Battery system of an electric vehicle

A method of operating an electric vehicle including a battery system having a plurality of battery modules electrically connected together and a battery management system configured to control the operation of the battery system, wherein each battery module of the plurality of battery modules includes (a) a casing enclosing a plurality of battery cells therein, and (b) one or more heaters positioned within the casing and powered solely by the plurality of battery cells enclosed in the casing, the method comprising:

• selectively activating, by a controller of the battery management system, the one or more heaters of a battery module of the plurality of battery modules to modify a temperature of the battery module;
• passing a cooling loop within each casing by each of the plurality of battery cells, each cooling loop comprising an inlet and an outlet positioned on a common side of the respective casing, the one or more heaters being positioned within the cooling loop adjacent a central portion of the cooling loop;
• and
• selectively opening or closing, by the controller of the battery management system, the inlet and/or the outlet of the cooling loop positioned within the casing of the battery module to modify the temperature of the battery module.

A battery pack, comprising:

• at least one battery module, including:
• a casing;
• a fluid loop configured to pass a fluid through a volume enclosed by the casing, the fluid loop comprising an inlet and an outlet positioned on a common side of the casing;
• a heater positioned within the casing opposite the common side of the casing, and configured to heat the fluid within the fluid loop;
• a plurality of battery cells configured and positioned within the volume so that a temperature of the plurality of cells and a temperature of the fluid in the fluid loop are related to each other, such that the heater is operable to heat the plurality of battery cells via the fluid in the fluid loop passing by each of the battery cells;
• a temperature sensor configured to sense a temperature of the at least one battery module;
• and
• a battery controller configured to:
• selectively operate the heater of the at least one battery module and selectively open or close the inlet and/or the outlet of the fluid loop of the at least one battery module to modify the temperature of the at least one battery module.