Battery — concepts and standards (Focus Turnier 1)

Designation: is located on the battery case and specifies the battery characteristics. Example: "12V 40Ah 200A" (12V is the nominal voltage; 40Ah - nominal capacity; 200A - test current at low temperatures).

Nominal voltage: total output (unit of measurement "V"). In all Focus models it is 12 V. The actual voltage depends on the state of charge of the battery. It can be higher or lower than the nominal voltage.

Nominal capacity: means the battery capacity, measured in ampere-hours (Ah). This is the capacity that a fully charged battery can deliver for 20 hours at a temperature of 27°C, without the voltage dropping below 10.5 V (the voltage of a discharged battery). For example, the parking lights of your Focus consume 25 W. With an on-board voltage of 12 V, the battery, according to the formula "current (A) = power (W) divided by voltage (V)", delivers a current of 2.08 A. With a battery of 43 Ah, theoretically, in your Focus, all the lights would go out after about 20.3 hours. Let us emphasize again - theoretically, since in practice the battery is discharged after about 16 hours.

Capacity: the amount of current supplied in ampere hours (Ah) It depends primarily on the discharge current, temperature, state of charge and the general condition of the battery (age).

Test current at low temperatures: means the starting capacity of the battery in cold weather (unit of measurement - ampere (A). A certain discharge current that can be taken from a battery with a voltage of 12 V at -18°C, while the voltage does not fall below 9 V for 30 s, below 6 V for 150 s.

Self-discharge: chemical processes in the battery cells lead to discharge, even if no consumer is connected. A charged new car battery loses about 0.5% of its charge daily. High temperatures, damage and contamination of the battery cover accelerate self-discharge.

(The material was copied from an information website: FORDBOOK.ru)