Abstract:
An electric vehicle battery pack includes an array of battery cells each cell having an upper cell surface and a lower cell surface, the lower cell surface having a positive and a negative terminal; and a thermal assembly in thermally-conductive contact with the upper cell surfaces of the array. A battery pack cooling method is also disclosed.
Abstract:
Systems and methods for operating a battery pack supplying power to propel a vehicle are disclosed. One example method comprises, adjusting a battery pack state of charge window in response to vehicle mass. Adjusting the battery pack state of charge window in response to vehicle mass may allow the battery pack to provide an increased amount of energy to a motor so that the motor may provide torque to a driveline for a longer period of time and/or absorb more vehicle generator produced power during vehicle operations.
Abstract:
A current sensor fault detection system is disclosed which enables detection of a current sensor fault while the current sensor is operating and providing a current sensor output which is within a normal operating range. The current sensor is monitored by at least one controller which compares a change in battery state of charge error with a predetermined threshold. The change in battery state of charge error is a difference between a first change in battery state of charge calculated by integrating battery current with respect to a time and a second change in battery state of charge calculated based on the battery open circuit voltage during the time.
Abstract:
An electric vehicle battery pack includes an array of battery cells each cell having an upper cell surface and a lower cell surface, the lower cell surface having a positive and a negative terminal; and a thermal assembly in thermally-conductive contact with the upper cell surfaces of the array. A battery pack cooling method is also disclosed.
Abstract:
A hybrid-electric vehicle includes a traction battery. A controller may operate the traction battery within certain state of charge and voltage limits. The controller may define a minimum operating voltage or state of charge below which no power may be requested from the traction battery. The minimum voltage and state of charge may be based on an electrical resistance of the traction battery. The voltage may also be based on a minimum power level required to crank the engine while meeting emissions standards. As the battery ages, the minimum voltage level may be adjusted such that the minimum power level is available at the minimum voltage level.
Abstract:
A current sensor fault detection system is disclosed which enables detection of a current sensor fault while the current sensor is operating and providing a current sensor output which is within a normal operating range. The current sensor is monitored by at least one controller which compares a change in battery state of charge error with a predetermined threshold. The change in battery state of charge error is a difference between a first change in battery state of charge calculated by integrating battery current with respect to a time and a second change in battery state of charge calculated based on the battery open circuit voltage during the time.
Abstract:
A vehicle includes a traction battery having cells and at least one controller. The controller is programmed to charge and discharge the traction battery according to a net current for the traction battery derived from sets of temperature-based current values, each of the sets corresponding to a different one of the cells, and each of the values for a given one of the sets corresponding to a different zone of the cell.
Abstract:
A vehicle includes a traction battery and a controller in communication with the battery and programmed to control battery charging in response to a user-selected one of a plurality of charging strategies having different charging rates based on detection of lithium plating in the battery. The charging strategies may include options for faster charging with an urgent or emergency charging strategy selectable a limited number of times to mitigate battery performance degradation associated with lithium plating. A method implemented by a vehicle controller in a vehicle having a traction battery, may include controlling, by the controller, battery charging in response to a user-selected charging strategy selected from one of a plurality of available charging strategies each having a different charging rate and displayed on a user interface in response to detection of lithium plating in the traction battery, at least one charging strategy associated with additional lithium plating if selected.
Abstract:
A vehicle having a traction battery with at least one cell includes a controller coupled to the traction battery and programmed to control charging and discharging of the traction battery in response to detecting lithium plating in the at least one cell indicated by a ratio of differential voltage of the at least one cell as a function of time to cell charging rate of the at least one cell. In various embodiments, the ratio is compared to a threshold associated with current battery state of charge to indicate lithium plating when the ratio is below the threshold. Lithium plating can also be detected based on a measured cell open circuit voltage (OCV) relative to a previously stored OCV value. In various embodiments, the measured OCV value is calculated based on a measured cell voltage and current, and a previously stored cell internal resistance.
Abstract:
A diagnostic method for contact resistance failure includes estimating electrical contact surface resistance of at least one contactor, determining a faulted status of the at least one contactor and indicating the faulted status of the at least one contactor if the at least one contactor is in the faulted status.