Patent ID: 11936228
Assignee: BLACK & DECKER, INC.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  G  Y | IPC H

Claim 13:
14. A method of charging a battery pack, comprising:
providing an AC impedance circuit, the AC impedance circuit applying a sinusoidal AC excitation signal to a connected battery pack and measuring a battery pack response to the sinusoidal AC excitation signal;
providing a charger controller, the charger controller (1) calculating an impedance value of the connected battery pack based on the sinusoidal AC excitation signal and the battery pack response and (2) selecting a charging scheme based on the impedance value of the connected battery pack;
providing a power supply including charging circuitry, the power supply providing the charging scheme selected by the charger controller, wherein:
the sinusoidal AC excitation signal is applied prior to and separate from the charging scheme being provided, and
the charging scheme is provided after the sinusoidal AC excitation signal is applied and the charging scheme has been selected; and

when the charger controller selects a maximum charging rate charging scheme, the charger controller applying a constant current with a variable termination voltage based on a magnitude of the impedance value of the connected battery pack when the sinusoidal AC excitation signal is set to a value that produces a positive phase shift.