Abstract: A system includes a battery pack having a fluid inlet, a fluid outlet, and battery cells. The system also includes a thermal system having heat transfer fluid, a flow device, an inlet thermocouple, one or more internal thermocouples connected to a respective one of the battery cells, and a controller. The controller receives and processes temperature signals from the thermocouples using a thermal model to diagnose performance of the flow device. The system may estimate values when an outlet thermocouple is not used. A method includes circulating the fluid through the battery pack, positioning an inlet thermocouple proximate to the fluid inlet, and connecting one or more internal thermocouples to respective battery cells. A controller receives and processes temperature signals from the inlet thermocouple and the internal thermocouple(s) to diagnose performance of the flow device using the thermal model.

Abstract: A system includes a controller, battery pack, fluid, heater, a pump that circulates the fluid to the battery pack through the heater, and a temperature sensor positioned between the heater and battery pack. The controller processes temperature signals from the sensor, diagnoses the pump and heater by turning on the pump in response to a received enabling signal, calculates an absolute value of a temperature gradient of the fluid while the pump remains on, and records a passing pump diagnostic code if the absolute value of the temperature gradient exceeds a calibrated rate. The controller executes a heater diagnostic, after calculating the absolute value of the temperature gradient, only when heating is requested or the absolute value of the temperature gradient does not exceed the calibrated rate. The heater diagnostic includes turning off the pump, cycling the heater on and off, and monitoring the temperature signals for a temperature rise.

Abstract: An automotive battery module with one or more battery cells and a coolant loss detection and remediation system cooperative with coolant that is configured to provide thermal management of the battery module. Coolant levels in or around the battery module may be detected, while cooperation with a controller permits corrective action in the event that a leakage of coolant is detected. The controller senses a coolant level sensor which is located in a coolant reservoir to determine when the coolant level drops below a predetermined level. When the coolant level is determined to be low, the controller reports the low level condition and takes remedial action. The controller also has a set of enablement conditions that must be satisfied before the controller senses the coolant level sensor.

Abstract: Methods and electric vehicle diagnostic systems are provided for diagnosing performance of an active cooling system for cooling a rechargeable energy storage system (RESS) with a coolant. In one embodiment, a method includes determining, via a controller, whether the coolant temperature (TC) is less than the ambient temperature plus a first calibrated value (TA+V1). The method also includes determining, via a controller, whether the coolant temperature (TC) is less than the RESS temperature plus a second calibrated value (TR+V2). When the coolant temperature is less than the ambient temperature plus the first calibrated value and less than the RESS temperature plus the second calibrated value, the method provides for recording a diagnostic pass.

Abstract: A vehicle or other system includes a flow device, component, and controller. The controller executes a method of diagnosing flow performance in the vehicle/system. The flow device is a pump, blower, or fan. A calibrated upper speed limit is commanded from the flow device in response to detected enabling conditions. The device is turned off after maintaining the upper speed limit for a calibrated duration. The speed of the flow device is determined during a coast-down interval defined by a period between command of the upper speed limit and attaining a calibrated lower speed limit. An absolute rate of change of the speed over the coast-down interval is calculated, with the controller executing a control action when a maximum absolute slope of the calculated rate of change falls outside of a calibrated range during the coast-down interval.

Abstract: A vehicle or other system includes a flow device, component, and controller. The controller executes a method of diagnosing flow performance in the vehicle/system. The flow device is a pump, blower, or fan. A calibrated upper speed limit is commanded from the flow device in response to detected enabling conditions. The device is turned off after maintaining the upper speed limit for a calibrated duration. The speed of the flow device is determined during a coast-down interval defined by a period between command of the upper speed limit and attaining a calibrated lower speed limit. An absolute rate of change of the speed over the coast-down interval is calculated, with the controller executing a control action when a maximum absolute slope of the calculated rate of change falls outside of a calibrated range during the coast-down interval.

Abstract: A method that considers battery capacity for providing cell balancing for battery cells in a battery pack. The method includes providing a current state-of-charge for each battery cell in the battery pack for a current time frame and a previous state-of-charge for each battery cell in the battery pack from a previous time frame. The method also includes subtracting the current state-of-charge from the previous state-of-charge for each battery cell to generate a cell delta state-of-charge for each cell and providing an average cell delta state-of-charge of the cell delta state-of-charges for all of the cells. The method also includes dividing each cell delta state-of-charge by the average cell delta state-of-charge to provide a relative cell delta state-of-charge for each cell and dividing the current state-of-charge by the relative cell delta state-of-charge for that cell to generate a capacity adjustment state-of-charge that identifies the capacity of the cell.

Abstract: A system includes a battery pack having a fluid inlet, a fluid outlet, and battery cells. The system also includes a thermal system having heat transfer fluid, a flow device, an inlet thermocouple, one or more internal thermocouples connected to a respective one of the battery cells, and a controller. The controller receives and processes temperature signals from the thermocouples using a thermal model to diagnose performance of the flow device. The system may estimate values when an outlet thermocouple is not used. A method includes circulating the fluid through the battery pack, positioning an inlet thermocouple proximate to the fluid inlet, and connecting one or more internal thermocouples to respective battery cells. A controller receives and processes temperature signals from the inlet thermocouple and the internal thermocouple(s) to diagnose performance of the flow device using the thermal model.

Abstract: A system includes a controller, battery pack, fluid, heater, a pump that circulates the fluid to the battery pack through the heater, and a temperature sensor positioned between the heater and battery pack. The controller processes temperature signals from the sensor, diagnoses the pump and heater by turning on the pump in response to a received enabling signal, calculates an absolute value of a temperature gradient of the fluid while the pump remains on, and records a passing pump diagnostic code if the absolute value of the temperature gradient exceeds a calibrated rate. The controller executes a heater diagnostic, after calculating the absolute value of the temperature gradient, only when heating is requested or the absolute value of the temperature gradient does not exceed the calibrated rate. The heater diagnostic includes turning off the pump, cycling the heater on and off, and monitoring the temperature signals for a temperature rise.

Abstract: Methods and electric vehicle diagnostic systems are provided for diagnosing performance of an active cooling system for cooling a rechargeable energy storage system (RESS) with a coolant. In one embodiment, a method includes determining, via a controller, whether the coolant temperature (TC) is less than the ambient temperature plus a first calibrated value (TA+V1). The method also includes determining, via a controller, whether the coolant temperature (TC) is less than the RESS temperature plus a second calibrated value (TR+V2). When the coolant temperature is less than the ambient temperature plus the first calibrated value and less than the RESS temperature plus the second calibrated value, the method provides for recording a diagnostic pass.

Abstract: A method that considers battery capacity for providing cell balancing for battery cells in a battery pack. The method includes providing a current state-of-charge for each battery cell in the battery pack for a current time frame and a previous state-of-charge for each battery cell in the battery pack from a previous time frame. The method also includes subtracting the current state-of-charge from the previous state-of-charge for each battery cell to generate a cell delta state-of-charge for each cell and providing an average cell delta state-of-charge of the cell delta state-of-charges for all of the cells. The method also includes dividing each cell delta state-of-charge by the average cell delta state-of-charge to provide a relative cell delta state-of-charge for each cell and dividing the current state-of-charge by the relative cell delta state-of-charge for that cell to generate a capacity adjustment state-of-charge that identifies the capacity of the cell.