An apparatus for heating a DC battery in a vehicle including an electric motor. The apparatus comprises an AC generating module coupled to the battery and the electric motor that generates three AC phases. The first, second, and third AC phases are applied to first, second, and third windings of the electric motor, respectively. The first, second, and third AC phases create zero torque in the electric motor because the first AC phase amplitude is equal to the sum of the second and third AC phase amplitudes and the second and third AC phases are 180 degrees out of phase with the first AC phase. The AC generating module creates a heating alternating current in the DC battery.