Lithium-based battery pack

• US 10,431,857 B2
• Filed: 11/26/2018
• Issued: 10/01/2019
• 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: Johnson, Todd W., Grzybowski, Dennis J., Kubale, Mark A., Rosenbecker, Jay J., Meyer, Gary D., Zeiler, Jeffrey M., Glasgow, Kevin L., Scheucher, Karl F.
• Primary Examiner(s): Fantu, Yalkew
• Application Number:
  US16/200,171
• Publication Number:
  US 20190097279A1
• Time in Patent Office: 309 Days
• Field of Search: 320114
• CPC Class Codes: B25F 5/00 Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
• CPC Class Codes: G01R 31/382 Arrangements for monitoring battery or accumulator variables, e.g. SoC
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/4207 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/425 Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing printed circuits H05K1/00
• CPC Class Codes: H01M 10/441 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 10/482 for several batteries or cells simultaneously or sequentially
• CPC Class Codes: H01M 2010/4271 Battery management systems including electronic circuits, e.g. control of current or voltage to keep battery in healthy state, cell balancing
• CPC Class Codes: H01M 2200/00 Safety devices for primary or secondary batteries
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 50/213 adapted for cells having curved cross-section, e.g. round or elliptic H01M50/209, H01M50/216 take precedence
• CPC Class Codes: H01M 50/247 specially adapted for portable devices, e.g. mobile phones, computers, hand tools or pacemakers
• CPC Class Codes: H01M 50/262 with fastening means, e.g. locks
• CPC Class Codes: H01M 50/296 characterised by terminals of battery packs terminals of batteries H01M50/543
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0025 : Sequential battery discharge in systems with a plurality of batteries
• CPC Class Codes: H02J 7/0031 : using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/0034 : using reverse polarity correcting or protecting circuits mechanical means of polarity protection H02J7/0045
• 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 7/005 : Detection of state of health [SOH]
• CPC Class Codes: H02J 7/0063 : with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/0071 : with a programmable schedule
• CPC Class Codes: H02J 7/04 : Regulation of charging current or voltage
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y10T 408/65 : Means to drive tool

Abstract

An electrical combination including a power tool and a battery pack. The power tool includes power tool terminals. The battery pack is configured to be interfaced with the power tool. The battery pack includes a battery pack housing, at least three terminals, and a plurality of battery cells. The battery pack terminals include a positive terminal, a negative terminal, and a sense terminal. The at least three terminals are configured to be interfaced with the power tool terminals. The plurality of battery cells are arranged within and supported by the battery pack housing. Each of the battery cells has a lithium-based chemistry and a respective state of charge, and power is transferable between the battery cells and the power tool. A circuit is configured to monitor the battery cells, detect a charge imbalance among the battery cells, and prevent the battery pack from operating when the charge imbalance is detected.

Claims

1. A battery pack configured to be interfaced with an electrical device, the battery pack comprising:

a battery pack housing;

a positive terminal, a negative terminal, and a sense terminal configured to be interfaced with corresponding terminals of the electrical device;

a plurality of battery cells arranged within the housing, each of the plurality of battery cells having a lithium-based chemistry and a respective state of charge, power being transferable between the plurality of battery cells and the electrical device;

means for monitoring the plurality of battery cells;

means for detecting a charge imbalance among the plurality of battery cells based on the respective state of charge of each of the plurality of battery cells; and

a microprocessor programmed to disable the battery pack when the charge imbalance is detected;

wherein the microprocessor is further programmed to identify an imbalanced battery cell having a high state of charge relative to a state of charge of another battery cell of the plurality of battery cells;

wherein the microprocessor is further programmed to initiate a controlled discharging process to discharge the imbalanced battery cell when the charge imbalance is detected.

2. The battery pack of claim 1, wherein the electrical device is a power tool.

3. The battery pack of claim 1, wherein the respective states of charge of each of the plurality of battery cells are monitored at approximately the same time.

4. The battery pack of claim 1, wherein the microprocessor is further programmed to monitor the state of charge of each of the plurality of battery cells during the controlled discharging process.

5. The battery pack of claim 1, wherein the means for monitoring the plurality of battery cells includes the microprocessor.

6. The battery pack of claim 1, wherein the means for detecting the charge imbalance among the plurality of battery cells includes the microprocessor.

7. An electrical combination comprising:

a power tool including power tool terminals;

a battery pack configured to be interfaced with the power tool, the battery pack including

a battery pack housing,

a positive terminal, a negative terminal, and a sense terminal configured to be interfaced with the power tool terminals, and

a plurality of battery cells arranged within the battery pack housing, each of the plurality of battery cells having a lithium-based chemistry and a respective state of charge, power being transferable between the plurality of battery cells and the power tool;

means for monitoring the plurality of battery cells;

means for detecting a charge imbalance among the plurality of battery cells based on the respective state of charge of each of the plurality of battery cells; and

a microprocessor programmed to prevent the battery pack from operating when the charge imbalance is detected;

wherein the microprocessor is further programmed to identify an imbalanced battery cell having a high state of charge relative to a state of charge of another battery cell of the plurality of battery cells;

wherein the microprocessor is further programmed to initiate a controlled discharging process to discharge the imbalanced battery cell when the charge imbalance is detected.

8. The electrical combination of claim 7, wherein the respective state of charge of each of the plurality of battery cells is monitored at approximately the same time.

9. The electrical combination of claim 7, wherein the microprocessor is further programmed to monitor the state of charge of each of the plurality of battery cells during the controlled discharging process.

10. The electrical combination of claim 7, wherein the means for monitoring the plurality of battery cells includes the microprocessor.

11. The electrical combination of claim 7, wherein the means for detecting the charge imbalance among the plurality of battery cells includes the microprocessor.

12. The electrical combination of claim 7, wherein the microprocessor, the means for monitoring the plurality of battery cells, and the means for detecting the charge imbalance among the plurality of battery cells are located within the battery pack housing.

13. A method of operating a battery pack configured to be interfaced with an electrical device, the battery pack including a battery pack housing, a positive terminal, a negative terminal, a sense terminal configured to be interfaced with corresponding terminals of the electrical device, and a plurality of battery cells arranged within the housing, each of the plurality of battery cells having a lithium-based chemistry and a respective state of charge, power being transferable between the plurality of battery cells and the electrical device, the method comprising:

monitoring the plurality of battery cells;

detecting a charge imbalance among the plurality of battery cells based on the respective state of charge of each of the plurality of battery cells;

disabling the battery pack when the charge imbalance is detected;

identifying an imbalanced battery cell having a high state of charge relative to a state of charge of another battery cell of the plurality of battery cells; and

initiating a controlled discharging process to discharge the imbalanced battery cell when the charge imbalance is detected.

14. The method of claim 13, wherein the electrical device is a power tool.

15. The method of claim 13, wherein the respective states of charge of each of the plurality of battery cells are monitored at approximately the same time.

16. The method of claim 13, further comprising monitoring the state of charge of each of the plurality of battery cells during the controlled discharging process.

17. The method of claim 13, wherein monitoring the plurality of battery cells includes monitoring the plurality of battery cells with a microprocessor of the battery pack.

18. The method of claim 13, wherein detecting the charge imbalance among the plurality of battery cells includes detecting the charge imbalance among the plurality of battery cells with a microprocessor of the battery pack.