Abstract: A method for providing energy from a stationary energy source to an electric vehicle having the steps of: determining an energy requirement of the electric vehicle; deriving an energy transfer rate; and transferring energy from the source to the electric vehicle at the rate. An energy transfer device to implement this method includes: a stationary energy source; a device for determining an energy requirement of the electric vehicle; means for deriving an energy transfer rate based on the requirement; and a device for transferring energy from the source to the electric vehicle at the rate.

Abstract: A hybrid drive system for use in an electric vehicle comprising an electric motor generator for moving the vehicle, plural electrical energy sources in electric contact with electric motor/generator and a control source in electrical contact with the plural electrical energy sources include a variable-rate energy storage system, a low-rate energy storage system and a high-rate energy storage system. In operation, the control source determines the average power consumption of the vehicle during emission operation throughout its ongoing duty cycle and controls the extent to which each of the energy sources energizes the electric motor/generator to move the vehicle, such that the vehicle may be efficiently operated in both emission and non-emission modes in accordance with environmental restrictions and operator-imposed power demands.

Abstract: A combined battery state of charge evaluator and motor control system for an electric vehicle comprises a traction battery 10, a motor controller 14, a traction motor 11, a micro computer 16 and an interface circuit 15. The micro computer 16 receives signals representing battery temperature, total battery voltage, and battery current and calculates the charge withdrawn from the battery by integrating battery current and also calculates the remaining charge in the battery as a function of battery voltage. By summing the remaining charge and the charge withdrawn, the present charge storage capacity value of the battery is calculated. The micro computer 16 compares the present charge storage capacity value with a value representing 85% of the nominal charge storage capacity of the battery when new and selects the lower of these two values. The state of charge is then calculated as a function of the charge withdrawn and this lower value and displayed on a meter 34.