Low temperature fast charge

• US 8,901,885 B2
• Filed: 03/09/2012
• Issued: 12/02/2014
• Est. Priority Date: 03/09/2012
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Tesla Motors Incorporated (Tesla Inc.)
• Inventors: Kelty, Kurt Russell, Kishiyama, Clay Hajime, Stewart, Sarah G.
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US13/416,251
• Publication Number:
  US 20130234648A1
• Time in Patent Office: 998 Days
• Field of Search: 320/107, 320/116, 320/118, 320/119, 320/125, 320/150, 320/160
• US Class Current: 320/116
• CPC Class Codes: B60L 1/02 to electric heating circuits
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 2240/662 Temperature
• CPC Class Codes: B60L 53/00 Methods of charging batteries, specially adapted for electric vehicles; Charging stations or on-board charging equipment therefor; Exchange of energy storage elements in electric vehicles
• CPC Class Codes: B60L 53/11 DC charging controlled by the charging station, e.g. mode 4
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: B60L 58/27 by heating
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/007194 of the battery
• 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 10/72 Electric energy management in electromobility
• 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

Abstract

An automated charge preparation method periodically determines critical parameters for the set of relevant operating conditions, determines whether fast charging is possible, applies fast charging when possible, otherwise applies a dynamically scaled charging rate that is optimized based upon current critical parameters (while optionally heating the individual battery cells as long as fast charging is not available) to reduce/eliminate a risk of lithium-plating.

Claims

1. An automated charge preparation method for a plurality of intercoupled energy storage elements having a risk responsive to application of a first charging process to the plurality of intercoupled energy storage elements under a set of predefined conditions, the method comprising the steps of:

(a) determining periodically, using a microprocessor, a periodic set of critical parameters for the set of predefined conditions of the plurality of intercoupled energy storage elements;

(b) determining periodically, using the microprocessor and responsive to an evaluation of said periodic set of critical parameters, whether the first charging process may be applied to the plurality of intercoupled energy storage elements without the risk; and

thereafter

(c) charging the plurality of intercoupled energy storage elements using the first charging process whenever said determining step b) determines that the first charging process may be applied to the plurality of intercoupled energy storage elements without the risk; and

(d) charging the plurality of intercoupled energy storage elements using a second charging process that may be applied to the plurality of intercoupled energy storage elements without the risk whenever said determining step b) does not determine that the first charging process may be applied to the plurality of intercoupled energy storage elements without the risk;

(e) modifying said periodic set of critical parameters to increase said second energy transfer rate by operating on the plurality of energy storage cells during said charging step (d)

wherein said second charging process has a second energy transfer rate slower than a first energy transfer rate associated with the first charging process; and

wherein said second charging process dynamically scales said second energy transfer rate responsive to said periodic set of critical parameters.

2. The automated charge preparation method of claim 1 wherein the risk includes lithium-plating and wherein the set of predefined conditions include both a state of charge (SOC) and a temperature of one or more elements of the plurality of energy storage elements.

3. The automated charge preparation method of claim 1 wherein a temperature control system is coupled to the plurality of energy storage elements and wherein said modifying step (e) includes heating the plurality of energy storage elements using said temperature control system.

4. The automated charge preparation method of claim 1 further comprising the steps of:

f) establishing a cell history for the plurality of intercoupled energy storage elements; and

g) adjusting said energy transfer rates responsive to said cell history.

5. The automated charge preparation method of claim 1 wherein said determining step (b) includes accessing a memory, responsive to a current one set of said periodic sets of critical parameters, to retrieve an optimum riskless energy transfer rate and wherein said charging step (d) includes setting said second energy transfer rate equal to said optimum riskless energy transfer rate.

6. The automated charge preparation method of claim 5 further comprising the steps of:

f) establishing a cell history for the plurality of intercoupled energy storage elements; and

g) adjusting said energy transfer rates responsive to said cell history.

7. An automated charge preparation method for a plurality of intercoupled energy storage elements having a risk responsive to application of a first charging process to the plurality of intercoupled energy storage elements under a set of predefined conditions, the method comprising the steps of:

(a) determining periodically, using a microprocessor, a periodic set of critical parameters for the set of predefined conditions of the plurality of intercoupled energy storage elements;

(b) determining periodically, using the microprocessor and responsive to an evaluation of said periodic set of critical parameters, whether the first charging process may be applied to the plurality of intercoupled energy storage elements without the risk; and

thereafter

(c) charging the plurality of intercoupled energy storage elements using the first charging process whenever said determining step b) determines that the first charging process may be applied to the plurality of intercoupled energy storage elements without the risk;

(d) charging the plurality of intercoupled energy storage elements using a second charging process that may be applied to the plurality of intercoupled energy storage elements without the risk whenever said determining step b) does not determine that the first charging process may be applied to the plurality of intercoupled energy storage elements without the risk;

e) establishing a cell history for the plurality of intercoupled energy storage elements; and

f) adjusting said energy transfer rates responsive to said cell history;

wherein said second charging process has a second energy transfer rate slower than a first energy transfer rate associated with the first charging process; and

wherein said second charging process dynamically scales said second energy transfer rate responsive to said periodic set of critical parameters.

8. An automated charge preparation apparatus charging a plurality of intercoupled energy storage elements having a risk responsive to application of a first charging process to the plurality of intercoupled energy storage elements under a set of predefined conditions comprising:

a critical parameter acquisition system determining a periodic set of critical parameters for the set of predefined conditions of the plurality of intercoupled energy storage elements;

a controller evaluating said periodic set of critical parameters and determining, responsive to said evaluation, whether the first charging process may be applied to the plurality of intercoupled energy storage elements without the risk;

a charging system, coupled to the plurality of intercoupled energy storage elements, charging the plurality of intercoupled energy storage elements using the first charging process whenever said controller determines that the first charging process may be applied to the plurality of intercoupled energy storage elements without the risk;

otherwise charging the plurality of intercoupled energy storage elements using a second charging process that may be applied to the plurality of intercoupled energy storage elements without the risk whenever said controller does not determine that the first charging process may be applied to the plurality of intercoupled energy storage elements without the risk; and

a temperature control system coupled to the plurality of energy storage elements;

wherein said controller operates said temperature control system to heat the plurality of energy storage elements whenever said second charging process is applied to the plurality of energy storage elements;

wherein said second charging process has a second energy transfer rate slower than a first energy transfer rate associated with the first charging process; and

wherein said controller dynamically scales said second energy transfer rate responsive to said periodic set of critical parameters.

9. The automated charge preparation apparatus of claim 8 wherein the risk includes lithium-plating, wherein the set of predefined conditions include both a state of charge (SOC) and a temperature of one or more elements of the plurality of energy storage elements, and wherein said critical parameter acquisition system includes one or more temperature sensors coupled to the plurality of energy storage elements.

10. The automated charge preparation apparatus of claim 8 wherein said controller further comprises a memory storing data relating specific values for said periodic sets of critical parameters to an optimum riskless energy transfer rate for the specific values;

wherein said controller accesses said memory, responsive to a current one set of said periodic sets of critical parameters, to retrieve said optimum riskless energy transfer rate for the specific values and wherein said controller sets said second energy transfer rate equal to said optimum riskless energy transfer rate.

11. The automated charge preparation apparatus of claim 8 wherein said controller establishes a cell history for the plurality of intercoupled energy storage elements;

and adjusts said energy transfer rates responsive to said cell history.

12. The automated charge preparation apparatus of claim 10 wherein said controller establishes a cell history for the plurality of intercoupled energy storage elements and adjusts said energy transfer rates responsive to said cell history.

13. An automated charge preparation apparatus charging a plurality of intercoupled energy storage elements having a risk responsive to application of a first charging process to the plurality of intercoupled energy storage elements under a set of predefined conditions comprising:

a critical parameter acquisition system determining a periodic set of critical parameters for the set of predefined conditions of the plurality of intercoupled energy storage elements;

a controller evaluating said periodic set of critical parameters and determining, responsive to said evaluation, whether the first charging process may be applied to the plurality of intercoupled energy storage elements without the risk;

a charging system, coupled to the plurality of intercoupled energy storage elements, charging the plurality of intercoupled energy storage elements using the first charging process whenever said controller determines that the first charging process may be applied to the plurality of intercoupled energy storage elements without the risk;

otherwise charging the plurality of intercoupled energy storage elements using a second charging process that may be applied to the plurality of intercoupled energy storage elements without the risk whenever said controller does not determine that the first charging process may be applied to the plurality of intercoupled energy storage elements without the risk; and

wherein said second charging process has a second energy transfer rate slower than a first energy transfer rate associated with the first charging process;

wherein said controller dynamically scales said second energy transfer rate responsive to said periodic set of critical parameters; and

wherein said controller establishes a cell history for the plurality of intercoupled energy storage elements and adjusts said energy transfer rates responsive to said cell history.