Methods of Electric Vehicle On-board Energy Dissipation

An electric vehicle comprising:

• a battery pack;
• an electric traction motor for selectively driving at least one driving wheel of the vehicle;
• a DC-AC inverter in electrical communication with the battery pack and the electric traction motor;
• one or more electrical loads in electrical communication with the battery pack;
• and
• a battery management system including a controller in electrical communication with the battery pack and the inverter and the one or more electrical loads, the controller being configured to execute a program stored in the controller to:
• (i) cause electricity to flow from the battery pack to the inverter and/or to the one or more electrical loads to dissipate energy stored in the battery pack, and
• (ii) calculate a battery pack characteristic during or after when the electricity flows from the battery pack to the inverter and/or to the one or more electrical loads to dissipate energy stored in the battery pack.

A method for determining a characteristic of a battery pack in an electric vehicle including an electric traction motor for selectively driving at least one driving wheel of the vehicle, a DC-AC inverter in electrical communication with the battery pack and the electric traction motor, and one or more electrical loads in electrical communication with the battery pack, the method comprising:

• (a) providing a controller in electrical communication with the battery pack and the inverter and the one or more electrical loads;
• (b) causing, in the controller, electricity to flow from the battery pack to the inverter and/or to the one or more electrical loads to dissipate energy stored in the battery pack;
• and
• (c) calculating, in the controller, a battery pack characteristic during or after when the electricity flows from the battery pack to the inverter and/or to the one or more electrical loads to dissipate energy stored in the battery pack.

A method for mitigating or avoiding an unsafe condition in a battery pack in an electric vehicle including an electric traction motor for selectively driving at least one driving wheel of the vehicle, a DC-AC inverter in electrical communication with the battery pack and the electric traction motor, and one or more electrical loads in electrical communication with the battery pack, the method comprising:

• (a) receiving, in a controller in electrical communication with the battery pack and the inverter and the one or more electrical loads, electrical signals based on readings from a sensor in or adjacent the battery pack;
• (b) determining, in the controller, whether one or more of the electrical signals exceeds a safety threshold;
• and
• (c) when the one or more of the electrical signals exceeds the safety threshold, causing electricity to flow from the battery pack to the inverter and/or to the one or more electrical loads to dissipate energy stored in the battery pack.