The only source of current when starting the car is the battery. It starts the engine, which in turn starts the generator. From this moment on, the battery ceases to be a current source and becomes its consumer. During the operation of the motor, the voltage of a charged car battery rises and returns to normal.
However, during frequent short journeys, the battery does not have time to charge, there is a constant and regular decrease in charge. In this case, it is necessary to restore the current level using external devices. Consider to what level this is done, and how much time it takes for such a process.
Most situations in which a car battery is discharged are the fault of drivers. Less commonly, the reason lies in the design features or factory defects. The battery often loses its charge if there is insufficient tension on the alternator belt. Due to this, the belt slips and the generator does not work efficiently.
The same problem occurs when the door is not tightly closed or the trunk is not slammed to the end. The fault in this case will be working light bulbs. In a few hours, they can significantly lower the charge level.
Normal parameters for the battery
There are a number of parameters that a normally working battery must meet. Let's consider to what voltage a car battery can be discharged, but at the same time you need to know that too strong a discharge level contributes to a rapid deterioration in battery performance.
A battery is considered healthy if:
- open circuit - 12.6-12.8V;
- with the engine running, "high beam" on and speeds of about 1500 rpm - 13.8-14.2V;
- on serviced batteries, the density of the electrolyte at +20 C will be 1.28 g/ml.
There are also indicators at which it is required to raise the voltage in the battery:
- with the terminals open, the charge voltage of the car battery is less 12.6 V;
- the density of the electrolyte in the serviced battery is significantly lower 1.26 g/ml;
- the difference in density between the battery banks is more than 0.2 g/ml.
The electrolyte density level is measured under normal conditions, which are characterized by an atmospheric pressure of 760 mm r.s. and +20 C. At negative temperatures, it is desirable to increase the density of this liquid. The normal parameter for -20 C is the density of 1.4 g / ml, since 1.2 g / ml begins to freeze under such conditions.
Proper battery charging
If the measurement with a voltmeter or multimeter shows the minimum voltage of the car battery, then we recharge. For this operation, you need to configure the charging device to deliver current in the range from 0.05 to 0.1 of the numerical value of the capacitance. Accordingly, for a 55 Ah battery, an amperage of 2.75-5.5 A is used. The most gentle mode will be with lower values.
The output voltage for this operation should be at the level of 14.4-14.6 V. It is desirable that the device has the ability to set a static value. When a battery with a capacity of 55 Ah is completely discharged, it is necessary to withstand 10 hours with a current of 5.5 A.
A sign of the end of this procedure can be the invariance of the voltage at the terminals for 1-2 hours after the establishment of the specified parameters.
There may also be slight signs of boiling with slight gas formation. On automated chargers, shutdown occurs automatically. In the same way, the supply of current and voltage is regulated.
Safety regulations
You need to know that the basis for the electrolyte is acid, so the battery must be handled with extreme care. Avoid getting liquid on your hands, while protecting the skin with rubber gloves.
During boiling, toxic gases are released inside the battery. They cannot be inhaled, so it is advisable to organize the charging process in a room with good ventilation, preferably forced. It is also possible to release explosive hydrogen, so the use of open flame and sparking should be excluded. Do not leave homemade chargers unattended for a long time.
