Electric vehicle battery lifetime optimization operational mode

• US 8,970,173 B2
• Filed: 02/28/2012
• Issued: 03/03/2015
• Est. Priority Date: 02/28/2012
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Tesla Motors Incorporated (Tesla Inc.)
• Inventors: Kelty, Kurt Russell, Hermann, Weston Arthur, Kohn, Scott Ira, Kishiyama, Clay Hajime, Mehta, Vineet Haresh, Stewart, Sarah G.
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US13/407,573
• Publication Number:
  US 20130221928A1
• Time in Patent Office: 1,099 Days
• Field of Search: 320/109, 320/132, 320/149, 320/150
• US Class Current: 320/132
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• CPC Class Codes: B60L 58/16 responding to battery ageing, e.g. to the number of charging cycles or the state of health [SoH]
• CPC Class Codes: B60L 58/24 for controlling the temperature of batteries
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

A method of setting the operational mode of an electric vehicle is provided, where the operational mode is selected from a plurality of operational modes that include at least a Battery Life mode and a Standard mode, wherein the Battery Life mode is configured to select operating and charging parameters that emphasize battery health and battery life over vehicle range and/or vehicle performance. The system includes a thermal management system for maintaining the vehicle'"'"'s battery pack to within any of a plurality of temperature ranges, and a charging system for charging the vehicle'"'"'s battery pack to any of a plurality of minimum and maximum SOC levels and at any of a plurality of charging rates.

Claims

1. A method of setting an operational mode of an electric vehicle, the method comprising the steps of:

displaying a plurality of user accessible operational modes, wherein a first mode of said plurality of user accessible operational modes is a Battery Life mode and a second mode of said plurality of user accessible operational modes is a Standard mode;

providing a selection means for a user to select a preferred mode of said plurality of user accessible operational modes;

displaying an indicator of said preferred mode selected by said user;

adjusting a charging maximum state-of-charge (SOC) level for a battery pack of said electric vehicle to a first maximum SOC level when said Battery Life mode is selected and to a second maximum SOC level when said Standard mode is selected, wherein said first maximum SOC level is at least 10% lower than said second maximum SOC level;

adjusting a maximum charge rate for said battery pack to a first maximum charge rate when said Battery Life mode is selected and to a second maximum charge rate when said Standard mode is selected, wherein said second maximum charge rate is higher than said first maximum charge rate; and

adjusting a maximum discharge rate for said battery pack to a first maximum discharge rate when said Battery Life mode is selected and to a second maximum discharge rate when said Standard mode is selected, wherein said second maximum discharge rate is higher than said first maximum discharge rate.

2. The method of claim 1, further comprising the steps of setting said first maximum SOC level to 60% or less, setting said first maximum charge rate to C/20 or less, and setting said first maximum discharge rate to 1 C or less.

3. The method of claim 1, further comprising the step of adjusting a minimum SOC level to a first level when said Battery Life mode is selected and to a second level when said Standard mode is selected, wherein said first level is at least 5% higher than said second level.

4. The method of claim 1, further comprising the step of adjusting a minimum SOC level to a first level when said Battery Life mode is selected and to a second level when said Standard mode is selected, wherein said first level is at least 15% higher than said second level.

5. The method of claim 1, further comprising the step of setting a minimum loaded voltage to a preset level of approximately 3.0 volts when said Battery Life mode is selected.

6. The method of claim 1, further comprising the steps of maintaining a battery pack temperature corresponding to said battery pack of said electric vehicle to a first temperature within a first range of temperatures when said Battery Life mode is selected and said battery pack is discharging, and maintaining said battery pack temperature to a second temperature within a second range of temperatures when said Standard mode is selected and said battery pack is discharging, wherein said first range of temperatures is less than said second range of temperatures.

7. The method of claim 6, further comprising the steps of setting said first range of temperatures to 25°

C. to 30°

C., and setting said second range of temperatures to 30°

C. to 35°

C.

8. The method of claim 1, further comprising the steps of monitoring a battery pack temperature, wherein said step of adjusting said maximum charge rate for said battery pack to said first maximum charge rate when said Battery Life mode is selected further comprises the steps of setting said first maximum charge rate to C/20 or less if said battery pack temperature is above 10°

C. and to C/50 or less if said battery pack temperature is below 10°

C.

9. The method of claim 1, further comprising the steps of maintaining a thermal balance between a plurality of cells comprising said battery pack within a first preset limit when said Battery Life mode is selected and within a second preset limit when said Standard mode is selected, wherein said first preset limit is less than said second preset limit.

10. The method of claim 9, further comprising the steps of setting said second preset limit to approximately 10°

C. and setting said first preset limit to approximately 5°

C.

11. The method of claim 1, wherein during an extended charging cycle said method further comprises the steps of allowing said battery pack to self-discharge to a first minimum SOC level prior tore-initiating charging when said Battery Life mode is selected and to a second minimum SOC level prior tore-initiating charging when said Standard mode is selected, wherein said first minimum SOC level is at least 25% less than said second minimum SOC level.

12. The method of claim 11, further comprising the steps of setting said first minimum SOC level to at least 30% less than said first maximum SOC level.

13. The method of claim 11, wherein said selection means is selected from the group consisting of touch-screen displays, push-buttons, toggle switches, rotating switches, slide switches, voice recognition systems, RF remote mode selectors and remote mode selectors communicating with a vehicle communication interface via a network.