Granted Patent B2

US 12,348,072 · App. 18/058,580 · Granted Jul 1, 2025

Inventors: William Rigdon (Baltimore, MD); Lisa M. King (Towson, MD); Bhanuprasad V. Gorti (Perry Hall, MD); Brian K. Wohltmann (Shrewsbury, PA); Hussein M. Nosair (Parkville, MD); Michael Muilwyk (Felton, PA)

Assignee: Black & Decker Inc.

H02J7/00712H02J7/0013H02J7/0047H02J7/02

Abstract

Claims (47)

1. A method for charging a battery pack, the method comprising:

determining a battery pack identification (ID) from a battery pack identification (ID) component of the battery pack;

setting a set of reference impedance values based on the battery pack ID, wherein:

the set of reference impedance values is associated with a number of parallel connections of a set of battery cells within the battery pack,

the set of reference impedance values includes multiple different ranges of reference impedance values, and

each of the multiple different ranges of reference impedance values corresponds to a different one of the number of parallel connections of battery cells within the battery pack;

applying a sinusoidal AC excitation signal to a set of battery cells of the battery pack;

calculating an impedance value of the battery pack based on the sinusoidal AC excitation signal;

accessing the set of reference impedance values;

comparing the impedance value of the battery pack to the multiple different ranges of reference impedance values based on the number of parallel connections of the set of battery cells within the battery pack and the battery pack ID;

selecting a charging current based on the comparison; and

charging the battery pack using the charging current.

2. The method of claim 1 , wherein applying the sinusoidal AC excitation signal is performed before charging the battery pack.

3. The method of claim 1 , wherein selecting the charging current includes selecting a maximum charge rate for the battery pack when the comparison of the impedance value of the battery pack to the set of reference impedance values associated with the battery pack ID indicates the battery pack is without electrical abnormalities within a plurality of strings of the set of battery cells in the battery pack.

4. The method of claim 1 , wherein:

selecting the charging current includes reducing a current charge rate applied to the battery pack below a normal current charge rate when the impedance value of the battery pack is higher than impedance values of the set of reference impedance values associated with the battery pack ID.

5. The method of claim 1 , further comprising:

periodically applying the sinusoidal AC excitation signal to the set of battery cells of the battery pack;

calculating a new impedance value of the battery pack;

comparing the new impedance value of the battery pack to the multiple different ranges of reference impedance values based on the number of parallel connections of the set of battery cells within the battery pack and the battery pack ID;

selecting a new charging current based on the comparison; and

charging the battery pack using the new charging current.

6. The method of claim 1 , wherein the sinusoidal AC excitation signal is at approximately 1 kHz.

7. A device, comprising:

an AC impedance circuit to apply a sinusoidal AC excitation signal to a set of battery cells of a battery pack; and

a controller to:

determine a battery pack identification (ID) from a battery pack identification (ID) component of the battery pack,

set a set of reference impedance values based on the battery pack ID, wherein:

the set of reference impedance values is associated with a number of parallel connections of a set of battery cells within the battery pack,

the set of reference impedance values includes multiple different ranges of reference impedance values, and

each of the multiple different ranges of reference impedance values corresponds to a different one of the number of parallel connections of battery cells within the battery pack;

calculate an impedance value of the battery pack based on the sinusoidal AC excitation signal,

access the set of reference impedance values,

compare the impedance value of the battery pack to the multiple different ranges of reference impedance values based on the number of parallel connections of the set of battery cells within the battery pack and the battery pack ID, and

select a charging current based on the comparison.

8. The device of claim 7 , wherein the controller causes a charging circuit to charge the battery pack using the charging current.

9. The device of claim 8 , wherein the AC impedance circuit applies the sinusoidal AC excitation signal before the controller causes the charging circuit to charge the battery pack.

10. The device of claim 7 , wherein the controller selects a maximum charge rate for the battery pack when the comparison of the impedance value of the battery pack to the set of reference impedance values associated with the battery pack ID indicates the battery pack is without electrical abnormalities within a plurality of strings of the set of battery cells in the battery pack.

11. The device of claim 7 , wherein the controller reduces a current charge rate applied to the battery pack below a normal current charge rate when the impedance value of the battery pack is higher than impedance values of the set of reference impedance values associated with the battery pack ID.

12. The device of claim 7 , wherein:

the AC impedance circuit periodically applies the sinusoidal AC excitation signal to the set of battery cells of the battery pack; and

the controller:

calculates a new impedance value of the battery pack,

compares the new impedance value of the battery pack to the multiple different ranges of reference impedance values based on the number of parallel connections of the set of battery cells within the battery pack and the battery pack ID, and

selects a new charging current based on the comparison.

13. The device of claim 12 , wherein the controller causes a charging circuit to charge the battery pack using the new charging current.

14. The device of claim 7 , wherein the sinusoidal AC excitation signal is at approximately 1 kHz.

Assignments (1)

Continuity (3)

References Cited (121)