Method for validating a temperature sensor, comprising the steps of: determining an internal resistance of at least one battery cell in thermal contact with the temperature sensor; determining a state of charge, SOC, of the at least one battery cell; determining at least one reference temperature from a lookup table, LUT, or functional relationship connecting the internal resistance, the SOC, and a temperature of a reference battery cell; and comparing the at least one reference temperature with at least one temperature measurement of the temperature sensor, wherein said lookup table, LUT, or said functional relationship connecting the internal resistance, the SOC, and a temperature of a reference battery cell are both obtained according to the following steps: obtaining a plurality of reference measurements of an internal resistance of said reference battery cell at a plurality of different temperatures and for a plurality of difference SOC values; combining an equivalent circuit model of the reference battery with said plurality of reference measurements; deriving from the equivalent circuit model a parametrized function connecting the SOC, the internal resistance and the temperature of the battery cell; and fitting the parameters of said function to the plurality of reference measurements to obtain a fitted parametrized function connecting the at least one reference temperature to any combination of an SOC and internal resistance of the at least one battery cell thus providing said LUT or said functional relationship. determining an internal resistance of at least one battery cell in thermal contact with the temperature sensor; determining a state of charge, SOC, of the at least one battery cell; determining at least one reference temperature from a lookup table, LUT, or functional relationship connecting the internal resistance, the SOC, and a temperature of a reference battery cell; and comparing the at least one reference temperature with at least one temperature measurement of the temperature sensor, wherein said lookup table, LUT, or said functional relationship connecting the internal resistance, the SOC, and a temperature of a reference battery cell are both obtained according to the following steps: obtaining a plurality of reference measurements of an internal resistance of said reference battery cell at a plurality of different temperatures and for a plurality of difference SOC values; combining an equivalent circuit model of the reference battery with said plurality of reference measurements; deriving from the equivalent circuit model a parametrized function connecting the SOC, the internal resistance and the temperature of the battery cell; and fitting the parameters of said function to the plurality of reference measurements to obtain a fitted parametrized function connecting the at least one reference temperature to any combination of an SOC and internal resistance of the at least one battery cell thus providing said LUT or said functional relationship. obtaining a plurality of reference measurements of an internal resistance of said reference battery cell at a plurality of different temperatures and for a plurality of difference SOC values; combining an equivalent circuit model of the reference battery with said plurality of reference measurements; deriving from the equivalent circuit model a parametrized function connecting the SOC, the internal resistance and the temperature of the battery cell; and fitting the parameters of said function to the plurality of reference measurements to obtain a fitted parametrized function connecting the at least one reference temperature to any combination of an SOC and internal resistance of the at least one battery cell thus providing said LUT or said functional relationship.