How to check the car battery

How to check the car battery

Equipping a car with a battery has not only made life easier for the motorist, it has also become a source of additional, known specific problems. The main of these problems is the inability to start the engine and start the car. The good condition of the battery becomes especially important in winter, a weak battery cannot turn the crankshaft as often as desired, the engine “sneezes”, but does not start.

To avoid problems with starting the car, every driver should know how to check the car battery. It is best of all to carry out this operation during seasonal service of the car at TO station. But not always for various reasons, this is possible. Today we will see how to independently check the battery of the car.

Visual inspection

This type of battery check is the simplest, but no less important. After all, the performance of the battery depends on the external state. During the inspection, attention should be paid to the presence of moisture on the surface of the battery, its presence leads to self-discharge of the battery. The conductor of electricity can accumulate on the dust of the lid, in addition it leads to a decrease in the battery charge. Moisture and dust must be cleaned with particular care in the area of ​​the battery terminals.

Pay particular attention to the condition of the battery terminals. They must be clean, free of deposits and free from damage. Contact with wires must be reliable, loose terminals are not allowed. Through damage and cracks in the case, the electrolyte leaking through them will not allow the plates to close and damage the parts of the car. If the battery has water outlets, they should be wrapped tightly in the case.

Sound test

By knowing how to check the car battery, you can avoid most problems when starting a car. It is very easy to check the technical condition of the battery as follows. On a cold car, turn on the high beams for 1 minute, after turning it off, immediately press the car horn. If the signal sound is strong and the battery is not heated, the battery is in good technical condition. If the car horn is weak, a more accurate and tested battery should be done with the tool. If the battery is very hot, then it urgently needs to be changed, since such “heaters” have exploding properties.

How to check the battery with a multimeter

The charge level of the battery is not only an indicator of its health, but also the state of the entire electrical system of the car. This will help a fairly inexpensive device – a multimeter. Before checking the battery with a multimeter, the device must be set to constant voltage test mode. Using a multimeter to remove voltage at no-load battery terminals. Therefore, the negative wire must be disconnected for the test.

Car battery repair and inspection. The man measures the voltage and capacity of the battery with a tester. Car service.

A healthy battery with no load should produce at least 12.6 volts

According to the readings determine the degree of discharge of the battery. In a fully charged and good 12-volt battery, a multimeter should display a voltage of 12.6 volts. If the device indicates 12.2 volts, this indicates that the discharge is approximately 50% and that the battery needs to be charged. Indications below 12 volts suggest that the battery needs urgent resuscitation or even preparing for a replacement. Checking the battery with a multimeter is quite simple – this is the fastest way to check yourself.

Checking the battery capacity multimeter

The voltage check does not provide a complete picture of the battery status. As well as checking the battery charge when it doesn’t always work out, you can do it yourself with a multimeter and the selected load. The hardest thing is to take the load on the battery, it should take about half the battery current. For this purpose, you can use several lamps from the headlights connected to each other. Using the lamps provides a vivid example of the state of the battery under test. Testing under load with a multimeter must be performed with a fully charged battery.

Car starter battery voltage measured with multimeter.

There are highly targeted professional testers to test car batteries.

The essence of control is simple. We connect to the battery circuit with a load for two minutes. If the bulbs used are heavily faded, the test can be omitted. This clearly shows the status of the test battery. If the bulbs do not go out, it is necessary, without removing the load, to measure the voltage at the terminals. The battery capacity is full, if the multimeter shows a voltage of 12.4 volts. Voltage 12-12.4 volts indicates that in winter there may be problems with starting the car. Well, with smaller readings, you should think about replacing the battery.

How to check the battery density

To check the density of the electrolyte you will need a special device – a hydrometer and reference tables. Before checking the battery density, it is necessary to know the safety measures, as the electrolyte can cause serious damage to health. Check that the electrolyte density has been made after charging the battery to bring it to the desired performance. Before measuring the battery density it should be at least 6 hours after charging. It should be remembered that the density of the electrolyte varies significantly with temperature, so when calculating the indicators it is necessary to use a special table to bring the density to the normative data.

Checking the battery charge with a hydrometer

The measurement process is simple, but it requires caution. The test is performed using a glass tube. Before checking the battery density, make sure the electrolyte level is 0.5-1cm above the protective grid. The hydrometer is of two types with floating graduated floats and pop-up floats of different densities. The electrolyte is introduced into the body of the device using a rubber bulb. The floats indicate the density of the electrolyte in the battery.

By knowing how to check a car’s battery for working capacity and observe a few simple rules for its care, you can significantly extend its service life and have confidence in your iron horse. But if during the checks it turned out that the battery is defective and needs to be replaced, do not throw it in the bin, because its elements and the electrolyte can cause serious damage to nature. Currently, many organizations are collecting dead batteries, and auto shops contain promotions where old batteries can be replaced with new ones for an additional fee.