For technical professionals, selecting the appropriate automotive battery involves understanding the various industry standards and how part numbers convey specific details. GS Yuasa, Yuasa, and GS batteries use the BBMS numbering system for the classification of battery types. BBMS, DIN, ETN, and other systems include a mix of identifiers related to case size, performance, capacity, and cold-cranking ability.

Part numbers

GS Yuasa, GS, and Yuasa part numbers: BBMS numbering
Yuasa battery part numbers adhere to BBMS (British Battery Manufacturers Society) numbering, a familiar system in the UK aftermarket. This consistency enables users to identify and cross-reference Yuasa products effectively within the UK-specific automotive battery market.

DIN number: German industrial standard

The DIN (Deutsches Institut für Normung) Part Number, known as DIN 72310 (1988), has long been utilised in Europe to specify battery types. Though largely replaced by the ETN system, the DIN standard is still relevant for legacy references. The DIN number format, such as 560.49, provides the following breakdown:

1st digit
Voltage:
1-2 = 6V Battery
5-7 = 12V Battery

2nd & 3rd digits
Nominal capacity (measured at the 20-hour rate)
560 = 60Ah
660 = 160Ah

4th & 5th digits
Unique code number: this code offers insights into battery performance and specific features.

Each element of the DIN number provides a quick overview of the battery's main attributes, making it a straightforward identifier for European automotive standards, although newer standards have since evolved.

ETN Number: European Type Number

The ETN (European Type Number) was introduced as a more detailed, modernized alternative to DIN, designed to align with Europeanized battery standards. ETN integrates DIN’s core structure while adding further technical details, resulting in a 9-digit format. Despite Eurobat's control over ETN numbering up until 2006, the lack of central record-keeping for numbers issued post-2006 has complicated cross-referencing. An ETN number, such as 536 046 030, decodes as follows:

1st digit
Voltage:
1-2 = 6V Battery
5-7 = 12V Battery

Follows the same pattern as DIN (e.g., 560 = 60Ah, 660 = 160Ah)

4th, 5th & 6th digits
Unique code number:
This code represents endurance level, cold-cranking performance, vibration resistance, lid type, terminal design, and clamping characteristics.

Sometimes the 5th and 6th digits also reference the original DIN standard's 4th and 5th digits, adding a layer of backward compatibility for older designs.

7th, 8th & 9th digits
Cold cranking performance:
Cold Cranking Performance (CCA) ratings can vary between the EN1 and EN2 standards, a distinction that is often unclear to end users. This lack of clarity is particularly problematic with digital conductance testers, which cannot currently assess both EN standards simultaneously.

The ETN numbering system, while complex, offers significantly more detailed information than DIN, which is useful for technical assessments and specific performance matching. However, the dual EN rating can lead to confusion without a standard central index.

Standards

All GS Yuasa automotive design and rating is in accordance with the EN standard:

EN Standard (EN50342.1)

The EN standard specifies that batteries must deliver their rated CCA (Cold Cranking Amps) at -18°C with the following pass conditions:

• Requires 7.5V after 10 seconds.
• 6V after 73 seconds (total 90 seconds with second discharge at 0.6 x original current).

The standard previously included EN1 (now known as EN) and EN2, each representing different endurance and durability levels. The EN2 test is now obsolete, but for comparison, based on Yuasa's benchmarking, the EN2 rating equates to about 0.85 to 0.92 of EN/EN1 performance, reflecting design variability. For reference, EN2 requires that batteries at -18°C must deliver their rated CCA with the following conditions:

EN2:

• Similar initial discharge to EN but extended to reach 6V after 133 seconds (total of 150 seconds)

Other common standards used in the automotive battery industry:

SAE Standard (J537)

The SAE (Society of Automotive Engineers) standard, widely used in the U.S., measures CCA at -18°C. Batteries must deliver their rated CCA for 30 seconds while maintaining a minimum voltage of 7.2V (or 3.6V for 6V batteries).

Relationship to DIN: Due to design differences, the following approximation is often used for cross-referencing:
SAE = (DIN x 1.5) + 40

DIN Standard (German Industrial Standard at -18°C)

DIN also specifies cold-cranking requirements at -18°C. To pass, a fully charged battery must discharge to 6V at the test current while maintaining at least 9.0V after 30 seconds. The battery must last at least 150 seconds before reaching 6V, a measure of durability rather than startability.

Relationship to SAE:
•    DIN = (SAE - 40) x 0.66
Since modern fuel-injected vehicles require faster starts, DIN’s popularity has declined among manufacturers, but it remains a useful standard for assessing a battery's material composition.

IEC Standard (IEC 60095-1)

The IEC (International Electrotechnical Commission) test standard, performed at -18°C, involves staged voltage testing. After a 24-hour rest period, the battery is cooled until the middle cell reaches -18°C, then discharged according to the standard, requiring:

Option 1

• 7.5V after 10 seconds
• 6V after 73 seconds (total 90 seconds with second discharge at 0.6 x original current)

Option 2

• Voltage of 7.2V after 30 seconds

Option 1 of the IEC test correlates with the EN test, whereas option 2 aligns with the SAE test. This alignment of test standards allows for the simplified cross-comparison of ratings between the different standards.

JIS Standard (D5301)

The JIS (Japanese Industrial Standard) test, conducted at -15°C, differs slightly and is less commonly used in European markets. It typically tests automotive batteries at either 150A or 300A with specific 10-second/30-second voltage and endurance requirements down to 6V.

Due to differences in testing conditions, JIS results are not directly comparable to European standards, and the test itself lacks clarity for European consumers regarding startability.