A heating system and a method for heating a battery module are provided. The method includes determining if the temperature signal indicates that the temperature level is less than a threshold temperature level. If the temperature level is less than the threshold temperature level, then the method further includes generating a first control signal to induce the switch to have the first operational position to at least partially discharge the first and second battery cell groups through a resistor to generate heat energy in the resistor. The method further includes generating a second control signal to turn on a fan to distribute the heat energy in the battery module to increase a temperature level of the battery module.