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

Claim 26:
27. A battery charger, comprising:
an AC impedance circuit to apply a sinusoidal AC excitation signal to a connected battery pack and to measure a battery pack response to the sinusoidal AC excitation signal;
a charger controller including first circuitry to:
calculate a first impedance value of a first connected battery pack,
set a first charging rate to a maximum value for the first connected battery pack,
calculate a first variable termination voltage based on a magnitude of the impedance value of the first connected battery pack when the sinusoidal AC excitation signal is set to a value that produces a positive phase shift, or
calculate a second impedance value of a second connected battery pack,
set a second charging rate to a maximum value for the second connected battery pack,
calculate a second variable termination voltage based on a magnitude of the impedance value of the second connected battery pack when the sinusoidal AC excitation signal is set to a value that produces a positive phase shift; and
when the charger controller sets the first charging rate to the maximum value for the first connected battery pack or the second charging rate to the maximum value for the second connected battery pack, apply a constant current based on the first variable termination voltage as calculated as the first connected battery pack is charged or based on the second variable termination voltage as calculated as the second connected battery pack is charged; and

a power supply including second circuitry to provide the first charging rate or the second charging rate set by the charger controller,
wherein the first charging rate and the first variable termination voltage for the first connected battery pack is different than the second charging rate and the second variable termination voltage for the second connected battery pack.