Multi-battery fuel saving and emissions reduction system for automotive vehicles

Abstract

A multi-battery charging system for reduced fuel consumption and emissions for an automotive vehicle. The system starts the vehicle with a start battery in a fuel savings manner, removing electrical torque from the alternator shaft, and allows a second (run) battery to provide all or some of the current required by the vehicle loads as a fuel savings measure. The system also utilizes an electrically heated catalytic converter (EHC) and a third (EHC or storage) battery to provide a 3 to 15 second preheat and/or a 20 second current, during vehicle start, to the EHC heater coil, e.g., of a small EHC located in series with a standard catalytic converter for emissions reduction to reduce emissions during start. The start battery is recharged after start and switched out of the system fully charged for future vehicle starts. The run battery is recharged when its charge level drops below a predetermined level with an on board battery charging device powered from a 115 volt or 220 volt ac power line source external to the vehicle.

Description

Proper selection of component values in the differentiating equation will produce an output voltage having the proper magnitude for a predetermined vehicle deceleration rate.

The voltage at the output of amplifier 5A1 is amplified by amplifier 5A2 and applied to the non-inverting input of amplifier 5A3. When the applied voltage exceeds the reference voltage provided on the inverting input of amplifier 5A3, amplifier 5A3 switches from a low state to a high state.

Alternately, pendulum circuit 70 can be replaced with any type of vehicle deceleration detection circuit device, including wheel speed pickoff types, that can be modified to provide an output voltage having a magnitude and rise time sufficiently proportional to vehicle deceleration to operate with deceleration circuit 90.

Referring now to FIG. 6, voltage regulator 42, in accordance with the non-microprocessor controlled version of the present invention, is similar to many off-the-shelf type of voltage regulators that control the magnitude of the output voltage V_A of alternator 40. The regulation principle is well known and has been in use almost as long as the automobile has been in existence. Early voltage regulator circuits sensed the level of the output voltage V_A from the alternator 40 and commanded a relay contact to remain closed for a longer period of time than open when the output voltage V_A was below a preset level, such as 14.0 volts dc. When the sensed output voltage V_A was above the reference level, the contact was commanded to remain open for a longer period of time than closed. This switching action maintained the output voltage V_A in the vicinity of 13.6 volts dc in a reasonable manner.

The voltage regulator circuit also sensed the ambient temperature and modified the on-off switching time as a function of temperature. It also modified the switching on-off time to cause the contact to remain on for a slightly longer period when ambient temperature was low and to remain off for a slightly longer period of time when the ambient temperature was high. This raised alternator nominal 14.0 volt dc output level to 14.8 volts at low temperatures and reduced the nominal 14.0 volt output to 13.6 volts dc at high ambient temperatures. The nominal output voltage, when raised to 14.8 volts dc, provided more current to the alternator rotor coil 44R at low ambient temperatures and less current when it was reduced to 13.6 volts at high ambient temperatures, thus maintaining a proper charging current to the start battery under all driving and ambient temperature conditions.

Relay contact controlled voltage regulators have been replaced with more reliable transistor switching types that control the alternator rotor, and thus field current, in much the same manner as described above, i.e., by changing the duty cycle of the current.

In accordance with the present invention, referring to FIG. 6, voltage regulator 42 includes an on-off switching circuit comprised of a logic NAND gate G1, a pnp transistor Q606, temperature sensitive diodes 6D1, 6D2, zener diode 6Z1, operational amplifier 6A1, voltage driver resistors 6R1, 6R2 and darlington power switching transistors 6Q1 and 6Q2.

When wiper W3 of ignition switch 30 is placed in the run position (contact 37) prior to start, an exciter current from start battery 10 is delivered through rotor coil 44R of alternator 40 and series transistor 6Q2 to ground. This provides sufficient current to overcome the residual magnetism in rotor coil 44R which allows coil 44R to develop the required current to operate properly alternator 40.

There are a variety of solid state switching voltage regulators in operation at the present time. Most of them can be activated and deactivated to switch the current into rotor 44R on and off by grounding a key signal line in the circuit. This can be manually done with a switch and automatically done with inputs of the type illustrated in FIGS. 1 and 6 or with a microprocessor.

When the output voltage V_A of alternator 40 is below a nominal 14.0 volt dc level, zener diode 6Z1 does not contact current. Consequently, the voltage at its base on top of resistor 6R3 is zero. The second alternator output voltage V_A is, however, present at the non-inverting input to amplifier 6A1, thus causing it to switch to a high state output voltage level. This causes transistors 6Q1 and 6Q2 to turn on. This in turn causes current to flow through rotor coil 44R which raises the current in field windings 703. The increased current in field windings 703 (stator coils 44S) raises the alternator output voltage V_A above 14.0 volts. The output voltage V_A is produced by the phase rectifier bridge comprising diodes 7D4, 7D5, 7D6, 7D7, 7D8, and 7D9 (and the feedback output voltage V_A2 is provided by an exciter bridge comprising diodes 7D1, 7D2, 7D3) in a conventional manner.

When output voltage V_A rises above 14.0 volts, zener diode 6Z1 conducts current and a voltage appears at the inverting input of amplifier 6A1 that is higher than the voltage on the non-inverting input. This causes amplifier 6A1 to switch from a high voltage state to a low voltage state, thus turning transistor 6Q1 and 6Q2 off. This reduces the output voltage V_A below 14.0 volts.

This on-off switching action maintains the alternator output voltage V_A at 14.0 volts dc, regardless of changes in the alternator shaft rotational speed.

The forward voltage drop of diodes 6D1 and 6D2 decreases at high temperature which increases the voltage level at the top of zener diode 6Z1. This causes zener diode 6Z1 to turn off the voltage regulator 42 earlier in the switching cycle. This causes the nominal alternator output charging voltage to drop to a selected level below 14.0 volts.

The forward voltage drop of diodes 6D1 and 6D2 increases in a low ambient temperature which decreases the voltage level at the top of zener diode 6Z1. This causes zener diode 6Z1 to conduct later in each switching cycle. This causes the nominal alternator output charging voltage to increase above the 14.0 level.

Diode 6D1 could be placed near start battery 10 to obtain a better measure of battery temperature. Alternately, a more suitable temperature sensitive circuit could be used in its place.

The voltage regulator circuit 42 described above is disabled by reducing the base voltage of transistor Q606 to zero. This occurs when all the inputs to NAND gate G1 are in a high state and the input on line L46 is a low state. This set of conditions causes the output of NAND gate G1 to switch to the low state and turn transistor Q606 on. When transistor Q606 switches on it reduces the voltage level on line L606 to the non-inverting input of amplifier 6A1 to zero. This prevents amplifier 6A1 from turning voltage regulator 42 on.

When the overriding deceleration input from circuit 90 on line L46 goes to the high state during vehicle deceleration, the base of transistor Q606 is raised, regardless of the input signal levels to NAND gate G1. This causes transistor Q606 to turn off, thus allowing amplifier 6A1 to operate voltage regulator 42 as required. When any of the lines L6, L7 and L306 are in the low state, the output of NAND gate G1 switches high to the state, thus raising the base of transistor Q606, and enabling voltage regulator 42. When all three lines L6, L7 and L306 are in the high state, regulator 42 is disabled (unless overridden by a high state input on line L46 from the deceleration circuit 90).

Logic NAND gate G1 can be replaced, if desired, by a manual switch operated by the driver. A manual switch can be used to turn voltage regulator circuit 42 on and off in order to switch alternator 40 in and out of the system. A second manual switch could be used to turn solid state switch 32SB on and off to switch start battery 10 in and out of the system.

A meter indicating the state of charge of each battery could be located along with manual solid state switch controls on the instrument panel of the vehicle or in another suitable location. It is to be understood that all of the functions described above and illustrated in FIGS. 1-6 could be performed by manually operated switches if desired.

MICROPROCESSOR SYSTEM CONTROLLED EMBODIMENT OF THE INVENTION

Vehicle Run and Battery Charge Control with a Microprocessor

The non-microprocessor embodiment of the invention described above does not require the sophistication of a microprocessor to control the level of alternator current required to provide rectified output current to the batteries and vehicle loads or alternately to allow the run battery to provide all the vehicle load current.

Nevertheless, there are advantages afforded by using a microprocessor controlled voltage regulator including the ability to operate a complex voltage regulator, to operate a complex display, complex decision making capability, reprogramming flexibility, and a less complex vehicle installation (both as original vehicle equipment and as an aftermarket retrofit apparatus) than the non-microprocessor version.

Most four to sixteen bit microprocessors having suitable memory capacity can be used to replace the discrete circuit non-microprocessor based voltage regulator described in the non-microprocessor system version of the invention, as will be clear from the following.

Referring to FIG. 7, one suitable microprocessor 200 is a 16-bit microprocessor, Model No. 8397-90, which is available from Intel. This model microprocessor includes a 10-bit analog-to-digital converter, interrupt source inputs, a pulse width modulated output port, a 232 byte register, memory to memory architecture, a 16×16 bit multiplier, a 32 by 16 bit divider, a full duplex serial port, five 8 bit input/output ports, watchdog timers, four 16 bit timers, two external 64K (8K by 8 bits) memory devices, a one milliamp standby current drain, and a display driver interface including an eight segment liquid crystal display 80 and a 6×6 button keyboard 82.

One suitable memory device 845 for use with microprocessor 200 is EPROM Model P27C64/87C64, which is available from Intel. This device includes two 64K (8K×8 bit) memory units which are conventionally connected to the Intel model 8397-90 microprocessor. The pin designations are those provided by the manufacturer. Instructions for programming the Intel Model 8397-90 microprocessor can be found on pages 19-10 through 19-27 of the Intel Automotive Handbook, part order number 231792-002, available from Intel.

In the preferred embodiment, microprocessor 200 is provided with suitable software program instructions in memory so that the vehicle operator can obtain and display information regarding time, date, an alarm function, estimated time of arrival, time on remaining fuel to recharge station, time on remaining fuel to an empty fuel tank, the remaining distance to go on a trip, the distance to travel since the fuel tank was last filled, and the distance to travel on the remaining fuel. Many of these functions may be programmed in a conventional manner by a person of ordinary skill in the art. Devices commonly referred to as trip computers, which incorporate many of these functions, have been commercially available in automotive vehicles at least since 1986.

In accordance with the present invention, microprocessor 200 also may be programmed to provide information regarding fuel efficiency and fuel being consumed in the fuel tank (based on the octane reading of the fuel). This would indicate average fuel efficiency and miles per gallon, the instantaneous fuel efficiency, the total fuel used on the trip since the trip began, the fuel used since the tank was last refilled, and the fuel left in the tank. Also, the microprocessor 200 may provide information regarding how long the vehicle may continue operating until an external battery recharge is required, the time required to recharge run battery 20 after alternator 40 is switched back in to recharge run battery 20, and how long the vehicle may safely operate in the run state before requiring a recharge. It is noted that in the run state refers to alternator 40 being either switched out or operating at a reduced voltage output that merely maintains a trickle charge on run battery 20 without attempting to fully recharge battery 20.

Also, microprocessor 200 may provide information regarding average vehicle speed and may includes an anti-theft capability, based on requiring the driver to enter a code on the keyboard 82 prior to starting the vehicle. Microprocessor 200 also may be utilized to monitor vehicle inputs not indicated above for vehicle diagnostic purposes. By sampling the alternator output load conditions, battery current levels, battery state of charge levels (in amp-hours), and alternator voltage levels, in addition to other vehicle sensory inputs, microprocessor 200 can perform many useful diagnostic functions. For example, a gradual inability to recharge properly any of the batteries, or for any battery to provide appropriate load currents upon demand in certain situations, can result in a diagnostic message indicating a problem with either the given battery, alternator 40, the wiring harness of the vehicle, vehicle loads (R_L and R_A), or even battery terminal connections. Microprocessor 200 also can be programmed to identify the following diagnostic conditions: a bad battery, a malfunctioning alternator, a short in a vehicle accessory or wiring harness causing excessive current drain, a bad diode bridge, the onset of a load dump condition, and other related diagnostic matters based on sensed states-of-charge, voltages and currents over time. The bases for these determinations are more fully described in the copending and commonly assigned application Ser. No. 07/919,011.

The input/output circuits 744, 745, 746, and 747 which interface microprocessor 200 and the vehicle sensor signals, are standard scaling, gain, and reset circuits. The design and construction of these circuits as well as the programming of microprocessor 200 are within the abilities of the person of ordinary skill in the art, are well known, and do not require elaboration.

In this embodiment, a pulse width modulated signal is output on line L39 at pin 39 of microprocessor 200, when it passes through input output interface circuit 747. The corresponding pulse width modulated output from circuit 747 on line L747, which is input to the darlington drive transistors 7Q1 and 7Q2, is a pulse train having a fixed period of 256 state times and a programmable width of from 0 to 255 state times. Pulse width is programmed by loading the desired value for optimum fuel economy, as determined by microprocessor 200, into a microprocessor pulse width modulation (PWM) control register (not shown). The varied number of state pulses over the 256 pulse period determines the average current provided by drive transistor 7Q1 and 7Q2 in FIG. 7 to the coil of rotor 44R of alternator 40. Rotor 44R generates a conventional three phase electromagnetic field voltage in the stator coils 44S (see also coils 703 in FIG. 6) having a magnitude proportional to the level of the dc input field current I_F. The alternating field current of the stator coils 44S is then rectified by diode bridges 740 (diodes 7D1, 7D2, 7D3) and 742 (diodes 7D4, 7D5, 7D6, 7D7, 7D8, 7D9) to provide the dc output voltage V_A on line L5.

Preferably, microprocessor 200 is programmed for receiving and processing the various sensor input parameters and controlling the alternator 40 output voltage V_A on line L5 between alternator 40 and run battery 20 over the range of 0 to 17 volts, according to a set of defined operating conditions stored in a look-up table or an algorithm. Preferably, look-up tables are used which comprise data curves of, for example, alternator output voltages (start and run conditions, including EHC preheat operations) versus various vehicle load and ambient temperature conditions, states of charge, and other data useful for the aforementioned diagnostic purposes. The data curves preferably correlate the range of sensor parameters and predetermined operating conditions and, in response to the determined inputs, provide a suitable output voltage to maximize fuel economy. The look-up tables utilized by the microprocessor may be empirically derived according to the specific vehicle operating conditions, operating mode, and battery characteristics.

In this embodiment, microprocessor 200 may monitor ambient temperature conditions and engine speed and regulate the bias of the alternator output voltage in a conventional manner. In accordance with the present invention, microprocessor 200 also may monitor the charging current I_CH by sensing the voltage signal representing the deceleration of the vehicle, and the state of charge and current signals charge/discharge from BSOC channels 60a, 60b and 60c.

These sensed parameters are then compared to data in the look-up tables and an appropriate output voltage is selected. The look-up table and data stored in memory device 845 provide fuel economy calculation information. Software for microprocessor 200 and the look up tables and algorithms may be created in a conventional manner using an emulator board and stored in memory 845.

A watchdog circuit (not shown in FIG. 7), is located between pins 55 and 45 of Intel model 8377-90 microprocessor 200 and provides a graceful recovery from software errors. In this regard, a 16 bit counter in microprocessor 200 will count state times until it overflows. If an overflow occurs prior to correction of an error, microprocessor 200 is reset. A clock 204 is used for state timing and other signal processing functions. Preferably a 12 MHz clock 204 is employed.

Referring to FIG. 7, the interconnection between microprocessor 200, keyboard 82 and display 80 is shown. In this embodiment, keyboard 82 is a conventional 6×6 keyboard having vertical and horizontal contact lines laid out in a 6×6 grid, and an associated eight character LCD display 80. Such keyboard devices can be readily implemented using the Intel 8397-90 microprocessor. Six of the keyboard lines are connected along line L32B-A, which is a parallel data bus, to pins P2.6, P2.7, P4.7, P4.0, P0.1, and P0.0 on microprocessor 200. The pin numbers are not shown in FIG. 7 for clarity of illustration. The other six keyboard lines are connected by line L32B-B, also a parallel data bus, to pins P4.1-P4.6 on microprocessor 200. The key designation of keyboard 82 is selected by appropriate programming of intersecting contact lines.

Outputs P1.0-P1.4 of microprocessor 200 are connected by line L24B-A, a parallel data bus, to a binary coded decimal digit driver circuit 81, which in turn is connected to display 80. Also, microprocessor 200 outputs P3.0-P3.7 are connected along line L24B-B, a parallel data bus, to segment driver 83, which, in turn, provides information to display 80.

In this driver interactive system, the driver may select which condition of the vehicle or which diagnostic parameter or trip computer function to display at any given time. Accordingly, specific keys in keyboard 82 may be dedicated for displaying state of charge of run battery 20, start battery 10 or EHC battery 300 upon actuation. Alternatively, the key functions may be selected according to a displayed menu of selections, such that different keys have different functions depending on the menu selected.

In addition, microprocessor 200 may be programmed to display the state of charge measures automatically when the state of charge of the respective battery falls below a preselected level or to display an appropriate message when a diagnostic routine indicates that a problem has been detected. Such an automatic display may be accompanied by a warning indication, e.g., a indicator light on the instrument panel or an audible tone. A distinctive warning could be used to indicate to the driver that the vehicle has switched from run battery operation only to running on the alternator, e.g., during a recharge of run battery 20. A suitable message also may be displayed to indicate how long it will take to recharge the battery with the alternator before automatically switching back to run battery operation. Other variations may be selected as a matter of design choice, provided that the selected microprocessor 200 and memory 845 have sufficient processing capability.

The previously discussed microprocessor pulse width modulation (PWM) circuit output on pin 39 and line L39 of microprocessor 200 smoothly varies the current to driver transistors 7Q1 and 7Q2, which in turn smoothly varies the current into rotor 44R in response to system sensor inputs and the dc output level (V_A2) of alternator 40 on line L602.

Microprocessor 200 compares the level of alternator voltage V_A2 on line L602 (through interface circuit 747) with a reference voltage level stored in memory. When V_A2 is higher than the reference voltage, e.g., a nominal 14.6 volts dc, the duty cycle of the PWM output is lowered until V_A2 returns to 14.6 volts dc. When V_A2 is below 14.6 volts dc, microprocessor 200 increases the duty cycle until V_A2 is at 14.6 volts dc. The nominal 14.6 volt level may be altered if required with a software change.

Microprocessor 200 also senses a signal on line L748 from ambient temperature sensor circuit 748, which is passed through input output interface circuit 745 for scaling and shaping, and accordingly adjusts the duty cycle of its PWM output on line L39 to vary the alternator charging voltage (V_A2) between 16.4 and 13.6 volts in accordance with conventional battery charging current versus temperature requirements.

When wiper W1 of ignition switch 30 is turned to the start position, as shown in FIG. 1, ignition switch contact 32 provides current to actuate start solenoid 31 which pulls in contact 52 thus allowing start battery 10 to provide the current required to operate start motor 50. Microprocessor 200 also actuates EHC solenoid coil 323 during vehicle start by turning on solid state switches 331EHC and 332EHC for a selected timing period of twenty seconds. When switches 331EHC and 332EHC are turned on, as noted, solenoid 323 pulls in ganged power contacts 322 and 324. Power contact 322 routes heater current from EHC battery 300 to the EHC heater coil 320 and contact 324 shorts out shunt 303. At the end of the selected timing period, microprocessor 200 opens solid state switches 331EHC and 332EHC. In the event that microprocessor 200 detects a signal from engine thermistor circuit 350 that corresponds to the engine temperature being above a preselected “hot” temperature, microprocessor 200 opens solid state switch 331EHC, which prevents current from reaching the EHC solenoid coil 323, thus preventing heater current from flowing into the EHC heater coil 320. Separate control lines L331 and L332 respectively connect microprocessor 200 to switches 331EHC and 332EHC. It should be understood that, rather than a timing period, a first signal could be used to close switches 331EHC and the thermistor circuit 350 could be used to open circuit the switch once the engine has reached the desired temperature.

When wiper W1 is returned to the run position, as indicated in FIG. 7, a high input signal is applied on line L35 through I/O circuit 745. This high signal is sensed by microprocessor 200 which, in response, monitors the outputs of BSOC channels 60a, 60b and 60c on lines L25, L6 and L306 respectively, and maintains the output voltage of alternator 40 at a level required to recharge the start, run and EHC batteries 10, 20 and 300 in accordance with ambient temperature requirements. This charging continues until their respective charge levels are above a predetermined point. Again, as in the non-microprocessor version, contact 324 may be omitted where the shunt 303 is a length of battery cable, and BSOC channel 60c may be omitted.

When microprocessor 200 receives signals on lines L25, L6 and L306 from BSOC channels 60a, 60b and 60c respectively indicating that all three batteries are recharged, it reduces the PWM duty cycle on line L39 to cause the alternator output voltage V_A to drop to a level low enough to allow the terminal voltage of run battery 20 to back bias the rectifier diodes 742 on line L5. This removes the engine torque from the shaft of alternator 40 and allows the run battery 20 to provide all the vehicle load current. This is the preferred mode of operation for maximum fuel savings.

Thereafter, when microprocessor 200 receives a signal on line L7 from BSOC channel 60b that indicates run battery 20 state of charge is below a predetermined charge level, microprocessor 200 increases the alternator output voltage to a point where it can operate the vehicle in such a manner that it provides the required load current and a recharge current to run battery 20. (Alternately, the alternator output voltage is raised to a point where run battery 20 does not discharge further, but is not necessarily recharged.) The driver is also warned by display 80 that a source of charge external to the vehicle should be located as soon as possible to recharge run battery 20. An on board battery charger is preferably provided (not shown in FIG. 7, see FIG. 1).

Microprocessor 200 also monitors battery recharge current on lines L390, L391 and L392 which are respectively passed through input output circuit 744, to determine when recharge occurs. (See the output of amplifier A2 on FIG. 2).

In this embodiment, a wheel speed indicator circuit 95 is provided. Circuit 95 includes a permanent magnet 96 on a wheel speed or transmission shaft 97. It produces pulses proportional to wheel speed which are sensed each time magnet 96 passes a stationary pickup coil 98. Consequently, a train of pulses having a period inversely proportional to wheel speed is transmitted on line L95 to a pulse squaring circuit 99. The output of pulse squaring circuit 99 is transmitted on line L99, passed through input output interference circuit 745, to microprocessor 200. Microprocessor 200 thus can sense and record vehicle instantaneous speed, average speed, deceleration, and acceleration. It can use this information in the software program for controlling the system in response to these inputs. Vehicle deceleration, for instance, is computed by calculating the reduction in vehicle speed over a given time period. In particular, the use of wheel speed circuit 95 makes the pendulum circuit 70 of the non-microprocessor embodiment (see FIG. 1) unnecessary in the microprocessor controlled embodiment.

When microprocessor 200 senses vehicle deceleration it increases the output voltage V_A2 of alternator 40. As a result, the vehicle momentum, rather than the engine, is used to apply torque to the alternator shaft and provide a recharge current for charging run battery 20. This procedure applies recharge current without any fuel expenditure, and effectively extends the time the vehicle loads R_L+R_A can be operated off of run battery 20 without requiring an external recharge or recharging battery 20 by burning fuel.

Microprocessor 200 provides the operational advantage of not having to reduce the excitation current completely from rotor 44R of alternator 40 when the system is operating with run battery 20 providing current to the vehicle electrical loads. Microprocessor 200 can, in response to sensor inputs, provides a pulse width modulated current having a duty cycle just sufficient to provide the lowest possible current to alternator rotor 44R required to avoid sharing current with run battery 20 when it is being used. This removes the alternator torque from the engine as effectively as when all the current is turned off to rotor 44R.

The current to rotor 44R can be smoothly varied by microprocessor 200 to vary the output voltage level of alternator 40 to allow it to (a) share any portion of its output current to the vehicle loads along with run battery 20, (b) share none of its output current with the run battery 20, or (c) provide all of its output current to the vehicle loads and charge run battery 20. The desired alternator operating mode, a, b or c, above could be programmed from keyboard 82 by the system operator.

Microprocessor 200 also provides the capability of being reprogrammed to accommodate changing vehicle operating requirements that may occur between vehicles and with the addition of options.

Current outputs from BSOC channels 60a, 60b, and 60c on lines L390, L391, and L392, respectively, also are sensed by microprocessor 200 at the corresponding outputs of I/O circuit 744. The direction and amplitude of the currents into and out of batteries 10, 20 and 300 on the above lines are monitored for control and display purposes.

Microprocessor 200 also monitors the battery current in each of shunts 11, 21, and 303 for diagnostic and reset purposes. Failure of the charge current to drop below a preselected level on lines L390, L391 and L392 when the state of charge voltage of the monitored battery is above a preset level on lines L25, L6 and L306 respectively, is an indication of a bad cell in the associated battery.

Microprocessor 200 may be used to turn off automatically selected vehicle electrical accessories when the vehicle is parked, the ignition key is in the accessory position, and the start battery state of charge is below a preselected level. In this regard, a high voltage state signal from the “PRNDL” gear shift circuit 15 is transmitted on line L15 (through I/O circuit 745) when the shift lever (not shown) is in the park “P” position. A high voltage state signal also is transmitted on line L38 (passed through I/O circuit 745) when ignition switch wiper W4 is in the accessory position (contact 38) and a low voltage level signal is transmitted on line L25 when the state of charge of start battery 10 is below a preselected level. When these three conditions are satisfied, microprocessor 200 transmits a turn off signal on line L34 to solid state switch 34AC which removes battery discharge current from selected vehicle accessories R_L and R_A.

EXAMPLES

The advantages of the present invention are illustrated with reference to the fuel consumption test drives made with a 1988 General Motors Oldsmobile Cutlass, shown in FIG. 8, and a 1984 Ford Mercury Lynx, shown in FIG. 9.

All fuel measurements were made based on two-hour runs, under the weather conditions described below and the load currents on the alternator specified. Plot 8A represents highway driving in warm and dry road conditions. Plot 8B represents a combination of city and highway driving in light to heavy traffic and cool and raining road conditions. Plot 8C represents suburban driving in cool and dry road conditions. Plot 8D represents city driving in cool and dry road conditions. Plot 8E represents city driving in heavy traffic in cool and dry road conditions. Plot 9A represents highway driving. Plot 9B represents suburban driving in light traffic. Plot 9C represents suburban driving in heavy traffic. Plot 9D represents city driving in heavy traffic. For highway traffic, each car was driven one hour in one direction and one hour in the opposite direction, to balance out windage and other factors. Similarly, for suburban and city traffic, the path followed during one hour was essentially reversed during the second hour.

The current load on the alternator was varied by turning on various electrical devices in the car (such as the radio, windshield wiper, headlights, etc.), and was measured by one shunt in series with the alternator and one shunt in series with the battery. The fuel measurements were made by connecting a first fuel-flow meter in series with the gasoline tank supply line and a second fuel-flow meter in series with the fuel pump return line and subtracting the difference.

The percentage fuel savings achieved by operating at zero-load conditions, as compared with various current load conditions, can be calculated by the expression: $\%\text{Fuel savings}=\frac{{\mathrm{MPG}}_0-{\mathrm{MPG}}_{\mathrm{LOAD}}}{{\mathrm{MPG}}_{\mathrm{LOAD}}}\times 100$
wherein MPG₀ is miles per gallon at zero current load on the alternator and MPG_LOAD is miles per gallon at the selected load conditions and current load in amps.

The percentage fuel savings for the 1988 Oldsmobile Cutlass are shown below under Table I and in FIG. 8, while those for the 1984 Mercury Lynx are shown under Table II and in FIG. 9. The average of both is shown under Table III. The current load at 18 amps is a hypothetical driving condition based on the curves in FIGS. 8 and 9. With respect to Table III, the overall average includes highway, suburban and city driving, assuming that there is an equal amount of driving in each of these categories.

In FIGS. 8 and 9, the parenthetical numbers correspond to (amps, miles per gallon) (% fuel savings).

TABLE I
1988 OLDSMOBILE CUTLASS
			Current	%
			Load	Fuel
Driving Conditions	MPG0	MPGLOAD	(amps)	Savings
Highway Traffic	17.7	17.3	8	2.3
	17.7	16.8	18	5.4
Warm, Dry Conditions	17.7	16.25	26	8.9
	17.7	14.64	46	20.9
Highway and City	17.0	16.5	8	3.0
Traffic	17.0	16.3	18	4.3
Rainy, Cool Conditions	17.0	15.9	26	6.9
	17.0	13.8	46	23.2
Suburban Traffic	12.32	11.9	8	3.5
	12.32	11.05	18	7.6
Cool, Dry Conditions	12.32	10.97	26	12.3
	12.32	10.3	46	19.6
City Traffic	12.0	11.5	8	4.3
	12.0	11.1	18	8.1
Cool, Dry Conditions	12.0	10.6	26	13.2
	12.0	9.9	46	21.2
Heavy City Traffic	9.7	9.25	8	4.8
	9.7	8.8	18	10.2
	9.7	8.3	26	16.9
	9.7	6.8	46	42.6

TABLE II
1984 MERCURY LYNX
			Current	%
			Load	Fuel
Driving Conditions	MPG0	MPGLOAD	(amps)	Savings
Highway Traffic	32.5	31.8	8	2.2
	32.5	30.8	18	5.5
	32.5	30.2	26	7.6
	32.5	26.5	48	22.6
Suburban Light Traffic	25.5	24.2	8	5.4
	25.5	23.0	18	10.9
	25.5	21.5	26	18.6
	25.5	18.0	48	41.7
Suburban Heavy Traffic	23.2	23.1	8	0.4
	23.2	21.3	18	8.9
	23.3	20.5	26	13.2
	23.22	16.8	48	38.1
City Heavy Traffic	17.4	16.45	8	5.8
	17.4	15.0	18	16.0
	17.4	14.0	26	24.3
	17.4	11.8	48	47.5

TABLE III
Fuel Savings Average for Both Cars
Current Load	Driving Conditions	Percentage Fuel Savings
8	amps	Highway average	2.5
		Suburban average	3.1
		City average	5.0
		Overall average	3.53
18	amps	Highway average	5.3
		Suburban average	9.3
		City average	11.4
		Overall average	8.53
26	amps	Highway average	7.8
		Suburban average	14.6
		City average	18.1
		Overall average	13.5
46	amps	Highway average	22.2
		Suburban average	33.1
		City average	37.1
		Overall average	30.8

The cost savings from recharging run battery 20 from a conventional 115-volt line source is illustrated from the information set forth in Table IV. This information compares the cost of fuel to supply each of a very heavy current load, a moderately heavy current load, and a light current load from the alternator, to the cost of recharging the battery using an external line power charger. All of the examples are based on a 60 amp-hour and 720 volt-amp-hours discharge/charge (a 12-volt battery) while the vehicle was travelling in highway traffic at 60 mph.

The cost of electricity is based on 11.6¢ per Kw hr, which is a calculated average rate for electricity (summer and winter) for residential use in New York City ca. 1991-92, independent of taxes and other charges. Commercial rates for electricity tend to be higher depending upon volume and time of consumption. If the power source is the battery, corresponding to no load current from the alternator, the cost of electricity to recharge the battery from an external battery charger and restore 720 volt-amp-hours (0.72 Kw-hr), at 11.6¢ per Kw-hr, would be 8.4¢. This amount is the same for all examples.

The cost of fuel is based on $1.30/gallon. If the power source is the alternator, such that no current is provided by the battery, the fuel cost for running the electrical load off the alternator would be: $\mathrm{Cost}\left(\$\right)=\frac{{\mathrm{MPG}}_0-{\mathrm{MPG}}_{\mathrm{LOAD}}}{{\mathrm{MPG}}_{\mathrm{LOAD}}}\times \frac{\left[\mathrm{time}\mathrm{period}\times 60\mathrm{MPH}\right]}{{\mathrm{MPG}}_{\mathrm{LOAD}}}$
The time period is selected to obtain the 60 amp-hour discharge for the given current load at 60 MPH. The result of the calculations using the above formula and the data points on Tables I and II are set froth under Table IV below.

TABLE IV
			Cost of
	Time	Cost of	Operating
Current	60 Amp-Hour	Recharging	Off The	Cost Ratio
Load	Discharge	From External	Alternator	Fuel/
(Amps)	(hours)	Charger (¢)	(¢)	Electricity
1984 Mercury Lynx-Highway driving at 60 mph
8	7.5	39	8.4	4.6/1
26	2.3	42	8.4	5/1
48	1.25	67.6	8.4	8/1
1988 Oldsmobile Cutlass-Highway driving at 60 mph
8	7.5	76.4	8.4	9.1/1
26	2.3	91	8.4	10.8/1
48	1.3	$1.20	8.4	14.3/1

Generally, the greater the current load of the vehicle, the greater the savings when the current load is driven by run battery 20 only, provided that run battery 20 is recharged by an external line power charger.

The improvement in fuel economy realized by the present invention is proportional to the time the alternator is operated at a relatively reduced output voltage, e.g., at 12 or zero volts versus 13.6 to 14.7 volts.

A 10% fuel saving on every gas powered vehicle in the United States would amount to a reduction of 13.5 billion gallons of gasoline per year in the USA. This corresponds to saving approximately 20 billion dollars a year at the retail pump. It also translates into substantial reduction in undesirable gaseous and particulate emissions which result from fuel consumption.

One skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments which are presented for purposes of illustration and not of limitation.

Claims

1. A battery charging system for an automotive vehicle including a starter motor, a catalytic converter for reducing emissions, a fuel burning engine, and vehicle load and accessory load circuits, comprising:

a start battery for providing a discharge current for operating the starter motor to start the engine;

a run battery for operating vehicle load and accessory load circuits;

a storage battery having a first very high discharge current;

a heater for heating the catalytic converter to an elevated temperature in response to the first high discharge current;

means for initiating a starting operation by connecting the start battery to the start motor for a first period of time and for connecting the storage battery to the heater for a second period of time;

an alternator having a variable output condition including a regulated and selectable output voltage with an output current, the alternator being driven by the vehicle engine;

a first circuit for connecting the alternator output to the start battery for recharging the start battery;

a second circuit for connecting the alternator output to the run battery for recharging the run battery; and

a third circuit for recharging the alternator output to the storage battery for recharging the storage battery.

2. The system of claim 1 wherein the initiating means further comprises an ignition switch and control circuit for connecting the storage battery to the heater for at least a portion of the second time period prior to connecting the start battery to the start motor so that the catalytic converter is heated to an elevated temperature before actuating the start motor.

3. The system of claim 1 further comprising:

a fourth circuit for monitoring the state of charge of the start battery;

a fifth circuit for monitoring the state of charge of the run battery;

a control circuit for controlling the output of the alternator in response to the second states of charge of the start and run batteries, wherein the alternator output has one of a first output condition when the sensed state of charge of the start battery is above a first charge threshold and the sensed state of charge of the run battery is above a second charge threshold;

a second output condition when the sensed state of charge of the start battery is below the first charge threshold; and

a third output condition when the sensed state of charge of the start battery is above the first charge threshold and the sensed state of charge of the run battery is below the second charge threshold.

4. The system of claim 1 further comprising:

a fourth circuit for monitoring the state of charge of the start battery;

a fifth circuit for monitoring the state of charge of the run battery;

a sixth circuit for monitoring the state of charge of the storage battery;

a control circuit for controlling the output of the alternator in response to the sensed states of charge of the start, run and storage batteries, wherein the alternator output has one of

a first output condition when the sensed state of charge of the start battery is above a first charge threshold, the sensed state of charge of the run battery is above a second charge threshold, and the sensed state of charge of the storage battery is above a third charge threshold;

a second output condition when one of the sensed state of charge of the start battery is below the first charge threshold and the sensed state of charge of the storage battery is below the third charge threshold; and

a third output condition when the sensed state of charge of the start battery is above the first charge threshold and the sensed state of charge of the run battery is below the second charge threshold.

5. The system of claim 4 further comprising a first switch for switching the start battery out of the system when the start battery state of charge is above the first charge threshold and for connecting the start battery to the alternator output when the start battery state of charge is below the first charge threshold.

6. The system of claim 4 further comprising a first switch for switching the storage battery out of the system when the storage battery state of charge is above the third charge threshold and for connecting the storage battery of the alternator output when the storage battery state of charge is below the third charge threshold.

7. The system of claim 4 wherein the first output condition corresponds to no current being provided by the alternator to any of the run, start, and storage batteries and the second output condition corresponds to a recharge voltage and current being provided by the alternator to the start battery.

8. The system of claim 7 wherein the second and third output conditions are the same.

9. The system of claim 4 further comprising a line power charger for recharging the start, run, and storage batteries.

10. The system of claim 9 further comprising a switching network for selectively connecting the line power charger to those batteries that have less than a full state of charge.

11. The system of claim 4 further comprising a switch for disconnecting selected accessory loads from the run battery when the run battery state of charge falls below a fourth selected charge threshold.

12. A method of operating a battery charging system for an automotive vehicle including a starter motor, a catalytic converter for reducing emissions, a fuel burning engine, and vehicle load and accessory load circuit, comprising:

providing a start battery for providing a discharge current for operating the starter motor to start the engine;

providing a run battery for operating vehicle load and accessory circuits;

providing a storage battery having a first very high discharge current;

providing a heater for receiving the first high discharge current and heating the catalytic converter to an elevated temperature;

providing an alternator having a variable output condition including a selectable output voltage with an output current, the alternator being driven by the vehicle engine;

monitoring the state of charge of the start battery;

initiating a starting operation by connecting the start battery to the start motor for a first period of time and connecting the storage battery to the heater for a second period of time; placing the alternator output at a first output condition when the state of charge of the start battery is below a first charge threshold;

connecting the start battery to the alternator output for recharging the start battery following the starting operation; and

disconnecting the start battery from the alternator output when the start battery state of charge is above the first charge threshold.

13. The method of claim 12 further comprising:

monitoring the state of charge of the run battery;

setting the alternator output at a second output condition when the state of charge of the run battery is above a second charge threshold, the second charge threshold being less than a full charge; and

setting the alternator output at a third output condition when the state of charge of the run battery falls below a second charge level and applying the alternator third output condition to the run battery until the run battery is fully charged, the third output condition being at a higher voltage level than the second output condition.

14. The method of claim 13 wherein the third output condition provides for a fast recharge of the run battery, the method further comprising resetting the alternator output to the second output condition output when the run battery is fully charged.

15. The method of claim 12 further comprising:

monitoring the state of charge of the storage battery;

setting the alternator output voltage at a second output condition when the state of charge of the storage battery is above a second charge threshold, the second charge threshold being less than a full charge; and setting the alternator output voltage at a third output condition when the state of charge of the storage battery falls below the second charge threshold and applying the alternator third output condition to the storage battery until the storage battery is fully charged, the third output condition being at a higher output voltage level than the second output condition.

16. The method of claim 12 wherein initiating a starting operation further comprises connecting the storage battery to the heater for at least a portion of the second time period prior to connecting the start battery to the start motor so that the catalytic converter is heated before connecting the start battery to the start motor.

17. The method of claim 12 further comprising:

monitoring the state of charge of the run battery;

monitoring the state of charge of the storage battery;

controlling the output of the alternator in response to the sensed states of charge of the start, run and storage batteries, wherein the alternator output is selected to be one of

a first output condition when the sensed state of charge of the start battery is above a first charge threshold, the sensed state of charge of the run battery is above a second charge threshold, and the sensed state of charge of the storage battery is above a third charge threshold;

a second output condition when the sensed state of charge of the start battery is below the first charge threshold;

the second output condition when the sensed state of charge of the storage battery is below the third charge threshold; and

a third output condition when the sensed state of charge of the start battery is above the first charge threshold and the sensed state of charge of the run battery is below a fourth charge threshold.

18. The method of claim 17 further comprising switching the start battery out of the system when the start battery state of charge is above the first charge threshold and connecting the start battery to the alternator output when the start battery state of charge is below the first charge threshold.

19. The method of claim 17 further comprising switching the storage battery out of the system when the storage battery state of charge is above the third charge threshold and for connecting the storage battery to the alternator output when the storage battery state of charge is below the third charge threshold.

20. The method of claim 17 wherein in response to the run battery state of charge falling below the third level, the alternator output is maintained at the third output condition until the run battery is fully charged.

21. The method of claim 17 wherein the first output condition corresponds to no current being provided by the alternator to any of the run, start, and storage batteries.

22. The method of claim 21 wherein the second and third output conditions are the same and apply a charging current.

23. The method of claim 17 further comprising recharging the start, run, and storage batteries using a line power charger.

24. The method of claim 23 wherein the recharging step using a line power charger further comprises selectively connecting the line power charger to each of the start, run and storage batteries that have less than a full state of charge.

25. A battery charging system for an automotive vehicle having electrical accessory circuits and a fuel consuming engine comprising:

a start battery for starting the engine;

a rechargeable storage battery for operating the accessory circuits;

a circuit for monitoring the state of charge of the storage battery;

means for indicating when the storage battery state of charge is below a selected threshold charge level; and

a line power charger for recharging the storage battery having an input for receiving a supply of electricity.

26. The system of claim 25 further comprising:

an alternator having a selectable output voltage;

a circuit for electrically connecting the alternator output voltage to the battery for charging the battery;

a fuel consuming engine for driving the alternator; and

a control circuit for selecting the output voltage of the alternator in response to the sensed state of charge of the battery wherein the alternator output voltage has a first level when the sensed state of charge is above a first charge threshold and a second level when the sensed state of charge is below the first charge threshold.

27. The system of claim 26 wherein the second voltage level is selected to charge the battery to a full state of charge.

28. The system of claim 26 further comprising:

a start battery for starting the engine;

a second circuit for monitoring the state of charge of the start battery;

a first switch circuit for switching the start battery out of the system when the engine is operating and the start battery is fully charged;

an EHC battery for heating an EHC coil during vehicle starting;

a circuit for monitoring the engine temperature;

a second switch circuit for switching the EHC battery out of the system in response to one of the engine temperature being above a selected temperature and the end of a preselected time period; and

a switching network for connecting the line power charger to each of the storage battery, the start battery and the EHC battery.

29. The system of claim 25 wherein the line power charger is mounted on board the vehicle.

30. In an automotive vehicle having a start battery, a start motor, an ignition switch having a vehicle start operation for connecting the start battery to the start motor for starting the vehicle engine and a catalytic converter for reducing undesired vehicle engine emissions, a system for reducing vehicle emissions during starting comprising:

a rechargeable storage battery having a very high discharge current capacity;

a line power charger for recharging the storage battery having an input for receiving a supply of electricity;

a heater for heating the catalytic converter to an elevated temperature in response to receiving the high discharge current;

a switch having a closed condition for connecting the storage battery to the heater so that the high discharge current will pass into the heater which then heats the catalytic converter and an open condition for switching the storage battery out of the system; and

a control circuit for placing the switch in the closed condition during the vehicle start operation so that the high discharge current will pass into the heater which heats the catalytic converter.

31. The system of claim 30 further comprising:

a circuit for monitoring the state of charge of the storage battery; and

a switch for connecting the storage battery to the line power charger when the sensed state of charge of the storage battery is below a selected charge threshold for charging the storage battery.

32. The system of claim 30 wherein the control circuit further comprises a timing circuit for closing the switch for a selected first period of time in response to the onset of the vehicle start operation.

33. The system of claim 32 wherein the control circuit further comprises:

a sensor for providing a signal representing the temperature of the vehicle engine; and

a second switch for disconnecting the storage battery from the heater in response to the sensed engine temperature being above a selected temperature corresponding to the temperature at which the catalytic converter is effective to reduce engine emissions.

34. The system of claim 32 wherein the control circuit further comprises a delay circuit, responsive to the beginning of the vehicle start operation, for delaying connecting the start battery to the start motor for a selected second time period following closing of the switch for connecting the storage battery to the heater so that the catalytic converter is heated prior to starting the vehicle engine.

35. The system of claim 34 wherein the second time period is shorter than the first time period.

36. The system of claim 32 wherein the first time period is on the order of twenty seconds.

37. The system of claim 32 further comprising a second catalytic converter in series with the other catalytic converter, wherein the second catalytic converter is normally heated to an effective operating temperature by the engine.

38. The system of claim 31 in which the vehicle includes an alternator for charging the start battery, wherein the storage battery has greater voltage rating than the start battery and the system further comprises a voltage converter for charging the storage battery from the alternator.

39. The system of claim 30 in which the vehicle includes an alternator for charging the start battery, further comprising:

a switch for selectively connecting either the alternator or the line power charger to the storage battery to recharge the storage battery.

40. In an automotive vehicle having a start battery, a start motor, an ignition switch having a vehicle start operation for connecting the start battery to the start motor for starting the vehicle engine, and a catalytic converter for reducing undesired vehicle engine emissions, a method for reducing vehicle emissions during starting comprising:

(a) providing a rechargeable storage battery having a very high discharge current;

(b) providing a line power charger for recharging the storage battery having an input for receiving a supply of electricity;

(c) providing a heater for heating the catalytic converter to an elevated temperature in response to receiving the high discharge current;

(d) connecting the storage battery to the heater during the starting operation so that the high discharge current will pass into the heater which heats the catalytic converter; and

(e) switching the storage battery out of the system after the vehicle engine has started.

41. The method of claim 40 in which the vehicle includes an alternator for charging the start battery, further comprising:

monitoring the state of charge of the storage battery; and

connecting the storage battery to the line power charger when the sensed state of charge of the storage battery is below a selected charge threshold for charging the storage battery.

42. The method of claim 40 wherein step (d) further comprises connecting the storage battery to the heater for a selected first period of time in response to the beginning of the vehicle start operation.

43. The method of claim 42 wherein steps (d) and (e) further comprise:

sensing the temperature of the vehicle engine; and

disconnecting the storage battery from the heater in response to the sensed engine temperature being above a selected temperature corresponding to the temperature at which the catalytic converter is effective to reduce engine emissions.

44. The method of claim 42 further comprising delaying connecting the start battery to the start motor for a selected second time period in response to beginning the vehicle start operation and following connecting the storage battery to the heater so that the catalytic converter is heated prior to starting the vehicle engine.

45. The method of claim 44 wherein the second time period is shorter than the first time period.

46. The method of claim 42 wherein the first time period is on the order of twenty seconds.

47. The method of claim 40 in which the vehicle includes an alternator for charging the start battery, wherein the storage battery has a greater voltage rating than the start battery and the method further comprises providing a voltage converter for charging the storage battery from the alternator.

48. The method of claim 40 in which the vehicle includes an alternator for charging the start battery, further comprising:

selectively connecting either the alternator or the line power charger to the storage battery to recharge the storage battery.

49. The method of claim 40 further comprising providing a second catalytic converter in series with the other catalytic converter and heating the second catalytic converter to an effective operating temperature from the engine.

50. A method of operating an automotive vehicle that contains a fuel consuming engine, an electric generator driven by the engine, a battery charger, and at least one rechargeable run battery of the deep discharge type, capable of being discharged to and recharged from a deep discharge level repeatedly, said method comprising the steps of:

(a) supplying energy to the vehicle from the at least one run battery;

(b) discharging the at least one run battery to a substantially deep discharge level while the at least one run battery is supplying energy to the vehicle;

(c) determining when the at least one run battery has discharged to the substantially deep discharge level;

(d) automatically charging the at least one run battery from the substantially deep discharge level to a recharged level by supplying energy from the electric generator to the at least one run battery;

(e) repeating steps (b), (c) and (d) a multiplicity of times;

(f) recharging the at least one run battery from an external power source using the battery charger, the battery charger converting voltage from the external power source to a d-c voltage of a suitable level for recharging the at least one run battery; and

(g) repeating step (f) a multiplicity of times.

51. The method of claim 50, wherein the recharged level is about at a full charge of the at least one run battery, and wherein said step (d) includes automatically charging the at least one run battery from the substantially deep discharge level to about the full charge.

52. A method of operating an automotive vehicle that contains a fuel consuming engine, an electric generator driven by the engine, a battery charger, and at least one rechargeable run battery of the deep discharge type, capable of being discharged to and recharged from a deep discharge level repeatedly, said method comprising the steps of:

(a) supplying energy to the vehicle from the at least one run battery;

(b) discharging the at least one run battery to a substantially deep discharge level while supplying energy to the vehicle;

(c) determining when the at least one run battery has discharged to the substantially deep discharge level;

(d) automatically supplying energy from the electric generator to the at least one run battery to maintain the charge of the at least one run battery at about the substantially deep discharge level, while the at least one run battery is supplying energy to the vehicle;

(e) recharging the at least one run battery from an external power source using the battery charger, the battery charger converting voltage from the external power source to a d-c voltage of a suitable level for recharging the at least one run battery; and

(f) repeating steps (b), (c), (d) and (e) a multiplicity of times.

53. A method of operating an automotive vehicle that contains a fuel consuming engine, an electric generator driven by the engine, a battery charger, and at least one rechargeable run battery of the deep discharge type, capable of being discharged to and recharged from a deep discharge level repeatedly, said method comprising the steps of:

(a) supplying energy to the vehicle from the at least one run battery;

(b) discharging the at least one run battery from approximately its full charge level to a predetermined level that is no more than 50% below its full charge level, while the at least one run battery is supplying energy to the vehicle;

(c) determining when the at least one run battery has discharged to the predetermined level;

(d) automatically charging the at least one run battery from the predetermined level toward a recharged level by supplying energy from the electric generator to the at least one run battery;

(e) repeating steps (b), (c) and (d) numerous times;

(f) recharging the at least one run battery from a home power source using the battery charger, the battery charger converting voltage from the power source to a d-c voltage of a suitable level for recharging the at least one run battery; and

(g) repeating step (f) numerous times.

54. The method of claim 53, wherein the recharging of the at least one run battery is done from the home power source numerous times when the state of charge of the at least one run battery is above the predetermined level.

55. The method of claim 53, wherein the recharging of the at least one run battery from the electric generator is done repeatedly, whenever the state of charge of the at least one run battery decreases to the predetermined level.

56. The method of claim 53, wherein the at least one run battery generates a first dc voltage potential, said method further comprising the step of converting the first dc voltage potential to a second dc voltage potential, said step (a) including applying the second dc voltage potential to the vehicle.

57. The method of claim 53, further comprising the steps of:

sensing the deceleration of the vehicle; and

automatically supplying a charging current to the at least one run battery in response to the deceleration of the vehicle.

58. The method of claim 53, further comprising the steps of:

sensing when the vehicle is accelerating and decelerating in stop and go traffic; and

automatically supplying a charging current to the at least one run battery when the vehicle is decelerating in stop and go traffic.

59. The method of claim 53, further comprising the steps of:

indicating how long it will take to recharge the at least one run battery.

60. The method of claim 53, further comprising the step of:

providing an indication, after the at least one run battery has begun to discharge, when a preselected charge level of the at least one run battery has been reached, the preselected charge level being above the predetermined level to give an advance warning that the charge of the at least one run battery is approaching the predetermined level.

61. A method of operating an automotive vehicle that contains a fuel consuming engine, an electric generator driven by the engine, and at least one rechargeable run battery of the deep discharge type, capable of being recharged from a deep discharge repeatedly, said method comprising the steps of:

(a) supplying energy to the vehicle from the at least one run battery;

(b) discharging the at least one run battery to a predetermined level while the at least one run battery is supplying energy to the vehicle;

(c) determining when the at least one run battery has discharged to the predetermined level;

(d) automatically supplying energy from the electric generator to the at least one run battery, once the charge on the at least one run battery has discharged to said predetermined level, to increase the charge on the at least one run battery;

(e) recharging the at least one run battery from an external power source using a battery charger, the battery charger converting voltage from the external power source to a d-c voltage of a suitable level for recharging the at least one run battery; and

(f) repeating steps (b), (c), (d) and (e) numerous times.

62. A passenger car comprising:

at least one rechargeable run battery of the deep discharge type, capable of being discharged to and recharged from a deep discharge level repeatedly;

a fuel consuming engine;

an electric generator coupled to said engine and to said at least one run battery, and responsive to said engine for charging said at least one run battery;

a first circuit connected to said at least one run battery and configured to determine when said at least one run battery has discharged to a predetermined discharge level;

a second circuit, responsive to said first circuit and coupled to said generator, for automatically supplying energy repeatedly from said generator to said at least one run battery each time said predetermined discharge level is determined, the energy supplied from said generator to said at least one run battery being a charging current that charges said at least one run battery toward as recharged level; and

a battery charger mounted onboard the car for repeatedly recharging said at least one run battery from an external power source, said battery charger converting a-c voltage from the external power source to a d-c voltage of a suitable level for recharging said at least one run battery.

63. A passenger car as in claim 62, further comprising:

an indicator in the car for indicating how long it will take to recharge the at least one run battery.

64. A passenger car as in claim 62, further comprising:

an indicator in the car for indicating the charge remaining on said at least one run battery during the time said at least one run battery is discharging to said predetermined discharge level.

65. A passenger car as in claim 64, further comprising:

a warning indicator that provides a visible or audible warning a preselected time before the predetermined discharge level is reached.

66. A passenger car comprising:

at least one rechargeable run battery of the deep discharge type, capable of being discharged to a deep discharge level and recharged repeatedly;

a fuel consuming engine;

an electric generator coupled to said engine and to said at least one run battery, and responsive to said engine for charging said at least one run battery;

a first circuit connected to said at least one run battery and configured to determine when said at least one run battery has discharged to a predetermined discharge level;

a second circuit, responsive to said first circuit and coupled to said generator, for automatically supplying energy from said generator to said at least one run battery when said at least one run battery has discharged to the predetermined level, the energy supplied from said generator to said at least one run battery being a charging current that charges said at least one run battery toward a recharged level; and

a battery charger mounted onboard the car and connected to said at least one run battery for repeatedly recharging said at least one run battery from an external power source, said battery charger converting voltage from the external power source to a d-c voltage of a suitable level for recharging said at least one run battery.

67. A passenger car as in claim 66, wherein:

said first circuit determines each time said at least one run battery has discharged to the predetermined level;

and wherein said second circuit responds to a signal from said first circuit each time said first circuit determines that said at least one run battery has discharged to the predetermined level, to supply energy repeatedly from the generator to said at least one run battery.

68. A passenger car as in claim 66, further comprising:

a sensing circuit for sensing deceleration of the car; and

a battery charging circuit responsive to said sensing circuit for supplying a charging current to said at least one run battery when deceleration of the car is sensed.

69. A passenger car as in claim 66, further comprising:

a sensing circuit for sensing when the car is accelerating and decelerating in stop and go traffic; and

a battery charging circuit responsive to said sensing circuit for supplying a charging current to said at least one run battery when the car is decelerating in stop and go traffic.