A heater assembly used in connection with a diesel emissions fluid tank in a vehicle, the heater assembly including a first heater connectable to an alternating current power supply; a second heater connectable to a direct current power supply within the vehicle; wherein the first heater is adapted to operate at a higher power than the second heater; wherein the first heater is closer to the tank than the second heater; a temperature sensor in sensing communication with the tank and adapted to provide a tank temperature; a control circuit connected to the second heater and the vehicle power supply, wherein the temperature sensor communicates the tank temperature to the control circuit, wherein the control circuit selectively activates the second heater to obtain a desired tank temperature.