Power tool system and method for controlling power tool system

Patent metadata

Field	Value
Publication number	US-11095142-B2
Application number	US-201916284480-A
Country	US
Kind code	B2
Filing date	Feb 25, 2019
Priority date	Sep 13, 2016
Publication date	Aug 17, 2021
Grant date	Aug 17, 2021

Abstract

A battery pack of a power tool includes a plurality of cells connected in series, a controller, which is configured to detect a charge current and/or a discharge current of the plurality of cells, estimate remaining capacity of the plurality of cells at least base on an integral of the charge current and/or the discharge current of the plurality of cells over time and generate or select a power supply capability parameter for limiting power of the power tool at least base on the remaining capacity of the plurality of cells, and a memory, which is configured to store data related to the remaining capacity of the plurality of cells.

First claim

What is claimed is:

1. A battery pack of a power tool, comprising:
a plurality of cells connected in series;
a controller configured to:
detect a charge current and a discharge current of the plurality of cells;
estimate a charge capacity of the battery pack at least based on an integral of the charge current of the plurality of cells over time;
select a charge-discharge coefficient related to the discharge current of the plurality of cells at least based on one or more of the discharge current of the plurality of cells, charge times, discharge times, total charge duration, total discharge duration, temperature of the plurality of cells and an internal resistance of the plurality of cells during discharging of the plurality of cells;
estimate dischargeable capacity of the battery pack based on the charge capacity and the charge-discharge coefficient; and
estimate a power supply capability parameter of the battery pack based on the dischargeable capacity; and

a memory configured to store data of the charge-discharge coefficient and data of a correspondence between the charge-discharge coefficient and one or more of the discharge current of the plurality of cells, charge times, the discharge times, the total charge duration and, the total discharge duration, temperature of the plurality of cells and an internal resistance of the plurality of cells during discharging of the plurality of cell.

2. The battery pack according to claim 1 , wherein the battery pack further comprises a timer configured to periodically activate the controller to correct a remaining capacity of the battery pack.

3. The battery pack according to claim 1 , wherein the battery pack further comprises a timer configured to activate the controller to correct a remaining capacity of the battery pack at a preset moment after the battery pack has been charged.

4. The battery pack according to claim 1 , wherein the battery pack further comprises a wireless communication module configured to wirelessly transfer data stored in the memory.

5. The battery pack according to claim 1 , wherein the battery pack further comprises a safety switch, disposed between a battery pack positive terminal and the battery pack, configured to turn on or turn off the connection between the battery pack positive terminal and the plurality of cells under the control of the controller.

6. The battery pack according to claim 1 , wherein the battery pack further comprises a current sensing resistor configured to detect a current passing through the plurality of cells.

7. A battery pack of a power tool, comprising:
a plurality of cells connected in series;
a memory configured to store data; and
a controller configured to:
detect a voltage of the plurality of cells;
detect a charge current and/or a discharge current of the plurality of cells;
estimate remaining capacity of the plurality of cells at least based on an integral of the charge current and/or the discharge current of the plurality of cells over time;
write a locking mark into the controller when a slope of the remaining capacity of the plurality of cells is less than a preset slope value or the remaining capacity of the plurality of cells is less than a preset capacity value, wherein the locking mark is read by the controller in a next charge or discharge control; and
lock the battery pack to disenable the battery pack to be charged or discharged after the locking mark is read.

8. The battery pack according to claim 7 , wherein the controller clears the locking mark in the memory when remaining capacity of the battery pack is greater than the preset capacity value.

9. The battery pack according to claim 7 , wherein the battery pack further comprises a timer configured to activate the controller to correct a remaining capacity of the battery pack at a preset moment after the battery pack has been charged.

10. The battery pack according to claim 7 , wherein the battery pack further comprises a wireless communication module configured to wirelessly transfer data stored in the memory.

11. The battery pack according to claim 7 , wherein the battery pack further comprises a safety switch, disposed between a battery pack positive terminal and the battery pack, configured to turn on or turn off the connection between the battery pack positive terminal and the plurality of cells under the control of the controller.

12. The battery pack according to claim 7 , wherein the battery pack further comprises a current sensing resistor configured to detect a current passing through the plurality of cells.

13. A power tool system, comprising:
a battery pack comprising:
a plurality of cells connected in series; and
a battery pack controller configured to:
detect a voltage of the plurality of cells and/or a voltage of the battery pack;
detect a charge current and/or a discharge current of the plurality of cells;
estimate remaining capacity of the battery pack at least based on an integral of the charge current and/or the discharge current of the plurality of cells over time;
estimate a discharge capability parameter of the battery pack at least based on the remaining capacity of the battery pack; and
estimate a maximum discharge current of the battery pack at least based on the voltage of the plurality of cells and/or the voltage of the battery pack;

a first tool host adapted to couple with the battery pack, comprising:
a first tool controller configured to:
communicate with the battery pack controller and transmitting data of the discharge capability parameter of the battery pack; and
control a current of a motor based on the discharge capability parameter of the battery pack; and

a second tool host adapted to couple with the battery pack, comprising:
a second tool controller configured to:
communicate with the battery pack controller and transmit data of the voltage of the plurality of cells and/or the voltage of the battery pack and data of the maximum discharge current; and
control the current of the motor based on the maximum discharge current and the voltage of the plurality of cells and/or the voltage of the battery pack.

14. The power tool system according to claim 13 , wherein the battery pack further comprises a timer configured to activate the controller to correct a remaining capacity of the battery pack at a preset moment after the battery pack has been charged.

15. The power tool system according to claim 13 , wherein the battery pack further comprises a wireless communication module configured to wirelessly transfer data stored in the memory.

16. The power tool system according to claim 13 , wherein the battery pack further comprises a safety switch, disposed between a battery pack positive terminal and the battery pack, configured to turn on or turn off the connection between the battery pack positive terminal and the plurality of cells under the control of the controller.

17. The power tool system according to claim 13 , wherein the battery pack further comprises a current sensing resistor configured to detect a current passing through the plurality of cells.

Assignees

• Nanjing Chervon Ind Co Ltd

Inventors

• Geng Zheng
• Yang Dezhong

Classifications

• H02J7/82

  Control of state of charge [SOC] · CPC title

• H02J7/947

  in response to integrated charge or discharge current · CPC title

• H02J7/485

  with provisions for charging different types of batteries · CPC title

• H02J7/94

  in response to battery current · CPC title

• H02J7/63

  against overdischarge · CPC title