Battery management system

Patent metadata

Field	Value
Publication number	US-11721995-B2
Application number	US-202017035178-A
Country	US
Kind code	B2
Filing date	Sep 28, 2020
Priority date	Dec 17, 2014
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

A method of discharging a battery assembly used to power at least part of an object includes detecting when power to the object is turned off, detecting, with aid of a timer, an amount of time elapsed since the power to the object is turned off, and initiating a controlled self-discharge of the battery assembly when the amount of time exceeds a threshold length of time. The controlled self-discharge of the battery assembly is performed by a self-discharging circuit electrically coupled to the battery assembly.

First claim

What is claimed is:

1. A method of discharging a battery assembly used to power at least part of an object, the method comprising:
detecting, with aid of one or more processors, when power to the object is turned off;
detecting, with aid of a timer, an amount of time elapsed since the power to the object is turned off;
initiating, with aid of the one or more processors, a controlled self-discharge of the battery assembly when the amount of time exceeds a threshold length of time, wherein the controlled self-discharge of the battery assembly is performed by a self-discharging circuit electrically coupled to the battery assembly;
terminating, with aid of the one or more processors, the controlled self-discharge of the battery assembly when the voltage reaches a threshold voltage value; and
controlling, with aid of the one or more processors, the battery assembly to enter a hibernation mode subsequent to terminating the controlled self-discharge of the battery assembly, wherein the hibernation mode is a low power consumption mode monitoring whether the battery assembly is in use again.

2. The method of claim 1 , further comprising detecting a voltage of the battery assembly during the controlled self-discharge of the battery assembly.

3. The method of claim 1 , wherein the threshold voltage value is about 50% of a nominal voltage of the battery assembly.

4. The method of claim 3 , wherein the threshold voltage value is about 38V.

5. The method of claim 1 , wherein the threshold voltage is configured to enable safe long-term storage of the battery assembly.

6. The method of claim 1 , further comprising detecting when the power to the object is turned on.

7. The method of claim 6 , further comprising terminating the controlled self-discharge of the battery assembly when the power to the object is turned on.

8. The method of claim 1 , further comprising detecting if the battery assembly powers the at least the part of the object.

9. The method of claim 8 , further comprising terminating the controlled self-discharge of the battery assembly if the battery assembly powers the at least the part of the object.

10. The method of claim 1 , wherein the self-discharging circuit comprises a self-discharging resistor and a control switch connected in parallel with positive and negative terminals of the battery assembly.

11. The method of claim 10 , wherein the controlled self-discharge is initiated when the control switch is switched to a closed state and is terminated when the control switch is switched to an open state.

12. The method of claim 1 , wherein the battery assembly comprises a plurality of battery cells.

13. The method of claim 1 , wherein the battery assembly comprises only a single battery cell.

14. The method of claim 1 , wherein the object is a movable object.

15. The method of claim 14 , wherein the movable object is an unmanned aerial vehicle (UAV).

16. The method of claim 15 , wherein the battery assembly is onboard the UAV.

17. The method of claim 15 , wherein the battery assembly is used to power a propulsion system of the UAV.

18. The method of claim 1 , wherein the battery assembly is within a housing of the object.

19. The method of claim 1 , wherein a voltage of the battery assembly is controlled to be decreased at a constant decreasing speed during the controlled self-discharge of the battery assembly.

Assignees

• Sz Dji Technology Co Ltd

Inventors

• Zhao Tao
• Zhan Juncheng
• Liu Yuancai
• Wang Lei
• Wang Wentao

Classifications

• H02J7/585

  Sequential battery discharge in systems with a plurality of batteries · CPC title

• H02J7/94

  in response to battery current · CPC title

• H02J7/54

  Passive balancing, e.g. using resistors or parallel MOSFETs · CPC title

• H02J7/96

  in response to battery voltage · CPC title

• H02J7/60

  including safety or protection arrangements · CPC title