Vehicle electric power network and switch

The system (2) has connections for two batteries (3,4) for connection to the system via two switches (5,6) depending on detected states. The two switches are connected together by a first cable (11), each switch is connected to one of the two batteries, the first switch is connected to a first load by a second cable and the second switch is connected to the second load by a third cable. The first switch is connected to a starter generator (10) and to a current generator (9). An independent claim is also included for a switch for an inventive on-board electrical system.