How to check the battery yourself

The main purpose of the battery is to start the engine and supply electricity to the load (light bulbs, backlight of the instrument panel, etc.). When the engine is not running and, accordingly, the generator does not generate electric current. If the battery does not start the engine starter, then the question of how to check the battery becomes very relevant.

Two elementary methods can be used to check the operating state of the battery . The first method is simpler and consists of a routine voltage test. It is this survey that will help you answer the question: "How to check the car's battery?".

If the battery has a built-in charging indicator, then its readiness is checked in accordance with the color of the indicator.

If the indicator is green, the battery is fully charged.

If it is black, this indicates that it needs recharging. And the light color of the indicator tells us that the electrolyte level is not enough for its normal operation.

The electrical voltage of the battery, where there is no built-in indicator, can be measured by the most common or, much better, digital voltmeter. We showed in the table the voltage levels for the battery and the levels of its readiness for operation (charging).

Readiness level (charging) Voltage of a 12-volt battery

100% 12.74

90% 12.61

80% 12.50

70% 12.39

60% 12.29

50% 12.20

40% 12.15

30% 12.07

20% 11.97

10% 11.92

Of course, it will be much more accurate if the voltage can be measured with the help of special chargers with a microprocessor and memory, in such a simple way answering the question: "How to check the battery?".

Modern devices can monitor both discharge and charge of the battery for several cycles. This method of verification is the most accurate.

Another way is to determine the density of the electrolyte. On this characteristic, we can also talk about the level of readiness (charging) of the battery. A meter is used to measure the density of the electrolyte in each bank of the battery. In this case, it is necessary to measure, in addition to the density, also the temperature of the electrolyte. If it is above thirty degrees or below zero Celsius, then a correction factor is introduced to the hydrometer readings.

The optimum temperature of the electrolyte when checking its density is the temperature from plus 16 to plus twenty eight degrees Celsius.

When checking the density of the electrolyte, care should be taken not to allow it to enter the body, car parts, clothing, shoes, especially hands or skin, since the electrolyte contains sulfuric acid, which is hazardous to metal and can also cause skin burns.

Given the density of the electrolyte, we can talk about the level of charge of the battery. The table shows the characteristics of the level of charge (readiness) of the battery and the density of the electrolyte corresponding to this level.

Level of charge (readiness) Electrolyte density

100% 1.263

90% 1.248

80% 1.231

70% 1.217

60% 1.203

50% 1.188

40% 1.174

30% 1.160

20% 1.146

10% 1.132

We hope that you have received an answer to the question: "How to check the battery yourself?" And now you can do it yourself.

A few words about one important characteristic of the battery - its capacity. It tells us how much time (in hours) the battery pack will be able to provide the current that is measured in amperes, the load. Accordingly, the capacity of the battery is measured in ampere-hours.

How can I check the battery capacity? The traditional method of checking the capacity of the battery is the method of control discharge. For example, to accurately determine the capacity of a battery rated at 60 ampere-hours, you must discharge it with a current of 3A for 20 hours. It is too long. However, now there are devices that make it possible to perform such a check in just a few seconds.