Gm Global Technolgoy Operations, Inc.

Gregory E Smith

Damon R Frisch

Brian James Koch

Jonathan R Schwarz

Ian L Hanna

James C Gibbs

Kurt M Johnson

Brandon R Jones

John E Novak

Monica E Dykas

Thomas K Dye

An exemplary system and method for use in cold environments in order to heat a high voltage vehicle battery, such as the type commonly found in hybrid vehicles. Some high voltage vehicle batteries&#x2014;like those based on lithium-ion chemistries&#x2014;perform better when their battery temperature is in a certain temperature range. In an exemplary embodiment, a battery heating system includes a switch, a battery heater and a high voltage vehicle battery, and initially uses electrical power from an external power source to heat the battery and then uses electrical power from an internal power source to heat the battery. The switch determines which power source is used to heat the battery, and may be dictated by whether the battery heating system is plugged into the external power source and/or a vehicle propulsion system is active, to cite several possibilities.

Method for heating a high voltage vehicle battery

A method and system for heating a vehicle battery, such as the type used for vehicle propulsion in a hybrid electric vehicle (HEV). Depending on the battery chemistry involved, such batteries may not perform well in extremely cold environments. For instance, a lithium-ion battery can exhibit a high internal resistance when the battery is extremely cold, which in turn can negatively affect the available power or other capabilities of the battery. According to an exemplary embodiment, the method and system take advantage of the high internal resistance in a cold vehicle battery by purposely cycling electrical current in and/or out of the battery so that heat is created. This heat warms up the vehicle battery and thereby improves its overall performance and capabilities.

Method and system for heating a vehicle battery

A method and system for manipulating, adjusting or otherwise controlling a state-of-charge (SOC) operating range for a high voltage vehicle battery, such as the type used for hybrid or electric vehicle propulsion. By providing a dynamic SOC operating range that changes in response to changing battery conditions, the battery performance may be improved so that the battery life is extended. Depending on the particular embodiment, the dynamic SOC operating range may have different combinations of hard and/or soft boundaries or limits.

Method and system for controlling a vehicle battery

A system and method for controlling a state-of-charge (SOC) of a vehicle battery, such as a high-voltage battery used by a hybrid electric vehicle (HEV) for vehicle propulsion, so that the SOC is maintained within a desired SOC range that is temperature-dependent. In an exemplary embodiment, the system and method use a battery temperature prediction to determine a desired SOC range, and then control the amount of charge on the vehicle battery such that the SOC is maintained within the desired SOC range. As the battery temperature prediction goes lower (i.e., as it gets colder), the desired SOC range may need to be adjusted or shifted upwards in order to account for increased internal battery resistance and to ensure that the vehicle battery has enough power to start the vehicle. Similarly, as the battery temperature prediction goes higher (i.e., as it gets warmer), the desired SOC range may need to be adjusted or shifted downwards in order to reduce degradation effects and improve battery. The exemplary system and method control the SOC of the vehicle battery and may seek to optimize a number of different parameters, including battery life, battery performance and/or vehicle fuel economy.

Method of controlling a state-of-charge (SOC) of a vehicle battery

A method for estimating the capacity of a vehicle battery while in service. The method includes providing a previous battery state-of-charge, battery temperature and integrated battery current amp-hours, and determining that battery contactors have been closed after they have been opened and disconnected from a load. The method determines if the battery has been at rest for a long enough period of time while the contactors were open, where the battery rest time is based on battery temperature, and determines an initial battery voltage from a last time step when the battery contactors were closed prior to the contactors being open during the battery rest time. The method determines a present battery state-of-charge from the initial battery voltage and the battery temperature and calculates the battery capacity based on the battery integrated current amp-hours divided by the difference between the present battery state-of-charge and the previous battery state-of-charge.

Algorithm for determining the capacity of a battery while in service

A method for use with a vehicle battery pack, where the method determines a voltage threshold that may prevent the vehicle battery pack from being overcharged. The voltage threshold may be a dynamic threshold that changes or adjusts over time in order to accommodate changing conditions in the vehicle battery pack, the vehicle and/or the surrounding environment. The method may consider one or more battery readings when determining the voltage threshold, including temperature, voltage and/or current readings. According to one embodiment, the method is designed to accommodate high-current, short-duration charging events, like regenerative breaking.

Growing community of inventors

Toledo, OH, United States of America

Gregory E Smith