Abstract: A method and apparatus utilizing a new parameter for assessing battery charge acceptance for controlling the charging process of the battery. The charge acceptance parameter comprises a terminal voltage profile which is determined during a variation in a diagnostic current. The slope of the terminal voltage profile is used in the charging process to assess the charge acceptance ability of the battery and thereby control the charging current. For a first group of batteries including lead-acid and nickel-cadmium batteries, the terminal voltage profile is characterized by an increasing profile slope as the charge acceptance ability of the battery is reached. For a second group of batteries comprising nickel-metal hydride batteries, the terminal voltage profile is characterized by a profile slope which approaches zero as the charge acceptance ability of the battery is reached.

Abstract: A battery pack and method for connecting battery modules to optimize current sharing and charging of the modules. The battery pack comprises a number of battery modules, each module having respective positive and negative terminals. Interconnecting cables are provided for connecting the respective positive terminals and the respective negative terminals. The interconnecting cables have equal electrical lengths so that the Ohmic resistance is the same for the cables. The battery modules are also arranged in close proximity to form an isothermal zone.

Abstract: A long chain battery, particularly for an electric vehicle, comprises a plurality of series connected cells or battery modules. To control the operation of the electrical functions, including discharge while the vehicle is being driven, charging when it is at a charging station, or regenerative charging during braking, a main control module and a plurality of battery monitoring modules are provided. The electric motor and a traction controller therefor are connected in series across the long chain battery, and other vehicle electrical loads are in parallel with the motor and controller. Each battery monitoring module will monitor a number of batteries, and the current carrying wire between them, so that incipient problems may be detected before failure or significant damage occurs. A serial communications bus is provided between the main control module and the battery monitoring modules, and data transmitted over that bus is generally digitally encoded.

Abstract: A charger for charging a rechargeable battery. The charger comprising a circuit for producing a charging current having a variable level and a control circuit for controlling the charging current. During a first charging period the current is maintained at a level to rapidly charge the battery at a rate in amperes which is greater than the capacity of the battery in ampere-hours. The controller includes means for interrupting the charging current for a predetermined interruption interval. During the interruption interval, the charging current is maintained at a non-zero value. The controller also includes means for determining a resistance free voltage for the battery. During a subsequent charging period, the charging current is controlled in response to the value of the resistance free voltage.

Abstract: A long chain battery, particularly for an electric vehicle, comprises a plurality of series connected cells or battery modules. To control the operation of the electrical functions, including discharge while the vehicle is being driven, charging when it is at a charging station, or regenerative charging during braking, a main control module and a plurality of battery monitoring modules are provided. The electric motor and a traction controller therefor are connected in series across the long chain battery, and other vehicle electrical loads are in parallel with the motor and controller. Each battery monitoring module will monitor a number of batteries, and the current carrying wire between them, so that incipient problems may be detected before failure or significant damage occurs. A serial communications bus is provided between the main control module and the battery monitoring modules, and data transmitted over that bus is generally digitally encoded.

Abstract: A method and apparatus for charging the traction battery of an electric vehicle are provided. Charging energy is delivered from a charging station at a predetermined voltage and at a delivery frequency in the range of from 10 kHz up to 200 kHz, The charging energy is transferred to the vehicle through an inductive coupler, having a primary side connected to the charging station and a secondary side mounted within the vehicle. A rectifier is mounted in the vehicle and interposed between the secondary side and the battery. When the vehicle is connected to a charging station, it is interrogated to determine the nature of the charge controller that is on board the vehicle; and logic decisions invoking the particular mode for charging the vehicle are made depending on the nature and type of charge controller that is on board the vehicle.

Abstract: A method and apparatus for charging the battery of an electric vehicle are provided. When the electric vehicle is connected to a charging station, it is interrogated to determine the nature of the charge controller that is on board the vehicle; and logic decisions invoking the particular mode for charging the vehicle are made depending on the nature and type of charge controller that is on board the vehicle. Thus, delivery of charging energy to the battery in the vehicle may be entirely under the control of a charge controller on board the vehicle; or if the control module in the vehicle is less sophisticated then delivery of charging energy will be under the control of a charging module within the charging station.