Abstract: A battery pack and charger platform including a voltage coupling circuit comprising an input that receives an input voltage and an output that sends an output voltage, a voltage monitoring circuit having an input coupled to the voltage coupling circuit output and an output, and a power source having an input coupled to the voltage monitoring circuit output, the power source input receives an input voltage representative of a charge instruction.

Abstract: A method is provided for indicating state of charge of a battery being charged by a charger. The method includes: supplying a charging current from a battery charger to a battery pack; determining voltage of battery cells residing in the battery pack; and illuminating a visual indicator on the battery charger to indicate state of charge of the battery pack, where brightness of the visual indicator correlates to the voltage of the battery cells in the battery pack.

Abstract: A method is provided for indicating state of charge of a battery being charged by a charger. The method includes: supplying a charging current from a battery charger to a battery pack; determining voltage of battery cells residing in the battery pack; and illuminating a visual indicator on the battery charger to indicate state of charge of the battery pack, where brightness of the visual indicator correlates to the voltage of the battery cells in the battery pack.

Abstract: A battery charger is provided for implementing a charging method having a stepped output current. The battery charger includes: a power supply circuit that receives an AC input signal and outputs a DC output signal. The power supply circuit includes a power supply controller configured to receive a feedback signal indicative of current being output by the power supply circuit via an amplifier and operates to control current output by the power supply circuit in accordance with the feedback signal. A charger controller is interfaced with the power supply controller to implement a charging method having a stepped output current. The charger controller may set the output current level by adjusting gain of an operational amplifier having a negative feedback configuration with the feedback signal input to a non-inverting input terminal of the operational amplifier, where the charger controller sets the output current level by changing the resistance at an inverting input terminal of the operational amplifier.

Abstract: A battery charger is provided for implementing a charging method having a stepped output current. The battery charger includes: a power supply circuit that receives an AC input signal and outputs a DC output signal. The power supply circuit includes a power supply controller configured to receive a feedback signal indicative of current being output by the power supply circuit via an amplifier and operates to control current output by the power supply circuit in accordance with the feedback signal. A charger controller is interfaced with the power supply controller to implement a charging method having a stepped output current. The charger controller may set the output current level by adjusting gain of an operational amplifier having a negative feedback configuration with the feedback signal input to a non-inverting input terminal of the operational amplifier, where the charger controller sets the output current level by changing the resistance at an inverting input terminal of the operational amplifier.

Abstract: A rechargeable battery pack comprises a battery having a high voltage side and a low voltage side, a positive terminal accessible external of the battery pack and connected to the high voltage side of the battery, a negative terminal accessible external of the battery pack and connected to the low voltage side of the battery, a control terminal accessible external of the battery pack, a switching element electrically connected between the control terminal and the high voltage side of the battery, and a control module operable to control the switching element so that the control terminal is selectively coupled to the high voltage side of the battery.