Norvik Technologies Inc.

Norvik Traction Inc.

Inco Limited

Norvik Inc.

Norvik Tractions Inc.

Jiri K Nor

Josef V Soltys

Victor A Ettel

Vladimir S Pavlovic

Robert B Field

Douglas K Charles

Jan Hohercak

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. Sensitive analog circuitry in the battery monitoring modules is located in proximity to the battery modules with which it is associated, and is galvanically isolated from the digital communication circuitry and the data communications bus transmitting the data to the main control module. Any switching or other controllers in the battery are galvanically isolated from the battery monitoring modules and the main control module. Means are provided to isolate specific cells or battery modules, as required; other means are provided to ensure that important voltage and/or current samplings are indicative of equilibrium of the electrical charge or discharge reactions, so that erroneous readings taken during fast acceleration or braking, or other circumstances except essentially steady state conditions, may be discarded. Other means are provided whereby the driver of an electric vehicle receives warnings as the available energy still within the battery depletes below specified levels; and further means are provided to ensure that rate of discharge or regenerative charging of the battery do not exceed predetermined limits.

Battery energy monitoring circuits

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.

Method and apparatus for charging batteries

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. The value of initial charging current is set either by an on board battery charging control module in the vehicle, or by the charge control module which is present in the charging station; or alternatively, by being preset at the charging station. Initial charging current, and the amount of charging energy to be delivered, may be established by insertion of a card into a data interface on the charging station. Under controlled conditions, a plurality of vehicles may be charged at a single establishment having a plurality of charging stations, by distributing energy to any one vehicle according to priority criteria to be established.

Traction battery charging with inductive coupling

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. Parameters of initial charging current and voltage are therefore set either by the on board battery charging controller, or the charge controller in the charging station; alternatively, those parameters may be set manually or by insertion of a card into a data interface to establish initial charging conditions. Under controlled conditions, a plurality of vehicles may be charged at a single establishment having a plurality of charging stations, either sequentially or simultaneously, depending on the criteria to be established. The charging station may be privately owned, so as to charge a fleet of vehicles; or there may be a plurality of charging stations at a publicly accessible service station.

Universal charging station and method for charging electric vehicle

A battery charge is provided which automatically controls the charging process independent of individual battery construction or temperature. Control of the charging process is achieved by periodically interrupting the charging current, determining resistance-free voltage of the battery in fixed intervals after interruptions of current, and comparing the resistance-free voltage with a reference voltage. Reference voltage is automatically determined for each recharging subject by analyzing the change in resistance-free voltage with respect to time during an initial, constant current period to locate certain characteristic points indicative of the onset of overcharge. The charging current is reduced as necessary, so that the resistance-free voltage does not exceed the reference voltage and significant overcharge is avoided.

Battery charger

A charger for rechargeable cells or batteries utilizes a mechanism whereby resistance-free voltage is continually monitored during periodic current-off intervals in the charging process and compared to an independent reference voltage to prevent overcharge. After a certain degree of charge has been obtained, the current is gradually reduced to a finishing charge. Several means are provided for terminating the finishing charge while avoiding overcharge. Another embodiment of a charger provides for measurement of the resistance-free voltage during the current-off period after sufficient time is allowed for the recombination of any oxygen which may have been produced during charging, thus taking into account inherent variations in cells of the same type.

A monitoring circuit is provided to monitor batteries while they are being charged or discharged, where the batteries comprise a series of modules or cells that are connected in series. A terminal is placed between each adjacent pair of modules and at each end of the battery, so that voltage across each module may be measured at the pair of terminals that define the module. Several different determinations of module voltage may be made during charge and/or discharge of the battery including the resistance free voltage of the module, and the module voltage while current is flowing through the battery. Generally, some or all of the modules are tested periodically, where the interruption interval for internal resistance free voltage determination may be in the order of 2 to 3 ms, and the testing frequency for the battery may be in the order of 0.5 to 25 Hz. Alarms may be triggered in the event of module voltages being sensed that are outside of predetermined limits, meaning that the charging and/or discharging characteristics of any of the modules has changed and is significantly different than those of the other modules. By such alarm indications, the module may be changed before serious damage occurs to the battery, either by overcharging or severely discharging the battery.

Monitoring system for batteries during charge and discharge

Circuits are provided whereby rechargeable batteries and cells are charged very fast by a controlled current, and substantially at a rate never exceeding the ability of the battery or cell to accept current--i.e., to convert electrical current to stored chemical energy. The resistance free terminal voltage of the battery or cell is detected during an interval when the charging current is interrupted, and compared against an independent reference voltage to control the charging current when a difference between the reference voltage and the sensed resistance free terminal voltage exists. The reference voltage may be altered at any instant in time, as a function of the ambient temperature, or the internal temperature or pressure of the battery, as a function of the charging current when it is within a predetermined range, or if a particular change in the value of the charging current occurs over a predetermined period of time. Charging characteristics may also be controlled and altered either through the passage of time or as a consequence of predetermined conditions occurring. The various provisions preclude thermal runaway for example, and assure very rapid and complete charging operations no matter what may be the condition of the battery--provided it is capable of accepting charge--and for various kinds of rechargeable batteries and cells including nickel cadmium, lead acid, and so on.

Charging circuits for rechargeable batteries and cells

A charging station for electric vehicles which have rechargeable batteries is provided. The charging station comprises a power section controlled by a fast acting power controller, a power connector and associated power cables for connecting to the vehicle, an interface with signal cables to carry status and/or control signals between the vehicle and the power controller, and a lockout which precludes delivery of power to the vehicle except when the power connector is in place. High charging currents are delivered to the battery of the vehicle as a consequence of signals at any instant in time to the power controller, so as to be able to turn delivery of the charging current on and off in less than a few milliseconds. The resistance free voltage of the vehicle battery is measured during intervals when the charging current is off, and the operation of the power controller is a function of the battery resistance free voltage at any instant in time. Operation may be manually controlled, whereby at least maximum voltage and current settings are preset by the operator; or operation may be completely automatic and under the control of a charge controller within the vehicle and associated with the battery. Thus, for each vehicle that is equipped with a charge controller, the operation of the charging station is battery specific, and may be quite different as to conditions of voltage and current being delivered to another electric vehicle which may be subsequently re-charged from the same charging station.

Charging station for electric vehicles

A charger for charging rechargeable batteries including circuitry for supplying electrical charging power to said rechargeable battery so as to rapidly charge said rechargeable battery, interrupting circuitry for repeatedly interrupting said electrical charging power to said rechargeable battery for a preselected timed interval so as to permit the detection of the internal resistance free voltage of said battery during said interruption of said power, electrical comparing circuitry for comparing the internal resistance free voltage of said battery with a preselected reference voltage, and electrical control circuitry for reducing said power to said battery when said internal resistance free voltage exceeds said preselected reference voltage so as to reduce gradually the rate of charging of said rechargeable battery and maintain said internal resistance free voltage of said battery at said preselected reference voltage.

Growing community of inventors

Oakville, Canada

Jiri K Nor