean and beautiful it is. It's time to look under the hood, you lift the lid and see the usual contents of the engine compartment, the engine and numerous systems that keep the car running.

In most cases, here, in the engine compartment, there is also a battery - a rectangular box with electrolyte inside, to which two wires are connected - positive and negative. These wires go to the distribution block, and from this massive electrolytic “battery” the entire machine and all its systems are powered with electricity.

Even if you don’t understand anything about cars and went for an independent inspection rather as part of a formality, you can still determine by the appearance of the battery what condition it is in.

During an external inspection, attention should be paid mostly to the integrity of the elements, and whether the battery itself and contacts are clean. There are a number of external factors, the presence of which immediately indicates the need to replace or at least clean the battery.

Dirt on contacts. In order for the battery to work, both contacts connected to it by wiring must be clean. If the contacts are dirty, this indicates that the battery is not new, and dirt will interfere with the correct operation of the contacts.
Oxidation of the terminals - foreign deposits can be seen on the battery terminals with the naked eye - this is oxidation, which in most cases is associated with electrolyte leakage. Electrolyte is an acid that is found inside the battery. If it spills and gets on the contacts, it can lead to poor battery performance and a reduction in the contact area.
Cracks on the case - the battery itself should be intact. The plastic box containing the electrolyte must not be damaged. This is also clearly visible without additional equipment and in good lighting.
Dirt, dust, electrolyte leaks - all this is removed with a rag, and the car should not be allowed to drive with a dirty battery, since the conductive deposit will contribute to its rapid discharge and deterioration of performance.

In addition to the external inspection, you can start the car engine. A cold start will be especially indicative if the engine has not been started for a long time and it is cold outside. If the car starts easily, the battery is in order, but if it does not start or starts with difficulty, the headlights shine dimly, and the instrument panel is also not brightly lit, then the battery should be changed. Or, at least, check it with instruments, which we will discuss below.

Measuring voltage with a multimeter

If you do not want to check the condition of the battery “by eye”, or simply want to have accurate results in numerical terms, you will need a device such as a multimeter.

So, how to check a car battery with a multimeter: the device itself has two probes, one of which is red and the other black. In order to measure the voltage on the battery, you need to put the multimeter in measurement mode and place the red probe against the “positive” terminal, and the black probe, respectively, against the “negative” terminal.

The procedure is carried out on the battery terminals without load. If the battery is properly charged, the result on the device will be about 12.6-12.9 volts. This is the normal voltage that should be present on a fully charged battery. If you mess up the colors of the probes, the number will be the same, it will just be displayed with a minus sign.

If the engine is running, then you can also check the operation of the battery with a multimeter, but in this case it will be checked whether it is working together with the generator, as well as the serviceability of the voltage regulator. When the motor is running, the readings should be slightly higher - from 13 to 14 volts. If the indicator is lower, this will mean charging problems for the battery, and if the indicator is higher, the process of water electrolysis will begin.

There is a method to determine the degree of battery discharge by voltage. Voltage 12.5 - says that the battery is 90% charged, voltage 12.1 - 50%, and 12 - 10 percent. Although the method is approximate, it is proven.

It is also advisable to measure with the device “cold”, since a car that has recently been running can give higher values and be misleading. The multimeter checks the degree of charge, but does not provide comprehensive information about its performance. To do this, it is better to use a load fork.

Checking the battery with a load fork

The load fork is a very precise tool, but is rarely used in “manual” use, as it is used mainly in service stations. The beauty of this method of verification is that thanks to it an absolutely accurate result will be known.

The load plug works in a similar way to a multimeter: it is also connected to the battery terminals, but produces a short circuit current. As we already said, without load the indicator should approach 13 volts. The load fork imitates the operation of a starter, which is why the voltage “sags” at the moment of use.

The drop should be no more than 9 volts. Otherwise, it will mean that the battery is very discharged. After removing the load, the indicator again “rolls back” to its original value. If under load the voltage “sags” to 5 or even 3 volts, this means that the battery will not be able to start the car engine.

It is recommended to think about changing the battery even if the voltage when using the load plug drops below 9 volts.

An extremely important note: the load plug supplies approximately 200 amps of voltage to the battery and is not recommended for use in low temperatures. The ideal conditions for “field” use of this device is a temperature of +20-25 degrees Celsius.

If you apply voltage to a cold battery, there is a risk of severely discharging it.

Checking the electrolyte level in the battery

Another convenient and reliable method, which, however, is only suitable for checking serviced batteries, is checking the electrolyte level. The method is a little more complicated than the previous ones, but it gives a good idea of the condition of the battery and tells you what’s inside it.

First, remove the battery and completely clean it of dirt. Let us remind you that it is better to do this with a rag; dirt and minor corrosion can also be cleaned off using an ammonia-based glass cleaner.

Next you need to open the two filler plugs. They need to be easily pryed with a screwdriver and unscrewed; six filler holes are hidden under them. The electrolyte level in them is checked by eye and can be seen with a flashlight. If the liquid level is the same everywhere, then everything is in order, if somewhere the liquid does not cover the plate, you need to add distilled water.

In general, this procedure must be carried out regularly, since each time the battery is charged, the electrolyte decomposes in small proportions into hydrogen and oxygen. Without regular maintenance, the battery will simply fail.

The norm is considered to be a level exceeding the height of the plates by about one centimeter, or below the neck of the filler hole by three millimeters. If necessary, it is worth adding distilled water to the battery being serviced, but we remind you once again: if the battery is marked “maintenance free”, or the manufacturers of this particular battery model do not recommend adding distilled water to it, you can only resort to the previous testing methods and, if necessary, replace the battery.

Knowing how to properly check a battery is important when buying a used car. Often, car sellers want to save money on small things, including selling a car with a dead battery, which can lead to negative consequences for the new owner. Always be alert and fact-check what the seller says about the health of your car.

And don't forget to check the car's history before purchasing. This can be done using the Autocode online service using VIN or state registration number. number. The system checks the car in more than 12 official databases: traffic police, EAISTO, RSA, taxi and bank registers, Federal Tax Service, Federal Customs Service and others. From the report you will find out: actual mileage, whether there are traffic police restrictions, compulsory motor liability insurance data, customs history, history of fines, participation in road accidents and much other important information.

If you do not have the opportunity to go for an inspection or you simply doubt your experience, order the Autocode on-site inspection service. An expert will come for an inspection and conduct a comprehensive diagnosis of the car, leaving no doubt about your choice of vehicle.

Checking the new or old battery for serviceability

Batteries can be easily damaged by a short circuit or remaining in a deep discharge for a long time. Every time such situations occur, as well as in case of mechanical damage to the product, it is necessary to thoroughly check the serviceability of the battery. How to carry out such research in various ways will be discussed in detail in this article.

What is required for verification

First of all, you need to remove the battery from the car and thoroughly clean its case from dust. Then you should prepare the tools and devices that may be needed to carry out various measurements. To determine the presence or absence of battery wear, you cannot do without:

Multimeter.
Load fork.
Hydrometer.
Screwdrivers.

It is also recommended to prepare a flashlight to visually determine the electrolyte level in the jars. When everything you need is prepared, you can begin detailed testing of the battery for performance.

What can you check in the battery?

You can check many parameters in a battery, including voltage, current, capacity and self-discharge current. In addition, during the inspection, the level of electrolyte in the banks and its density are measured.

In many cases, one of these measurements will be enough to give a fairly accurate test of the battery's health, but it is advisable to do a full test to get more accurate information.

Visual inspection

First of all, you should conduct a visual inspection of the battery. If, as a result of the inspection, chips and cracks are found on the case, then the cause of unsatisfactory operation of the battery may be an electrolyte leak. Even if the battery is in good technical condition, such damage may indicate a possible failure of the product in the very near future.

When purchasing a new battery, the presence of dents and abrasions will indicate that the product was subjected to increased mechanical stress during storage and transportation. Such external defects can lead to a very rapid failure of the battery, so it is better to refuse the purchase.

Electrolyte condition

Even if it is not possible to establish the exact current and voltage of the battery being serviced, its performance can be assessed by the state of the electrolyte. To get to the liquid poured into the jars, you will need to open the caps, which, as a rule, have cross-shaped cutouts for a screwdriver.

Some batteries are equipped with a charge indicator (eye on the battery cover), from which you can find out everything about the state of charge, liquid level and electrolyte density.

Charge indicator

By unscrewing the locking elements and shining a flashlight into each jar, you can determine the approximate electrolyte level. A very dangerous condition for the performance of the battery is the exposure of the plates, that is, if the liquid level drops below a critical level. Operating the battery in this condition will quickly lead to destruction of the grid filler, which can cause a short circuit.

If there is enough electrolyte in the jars, then the density of this liquid should be measured using a hydrometer. A fully charged battery must have a density of at least 1.27 g/cm3.

The presence of a brown tint in the electrolyte may also indicate destruction of the plates, therefore, in this case, it is better to carefully pump out the maximum amount of liquid using a bulb and pour in the same volume of a new acid solution.

Charge level

Knowing exactly what voltage at the battery terminals corresponds to 100% charge, you can correctly determine the battery charge level. For twelve-volt lead batteries, this value is 12.7 V. Measurements can be taken using any tester set to DC measurement mode. Read more HERE .

For this type of car battery, the presence of a voltage of 12 Volts at the terminals indicates that the battery is half discharged and requires immediate recharging from a network charger.

Determining capacity

The capacity is always indicated on the battery case, as well as in the product instructions. If there are no labels on the battery, then using additional devices you can roughly estimate the actual battery capacity.

To carry out the tests, you need to fully charge the battery, purchase or make your own 12-volt stabilizer, and also prepare an ammeter and stopwatch.

Considering the large starting current of the car battery, you will also need a load, which can be any twelve-volt device with a power of 100 - 200 watts.

The battery capacity is determined in the following sequence:

The battery, stabilizer, ammeter and load are connected in series to the electrical circuit.
When you turn on the electric current consumer, you must immediately activate the stopwatch and record the ammeter readings.
After the stabilizer cannot cope with maintaining the voltage at a given level, the stopwatch is stopped and the value of this device in hours is multiplied by the ammeter, expressed in amperes. The result will be the approximate battery capacity in Ah.

When measuring this parameter on a battery that is in good technical condition, the procedure may take several hours. You should also consider the negative impact of a full discharge on many models of lead batteries.

Checking the starting current

Cold cranking current is the most important parameter of any starter battery. This indicator is expressed in amperes and can reach a value of more than 1 thousand (cargo battery models). The starting current can be determined using a load with minimal resistance and an ammeter connected in series in a circuit.

As a rule, such measurements are carried out on a fully charged battery, and the battery should be discharged at a maximum current of no more than 30 seconds.

High leakage current

Presence of current leakage

If the battery is connected to the electrical network while the car is parked, then the presence of current leakage is normal. Even when the ignition is turned off, devices such as an alarm or radio can operate in standby mode, consuming a small amount of electricity.

To test the battery for leakage current, simply connect an ammeter between the positive terminal of the battery and the positive wire of the car. As a result, the digital display or dial gauge will display the exact value of the current consumed by the vehicle at rest.

Condition of plates and cans

It will not be possible to disassemble the battery and look at the plates to determine their condition, but you can use indirect signs to determine the presence of sulfation or a short circuit.

If, when the current recommended by the manufacturer is applied to the battery terminals, the electrolyte quickly boils, then this “behavior” of the battery almost always indicates the presence of sulfation of the plates.

A short circuit of the cans, on the contrary, will lead to the fact that the chemical process in a certain tank will not occur. That is, the electrolyte will not boil only in the can that is closed.

Date of issue

It is important to determine the year of manufacture of the battery before purchasing it because when a new battery is stored for a long time, its charge level decreases as a result of self-discharge. If a discharged battery is stored for a long time, the plates will sulfate, which will reduce the effective service life of the product.

Almost always, markings are applied to the top cover or handle of the product. Deciphering such a code can be difficult, but you can get accurate information on this topic on the manufacturer’s official website or in the product instructions.

In what case can the battery be used?

The battery can only be used if its main indicators are normal, namely:

The voltage and discharge current correspond to the nominal values.
The capacity of the product is equal to that declared by the manufacturer or is slightly reduced.

If the battery turns the starter perfectly when starting the engine, then most likely the above parameters fully correspond to the optimal values.

For what malfunctions is operation prohibited?

Operation of a car battery is prohibited if the following malfunctions occur:

The battery constantly boils when charging from the generator.
If there is a leak of sulfuric acid solution.
If the battery does not match the car in terms of starting current, voltage or dimensions.

Operation is also prohibited in all cases where there is a danger of explosion or fire of the battery.

Do you have any questions, haven’t been able to solve the problem, or have something to add to the article? Then write to us about it in the comments. This will help make the material more complete and useful!

How to check a car battery

The question “ how to check a car battery ” usually arises in two cases: when purchasing a new battery or if some kind of malfunction is discovered in the battery already under the hood. The cause of the malfunction can be either undercharging or overcharging of the battery.

Undercharging occurs due to sulfation of the battery plates, which occurs during frequent trips over short distances, a faulty alternator voltage regulator relay, and turning on the warm-up.

Overcharging also occurs due to a faulty voltage regulator, only in this case it supplies too much voltage from the generator. As a result, the plates fall off, and if the battery is of a maintenance-free type, it may be subject to mechanical deformation.

How to check the battery yourself

So, how to check the performance of a car battery ?

Battery diagnostics - checking voltage, level and density.

To do this you need to know how:

Of all these methods, the most accessible to the average person is to use a tester to check the car battery and visually inspect it, and perhaps look inside (if the battery is serviceable) in order to see the color and electrolyte level. And to fully check the car battery for performance at home, you also need a densimeter and a load fork. Only in this way will the picture of the battery condition be as clear as possible.

Therefore, if there are no such devices, then the minimum actions that are available to everyone are to use a multimeter, a ruler and use regular consumers.

How to check the battery yourself

To test a battery without special equipment, you need to know its power (say, 60 Ampere/hour) and load it halfway with consumers. For example, by connecting several light bulbs in parallel. If after 5 minutes of operation they begin to glow dimly, it means the battery is not working as it should.

As you can see, such a home test is too primitive, so you can’t do without instructions on how to find out the real condition of a car battery. We will have to consider in detail the principles and all available testing methods, right down to measuring the density of the electrolyte and testing with a load simulating the operation of the starter.

How to visually check the battery

Inspect the battery case for case cracks and electrolyte leaks. Cracks can occur in winter if the battery is poorly secured and has a fragile plastic case. When working on a battery, moisture, dirt, evaporation or electrolyte drips accumulate, which, together with oxidized terminals, contributes to self-discharge. You can check if you connect one voltmeter probe to “+” and run the second one across the surface of the battery. The device will show what self-discharge voltage is available on a particular battery.

How to check the electrolyte level in a battery

The electrolyte level is checked only on those batteries that require servicing. To check it, you need to lower a glass tube (with marked divisions) into the battery filler hole. Having reached the separator mesh, you need to pinch the upper edge of the tube with your finger and pull it out. The electrolyte level in the tube will be equal to the level in the battery. The normal level is 10-12 mm above the battery plates.

How to check battery electrolyte density

To measure the electrolyte density level, you will need a car hydrometer. You need to lower it into the battery filler hole and use a bulb to draw in such an amount of electrolyte so that the float dangles freely. Then look at the level on the hydrometer scale.

The peculiarity of this measurement is that the density of the electrolyte in the battery in winter and summer in some regions will be different depending on the season and the average daily temperature outside. The table presents the data that you should focus on.