BATTERY CHARGE STRATEGY USING DISCHARGE CYCLE

• US 20170341520A1
• Filed: 08/21/2017
• Published: 11/30/2017
• Est. Priority Date: 03/20/2015
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: CHANG, Xiaoguang, HO, Szushen, WANG, Xu, HE, Chuan
• Granted Patent: US 10,449,870 B2
• Time in Patent Office: Days
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 50/60 using power supplied by batteries in combination with fuel cells B60L50/75
• CPC Class Codes: B60L 53/11 DC charging controlled by the charging station, e.g. mode 4
• CPC Class Codes: B60L 53/665 Methods related to measuring, billing or payment
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 58/24 for controlling the temperature of batteries
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• 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 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y02T 90/167 Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y04S 30/14 Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

A battery management system for a vehicle includes a controller programmed to charge a battery at a predetermined charge current. The controller activates an electrical load to discharge the battery for a predetermined time in response to a charge current of the battery becoming less than the predetermined charge current at a predetermined voltage limit. After discharging for the predetermined time, the controller resumes charging at the predetermined charge current. A current magnitude during the discharge and the predetermined time may be based on factors including the predetermined charge rate, a battery temperature, and a charge current magnitude during charging.

Claims

1. A battery management system comprising:

a controller programmed to charge a battery at a predetermined charge current and, in response to a charge current of the battery becoming less than the predetermined charge current at a predetermined voltage limit, activate an electrical load to discharge the battery for a predetermined time and resume charging after the predetermined time at the predetermined charge current to reduce battery charge time.

2. The battery management system of claim 1 wherein the predetermined voltage limit is a battery charge voltage limit at which constant voltage charging is initiated.

3. The battery management system of claim 1 wherein a discharge rate magnitude during the discharge is less than a magnitude defined by the predetermined charge current.

4. The battery management system of claim 1 wherein a current magnitude during the discharge and the predetermined time are based on one or more of a battery temperature, a battery state of charge, and a battery impedance.

5. The battery management system of claim 1 wherein a current magnitude during the discharge and the predetermined time are based on a charge current magnitude during the charge.

6. A vehicle comprising:

an electrical load;

a battery; and

a controller programmed to charge the battery at a predetermined charge current and, in response to a charge current of the battery becoming less than the predetermined charge current at a predetermined voltage limit, operate the electrical load to discharge the battery for a predetermined time and resume charging after the predetermined time at the predetermined charge current to reduce battery charge time.

7. The vehicle of claim 6 wherein the predetermined voltage limit is a battery charge voltage limit at which constant voltage charging is initiated.

8. The vehicle of claim 6 wherein a discharge rate magnitude during the discharge is less than a magnitude defined by the predetermined charge current.

9. The vehicle of claim 6 wherein a current magnitude during the discharge and the predetermined time are based on a battery temperature.

10. The vehicle of claim 6 wherein a current magnitude during the discharge and the predetermined time are based on a charge current magnitude during the charge.

11. A method comprising:

charging a battery at a predetermined charge current;

operating an electrical load to discharge the battery for a predetermined time in response to a charge current of the battery becoming less than the predetermined charge current at a predetermined voltage limit; and

resuming charging the battery after the predetermined time at the predetermined charge current to reduce a battery charge time.

12. The method of claim 11 further comprising terminating the charging when a state of charge of the battery exceeds a predetermined state of charge indicative of a fully charged battery.

13. The method of claim 11 wherein the predetermined voltage limit is a battery charge voltage limit at which constant voltage charging is initiated.

14. The method of claim 11 wherein the predetermined charge current is based on one or more of a state of charge of the battery, a temperature of the battery, and an impedance of the battery.

15. The method of claim 11 wherein a discharge rate magnitude during the discharge is less than a magnitude defined by the predetermined charge current.

16. The method of claim 11 wherein a current magnitude during the discharge and the predetermined time are based on a battery temperature.

17. The method of claim 11 wherein a current magnitude during the discharge and the predetermined time are based on a charge current magnitude during the charge.