Battery having cell voltage and battery current detection and comprising only one electrical isolation device

A motor vehicle comprising:

• an electric drive motor for driving the motor vehicle;
• and
• a battery connected to the drive motor, the battery including:
• a plurality of battery cells connected in series between a positive terminal and negative terminal;
• a resistor connected in series with the plurality of battery cells;
• an amplifier connected between the resistor and the selected voltage measurement input of said one of the cell voltage detection units, the amplifier configured to amplify a voltage present across the resistor:
• and
• a plurality of cell voltage detection units, which each have a plurality of voltage measurement inputs connected to a respective group of battery cells of the plurality of battery cells, each cell voltage detection unit being configured to determine cell voltages of the connected respective group of battery cells, wherein:
• each cell voltage detection unit of the plurality of cell voltage detection units is connected to one another by a communications bus and is configured to communicate the determined cell voltages via the communications bus to a microcontroller which is DC-decoupled from the cell voltage detection units by an electrical isolation apparatus,
• a gain factor of the amplifier is predetermined such that a maximum permissible current of the battery effects an output voltage of the amplifier, which is lower than a maximum permissible input voltage of voltage measurement inputs of said one of the cell voltage detection units, and
• the resistor has at least one first connection connected to a selected voltage measurement input of one of the cell voltage detection units.

A battery comprising:

• a plurality of battery cells connected in series between a positive terminal and negative terminal;
• a resistor connected in series with the plurality of battery cells;
• a plurality of cell voltage detection units, which each have a plurality of voltage measurement inputs connected to a respective group of battery cells of the plurality of battery cells, each cell voltage detection unit being configured to determine cell voltages of the connected respective group of battery cells;
• an amplifier connected between the resistor and the selected voltage measurement input of said one of the cell voltage detection units, the amplifier configured to amplify a voltage present across the resistor, the amplifier including a first supply voltage connection for a lower supply voltage and a second supply voltage connection for an upper supply voltage;
• and
• a DC-to-DC converter configured to connect the first supply voltage connection to the first battery cell of the battery cells connected to said one of the cell voltage detection units and configured to connect the second supply voltage connection to the second battery cell of the battery cells connected to said one of the cell voltage detection units and configured to generate the upper supply voltage and the lower supply voltage and to output said voltages to the amplifier, wherein:
• the cell voltage detection units of the plurality of cell voltage detection units are connected to one another by a communications bus and are configured to communicate the determined cell voltages via the communications bus to a microcontroller, which is DC-decoupled from the cell voltage detection units by an electrical isolation apparatus;
• the first supply voltage connection is connected to a first battery cell of battery cells connected to said one of the cell voltage detection units and the second supply voltage connection is connected to a second battery cell of the battery cells connected to said one of the cell voltage detection units;
• and
• the resistor has at least one first connection connected to a selected voltage measurement input of one of the cell voltage detection units.