Kurt M Johnson

US Patent:

8525519, Sep 3, 2013

Filed:

Feb 16, 2011

Appl. No.:

13/028956

Inventors:

Kurt M. Johnson - Brighton MI, US
Gregory E. Smith - Toledo OH, US
Damon R. Frisch - Troy MI, US
Brian J. Koch - Berkley MI, US

Assignee:

GM Global Technology Operations LLC - Detroit MI

International Classification:

H01M 10/44
H01M 10/46

US Classification:

324427

Abstract:

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.

US Patent:

20130026989, Jan 31, 2013

Filed:

Jul 26, 2011

Appl. No.:

13/190741

Inventors:

James C. Gibbs - Brighton MI, US
Kurt M. Johnson - Brighton MI, US

Assignee:

GM GLOBAL TECHNOLOGY OPERATIONS LLC - Detroit MI

International Classification:

H02J 7/00

US Classification:

320116

Abstract:

A vehicle battery and charging method that may be used to balance cell voltages during a battery charging operation, and may do so in a way that protects the individual cells from over-charging and improves the overall efficiency of the operation. According to one example, the vehicle battery includes a number of cell-balancing current paths, each of which is connected in parallel to an individual battery cell and can shunt or bypass the corresponding cell when its voltage exceeds some maximum amount. This may enable under-charged battery cells to be charged at the same time that over-charged battery cells are bypassed. Each of the cell-balancing current paths may include a series-connected electronic switch and zener diode combination, where the electronic switch is controlled by a battery control module so that cell-balancing can be enabled during a battery charging operation and disabled at other times.

US Patent:

20130063094, Mar 14, 2013

Filed:

Sep 9, 2011

Appl. No.:

13/228608

Inventors:

James C. Gibbs - Brighton MI, US
Joseph Bisbing - White Lake MI, US
Kurt M. Johnson - Brighton MI, US
Damon R. Frisch - Troy MI, US
Brian J. Koch - Berkley MI, US

Assignee:

GM GLOBAL TECHNOLOGY OPERATIONS LLC - Detroit MI

International Classification:

H02J 7/00
G01N 27/416

US Classification:

320134, 324430

Abstract:

A method and system for use with a vehicle battery pack having a number of individual battery cells, where the method estimates, extrapolates or otherwise determines individual cell resistances. According to an exemplary embodiment, the method and system use a voltage and temperature reading for each of the individual battery cells, as well as a voltage and current reading for the overall battery pack to determine one or more cell resistance values, such as a minimum and maximum cell resistance for the battery pack. This approach relies upon temperature deviations in the battery pack to make assumptions or estimates regarding individual battery cell resistances. By having individual cell resistance values—instead of using an overall pack resistance value and building in a buffer to account for cell variations—better and more accurate cell-level data can be obtained that, in turn, can improve charging, discharging, cell balancing and/or other battery-related processes.

US Patent:

20130317771, Nov 28, 2013

Filed:

May 25, 2012

Appl. No.:

13/481290

Inventors:

Patricia M. Laskowsky - Ann Arbor MI, US
Brian J. Koch - Berkley MI, US
Damon R. Frisch - Troy MI, US
Ramesh Rebba - Rochester Hills MI, US
Kurt M. Johnson - Brighton MI, US

Assignee:

GM GLOBAL TECHNOLOGY OPERATIONS LLC - DETROIT MI

International Classification:

G01R 31/36
G06F 19/00

US Classification:

702 63

Abstract:

A method for modeling changes in the state of charge vs. open circuit voltage (SOC-OCV) curve for a lithium-ion battery cell as it ages. During battery pack charging, voltage and current data are gathered for a battery cell. A set of state equations are used to determine the stoichiometry and state of charge of the cathode half-cell based on the charging current profile over time. The voltage and current data, along with the stoichiometry and state of charge of the cathode half-cell, are then used to estimate maximum and minimum solid concentration values at the anode, using an error function parameter regression/optimization. With stoichiometric conditions at both the cathode and anode calculated, the cell's capacity and a new SOC-OCV curve can be determined.

US Patent:

20150285866, Oct 8, 2015

Filed:

Apr 4, 2014

Appl. No.:

14/245685

Inventors:

- Detroit MI, US
PATRICIA M. LASKOWSKY - ANN ARBOR MI, US
KURT M. JOHNSON - BRIGHTON MI, US

Assignee:

GM GLOBAL TECHNOLOGY OPERATIONS LLC - Detroit MI

International Classification:

G01R 31/36

Abstract:

System and methods for estimating a capacity of a battery are presented. A measure of data skewness may be calculated from a battery system terminal voltage measurement. Inflection points in the data skewness of the terminal voltage measurement may align with transition points associated with a battery system. These transitions points may be associated with known SOCs determined from testing and/or characterization of the battery system. Using the detected transitions and associated SOCs and an indication of an accumulated charge provided to/from the battery between the transitions, an estimated capacity of the battery system may be determined.

US Patent:

20140203785, Jul 24, 2014

Filed:

Jan 22, 2013

Appl. No.:

13/747275

Inventors:

- Detroit MI, US
KURT M. JOHNSON - BRIGHTON MI, US
ZACHARY D. BYLSMA - ROCHESTER HILLS MI, US
DAMON R. FRISCH - TROY MI, US
GEORGE ROBISON - BLOOMFIELD HILLS MI, US
ASHLEY MCALLISTER - MACOMB MI, US

Assignee:

GM GLOBAL TECHNOLOGY OPERATIONS LLC - DETROIT MI

International Classification:

H02J 7/00

US Classification:

320136

Abstract:

Systems and methods for estimating the relative capacity of individual battery subdivisions in a battery system are presented. In some embodiments, a system may include calculation system configured to analyze the electrical parameters to generate derivative values of the parameters over a period of time. The calculation system may further calculate summation values associated with individual battery subdivisions based upon the derivate values. A battery control system may utilize the summation values to generate one or more commands configured to control an aspect of an operation of the battery pack based on using the summation values. The summation values associated with battery subdivisions may be used to determine a relative capacity for storing electrical energy, according to some embodiments. The determination of relative capacity may be used by a control system to prevent over-discharge of a battery subdivision having the lowest energy storage capacity.

US Patent:

20140167776, Jun 19, 2014

Filed:

Dec 14, 2012

Appl. No.:

13/715656

Inventors:

- Detroit MI, US
KURT M. JOHNSON - BRIGHTON MI, US
DAMON R. FRISCH - TROY MI, US

Assignee:

GM GLOBAL TECHNOLOGY OPERATIONS LLC - Detroit MI

International Classification:

G01R 31/36

US Classification:

324434

Abstract:

System and methods for identifying a weak subdivision in a battery system are presented. In certain embodiments, a system may include a battery pack that includes multiple subdivisions. A measurement system may be configured to determine multiple subdivision electrical parameters associated with the subdivisions. A battery control system may identify a weakest subdivision based one on or more calculated derivative ratios of a subdivision electrical parameter associated with one subdivision of the battery pack relative to a subdivision electrical parameter associated with another subdivision.

US Patent:

20140152317, Jun 5, 2014

Filed:

Nov 30, 2012

Appl. No.:

13/690886

Inventors:

- Detroit MI, US
KURT M. JOHNSON - BRIGHTON MI, US
ZACHARY D. BYLSMA - ROCHESTER HILLS MI, US
DAMON R. FRISCH - TROY MI, US
WEI LIU - WARREN MI, US
DAVID S. MAXWELL - MADISON HEIGHTS MI, US

Assignee:

GM GLOBAL TECHNOLOGY OPERATIONS LLC - Detroit MI

International Classification:

G01N 27/416

US Classification:

324433

Abstract:

A battery system may include a plurality of subdivisions, such as battery cells or sub-packs. A measurement system configured to determine a subdivision electrical parameter associated with each of a plurality of subdivisions. A battery control may identify a subdivision satisfying a criterion based on the plurality of subdivision electrical parameters. According to some embodiments, the battery control system may determine a ratio of the subdivision electrical parameter of the identified subdivision to the electrical parameter of the battery pack. The ratio may be used to scale the electrical parameter associated with the battery pack by the ratio. According to other embodiments, the subdivision electrical parameter associated with the identified subdivision may be provided to a battery state estimation system. The scaled electrical parameter or the electrical parameter associated with the identified subdivision may be used by a battery state estimation system to generate an estimated battery state.