VDA 455 (02/2025) - english

Current electrical requirements and tests for electrical and electronic components in 12 V electrical systems rely on the use of 12 V lead-acid batteries, the use of an internal combustion engine, and the associated generator and 12 V starting system.

In the future, the 12 V electrical system will be supplied by a high-voltage/low-voltage (HV/LV) or low-voltage/low-voltage (LV/LV) DC/DC converter and, if necessary, supplemented by an energy storage unit. The previous use of 12 V lead-acid batteries will be expanded to include 12 V lithium batteries or other battery technologies. Yet another possibility is the development of storage-less electrical systems, i.e., electrical systems with the DC/DC converter as the sole energy source.

New introductions, such as X-by-wire systems or partially or fully automated driving, also lead to new requirements regarding the availability, reliability, and performance of the electrical systems. This, in turn, leads to new electrical system architectures requiring new electronic parts, such as active separating and connecting elements (ASC) instead of fuses.

To accommodate these changes, an adjustment of the existing specifications is necessary. To enable the use of various alternative 12 V storage technologies, a new description of the nominal voltage range is necessary. Tests that check scenarios that no longer occur due to the mentioned changes, such as the use of a DC/DC converter instead of a generator, can be omitted under the defined conditions.

These new conditions have a direct impact on the development of electrical and electronic components and the passive and active electronic parts used.