Cold weather smart battery heating and charging strategy utilizing multi-stage battery heating control

A method for preheating a battery of an electric vehicle (EV), comprising:

• measuring, by a temperature sensor, an ambient temperature of a battery of the EV:
• determining, by a processor, an estimated vehicle start time for an EV;
• determining, by the processor, whether the ambient temperature of the battery of the EV is less than −5° C.;
• when the ambient temperature of the battery is less than −5° C., controlling, by the processor, a battery heater to perform a level 1 heating function to heat the battery;
• when the ambient temperature of the battery is not less than −5° C., determining by the processor, whether the ambient temperature of the battery is between −5° C. and 5° C.;
• when the ambient temperature of the battery is between −5° C. and 5° C., controlling by the processor, the battery heater to perform a level 2 heating function to heat the battery;
• when the ambient temperature of the battery is not less than −5° C. and not between −5° C. and 5° C., then, determining, by the processor, whether the ambient temperature of the battery is between 5° C. and 10° C.;
• and
• when the ambient temperature of the battery is between 5° C. and 10° C., controlling, by the processor, the battery heater to perform a level 3 heating function to heat the battery.