초록 ▼

A battery charger for fast charging batteries, such as batteries requiring constant current charging, such as lithium ion batteries. The battery charger provides charging voltages across a battery pack having at least one rechargeable cell connected to battery terminals. The battery charger includes

A battery charger for fast charging batteries, such as batteries requiring constant current charging, such as lithium ion batteries. The battery charger provides charging voltages across a battery pack having at least one rechargeable cell connected to battery terminals. The battery charger includes a digital to analog converter circuit for controlling a current source for supplying a charging current to the battery pack. The digital to analog converter may provide a constant current or a constant voltage output as a function of the battery characteristics. An analog to digital converter measures a first voltage across the battery pack while the battery pack is being charged and a second voltage across the battery pack while the charging current is interrupted, and a digital processor determines the potential difference between the first voltage and the second voltage to determine a voltage drop across the terminals of the battery pack. A memory stores an optimum voltage level for charging the rechargeable cell, and a digital interface from the processor is used to adjust the setting of the digital to analog converter to provide the optimum voltage level at the rechargeable cell identified from the memory. The battery charger may include dual pockets for charging two battery packs.

대표청구항 ▼

[ What is claimed and desired to be secured by Letters Patent of the United States is:] [1.] A battery charger for providing a regulated voltage from a power supply for charging a battery, the battery charger comprising:a power transistor connected between the power supply and the battery to be char

[ What is claimed and desired to be secured by Letters Patent of the United States is:] [1.] A battery charger for providing a regulated voltage from a power supply for charging a battery, the battery charger comprising:a power transistor connected between the power supply and the battery to be charged;means for measuring the open circuit voltage of the battery;means for measuring the voltage of the battery under charge;means for determining the potential difference between the battery open circuit voltage and the battery voltage during charging; andmeans for controlling said power transistor responsive to said measuring means to provide a constant voltage to the battery as a function of the potential difference.