Method for operating a battery sensor, comprising at least - a first battery sensor connection (Vbat+) and a second battery sensor connection (Vbat-), - a current measurement device for recording a load current (Iload), with a first measuring resistor element (R1) and a second measuring resistor element (R2), wherein the first and the second measuring resistor element (R1, R2) are connected in series between a load current connection and the second battery sensor connection (Vbat-), - a reference current circuit with at least one reference resistor (Rref, Rref1, Rref2), wherein the reference resistor (Rref, Rref1, Rref2) is in contact with the first battery sensor connection (Vbat+) and a contact point provided between the measuring resistor elements (R1, R2), wherein the electrical resistance of the first measuring resistor element (R1) is determined by - switching on a reference current (Iref) and recording the respective resulting voltage drops (U1, U2) across the first and the second measuring resistor element (R1, R2) and the battery voltage (Vbat+), - determining the reference current (Iref) from the quotient of the battery voltage (Vbat+) and the electrical resistance of the reference resistor (Rref), characterized by - determining the electrical resistance of the first measuring resistor element (R1) from the recorded voltage drops (U1, U2), the reference current (Iref) and at least one correction factor (α, β) that characterizes the relationship between the electrical resistance of the first measuring resistor element (R1) and the electrical resistance of the second measuring resistor element (R2). - a first battery sensor connection (Vbat+) and a second battery sensor connection (Vbat-), - a current measurement device for recording a load current (Iload), with a first measuring resistor element (R1) and a second measuring resistor element (R2), wherein the first and the second measuring resistor element (R1, R2) are connected in series between a load current connection and the second battery sensor connection (Vbat-), - a reference current circuit with at least one reference resistor (Rref, Rref1, Rref2), wherein the reference resistor (Rref, Rref1, Rref2) is in contact with the first battery sensor connection (Vbat+) and a contact point provided between the measuring resistor elements (R1, R2), wherein the electrical resistance of the first measuring resistor element (R1) is determined by - switching on a reference current (Iref) and recording the respective resulting voltage drops (U1, U2) across the first and the second measuring resistor element (R1, R2) and the battery voltage (Vbat+), - determining the reference current (Iref) from the quotient of the battery voltage (Vbat+) and the electrical resistance of the reference resistor (Rref), characterized by - determining the electrical resistance of the first measuring resistor element (R1) from the recorded voltage drops (U1, U2), the reference current (Iref) and at least one correction factor (α, β) that characterizes the relationship between the electrical resistance of the first measuring resistor element (R1) and the electrical resistance of the second measuring resistor element (R2). <EOS>