Battery starting current. Car battery starting current

The main purpose of batteries is to provide power to various devices without connecting them to an alternating current network. To do this, the batteries must accumulate a charge and have the ability to store it until the moment the device starts functioning. Batteries, unlike ordinary batteries, have the ability to restore their charge. Many batteries were created as an alternative to conventional batteries. Reusable use makes them more economical and convenient to operate. The battery is a system of batteries that are connected in parallel or in series. Most often, a second type of compound is used. Such a method is necessary to obtain an increased value of the output voltage. Thanks to this scheme, it is possible to use several batteries, in which the output voltage is much lower than the total.

Technical characteristics of the battery

The main parameters of any battery include:

• Type (for example, lead-acid, helium, nickel-cadmium, nickel-metal hydride, lithium-ion, lithium-polymer , etc.);
• Starting current of the battery (starting capacity);
• Minimum voltage;
• battery capacity;
• Working voltage;
• Temperature characteristics.

What does the starting current of the battery mean?

This parameter is an important characteristic of car batteries. The starting current of the battery is closely related to the temperature regime of the device. This indicator is considered the main for regions with a harsh climate, since it shows the possibility of a battery to start a cold power unit of a vehicle, which is the most relevant in the winter. A numerical value that determines which starting current of the battery (nominal value) corresponds to the capacity of the battery, which it can deliver for 30 seconds at an ambient temperature of minus 18 degrees Celsius.

What determines the capacity of the battery?

The value that characterizes this parameter is determined by the value of the discharge current and the average value of the potential difference of the circuit, which is determined by measuring at regular intervals. The formula that calculates the starting current of the car battery is as follows: P (battery power) = I (discharge current) • U (discharge voltage). During the start of the power unit of the vehicle with a starter, the value of the nominal battery voltage is significantly reduced. And the discharge current in this case increases. Simply put, as a result of the fact that the starting current of the battery is a constant, The increase in the power that is expended by the battery to start the engine of the car, leads to a decrease in the potential difference at its terminals. It turns out that the lower the voltage, the more difficult for the starter to crank the crankshaft of the power unit. As a result, it is possible to derive an inverse relationship: the higher the start-up power of the battery, the more speed the starter makes when starting. All this allows you to start the car engine much faster.

Passport characteristics of the battery

When testing batteries with a predetermined duration, discharge an electric current. Its value is similar to the consumed value of the rated current of the starter. The discharge continues to a residual voltage of six volts. In the battery's passport, all measurement intervals are made, at which the readings of the potential difference on the battery outputs were taken. The time of the starter discharge characterizes the size of the electric reserve of the battery. In other words, it is a reserve of the capacity of the battery for starting the power unit. In this case, an important role is played by the nominal capacity of the battery - the higher it is, the more attempts are given to the owner in order to start the engine. In addition, it should be noted that the starting current of the battery can be different for absolutely identical in size and size of the nominal capacity of the batteries. This primarily depends on the materials used in the manufacture of the device, their properties, as well as its design features. An example is the ability of batteries to increase the value of the starting current by increasing the porosity level of the lead plates used, increasing their number, using orthophosphoric acid as an active paste, etc.

Starting current of the battery for "diesel"

As a rule, the increased value of starting capacity has battery, which are designed for operation with diesel power units. This is due to the fact that much more effort is required to crank the "diesel" crankshaft. Thus, batteries with a capacity of 55A-h for gasoline units have a starting current of 255A, and similar batteries for diesel engines - 300A.

Choosing a battery for your car

If, during the selection of the battery, you found that with equal parameters of capacitance, dimensions, etc., one of the considered variants has a large value of the starting current, then you can safely stop your choice on it. This will provide you with an additional plus when starting the powertrain in the winter. At the same time, it should not be feared that this parameter can have any negative impact on the performance of the electrical equipment of the car. After all, the starting current is a value that has an impact solely on the quality and reliability of starting the motor. Regardless of the value of this characteristic, the battery voltage remains standard, and only this factor influences the performance of electrical appliances.

Explanations to some of the selection parameters

The starting current of the new battery should not be lower than that of the old one (replaceable). In this case, do not take a new battery with a smaller value of the electrical capacity (A / h). The fact is that under certain operating conditions of the engine (for example, at idle speed) and minor daytime runs of the vehicle, the battery at night "helps" the generator to power the included consumers. As a result, with a small electrical capacity of the battery, the depth of discharge can be more than 40-50%, and this will lead to a decrease in battery performance in the start-up mode.

Common standards

When buying a battery, it should be borne in mind that the values of the starting currents on the battery case can be specified in different standards. So, in Germany, its type is adopted - DIN, in the USA - SAE, and in the European Union - EN. For convenience of orientation in these characteristics, the sellers of the battery can ask for a special sheet of compliance, which determines the starting current of the battery. The correspondence table for different standards is shown in the photo above.

What is the difference between the methods for determining the starting current?

Let's look more closely at how these parameters are determined in different countries:

1. In the European Union, it is common to measure (discharge the battery) at a temperature of minus 18 degrees Celsius to 7.5 V for ten seconds.

2. In Germany, during the tests, the car battery is discharged to nine volts for 30 seconds, under the same temperature conditions as in the EU.

3. In the US, the battery is discharged to a voltage of 7.2 V for 30 seconds, at the same temperature.

As you can see, only the magnitude of the boundary voltage and the discharge time change during the tests. It is believed that the closest standard to our GOST is the German method.

Conclusion

To summarize, it should be noted that car batteries with inrush current has a large supply can lead you in cold weather just like a battery with a small starting capacity. The thing is that any battery requires regular and very careful care. And this applies to so-called unattended batteries. In this case, the care consists in periodic recharging after a prolonged operation of the vehicle in the urban cycle. The main negative impact on the performance of the product is a small mileage car, driving at low speeds, as well as idle in traffic jams. Moreover, do not forget to carry out periodic diagnostics and eliminate the detected malfunctions of the electrical equipment of the system. These actions will allow you to significantly extend the life of the battery, as well as to avoid the troubles associated with the problems of starting the power unit in the winter.