System for battery charging based on cost and life

• US 7,786,704 B2
• Filed: 05/01/2009
• Issued: 08/31/2010
• Est. Priority Date: 07/18/2007
• Status: Active Grant

• Current Assignee: Tesla Motors Incorporated (Tesla Inc.)
• Original Assignee: Tesla Motors Incorporated (Tesla Inc.)
• Inventors: Berdichevsky, Eugene M., Kelty, Kurt R.
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): RAMADAN, RAMY O
• Application Number:
  US12/434,041
• Publication Number:
  US 20090216688A1
• Time in Patent Office: 487 Days
• Field of Search: None
• US Class Current: 320/155
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 3/0092 with use of redundant elements for safety purposes
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 53/305 Communication interfaces
• CPC Class Codes: B60L 53/64 Optimising energy costs, e.g. responding to electricity rates
• CPC Class Codes: B60L 55/00 Arrangements for supplying energy stored within a vehicle to a power network, i.e. vehicle-to-grid [V2G] arrangements
• CPC Class Codes: G06Q 30/0284 Time or distance, e.g. usage of parking meters or taximeters
• CPC Class Codes: G06Q 50/06 Energy or water supply
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• 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 10/126 the energy generation units being or involving electric vehicles [EV] or hybrid vehicles [HEV], i.e. power aggregation of EV or HEV, vehicle to grid arrangements [V2G]
• CPC Class Codes: Y04S 30/14 Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing
• CPC Class Codes: Y04S 50/14 Marketing, i.e. market research and analysis, surveying, promotions, advertising, buyer profiling, customer management or rewards

Abstract

One embodiment of the present subject matter includes a system that includes a battery, an electric vehicle, the battery coupled to the electric vehicle to propel the electric vehicle, and a charging circuit to charge the battery. The embodiment includes a charging cost circuit to estimate a charging cost rate and to turn on the charging circuit. The embodiment also includes a timer circuit to provide a time signal to the charging cost circuit. The embodiment is configured such that the charging cost circuit is to turn on the charging circuit during a first time period in which the charging cost rate is below a first threshold until the battery reaches a first energy stored level, and to turn on the charging circuit during a second time period in which the charging cost rate is above the first threshold.

Claims

1. A battery charging system, comprising:

a battery;

an electric vehicle, the battery coupled to a propulsion motor configured to propel the electric vehicle;

a charging circuit to charge the battery;

a charging cost circuit, wherein said charging cost circuit controls operation of said charging circuit; and

a timer circuit coupled to said charging cost circuit, wherein said timer circuit provides a plurality of timing signals to said charging cost circuit, said plurality of timing signals corresponding to at least a first time period and a second time period, wherein said second time period follows said first time period, and wherein the charging cost circuit turns on the charging circuit during said first time period in which the charging cost rate is below a first threshold and continues operation of said charging circuit until the battery reaches a first energy stored level, wherein the charging cost circuit terminates the charging circuit operation during said first time period only after said first energy stored level is reached, wherein the charging cost circuit pauses operation of said charging circuit whenever said charging cost rate is above the first threshold, and wherein the charging cost circuit turns on the charging circuit during said second time period in which the charging cost rate is above the first threshold and continues operation of said charging circuit until the battery reaches a second energy stored level or a user disrupts said charging circuit, wherein said second energy stored level is greater than said first energy stored level.

2. The battery charging system of claim 1 , further comprising

a trend circuit to record a plurality of charging stop times over a period of days, and to predict a predicted charging stop time based on the plurality of charging stop times, wherein the charging cost circuit automatically selects a charging circuit initiation time within said second time period to achieve said second energy stored level prior to reaching said predicted charging stop time.

3. The battery charging system of claim 1, further comprising a user controllable interface connected to the charging cost circuit such that the user can input the first threshold.

4. The battery charging system of claim 1, further comprising a user controllable interface connected to the charging cost circuit such that the user can input a charging stop time, wherein the charging cost circuit automatically selects a charging circuit initiation time within said second time period to achieve said second energy stored level prior to reaching said predicted charging stop time.

5. The battery charging system of claim 1, wherein the second energy stored level is less than a full energy stored level.

6. The battery charging system of claim 1, further comprising a user controllable interface connected to the charging cost circuit such that the user can input a charging circuit initiation time within said second time period.

7. The battery charging system of claim 1, further comprising a user controllable interface connected to the charging cost circuit such that the user can input a length of the first time period.

8. The battery charging system of claim 1, wherein the first energy stored level is 80% of full stored energy.

9. The battery charging system of claim 1, wherein the second energy stored level is 90% of full stored energy.

10. The battery charging system of claim 1, wherein the charging cost circuit receives a municipal charging cost rate from a power network and estimates the charging cost rate based on the municipal charging cost rate.

11. A method of charging a battery within an electric vehicle utilizing a battery charging system, the method comprising the steps of:

estimating cost rates for at least a first time period and a second time period, wherein said first time period precedes said second time period, wherein an estimated cost rate for said first time period is less than said estimated cost rate for said second time period, and wherein a charging stop time is anticipated to occur within said second time period;

initiating battery charging within said first time period;

pausing battery charging within said first time period whenever a measured cost rate exceeds said estimated cost rate for said first time period;

terminating battery charging within said first time period only after said battery reaches a first state of charge;

initiating battery charging within said second time period; and

terminating battery charging within said second time period after said battery reaches a second state of charge, wherein said second state of charge is greater than said first state of charge.

12. The method of claim 11, further comprising the step of decoupling said electric vehicle from a battery charging power source during said second time period.

13. The method of claim 12, wherein said decoupling step causes said charging stop time to be reached.

14. The method of claim 12, wherein said decoupling step occurs prior to said battery reaching said second state of charge.

15. The method of claim 11, further comprising the step of programming said charging stop time within said battery charging system.

16. The method of claim 15, further comprising the step of determining a start time for performing said step of initiating battery charging within said second time period, wherein said start time is selected to allow said second state of charge to be reached prior to occurrence of said charging stop time.

17. The method of claim 11, further comprising the steps of:

monitoring a daily charging system termination time; and

estimating said charging stop time based on results of said monitoring step.

18. The method of claim 17, further comprising the step of determining a start time for performing said step of initiating battery charging within said second time period, wherein said start time is selected to allow said second state of charge to be reached prior to occurrence of said charging stop time.

19. The method of claim 11, further comprising the step of setting said first state of charge to 80% of full state of charge.

20. The method of claim 11, further comprising the step of setting said second state of charge to 90% of full state of charge.

21. The method of claim 11, further comprising the step of obtaining a municipal charging cost rate from a power network, wherein said obtaining step is performed by said battery charging system.

22. The method of claim 11, further comprising the step of determining a start time for performing said step of initiating battery charging within said second time period, wherein said start time is selected to allow said second state of charge to be reached prior to occurrence of said charging stop time.

23. The method of claim 11, further comprising the steps of inputting said first time period, said second time period, and said estimated cost rates for said first and second time periods.

24. The method of claim 11, further comprising the step of overriding said battery charging system to prevent performance of said step of initiating battery charging within said second time period.