Battery pack and charging balancing method for the same

Patent metadata

Field	Value
Publication number	US-2021184473-A1
Application number	US-202017106814-A
Country	US
Kind code	A1
Filing date	Nov 30, 2020
Priority date	Dec 11, 2019
Publication date	Jun 17, 2021
Grant date	—

Abstract

Provided are a battery pack and a charging method for the same. The battery pack includes at least one cell set including multiple cells connected in series. The charging method includes detecting a temperature of the battery pack under a preset state and a voltage of each of the multiple cells, the preset state being a state in which a charging circuit is disconnected and the battery pack is inserted in a charger after the battery pack has been fully charged, calculating a voltage difference between at least two cells in the battery pack based on the voltage of each cell, and determining whether to activate a balancing operation based on the voltage difference and the temperature.

First claim

What is claimed is:

1 . A charging balancing method for a battery pack, the battery pack being configured to supply electrical energy for a power tool and comprising at least one cell set, the at least one cell set comprising a plurality of cells connected in series, the charging balancing method comprising:
detecting a temperature of the battery pack under a preset state and detecting a voltage of each of the plurality of cells, the preset state being a state in which a charging circuit is disconnected and the battery pack is inserted in a charger after the battery pack has been fully charged; calculating a voltage difference between at least two cells in the battery pack based on the voltage of each of the plurality of cells; and determining whether to activate a balancing operation based on the voltage difference and the temperature.

2 . The charging balancing method of claim 1 , wherein determining whether to activate the balancing operation based on the voltage difference and the temperature comprises activating the balancing operation when the voltage difference has an absolute value that is greater than or equal to a preset voltage value and the temperature of the battery pack satisfies a preset temperature value.

3 . The charging balancing method of claim 2 , wherein the preset voltage value lies in the range of 0 to 100 mV and the preset temperature value lies in the range of 30 to 55° C.

4 . The charging balancing method of claim 2 , wherein activating the balancing operation comprises performing a discharging operation on a cell having a relatively higher voltage than another cell in the at least two cells between which the voltage difference has an absolute value that is greater than or equal to the preset voltage value.

5 . A battery pack, comprising:
a voltage detection module configured to detect a voltage of each of a plurality of cells in the battery pack under a preset state; a temperature detection module configured to detect a temperature of the battery pack under the preset state; and a control module, electrically connected to the voltage detection module and the temperature detection module, configured to calculate a voltage difference between at least two cells in the battery pack based on the voltage of the each of the plurality of cells and determine whether to activate a balancing operation based on the voltage difference and the temperature.

6 . The battery pack of claim 5 , wherein the preset state is a state in which a charging circuit is disconnected and the battery pack is coupled to a charger after the battery pack has been fully charged.

7 . The battery pack of claim 5 , wherein the control module is configured to activate the balancing operation when the voltage difference is greater than or equal to a preset voltage value and the temperature of the battery pack satisfies a preset temperature value.

8 . The battery pack of claim 7 , wherein the preset voltage value lies in the range of 0 to 100 mV.

9 . The battery pack of claim 3 , wherein the preset temperature value lies in the range of 30 to 55° C.

10 . The battery pack of claim 5 , further comprising a discharging module connected in parallel with each of the plurality of cells, wherein the discharging module has a control end electrically connected to the control module, the discharging module is configured to perform a discharging operation on each of the plurality of cells, the discharging module comprises a switch and a resistor, a first end of the switch is electrically connected to a positive electrode of each of the plurality of cells, a second end of the switch is electrically connected to a first end of the resistor, a second end of the resistor is electrically connected to a negative electrode of the cell, and a third terminal of the switch is electrically connected to the control module.

11 . The battery pack of claim 10 , wherein the discharging module is configured to perform the discharging operation on a cell having a relatively higher voltage than another cell in the at least two cells between which the voltage different has an absolute value that is greater than or equal to the preset voltage value.

12 . A battery pack combination, comprising:
a battery pack; and a charger; wherein the battery pack comprises: a voltage detection module configured to detect a voltage of each of a plurality of cells in the battery pack under a preset state; a temperature detection module configured to detect a temperature of the battery pack under the preset state; and a control module, electrically connected to the voltage detection module and the temperature detection module, configured to calculate a voltage difference between at least two cells in the battery pack based on the voltage of the each of the plurality of cells and determine whether to activate a balancing operation based on the voltage difference and the temperature.

13 . A charging balancing method for a battery pack, the battery pack being configured to supply electrical energy for a power tool and comprising at least one cell set, the at least one cell set comprising a plurality of cells connected in series, the charging balancing method comprising:
detecting a temperature of the battery pack under a preset state and detecting a voltage of each of the plurality of cells, the preset state being a state in which a charging circuit is disconnected and the battery pack is inserted in a charger after the battery pack has been fully charged; after the battery pack has been fully charged, calculating a voltage difference between at least two cells in the battery pack based on the voltage of each of the plurality of cells; and determining whether to activate a balancing operation based on the voltage difference and the temperature.

14 . The charging balancing method of claim 9 , wherein determining whether to activate the balancing operation based on the voltage difference and the temperature comprises activating the balancing operation when the voltage difference has an absolute value that is greater than or equal to a preset voltage value and the temperature of the battery pack satisfies a preset temperature value.

15 . The charging balancing method of claim 10 , wherein the preset voltage value lies in the range of 0 to 100 mV and the preset temperature value lies in the range of 30 to 55° C.

16 . The charging balancing method of claim 9 , wherein activating the balancing operation comprises performing a discharging operation on a cell having a relatively higher voltage than another cell in the at least two cells between which the voltage difference has an absolute value that is greater than or equal to the preset voltage value.

Assignees

• Nanjing Chervon Ind Co Ltd

Inventors

• Geng Zheng

Classifications

• H02J7/977

  of the battery · CPC title

• H02J7/975

  in response to temperature · CPC title

• H02J7/965

  obtained with the battery disconnected from the charge or discharge circuit · CPC title

• H02J7/96

  in response to battery voltage · CPC title

• H02J7/80

  including monitoring or indicating arrangements · CPC title