BATTERY SYSTEM, METHOD FOR DIAGNOSING A BATTERY SYSTEM, AND MOTOR VEHICLE

A battery system having a battery pack with a negative pole, a positive pole and a battery cell, a coupling network having a first negative terminal and a first positive terminal, a pack voltage divider, and a coupling voltage divider. The first positive terminal is connectable to the positive pole via a switch. Optionally, the first negative terminal is connectable to the negative pole via a switch. The pack voltage divider includes a two resistors connected between the positive pole and a first reference point. A negative pack measurement resistor and a negative sub-pack measurement resistor are dis-connectable from the negative pole or the first reference point via a switch. A positive coupling measurement resistor and a positive sub-coupling measurement resistor are connected between the first positive terminal and the first reference point. Two resistors are connected between the first negative terminal and the first reference point.