CCA (Cold Cranking Amps) or what is the same, cold starting current, is the magnitude that determines the maximum current that a 12-volt battery can supply for 30 seconds at -18◦ C, while maintaining a voltage of at minus 7.2 volts.
All starter batteries are tested to determine this figure based on parameters imposed by a regulation, at FQS we are governed by the EN (European Norms). This standard is applicable to lead-acid batteries with a nominal voltage of 12 V, used mainly as a source of energy for starting internal combustion engines (ICE), lighting and also for auxiliary equipment of ICE vehicles. All batteries under this scope must fulfill basic functions that are tested under the application of UNE-EN 50342-1.
Batteries under the scope of the UNE-EN 50342-6 standard are used for micro-cycle applications in vehicles that can also be called Start-Stop, In cars with this special capacity, the combustion engine is switched off during a stop of the vehicle, during low-speed idling or during idling without the need to support the movement of the vehicle by the internal combustion engine. During the phases in which the engine is switched off, most of the electrical and electronic components of the car have to be powered by the battery without support from the alternator.
The electrolyte density and the open circuit voltage of the lead acid battery depend on the state of charge and temperature. Starting a combustion engine requires, in a short space of time, very high currents of up to hundreds of amps. The battery has to fulfill this requirement also in winter at low temperatures. Furthermore, the electrical voltage cannot be reduced considerably during the starting process, therefore, the batteries have a small internal resistance.
How is this test done? The test is carried out at -18 ° C. However, the EN requirement is divided into two levels: EN1 and EN2.
EN1 - The battery must reach a voltage of 7.5 V after 10 seconds, and after resting for another 10 seconds the battery must discharge to 0.6 V, thus completing a cycle of 73 seconds in the second phase, with a total combined period of 90 seconds. (The initial period equals (10 s / 0.6) 16.7 seconds).
EN2 - Like EN1, except that the second 0.6 V discharge period should reach 133 seconds, with a total time of 150 seconds. This process depends on the design of the battery and may be different depending on the manufacturer, even so, the relationship between EN1 and EN2 is: EN2 = 0.85% to 0.92% EN1.