BATTERY PACK, METHOD FOR DETECTING BATTERY PACK, CHARGING ASSEMBLY AND ELECTRIC TOOL

• US 20150185289A1
• Filed: 12/26/2014
• Published: 07/02/2015
• Est. Priority Date: 12/31/2013
• Status: Active Grant

• Current Assignee: Chervon (HK) Limited (Chervon Holdings Limited)
• Original Assignee: Chervon Intellectual Property Limited (Chervon Holdings Limited)
• Inventors: Yang, Dezhong, Shi, Pingbo, Liu, Lei, Duan, Junya, Geng, Zheng, Wang, Lei, Xiang, Yingdian
• Granted Patent: US 9,726,731 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: G01R 31/3835 involving only voltage measurements
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: G01R 31/54 Testing for continuity
• CPC Class Codes: G01R 31/68 Testing of releasable connections, e.g. of terminals mounted on a printed circuit board
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery pack, a method for detecting the battery pack, a charging assembly, and an electric tool are provided for detecting voltage and disconnection of the battery cells. The battery pack may have an output voltage of at least 56V and may include a plurality of series connection units. A voltage detecting module may be utilized for detecting voltage in the battery pack. A battery control module configured to control voltage detecting module may also be employed. The method may involve determining whether the series connection units are disconnected based on rates of voltage change or internal-resistance of the series connection units.

Claims

1. A battery pack comprising:

a plurality of series connection units forming a series connection;

a voltage detecting module configured to detect a voltage signal of a high-voltage side of each of the plurality of series connection units; and

a battery control module configured to receive the voltage signal detected by the voltage detecting module and determine a voltage of each of the plurality of series connection units;

wherein each of the plurality of series connection units comprises a plurality of battery cells, wherein the plurality of battery cells in each of the plurality of series connection units are connected in parallel;

wherein the battery control module is capable of determining whether the plurality of battery cells in each of the plurality of series connection units has been disconnected based on the voltage of each of the plurality of series connection units.

2. The battery pack of claim 1 wherein the battery control module comprises a disconnection detecting module configured to determine whether the plurality of battery cells in each of plurality of series connection units has been disconnected based on a relationship between time and the voltage of each of the plurality of series connection units.

3. The battery pack of claim 2 wherein the disconnection detecting module comprises:

a time calculating means for providing time data;

a slope calculation means configured to determine a slope of the voltage of each of the plurality of series connection units relative to the time data; and

a determining means configured to determine whether the plurality of battery cells in each of the plurality of series connection units has been disconnected based on the slope of each of the plurality of series connection units.

4. The battery pack of claim 1 wherein the battery control module comprises a disconnection detecting module configured to determine whether the plurality of battery cells in each of the plurality of series connection units has been disconnected based on an internal-resistance of each of the plurality of series connection units.

5. The battery pack of claim 4 wherein the disconnection detecting module comprises:

a current detecting means configured to detect a current of each of the plurality of series connection units;

an internal-resistance calculation means configured to determine the internal-resistance of each of the plurality of series connection units based on the voltage and the current of each of the plurality of series connection units; and

a determining means configured to determine whether the plurality of battery cells in each of the plurality of series connection units has been disconnected based on the internal-resistance of each of the plurality of series connection units.

6. A battery pack comprising:

a plurality of series connection units forming a series connection, each of the plurality of series connection units comprising a plurality of battery cells, wherein the plurality of battery cells in each of the plurality of series connection units are connected in parallel;

a voltage detecting module configured to detect a voltage signal of a high-voltage side of each of the plurality of series connection units;

a battery control module configured to receive the voltage signal detected by the voltage detecting module and determine a voltage of each of the plurality of series connection units; and

a disconnection detecting module configured to determine whether the plurality of battery cells in each of the plurality of series connection units has been disconnected based on the voltage of each of the plurality of series connection units.

7. The battery pack of claim 6, wherein the disconnection detecting module comprises:

a time calculating means for providing time data;

a slope calculation means configured to determine a slope of the voltage of each of the plurality of series connection units relative to the time data; and

a determining means configured to determine whether the plurality of battery cells in each of the plurality of series connection units has been disconnected based on the slope of each of the plurality of series connection units.

8. The battery pack of claim 6 wherein the disconnection detecting module comprises:

a current detecting means configured to determine a current of each of the plurality of series connection units;

an internal-resistance calculation means configured to determine an internal-resistance of each of the plurality of series connection units based on the voltage and the current of each of the plurality of series connection units; and

a determining means configured to determine whether the plurality of battery cells in each of the plurality of series connection units has been disconnected based on the internal-resistance of each of the plurality of series connection units.

9. A charging assembly comprising a battery pack and a charger for charging the battery pack, the charging assembly comprising:

a battery pack that comprises a plurality of series connection units forming a series connection, each of the plurality of series connection units comprising a plurality of battery cells connected in parallel;

a voltage detecting module configured to detect a voltage signal of a high-voltage side of each of the plurality of series connection units;

a battery control module configured to receive the voltage signal detected by the voltage detecting module and determine a voltage of each of the plurality of series connection units; and

a disconnection detecting module configured to determine whether the plurality of battery cells in each of the plurality of series connection units has been disconnected based on the voltage of each of the plurality of series connection units.

10. An electric tool comprising an electric device and a battery pack, the battery pack powering the electric device, the battery pack comprising a plurality of series connection units forming a series connection, each of the plurality of series connection units comprising a plurality of battery cells connected in parallel, the electric tool further comprising:

a voltage detecting module configured to detect a voltage signal of a high-voltage side of each of the plurality of series connection units;

a battery control module configured to receive the voltage signal detected by the voltage detecting module and determine a voltage of each of the plurality of series connection units; and

a disconnection detecting module configured to determine whether the plurality of battery cells in each of the plurality of series connection units has been disconnected based on the voltage of each of the plurality of series connection units.

11. A disconnection detecting method for detecting whether a conductor is disconnected from a plurality of battery cells connected in parallel in a battery pack, the battery pack comprising a plurality of series connection units forming a series connection, wherein each of the plurality of series connection units comprises a plurality of battery cells connected in parallel, the disconnection detecting method comprising:

detecting a voltage signal of a high-voltage side of each of the plurality of series connection units;

determining a slope for each of the plurality of series connection units based on a voltage of each of the plurality of series connection units relative to time; and

determining whether the plurality of battery cells in each of the plurality of series connection units has been disconnected based on the slope of each of the plurality of series connection units.

12. A disconnection detecting method for detecting whether a conductor is disconnected from a plurality of battery cells connected in parallel of a battery pack, the battery pack comprising a plurality of series connection units forming a series connection, wherein each of the plurality of series connection units comprises a plurality of battery cells connected in parallel, the disconnection detecting method comprising:

detecting a voltage signal of a high-voltage side of each of the plurality of series connection units;

determining an internal-resistance of each of the plurality of series connection units; and

determining whether the plurality of battery cells in each of the plurality of series connection units has been disconnected based on the internal-resistance of each of the plurality of series connection units.

13. A battery pack having comprising:

a plurality of series connection units forming a series connection;

a voltage detecting module configured to detect a voltage signal of a high-voltage side of each of the plurality of series connection units; and

a battery control module configured to receive the voltage signal detected by the voltage detecting module and determine a voltage of each of the plurality of series connection units;

wherein each of the plurality of series connection units comprises a plurality of battery cells, the plurality of battery cells in each of the plurality of series connection units being connected in parallel, and

wherein the voltage detecting module is electrically connected with the plurality of battery cells.

14. The battery pack of claim 13 wherein the voltage detecting module comprises:

a detecting circuit having a first end connected to the high-voltage side of one of the plurality of series connection units and a second end connected to the battery control module;

wherein the battery control module detects the voltage signal of the high-voltage side of each of the plurality of series connection units via a plurality of detecting circuits in a time-division manner.

15. The battery pack of claim 14 wherein the detecting circuit comprises a voltage-apportionment resistor for stabilizing the voltage signal received by the battery control module in a preset range.

16. The battery pack of claim 14 wherein the voltage detecting module further comprises:

a time-division module configured to control at least two of the plurality of detecting circuits,

wherein the battery control module, via the time-division module, enables the plurality of detecting circuits controlled by the battery control module to operate in the time-division manner.

17. The battery pack of claim 16, wherein the detecting circuit comprises:

a switch means controlled by the time-division module for turning the plurality of detecting circuits on/off, the switch means comprising two connection terminals enabling the switch means to connect with the plurality of detecting circuits, the switch means further comprising a control terminal for receiving a signal of the time-division module and controlling switching between on/off states of the two connection terminals,

wherein each of the two connection terminals comprise a detecting terminal connected to the high-voltage side of each of the plurality of series connection units, each of the two connection terminals further comprising an output terminal connected to the battery control module.

18. The battery pack of claim 14 wherein the battery control module comprises:

a first microcontroller configured to receive the voltage signals of a first portion of the detecting circuits; and

a second microcontroller configured to receive the voltage signals of a second portion of the detecting circuits,

wherein the voltage detecting module comprises;

a first time-division module configured to control the first portion of the plurality of detecting circuits by sending the voltage signal to the first microcontroller to be operated in a conducting state in the time-division manner; and

a second time-division module configured to control the second portion of the plurality of detecting circuits by sending the voltage signal to the second microcontroller to be operated in the conducting state in the time-division manner,

wherein the first microcontroller controls the first time-division module and the second microcontroller controls the second time-division module and transfers data to the first microcontroller.

19. The battery pack of claim 18, wherein each of the first portion of the plurality of detecting circuits sending the voltage signal to the first microcontroller is connected to the high-voltage side of the plurality of series connection units that are adjacent thereto, wherein each of the second portion of the plurality of detecting circuits sending the voltage signal to the second microcontroller is connected to the high-voltage side of the plurality of series connection units that are adjacent thereto.

20. The battery pack of claim 19, wherein a number of the plurality of detecting circuits controlled by the first microcontroller is equal to a number of the plurality of detecting circuits controlled by the second microcontroller.