A battery system for a vehicle is provided. The battery system includes: first and second output terminals; a battery pack including a primary pole and a secondary pole which are respectively electrically connected or connectable to one of the first and second output terminals; an electrically operable pre-charge switch electrically connected to the primary pole of the battery pack and to the first output terminal; a first resistor arranged in series with the electrically operable pre-charge switch; an isolation monitoring circuit adapted to monitor the overall isolation of the battery system; a semiconductor switch adapted to bidirectionally conduct a current in a first state and to bidirectionally block the current in a second state; and a second resistor arranged in series with the first resistor and in parallel with the semiconductor switch.