Battery charging time optimization system

• US 7,928,699 B2
• Filed: 11/05/2009
• Issued: 04/19/2011
• Est. Priority Date: 11/05/2009
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Tesla Motors Incorporated (Tesla Inc.)
• Inventors: Kohn, Scott Ira
• Primary Examiner(s): Tso; Edward
• Assistant Examiner(s): RAMADAN, RAMY O
• Application Number:
  US12/612,770
• Publication Number:
  US 20100134073A1
• Time in Patent Office: 530 Days
• Field of Search: 320/150, 320/152
• US Class Current: 320/150
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: H02J 7/0068 Battery or charger load switching, e.g. concurrent charging and load supply H02J7/0013 takes precedence
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y10S 320/11 Prioritized supply of power or power supply compensation

Abstract

A system for optimizing battery pack charging is provided. In this system, during charging the coupling of auxiliary systems (e.g., battery cooling systems) to the external power source are delayed so that the battery pack charge rate may be optimized, limited only by the available power. Once surplus power is available, for example as the requirements of the charging system decrease, the auxiliary system or systems may be coupled to the external power source without degrading the performance of the charging system.

Claims

1. A method for optimizing the charging cycle of a battery pack of an electric vehicle, the method comprising the steps of:

electrically connecting an external power source to a power control subsystem of said electric vehicle;

monitoring at least one operating condition of said battery pack;

periodically determining a set of optimal charging requirements of said battery pack;

monitoring at least one performance parameter corresponding to an electric vehicle auxiliary system;

comparing said at least one performance parameter corresponding to said electric vehicle auxiliary system to a preset value;

periodically determining a set of minimum power requirements of said electric vehicle auxiliary system based on an output of said comparing step;

periodically determining a set of optimal power requirements of said electric vehicle auxiliary system based on said at least one performance parameter;

determining a maximum available power obtainable from said external power source coupled to said electric vehicle;

determining an optimal power split by weighing said set of optimal charging requirements against said set of minimal power requirements of said electric vehicle auxiliary system and against said set of optimal power requirements of said electric vehicle, wherein a first priority is given to said set of minimum power requirements of said electric vehicle auxiliary system, wherein a second priority is given to said set of optimal charging requirements, and wherein a third priority is given to said set of optimal power requirements of said electric vehicle auxiliary system, wherein said first priority is higher than said second and third priorities, and wherein said second priority is higher than said third priority; and

distributing said maximum available power to a charging system coupled to said battery pack and to said electric vehicle auxiliary system in accordance with said optimal power split.

2. The method of claim 1, wherein said steps of determining said optimal split and distributing said maximum available power are performed periodically while said external power source is coupled to said electric vehicle.

3. The method of claim 1, wherein said at least one operating condition of said battery pack is state-of-charge.

4. The method of claim 1, wherein said electric vehicle auxiliary system is a battery pack thermal management system and wherein said at least one performance parameter corresponding to said electric vehicle auxiliary system is a temperature corresponding to said battery pack.