Test of Battery Junction Box (BJB/S-Box) in electric vehicles
Module of the Battery Management in electric cars
The Battery Junction Box (BJB) is a switching unit for the battery in an electric vehicle. It connects or disconnects the components in the vehicle, which need energy from the battery.
With one or more bus interfaces, this component is networked with the entire vehicle. The BJB is usually a switching box that switches the high-voltage connection on or off. It ensures that the high voltage is only applied to the necessary contacts when the ignition is switched on.
In these vehicles the high voltage can be up to 1000 VDC. The BJB has a safety function: in case of danger it disconnects the high-voltage battery from the electrical system including all electrical components of the vehicle.
For example, in the event of an accident it must be ensured that no high voltage is present in the vehicle in an uncontrolled state in order not to expose rescue workers to any danger.