Starting Battery Ratings
CCA, EN, SAE, JIS, DIN, and IEC
CA/cranking amps determine how much power you have to start your engine in most climates. The basic job of a battery is to start an engine; it must crank, or rotate the crankshaft while at the same time maintain sufficient voltage to activate the ignition system until the engine fires and maintains rotation. This requirement involves a high discharge rate in amperes for a short period of time.
Since it is more difficult for a battery to deliver power when it is cold, and since the engine requires more power to turn over when it is cold, the Cold Cranking rating is defined as: The number of amperes a lead-acid battery at 0 degrees F (-17.8 degrees C) can deliver for 30 seconds and maintain at least 1.2 volts per cell (7.2 volts for a 12-volt battery).
CCA/cold cranking amps determine how much power you have to start your engine on cold winter mornings.
EN (EN50342.1A1 Nov 2011 Item 5.3)
The test is performed at -18°C. The EN requirement is however split into two levels EN1 and EN2.
EN1: The battery is required to meet a voltage of 7.5V after 10 seconds and after 10 seconds rest, the battery is further discharged @ 0.6 x original current and is required to complete 73s in the second stage giving a total combined discharge period of 90 seconds (assume initial period equates to (10s/0.6)
EN2: As EN1 except that the second discharge period to 6.0V should achieve 133 seconds giving a total time of 150 seconds. The discharge current’s ability to meet both designs is very much subject to battery design and can vary from manufacturer to manufacturers and design to design.
SAE (J537 Jun 1994 American Standard)
This is the starting test according to the SAE (Society of Automotive Engineers). The test specifies that the battery at a temperature of –18°C will deliver a current equal to the Cold Cranking Amps for 30 seconds with the voltage staying above 7.2 volts (3.6 volts for a 6 volt battery).
JIS (D5301: 1999)
The Japanese Industrial Standard test is carried out at -15°C. The starting batteries are usually tested at either 150A or 300A with different 10s /30s voltage and durability requirement to 6V.
DIN (German Industrial Standard at -18°C)
As with SAE the test is carried out at -18°C. The fully charged battery is discharged to 6V with the rated test current. The voltage must be at least 9.0V after 30 seconds and the time to achieve 6V must be at least 150 seconds.
IEC (International Electro Technical Commission) (IEC 60095-1 Nov 2006)
The test is performed at -18°C . After a rest period of up to 24 hours after preparation according to 6.2 of standard, the battery is placed in a cooling chamber with air circulation at a temperature of -18°C +/- 1°C until the temperature of the middle cell has reached -18°C +/- 1°C. The battery is then discharged according to the standard and is required to meet a voltage of 7.5V after 10seconds and 7.2V after 30seconds, the battery is then rested for 20+/-1 seconds after which the battery is discharged at 60% of the original current and is required to meet a voltage of 6V after 40 seconds, in accordance with table 7 of the standard.