Abstract: A charge termination circuit which may be disposed within the battery cell pack and used in conjunction with known battery safety circuits to protect against charging conditions which reduce the life of a battery cell. In particular, the charge termination circuit is adapted to be used in conjunction with an off the shelf battery safety circuit and one or more power FETs coupled between the battery cell and the battery charger terminals on the battery cell package. The charge termination circuit includes a microcontroller and monitors the battery cell voltage by way of an I/O part and activates a first timer anytime the charging current to the battery is below a predefine threshold, for example, indicative of a maintenance or trickle charge. When the first timer times out after a predetermined time period, for example, two hours, the charge termination current forces the one or more of the serially coupled FETs switches to interrupt battery charging of the battery cells.

Abstract: A charge termination circuit which may be disposed within the battery cell pack and used in conjunction with known battery safety circuits to protect against charging conditions which reduce the life of a battery cell. In particular, the charge termination circuit is adapted to be used in conjunction with an off the shelf battery safety circuit and one or more power FETs coupled between the battery cell and the battery charger terminals on the battery cell package. The charge termination circuit includes a microcontroller and monitors the battery cell voltage by way of an I/O part and activates a first timer anytime the charging current to the battery is below a predefine threshold, for example, indicative of a maintenance or trickle charge. When the first timer times out after a predetermined time period, for example, two hours, the charge termination current forces the one or more of the serially coupled FETs switches to interrupt battery charging of the battery cells.

Abstract: 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.

Abstract: A battery charger for use with different types of batteries, such as batteries requiring constant current charging, such as nickel cadmium (NiCd) and nickel metal hydride (NiMH) batteries, as well as batteries which not only require constant current charging, but also require constant voltage charging, such as lithium ion batteries. The battery charger includes a pulse width modulator circuit for controlling a power transistor to provide a constant current or a constant voltage output as a function of the battery characteristics. The battery charger may include dual pockets for charging two modular batteries on a time division multiplex basis. In the dual pocket application, power is divided between the two pockets as a function of the charging characteristics of the battery and the power dissipation of the power transistors used for supplying charging current to the pockets.

Abstract: A battery charger for use with different types of batteries, such as batteries requiring constant current charging, such as nickel cadmium (NiCd) and nickel metal hydride (NiMH) batteries, as well as batteries which not only require constant current charging, but also require constant voltage charging, such as lithium ion batteries. The battery charger includes a pulse width modulator circuit for controlling a power transistor to provide a constant current or a constant voltage output as a function of the battery characteristics. The battery charger may include dual pockets for charging two modular batteries on a time division multiplex basis. In the dual pocket application, power is divided between the two pockets as a function of the charging characteristics of the battery and the power dissipation of the power transistors used for supplying charging current to the pockets.