The main purpose of rechargeable batteries is to provide power to various devices without connecting them to an alternating electric current network. To do this, the battery must carry out the accumulation of charge and have the ability to save it until the moment when the device begins to function. 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 use. A battery is a system of batteries that are connected in parallel or in series. Most often, the second type of compound is used. This method is necessary to obtain an increased value of the output voltage. Thanks to this scheme, several batteries can be used in which the output voltage is much lower than the total.
Battery Specifications
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 power);
- minimum voltage;
- battery capacity;
- operating voltage;
- temperature characteristics.
What does the battery starting current 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 one for regions with a harsh climate, since it shows the ability of the battery to start the vehicle’s cold power unit, which is most relevant in the winter. A numerical value that determines which inrush current the battery has (nominal value) corresponds to the battery power that it is capable of delivering within 30 seconds at an ambient temperature of minus 18 degrees Celsius.
What determines the battery power?
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 equal time intervals. The formula that calculates the starting current of a car battery has the following form: P (battery power) = I (discharge current) • U (discharge voltage). During the start of the power unit of the vehicle using the starter, the value of the nominal battery voltage is significantly reduced. And the discharge current increases. Simply put, as a result of the fact that the starting current of the battery is constant,
an increase in the power spent by the battery to start the car engine leads to a decrease in the potential difference at its terminals. It turns out that the lower the voltage, the harder it is for the starter to crank the
crankshaft of the power unit. As a result, we can deduce the inverse relationship: the higher the starting power of the battery, the more turns the starter will make when starting. All this allows you to start the car engine much faster.
Passport characteristics of the battery
When testing batteries with a given duration, they 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. All measurement intervals, on which the readings of the potential difference at the battery terminals are made, are entered into the battery passport. Starter discharge time characterizes the value of the electric reserve of the battery. In other words, this is a reserve of battery capabilities for starting the power unit. In this case, the value of the nominal capacity of the battery plays an important role - the higher it is, the more attempts are made 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 overall dimensions and the value 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 inrush current while increasing the porosity of the used lead plates, increasing their number, using phosphoric acid as an active paste, etc.
Starting current of the battery for "diesel"
As a rule, batteries with increased starting power are designed for operation with diesel power units. This is due to the fact that to crank the crankshaft of the "diesel" requires much more effort. So, batteries with a capacity of 55Ah for gasoline units have a starting current of 255A, and similar batteries for diesel - 300A.
Choosing a battery for your car
If, when selecting a battery, you find that with equal parameters of capacity, dimensions, and other things, one of the options considered has a high inrush current, then you can safely choose it. This will provide you with an additional plus when starting the power unit in the winter. At the same time, one should not be afraid that this parameter may have any negative impact on the operability of vehicle electrical systems. Indeed, inrush current is a value that has an influence solely on the quality and reliability of starting the motor. Regardless of the magnitude of the mentioned characteristics, the battery voltage will remain standard, and only this factor affects the performance of electrical appliances.
Explanation of some selection options
The starting current of the new battery should not be lower than that of the old (replaceable) one. In this case, you should not take a new battery with a lower electric capacity (Ah). The fact is that under certain operating modes of the motor (for example, at idle) and insignificant daytime runs of the vehicle, the battery at night "helps" the generator to power on consumers that are turned on. As a result, with a small electric capacity of the battery, the discharge depth can be more than 40-50%, and this will lead to a decrease in the battery’s working capacity in the start-up mode.
Generally accepted standards
When buying a battery, it should be borne in mind that the inrush currents on the battery case can be specified in various standards. So, in Germany its own type is adopted - DIN, in the USA - SAE, and in the European Union - EN. For ease of orientation in these characteristics, battery sellers can ask for a special compliance sheet that determines the starting current of the battery. The compliance table for various standards is shown in the photo above.
What is the difference in the methods for determining inrush current?
Let's look in more detail how these parameters are determined in different countries:
1. In the European Union, it is customary to measure (battery discharge) at a temperature of minus 18 degrees Celsius to 7.5 V for ten seconds.
2. In Germany, during testing, 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, when conducting tests, only the magnitude of the boundary voltage and the discharge time change. It is believed that the closest standard to our GOST is the German methodology.
Conclusion
Summing up, it should be noted that car batteries, the starting current of which has a large margin, can bring you in cold weather in the same way as a battery with a low starting power. The thing is that any battery requires regular and very thorough care. And this applies to the so-called maintenance-free batteries. In this case, care consists in periodically recharging after prolonged use of the vehicle in the urban cycle. The main negative impact on the performance of the product is exerted by a low mileage of the car, driving at low speeds, as well as idle time in traffic jams. Moreover, do not forget to conduct periodic diagnostics and eliminate the detected malfunctions of the electrical system. These actions will allow you to significantly extend the battery life, as well as to avoid the troubles associated with the problems of starting the power unit in the winter.