A system includes a vehicle with a charge socket and a contactor switching unit, and a charger for charging an electrical energy accumulator of the vehicle at a vehicle-external AC power system. The charger is a vehicle-external charger device. The charger is a portable charger. The charger has a DC-DC converter, and includes first and second charging cables. The first charging cable has an AC power system plug, and the second charging cable has a charge plug.