Precharging for direct current fast charging

A method for a vehicle, comprising:

• responsive to a first precharge mode signal, commanding a charging station to increase a voltage on a bus such that the bus is precharged using electric power from the charging station;
• responsive to a difference between a voltage of the traction battery and the voltage on the bus being less than a first threshold closing a precharge contactor between a battery and the bus such that the precharge contactor is in parallel with a first main contactor;
• and
• responsive to a second precharge mode signal, closing the precharge contactor without commanding the charging station to increase the voltage on the bus such that the bus is precharged using electric power from the battery and not power from the charging station.

A vehicle system comprising:

• one or more controllers configured to,
• responsive to a first precharge mode signal,
• command a charging station to increase a voltage on a bus such that the bus is precharged using power from the charging station, and
• responsive to an absolute value of voltage difference between a traction battery voltage and a bus voltage being less than a first threshold, close a precharge contactor, and
• responsive to a second precharge mode signal, close the precharge contactor without first commanding a charging station to increase the voltage on the bus such that the bus is precharged using power from the traction battery and not power from the charging station.