Method and Apparatus for Selectively Heating Individual Battery Modules Within a Battery Pack

• US 20170008419A1
• Filed: 07/08/2015
• Published: 01/12/2017
• Est. Priority Date: 07/08/2015
• Status: Active Grant

• Current Assignee: Atieva, Inc.
• Original Assignee: Atieva, Inc.
• Inventors: Kim, Jong Yon
• Granted Patent: US 9,758,053 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60L 1/02 to electric heating circuits
• CPC Class Codes: B60L 1/14 to electric lighting circuits
• CPC Class Codes: B60L 53/22 Constructional details or arrangements of charging converters specially adapted for charging electric vehicles
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/22 Balancing the charge of battery modules
• CPC Class Codes: B60L 58/27 by heating
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/443 in response to temperature
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 10/615 Heating or keeping warm
• CPC Class Codes: H01M 10/625 Vehicles
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

A system and method are provided which, when the battery pack is at a low charge level, selectively heat the battery or battery module with the lowest voltage, thereby decreasing the internal resistance and mitigating the magnitude of the voltage drop of the affected battery/battery module. As a result, termination of the battery pack'"'"'s discharge cycle is delayed and the driving range of the vehicle is increased, thereby giving the driver a little more time and driving range to reach a charging station.

Claims

1. A method of extending a driving range of an electric vehicle, said electric vehicle comprising a battery pack coupled to an electric drive train, said battery pack comprising a plurality of battery modules, wherein each battery module of said plurality of battery modules is comprised of at least one battery, said method comprising:

monitoring a current battery pack charge level;

determining when said current battery pack charge level falls to a preset level;

determining an output voltage for each battery module of said plurality of battery modules;

identifying a single battery module of said plurality of battery modules, wherein said output voltage of said single battery module is lower than said output voltage of each battery module of a remaining portion of said plurality of battery modules; and

selectively heating said single battery module to a higher temperature than said remaining portion of said battery modules, wherein said heating step decreases an internal resistance corresponding to said single battery module.

2. The method of claim 1, wherein said step of selectively heating said single battery module to said higher temperature is only performed after said current battery pack charge level falls to said preset level.

3. The method of claim 1, wherein said step of determining said output voltage of each battery module of said plurality of battery modules further comprises determining said internal resistance of each battery module of said plurality of battery modules.

4. The method of claim 1, wherein said step of selectively heating said single battery module to said higher temperature is performed using a module heating subsystem, wherein said module heating subsystem is independent of a battery pack thermal control system, wherein said battery pack thermal control system is configured to simultaneously heat or cool said plurality of battery modules.

5. The method of claim 1, further comprising activating an on-board warning indicator after said current battery pack charge level falls to said preset level.

6. The method of claim 1, further comprising reducing a load on said battery pack after said current battery pack charge level falls to said preset level.

7. The method of claim 6, wherein said step of reducing said load further comprises automatically altering a use setting of a vehicle auxiliary system.

8. The method of claim 7, said vehicle auxiliary system selected from the group consisting of a heating, ventilation and air conditioning (HVAC) system, an external lighting system, an internal lighting system, a navigation system and a vehicle entertainment system.

9. The method of claim 6, wherein said step of reducing said load further comprises limiting a motor load corresponding to said electric drive train, wherein said step of limiting said motor load reduces an acceleration and a top speed corresponding to said electric vehicle.

10. The method of claim 1, further comprising issuing a confirmation request prior to performing said step of selectively heating said single battery module, wherein said step of selectively heating said single battery module is automatically performed when a positive response to said confirmation request is received from a user of said electric vehicle, and wherein said step of selectively heating said single battery module is not performed when a negative response to said confirmation request is received.

11. The method of claim 1, further comprising:

estimating an energy requirement to perform said step of selectively heating said single battery module;

estimating an expected energy gain to be received by performing said step of selectively heating said single battery module; and

comparing said energy requirement to said expected energy gain, wherein said step of selectively heating said single battery module is automatically performed when said expected energy gain is greater than said energy requirement, and wherein said step of selectively heating said single battery module is not performed when said expected energy gain is less than said energy requirement.

12. The method of claim 11, wherein said expected energy gain is preset.

13. The method of claim 1, wherein said step of monitoring said current battery pack charge level further comprises determining a current state-of-charge (SOC) corresponding to said battery pack.

14. The method of claim 1, wherein said step of monitoring said current battery pack charge level further comprises determining a current state-of-energy (SOE) corresponding to said battery pack.

15. A battery management system coupled to a battery pack of an electric vehicle, wherein the battery pack is comprised of a plurality of battery modules, wherein each battery module of said plurality of battery modules is comprised of at least one battery, said battery management system comprising:

a battery management system controller;

a battery pack thermal control system, wherein said battery pack thermal control system is coupled to and controlled by said battery management system controller, wherein said battery pack thermal control system is comprised of a heating subsystem and a cooling subsystem, wherein said battery pack thermal control system is configured to simultaneously heat said plurality of battery modules with said heating subsystem upon receipt of a heating command from said battery management system controller, and wherein said battery pack thermal control system is configured to simultaneously cool said plurality of battery modules with said cooling subsystem upon receipt of a cooling command from said battery management system controller; and

a battery module heating system, wherein said battery module heating system is coupled to and controlled by said battery management system controller, wherein said battery module heating system is independent of said battery pack thermal control system, wherein said battery module heating system is configured to provide selective heating of a single battery module of said plurality of battery modules, and wherein said battery management system controller is configured to select said single battery module from said plurality of battery modules based on a battery characteristic and then selectively heat said single battery module with said battery module heating system.

16. The battery management system of claim 15, further comprising a plurality of sensors coupled to said battery management system controller, wherein said plurality of sensors monitor said battery characteristic corresponding to each of said plurality of battery modules.

17. The battery management system of claim 16, wherein said battery characteristic corresponds to an operating voltage of said corresponding battery module.

18. The battery management system of claim 16, wherein said battery characteristic corresponds to an internal resistance of said corresponding battery module.

19. The battery management system of claim 15, further comprising a charge level detection system coupled to said battery pack and said battery management system controller, wherein said battery management system controller is configured to select said single battery module from said plurality of battery modules and selectively heat said single battery module with said battery module heating system when a battery pack charge level monitored by said charge level detection system falls to a preset value.