A device for heating a traction battery of a vehicle, comprising: - at least one rechargeable battery; - at least two heating units (7, 8, 9) that can be arranged at a part of the traction battery; - at least one control unit for controlling electric energy supply from the rechargeable battery to the heating unit (7, 8, 9); and - at least one detection unit connected with the control unit for detecting at least one parameter of the traction battery and at least one parameter of the rechargeable battery, - wherein the control unit controls the electric energy supply according to the parameters detected by the detection unit, wherein - the rechargeable battery is configured to supply electric energy to the traction battery of the vehicle; - the detection unit is capable of detecting an environmental temperature, as parameter of the traction battery, a state of health and an internal resistance of the traction battery, and as parameter of the rechargeable battery, a state of charge of the rechargeable battery, - the device comprising two or more heating units (7, 8, 9), with one heating unit (7, 8, 9) per module of the traction battery, wherein the control unit is configured to control the electric energy supply to each heating unit (7, 8, 9) so that the heating units (7, 8, 9) are supplied with electric energy (a) if the state of charge of the rechargeable battery is higher than a particular value, the environmental temperature is lower than a particular temperature, and the rechargeable battery has enough electric energy to supply several heating units (7, 8, 9) with electric energy, the control unit controls the electric energy supply to each heating unit (7, 8, 9) so that the heating units (7, 8, 9) are simultaneously supplied with electric energy, and (b) if the state of charge of the rechargeable battery is lower than a particular value, the environmental temperature is lower than a particular temperature, and the rechargeable battery does not have enough electric energy to supply all heating units (7, 8, 9) with electric energy, the control unit controls the electric energy supply to each heating unit (7, 8, 9) so that the heating units (7, 8, 9) are alternately supplied with electric energy for uniformly heating up the traction battery. - at least one rechargeable battery; - at least two heating units (7, 8, 9) that can be arranged at a part of the traction battery; - at least one control unit for controlling electric energy supply from the rechargeable battery to the heating unit (7, 8, 9); and - at least one detection unit connected with the control unit for detecting at least one parameter of the traction battery and at least one parameter of the rechargeable battery, - wherein the control unit controls the electric energy supply according to the parameters detected by the detection unit, wherein - the rechargeable battery is configured to supply electric energy to the traction battery of the vehicle; - the detection unit is capable of detecting an environmental temperature, as parameter of the traction battery, a state of health and an internal resistance of the traction battery, and as parameter of the rechargeable battery, a state of charge of the rechargeable battery, as parameter of the traction battery, a state of health and an internal resistance of the traction battery, and as parameter of the rechargeable battery, a state of charge of the rechargeable battery, - the device comprising two or more heating units (7, 8, 9), with one heating unit (7, 8, 9) per module of the traction battery, wherein the control unit is configured to control the electric energy supply to each heating unit (7, 8, 9) so that the heating units (7, 8, 9) are supplied with electric energy (a) if the state of charge of the rechargeable battery is higher than a particular value, the environmental temperature is lower than a particular temperature, and the rechargeable battery has enough electric energy to supply several heating units (7, 8, 9) with electric energy, the control unit controls the electric energy supply to each heating unit (7, 8, 9) so that the heating units (7, 8, 9) are simultaneously supplied with electric energy, and (b) if the state of charge of the rechargeable battery is lower than a particular value, the environmental temperature is lower than a particular temperature, and the rechargeable battery does not have enough electric energy to supply all heating units (7, 8, 9) with electric energy, the control unit controls the electric energy supply to each heating unit (7, 8, 9) so that the heating units (7, 8, 9) are alternately supplied with electric energy for uniformly heating up the traction battery. (a) if the state of charge of the rechargeable battery is higher than a particular value, the environmental temperature is lower than a particular temperature, and the rechargeable battery has enough electric energy to supply several heating units (7, 8, 9) with electric energy, the control unit controls the electric energy supply to each heating unit (7, 8, 9) so that the heating units (7, 8, 9) are simultaneously supplied with electric energy, and (b) if the state of charge of the rechargeable battery is lower than a particular value, the environmental temperature is lower than a particular temperature, and the rechargeable battery does not have enough electric energy to supply all heating units (7, 8, 9) with electric energy, the control unit controls the electric energy supply to each heating unit (7, 8, 9) so that the heating units (7, 8, 9) are alternately supplied with electric energy for uniformly heating up the traction battery.