Method and apparatus for charging batteries

A battery charger, comprising:

• an input circuit configured to receive an ac input having a period of T seconds and to provide a first dc signal;
• a converter configured to receive the first dc signal and to provide a converter output across a dc bus, and having a peak voltage of V volts, configured to receive at least one control input;
• a plurality of user-removable output circuits, each configured to receive the first dc signal and each designed to provide a battery charging signal at a desired voltage and a desired current, wherein a chosen one of the plurality is connected at a time and the maximum power of the battery charging signal for any of the plurality of output circuits is P watts;
• a controller, including a power factor correction circuit, configured to provide at least one control signal to the converter;
• and
• a bus capacitor connected across the dc bus wherein the bus capacitor has a capacitance of at least (3PT)/(V2) farads.

A battery charger, comprising:

• an input circuit configured to receive an ac input having a period of T seconds and to provide a first dc signal;
• a converter configured to receive the first dc signal and to provide a converter output across a de bus having a peak voltage of V volts, configured to receive at least one control input;
• a plurality of output circuits, each configured to receive the first de signal and each designed to provide a battery charging signal at a desired voltage and a desired current, wherein the total power provided by the plurality is of output circuits is P watts;
• a controller, including a power factor correction circuit, configured to provide at least one control signal to the converter;
• and
• a bus capacitor connected across the dc bus wherein the bus capacitor has a capacitance of at least (3PT)/(V2) farads.

A method of battery charging, comprising:

• rectifying an ac input having a period of T seconds to provide a first dc signal;
• converting the first dc signal to provide a converter output across a dc bus at, having a peak voltage of V volts, and configured to receive at least one control input;
• switching the dc bus to provide a battery charging signal having a power of P watts;
• controlling, including power factor correcting, the converting, and
• storing energy across the bus on a bus having a capacitance of at least (3PT)/(V2) farads.

A method of charging a battery, comprising:

• rectifying an ac input having a period of T seconds to provide a first dc signal;
• converting the first dc signal to provide a converter output across a dc bus at, having a peak voltage of V volts, and configured to receive at least one control input;
• switching the dc bus with a plurality of output circuits to provide a plurality of battery charging signals having a combined power of P watts;
• controlling, including a power factor correcting, the converting, and
• storing energy across the bus on a bus having a capacitance of at least (3PT)/(V2) farads.

A battery charger, comprising:

• means for rectifying an ac input having a period of T seconds to provide a first dc signal;
• means for receiving the first dc signal and for converting it and providing a converter output across a dc bus at, having a peak voltage of V volts, and configured to receive at least one control input;
• means for switching the dc bus to provide a battery charging signal having a power of P watts;
• means for controlling, including power factor correcting, the converting, and
• means for storing energy across the bus on a bus having a capacitance of at least (3PT)/(V2) farads.

A battery charger, comprising:

• means for rectifying an ac input having a period of T seconds to provide a first dc signal;
• means for converting the first dc signal to provide a converter output across a dc bus at, having a peak voltage of V volts, and configured to receive at least one control input;
• means for switching the dc bus with a plurality of output circuits to provide a plurality of battery charging signals having a combined power of P watts;
• means for controlling, including power factor correcting, the converting, and
• means for storing energy across the bus on a bus having a capacitance of at least (3PT)/(V2) farads.