Method for charging a traction battery of a motor vehicle

A method for charging a traction battery of a motor vehicle having an electric traction motor by way of a stationary charging column,

• wherein the charging column has:
• a charging column charging controller for monitoring and controlling the charging process, a charging voltage converter for providing a DC charging column voltage fed in in charging lines, an insulation tester for testing the electrical insulation of the charging lines with respect to the ground potential and a charging-column-side charging plug, wherein the charging voltage converter provides a fixed maximum charging column voltage for charging the traction battery that may be a low voltage value or a high voltage value, and
• wherein the motor vehicle has:
• a vehicle charging controller for monitoring and controlling the charging process, an insulation tester for testing the electrical insulation of the charging lines with respect to the ground potential, a vehicle-side charging plug and a charging voltage adapter, by way of which the charging column voltage is adapted to the technical charging voltage level of the traction battery when needed, wherein the traction battery has a technical charging voltage level with the high voltage value,
• having the following method steps when the charging plugs are connected:
• registering a charging process by way of the vehicle charging controller to the charging column charging controller with the low voltage value as requested charging voltage,
• controlling an insulation test, carried out by way of the charging-column-side insulation tester, by way of the charging column charging controller for the requested charging voltage,
• reporting the maximum charging column voltage by way of the charging column controller to the vehicle charging controller, and
• if the reported maximum charging column voltage corresponds to the high voltage value:
• continuing or registering a charging process by way of the vehicle charging controller to the charging column charging controller with the high voltage value as requested charging voltage and setting the charging voltage adapter to a charging column voltage corresponding to the high voltage value.