12 V on-board electrical system
The 12 V on-board electrical system normally includes all components for voltage generation, voltage regulation and energy storage. The 12 V on-board electrical system supplies electrical energy to the electrical consumers of various systems, including the interior lighting, exterior lighting and engine management systems.
On vehicles with a 12 V alternator, the necessary electrical energy is generated when the combustion engine is running. This is stored in the 12 V on-board electrical system battery. Vehicles with 48 V technology and starter-alternator as well as hybrid vehicles and electric vehicles do not have a 12 V alternator. On these vehicles, the necessary electrical energy for the 12 V on-board electrical system is provided via a DC/DC converter by the 48 V on-board electrical system battery or by the high-voltage battery.
Schematic diagram of 12 V on-board electrical system |
1 | Energy management control (central controller unit or front central controller unit) |
2 | 12 V on-board electrical system battery (saves and supplies energy) |
3 | Battery sensor (records energy state of 12 V on-board electrical system battery) (except vehicles equipped with lithium-ion battery) |
4 | 12 V alternator (generates energy when the combustion engine is running) (vehicles with 12 V alternator) |
5 | Loads (e.g. seat heating) |
6 | Combustion engine control unit (alternator management, 12 V alternator) |
7 | DC/DC converter (energy transfer) (vehicles with 48 V technology, hybrid vehicles, electric vehicles) |
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