Method and system for charging multi-cell lithium-based battery packs

• US 10,374,443 B2
• Filed: 06/25/2018
• Issued: 08/06/2019
• Est. Priority Date: 11/22/2002
• Status: Expired due to Term

• Current Assignee: Milwaukee Electric Tool Corporation (Techtronic Industries Company Limited)
• Original Assignee: Milwaukee Electric Tool Corporation (Techtronic Industries Company Limited)
• Inventors: Meyer, Gary D., Rosenbecker, Jay J., Glasgow, Kevin L., Johnson, Todd W., Scheucher, Karl F.
• Primary Examiner(s): Pacheco, Alexis B
• Application Number:
  US16/017,788
• Publication Number:
  US 20180309304A1
• Time in Patent Office: 407 Days
• Field of Search: 320119, 320116, 320117, 320121, 320125, 320126, 320127, 320130, 320135, 320134, 320136, 320137, 320106, 320101, 320110, 320114
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H02J 7/00036 Charger exchanging data with battery
• CPC Class Codes: H02J 7/00038 using passive battery identification means, e.g. resistors or capacitors identification by mechanical connections H02J7/0045
• CPC Class Codes: H02J 7/00047 with provisions for charging different types of batteries
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/0019 using switched or multiplexed charge circuits
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0036 using connection detecting circuits H02J7/0034 takes precedence
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• CPC Class Codes: H02J 7/0045 concerning the insertion or the connection of the batteries
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/007194 of the battery
• CPC Class Codes: H02J 7/04 : Regulation of charging current or voltage
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries

Abstract

A method and system for charging multi-cell lithium-based batteries. In some aspects, a battery charger includes a housing, at least one terminal to electrically connect to a battery pack supported by the housing, and a controller operable to provide a charging current to the battery pack through the at least one terminal. The battery pack includes a plurality of lithium-based battery cells, with each battery cell of the plurality of battery cells having an individual state of charge. The controller is operable to control the charging current being supplied to the battery pack at least in part based on the individual state of charge of at least one battery cell.

Claims

1. An electrical combination comprising:

a battery charger including a housing;

at least one terminal to electrically connect to a battery pack supported by the housing, the battery pack including a plurality of lithium-based battery cells, each battery cell of the plurality of battery cells having an individual state of charge; and

a controller operable to control the battery charger to supply a charging current to the battery pack through the at least one terminal, the controller being operable to control the charging current being supplied to the battery pack based at least in part on the individual state of charge of at least one battery cell, the controller being further operable to control the battery charger to supply the charging current to the battery pack by controlling the battery charger to supply the charging current in a plurality of pulses of charging current, the plurality of pulses each having a first period of time, in which the charging current is being supplied to the battery pack at a predefined amplitude, and a second period of time, in which the supply of charging current is suspended, the controller being operable to control the charging current being supplied to the battery pack by modifying the first period of time and controlling the second period of time to be constant.

2. The electrical combination as set forth in claim 1 wherein the controller is operable to modify the first period of time by shortening the first period of time.

3. The electrical combination as set forth in claim 1 wherein the controller is operable to receive the individual state of charge of each battery cell of the plurality of battery cells.

4. The electrical combination as set forth in claim 1 wherein the controller is located within the housing of the battery charger.

5. The electrical combination as set forth in claim 1 wherein the controller includes a first charging module and a second charging module, the first charging module operable to provide a first charging current to the battery pack and the second charging module operable to provide a second charging current to the battery pack.

6. The electrical combination as set forth in claim 5 wherein the first charging current and the second charging current differ in one of average current amplitude and duty-cycle.

7. The electrical combination as set forth in claim 6 wherein the first charging module includes a fast charge module.

8. The electrical combination as set forth in claim 7 wherein the first charging current includes a fast charge current.

9. A method of operating an electrical combination, the electrical combination including a battery charger including a housing, at least one terminal to electrically connect to a battery pack supported by the housing, the battery pack including a plurality of lithium-based battery cells, each battery cell of the plurality of battery cells having an individual state of charge, and a controller, the method comprising:

controlling, with the controller, the battery charger to supply a charging current to the battery pack through the at least one terminal, the controller being operable to control the charging current being supplied to the battery pack based at least in part on the individual state of charge of at least one battery cell; and

controlling, with the controller, the battery charger to supply the charging current to the battery pack by controlling the battery charger to supply the charging current in a plurality of pulses of charging current, the plurality of pulses each having a first period of time, in which the charging current is being supplied to the battery pack at a predefined amplitude, and a second period of time, in which the supply of charging current is suspended, controlling the battery charger to supply the charging current including modifying, with the controller, the first period of time and controlling, with the controller, the second period of time to be constant.

10. The method as set forth in claim 9 wherein the controller modifies the first period of time by shortening the first period of time.

11. The method as set forth in claim 9 wherein the controller receives the individual state of charge of each battery cell of the plurality of battery cells.

12. The method as set forth in claim 9 wherein the controller is located within the housing of the battery charger.

13. The method as set forth in claim 9 further comprising implementing, with the controller, a first charging module and a second charging module, the first charging module operable to provide a first charging current to the battery pack and the second charging module operable to provide a second charging current to the battery pack.

14. The method as set forth in claim 13 wherein the first charging current and the second charging current differ in one of average current amplitude and duty-cycle.

15. The method as set forth in claim 14 wherein the first charging module includes a fast charge module.

16. The method as set forth in claim 15 wherein the first charging current includes a fast charge current.