Gm Global Technolgoy Operations, Inc.

Andrew C Baughman

Yue-Yun Wang

Daniel P Grenn

James C Gibbs

Yue Fan

Thomas John Timpf, Jr

Chunhao J Lee

Brian James Koch

Andrew M Zettel

Damon R Frisch

Xidong Tang

Yongjie Zhu

Meng Jiang

Jian Lin

Russell K Steele

Tao Wang

Yandong Zhang

Todd F Mackintosh

Fang Wang

Taylor R Garrick

Yangbing Zeng

Fiona E Meyer-Teruel

Karl C Dorgan

Voytek A Novak

Vivekananda Shripathy

Steven M Davis

Peter Kung Chiang

Xueyu Zhang

Rashed S Rabaa

Andrew J Cornelli

Christine E Cabrera

Todd W Bazzett

Salah Chamlal

Shital Patel

Philip J Prociw

Steven J Bunce

A method for monitoring a battery module in a vehicle includes selecting an upper cut-off voltage and a lower cut-off voltage for the battery module. The method includes charging the battery cell from an original state to a first benchmark voltage greater than an upper cut-off voltage, via a first charging process. The method includes discharging the battery cell from the first benchmark voltage to a second benchmark voltage less than a lower cut-off voltage, via a first discharging process. The battery module is then charged from the second benchmark voltage to the first benchmark voltage, via a second charging process. The method includes obtaining a ratio of a discharging capacity to a charging capacity of the battery module. Operation of the vehicle is controlled based in part on the ratio, including taking at least one remedial action if the ratio is less than a predefined threshold.

Control and monitoring of vehicle battery based on coulombic efficiency ratio

A vehicle, system and method for monitoring an occurrence of thermal runaway in a battery pack of the vehicle. The system includes a plurality of voltage sensors and a processor. The plurality of voltage sensors obtains a plurality of voltage measurements at each of a plurality of battery cells of the battery pack. The processor is configured to determine a mean value based on the plurality of voltage measurements, compare a voltage measurement obtained from a selected battery cell to the mean value, and generate a notification signal when a difference between the voltage measurement from the selected battery cell and the mean value is greater than or equal to a prognostic threshold.

Thermal runaway prognosis by detecting abnormal cell voltage and SOC degeneration

A battery system includes a rechargeable energy storage system (RESS) having battery cells, and a battery controller network configured to execute two-level logic to detect a thermal runaway condition. The network includes RESS-embedded cell monitoring units (CMUs) electrically connected to a respective cell group, and measuring and wirelessly transmitting cell data. A battery control module (BCM) is in communication with the CMUs. Thermal runaway sensors are mounted on the CMUs and/or the BCM. A master controller connected to the BCM includes a thermal runaway detection algorithm configured to detect a thermal runaway condition occurring within the RESS. The BCM uses data from the CMUs and thermal runaway sensors to execute first logic level which determines when to wake up the master controller. The master controller, in response to receipt of a wakeup signal, executes a second logic level to execute the algorithm.

Two-level method for thermal runaway detection

A system for self-discharge prognostics for vehicle battery cells with an internal short circuit includes a plurality of battery cells and a voltage sensor providing open-circuit voltage data over time for each battery cell. The system further includes a computerized prognostic controller operating programming to monitor the open-circuit voltage data over time for each of the plurality of battery cells and evaluate a voltage drop rate through a time window for each of the plurality of battery cells based upon the open-circuit voltage data. The controller further identifies one of the plurality of battery cells to include the internal short circuit based upon the voltage drop rate and signals an alert based upon the one of the plurality of battery cells including the internal short circuit.

Method and system for self-discharge prognostics for vehicle battery cells with an internal short circuit

A battery system with cell groups arranged in modules and with plurality of modules arranged in individual battery sub-packs includes a controller network configured to monitor the sub-packs. The network includes a plurality of cell monitoring units (CMUs); each CMU connected to one module for processing data for respective cell groups. The network also includes multiple voltage sensors on each CMU, with each sensor detecting voltage across one cell group. The network additionally includes an electronic controller programmed with an algorithm and in wireless communication with each CMU. The algorithm identifies when electrical power is disconnected from the RESS and directs electrical current through a selected sub-pack after power is restored. The algorithm also interrogates voltage sensors of a particular CMU, detects a change in voltage triggered by the current, and records a cross-reference between the particular CMU and the selected sub-pack when the change in voltage is detected.

Determination of battery module and sub-pack association in electrical energy storage systems

A rechargeable energy storage system includes a battery pack and a battery controller. The battery pack has a voltage current temperature module and multiple battery modules. Respective battery modules have multiple battery cells and are operable to store a module identifier that encodes at least one parameter of the battery cells, receive a configuration request from the voltage current temperature module, and transfer the module identifier to the voltage current temperature module in response to the configuration request. The battery controller is in communication with the voltage current temperature module and is operable to send a status request to the voltage current temperature module, receive the plurality of module identifiers from the voltage current temperature module in response to the status request, and compare the module identifiers to determine either a match or at least one mismatch among the module identifiers of the battery modules.

Rechargeable energy storage system with different cell chemistries

An electrical system includes a voltage bus, voltage sensor(s) measuring a first voltage between a positive bus rail and electrical ground, and a second voltage between a negative bus rail and electrical ground, a bias resistor, and a controller. When the switch is closed, the controller measures four or more discrete voltage samples of the first and second voltages. The samples are grouped into first and second sample groups each having three discrete voltage samples, with the second and third voltage samples of the first group being the first and second samples of the second group. The controller estimates a steady-state voltage of the first and second voltages using the sample groups, prior to the first and second voltages converging on actual steady-state voltage values. The controller executes a corresponding control action when the steady-state voltage estimate is stable or unstable relative to a defined stability threshold.

Method and system for noise-tolerant RC response prediction

A method and system are disclosed for estimating cell voltage excursion in a battery pack in the presence of a sensing fault in which actual cell voltages of first and second battery cells in a block of battery cells become unknown or missing. The sensing fault is detected, and a cell voltage is determined for each cell in the block other than the first and second cells. The method also includes measuring a block voltage, calculating an average cell voltage in the block, and estimating that the first cell is equal to the calculated average cell voltage. All excursion or deviation of the measured block voltage from a sum of the cell voltages and the estimated cell voltage of the first cell is assigned to the second cell. A control action is executed using the estimated cell voltages, including selectively enabling or disabling functionality of the battery pack.

Estimation of cell voltage excursion in the presence of battery pack sensing faults

A system and method are disclosed for diagnosing an open circuit of a cell voltage sensing board. The board includes, for each cell, a line balancing resistor, a line sense resistor, and a gate. Each gate connects and disconnects a given line balancing resistor to and from a corresponding cell. A cell voltage is measured for a selected battery cell, and a controller determines if the selected battery cell is an uppermost or lowermost cell in the battery stack. A line sense resistance value is calculated for the selected battery cell using a first set of equations when the selected battery cell is the uppermost cell, a second set of equations when the selected battery cell is the lowermost cell, and a third set of equations when the selected battery cell is neither. A control action is executed when the calculated line sense resistance exceeds a calibrated resistance threshold.

Battery cell voltage sensing circuit diagnostics

A fuse system includes a fuse element configured to receive a current. A controller is operatively connected to the fuse element and has a processor and tangible, non-transitory memory on which is recorded instructions for executing a method for determining a remaining fuse life (L) of the fuse element. Execution of the instructions by the processor causes the controller to determine a temperature (T) of the fuse element. The fuse system may be part of a vehicle. The controller may be configured to determine if the remaining fuse life is below first and second thresholds. If the remaining fuse life is above the second threshold, a first message may be displayed to a vehicle display. If the remaining fuse life is below the second threshold, the vehicle may be shifted to a predefined alternative operating mode.

Determination of fuse life in a fuse system

A method of identifying a non-communicative battery Cell Sensing Board (CSB) within a plurality of battery CSBs arranged in a serial chain includes sequentially reconfiguring the serial chain of the battery CSBs to sequentially define each of the plurality of battery CSBs as a last battery CSB in a temporary test serial chain. Communication with the last battery CSB of each temporary test serial chain is sequentially established with a loopback feature of the battery CSBs. When a disruption in communication between the battery system manager controller and the last battery CSB of the current temporary test serial chain is detected, the last battery CSB of the current temporary test serial chain is identified as the non-communicative battery CSB.

Detection diagnostic for communication loss between a battery system manager controller and a plurality of battery cell sensing boards

A method of monitoring a performance level of a battery of a vehicle having an electronic control unit (ECU) includes enabling a charging diagnostic module (CDM) and determining, with the CDM, a charging status of the battery. The method also includes enabling a discharging diagnostic module (DDM) and determining, with the DDM, a discharging status of the battery. The charging status and the discharging status are recorded in a memory location of the ECU.

System and method of monitoring a performance level of a battery

A method for estimating the voltage of a battery element of a battery system is provided. In one embodiment, the method comprises providing a balancing/sensing circuit having a series combination of a balancing switch and a balancing resistive element electrically connected in parallel with the battery element, and measuring the voltage across the balancing switch/balancing resistive element combination when the switch is presumed to be in a 'closed' state.' The method further comprises deriving a compensated value for the measured voltage by applying a calculated compensation factor to the measured voltage, the compensated value compensating for a voltage drop occurring in the balancing/sensing circuit when the balancing switch is in the 'closed&#x201d; state and represents an estimate of the battery element voltage. A battery system is also provided that includes a battery element, a balancing/sensing circuit, a sensor, and a control module configured to perform the method described above.

Method and system for estimating voltage of a battery element

A method for estimating the voltage of a battery element of a vehicle battery system is provided. The method comprises providing a balancing/sensing circuit having a series combination of a balancing switch and a balancing resistive element electrically connected in parallel with the battery element, and measuring the voltage across the combination of the balancing switch and balancing resistive element when the balancing switch is presumed to be in a 'closed' state. The method further comprises deriving a compensated value for the measured voltage using empirically-derived data, wherein the compensated value compensates for a voltage drop occurring in the balancing/sensing circuit when the balancing switch is in the 'closed' state and represents an estimate of the voltage of the battery element. A battery system is also provided that includes a battery element, a balancing/sensing circuit, a sensor, and a control module configured to perform the method described above.

Method and system for determining a battery element voltage

Methods and systems for balancing a state of charge of cell units of a battery pack of a vehicle are provided. Voltage sensors each measure a first value of state of charge of respective cell units at a first time, and a second value of state of charge of the respective cell units at a second time that is subsequent to the first time. A current sensor measures a current of the battery pack. A controller is coupled to the voltage sensors and the current sensor. The controller balances the state of charge around a predetermined calibrated value using the first values of state of charge, the second values of state of charge, and the current.

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Northville, MI, United States of America

Andrew C Baughman