Method for homogenizing the temperature distribution in the cells (11, 12) of a lithium ion battery for a motor vehicle having the following method steps: a) in order to cool the cells (11, 12) of the lithium ion battery cooling air is sucked into an air inlet line from a passenger compartment of the motor vehicle through a blower, fed from the air inlet line through the lithium ion battery, wherein the cooling air is conducted past the cells (11, 12) which are arranged in succession, and via an air outlet line into the passenger compartment, b) by means of temperature sensors the temperature conditions in the cells (11, 12) are detected and passed on to a regulating unit, c) in the regulating unit the temperature difference (ΔT) between a first cell and the second cell is detected, wherein the first cell is arranged closer to the air inlet line than the second cell, d) when a temperature difference (ΔT) above a limiting temperature difference is detected by the regulating unit, the regulating unit switches a directional control valve, arranged between the passenger compartment and the blower, in the air inlet line, in such a way that less cooling air or no cooling air is sucked in from the passenger compartment any more, and in that recirculation air from a return line which is arranged between the directional control valve and the air outlet line and which connects the air outlet line and the directional control valve in a fluid-communicating fashion is fed via the air inlet line through the lithium ion battery, and e) transmits a signal to the blower to increase the air feed capacity of the blower, characterized in that f) when it is detected that a determined average operating temperature of the lithium ion battery is exceeded, the regulating unit switches the directional control valve in such a way that the blower sucks in both cooling air from the passenger compartment of the motor vehicle and recirculation air from the return line and feeds it through the lithium ion battery. a) in order to cool the cells (11, 12) of the lithium ion battery cooling air is sucked into an air inlet line from a passenger compartment of the motor vehicle through a blower, fed from the air inlet line through the lithium ion battery, wherein the cooling air is conducted past the cells (11, 12) which are arranged in succession, and via an air outlet line into the passenger compartment, b) by means of temperature sensors the temperature conditions in the cells (11, 12) are detected and passed on to a regulating unit, c) in the regulating unit the temperature difference (ΔT) between a first cell and the second cell is detected, wherein the first cell is arranged closer to the air inlet line than the second cell, d) when a temperature difference (ΔT) above a limiting temperature difference is detected by the regulating unit, the regulating unit switches a directional control valve, arranged between the passenger compartment and the blower, in the air inlet line, in such a way that less cooling air or no cooling air is sucked in from the passenger compartment any more, and in that recirculation air from a return line which is arranged between the directional control valve and the air outlet line and which connects the air outlet line and the directional control valve in a fluid-communicating fashion is fed via the air inlet line through the lithium ion battery, and e) transmits a signal to the blower to increase the air feed capacity of the blower, characterized in that f) when it is detected that a determined average operating temperature of the lithium ion battery is exceeded, the regulating unit switches the directional control valve in such a way that the blower sucks in both cooling air from the passenger compartment of the motor vehicle and recirculation air from the return line and feeds it through the lithium ion battery.