The main purpose of the battery is to start the engine and supply electricity to the load (lighting bulbs, dashboard lights, etc.). When the engine does not work 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.
To check the operating status of the battery, you can use two elementary methods. The first method is simpler and consists of a simple voltage test. It is such an examination that will help you answer the question: “How to check the car’s battery?”.
If the battery has a built-in indicator of the charge level, then its availability 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 battery voltage, where there is no built-in indicator, can be measured by the most ordinary or, which is much better, digital voltmeter. We have given in the table the voltage levels for the battery and its levels of readiness for work (charge).
Ready (charge) level 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 you can measure the voltage using special chargers with a microprocessor and memory, in such a simple way, answering the question: "How to check the battery?".
Modern devices can track both discharge and battery charge over several cycles. This verification method is the most accurate.
Another way is to determine the density of the electrolyte. According to this characteristic, we can also talk about the level of readiness (charge) of the battery. A hydrometer is used to measure the electrolyte density in each battery bank. In this case, it is necessary to measure, in addition to 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 readings of the hydrometer.
The optimum temperature of the electrolyte when checking its density is a temperature of plus sixteen to plus twenty-eight degrees Celsius.
When checking the density of the electrolyte, you need to be careful not to get it on the body, car parts, clothes, shoes, and especially on your hands or skin, since the electrolyte contains sulfuric acid, which is dangerous for the 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 battery charge level (availability) and the electrolyte density corresponding to this level.
Charge Level (Ready) 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 received the answer to the question: "How to check the battery yourself?" And now you can do it yourself.
A few more words about one important characteristic of a battery - its capacity. She tells us how much time (in hours) the battery can provide the load, measured in amperes, with current. Accordingly, the battery capacity is measured in ampere-hours.
How to check battery capacity? The traditional way to check the battery capacity is a check discharge method. For example, in order to accurately determine the capacity of a battery with a nominal value of 60 ampere-hours, it is necessary to discharge it with a current of 3A for 20 hours. It is too long. However, now there are devices that can perform such a test in just a few seconds.