KR100310031B1 - 3-pole battery switch - Google Patents

Abstract

In a three-pole vehicle battery with a starting battery (2) and an auxiliary device battery (8), the device connects and disconnects the similar electrodes 6, 12 so that the electrodes accept charge, and the switch R2 is electrically assisted. A battery that connects and disconnects the device from an auxiliary battery. The device senses the state of charge of the auxiliary battery and senses the current flowing from the auxiliary battery to the starting battery. The microprocessor uses this and excess data to open R2 to prevent any discharge of the spare battery, close R1 to allow charging of the starter battery, and to help the starter battery to partially discharged batteries, Open R1 when overcharge is indicated.

In the second variant, only switch R1 is present but the detector senses the operator's needs to initialize the vehicle, and closes R1 to combine the output of the crank and the auxiliary battery.

Description

3 pole battery switch

1 shows a three pole battery and two relays forming part of a switch.

2a to 2c are flow charts of the switch.

3 is a circuit diagram of the device.

4 is a block diagram of the FIG. 3 circuit showing the input and output of the microprocessor.

5 shows a variation of one switch operation between similar poles of a battery using isolation voltage detection.

FIG. 6 is a perspective view of an automotive battery, a starter motor, and an ignition switch showing an installation manner of the FIG. 5 variant.

7 is a circuit diagram of the FIG. 5 variant.

8 is a circuit diagram of the FIG. 5 variation.

9 is a block diagram of input to output from a microprocessor for the FIG. 5 variant.

<Description of the symbols for the main parts of the drawings>

2: CRA battery 4: motor

8: AUX Battery 10: Conductor

16 current sensor 22 piezo disc

[Technical Field]

The present invention relates to a switch used for applying a three-pole battery to the junction box of a vehicle. This switch is used in vehicles with gasoline or diesel motors, ships, aircraft, and other vehicles where the risk of battery failure is expected.

Background Technology

The three-pole battery contains two batteries. First, a deep cycle auxiliary battery (AUX) is used for constant small loads such as ignition, headlights, radios and other accessories, and secondly there is a high output CRA battery (CRA).

The battery has one cathode, one anode for the AUX battery, and one for the CRA battery. This dual current capability means that the battery must be assisted by a control system that controls the interconnection of the two batteries in order for the battery to be installed in the vehicle's original junction box and function automatically, so that the current source is completely independent of the operator's mistake do.

The vehicle purification system / engine management system can attract up to 10A of current. Auxiliary circuits, ie air conditioning circuits and rear window heating, require more than 30 A when they are all switched on. This demand is addressed by AUX batteries. Cranking requires a short instantaneous current above 7OOA.

US Pat. No. 4,833,228 describes a three pole SLI battery and a switch for applying the battery to a junction box of a vehicle. This switch does not address the real problem of applying these two batteries to the vehicle.

Dividing the battery into two halves puts a certain burden on the switch. First, the switch must connect the CRA battery and the AUX battery for charging. Secondly, this switch should ensure that the CRA battery is not discharged and unusable if the vehicle is left unattended with some assistive devices turned on.

Third, when the vehicle is running, this switch must prevent gradual discharge of the CRA battery. For example, a city cab in heavy traffic, with heaters, wipers, radios and lights running, easily exceeds its output. The winch of the truck requires 100 A. Emergency service vehicles face the same problem, but they also have additional lights, medical equipment and monitors. These devices must also be able to handle such loads. The switch must be able to ignite at least the CRA battery after an alternator failure if the output of the AUX battery is insufficient. The switch must maximize the available stocking time even in emergency situations such as generator failure.

Fourth, if the AUX battery is discharged, the switch must connect two batteries to start the vehicle.

Fifth, when the two batteries are charged, the CRA battery voltage drops as you turn the starter motor, but the AUX battery must provide the full voltage to the ignition. The “hot” sparks made possible by disconnecting the battery promote reliable start-up even in cold weather.

In addition, the switch responds to charging and discharging and must respond to the driver's intention to start the vehicle. In addition, the switch is easy to assemble, is as universal as possible, functions equally well in all kinds of vehicles in which the switch is assembled, has a lifespan equivalent to a battery, and if possible the vehicle itself is low power consumption, for emergency services, navy or army use. It is desirable to be reliable enough and suitable for low-cost mass production.

The design of these switches has become more complex as new combinations of situations arise during testing. Some of these situations do not occur in 2-pole battery operation. First, it is common to connect the CRA battery and the AUX battery with a relay that slowly discharges the battery by flowing current on its own.

Second, for the AUX battery to be protected by the relay, the charge level at which the cut out occurs must be determined. If the charge level is too high, the running lights and heaters are disabled, and if it is too low, the driver can drain the battery significantly. There are several ways to determine the stage at which the relay should be interrupted. Only terminal voltage is an unreliable indicator. Terminal voltage is greatly affected by current flow. In other words, the state of charge of the battery cannot be evaluated solely with the available voltage. If a small load is applied to the AUX battery, the battery will discharge without a significant drop in available voltage, but if a large load is applied, a large voltage drop will appear immediately. The charge left in the battery tends to change in proportion to the prevailing load. To prevent accidents, it must be impossible to cut out the current during operation.

When discharged in cold weather, the battery electrolyte may freeze, so the cutout voltage should be chosen with consideration of freeze protection where possible. Third, when the voltage drops below a predetermined value, the AUX battery can be disconnected from the accessory devices to prevent the AUX battery from being severely discharged. Fourth, CRA batteries must be protected from the tendency to overcharge. This protection can be achieved by cutouts when the battery becomes too hot. The ambient temperature below the bonnet varies greatly. In practice, it is difficult to fix the operating thresholds for cutouts to get satisfactory results.

In Japanese Patent Document 3-49541A, a pair of batteries in a vehicle that guarantees start-up and is connected to an accessory device and prevents an error during a changeover, and a predetermined voltage drop can be detected in the battery under load. It describes a facility consisting of a switch that changes the load to another load.

Japanese Patent Document 4-200244 discloses a protection circuit for a vehicle battery, in which an audible alarm alerts the driver that the light is on when parked, and when the detected battery voltage drops to a predetermined threshold, the circuit turns off the light. Turn off

US 4 902 956 discloses a safety device for a conventional battery, which disconnects the battery from the accessory device when the microprocessor commands the shutdown according to the state of charge of the battery. The accessory is then disconnected from the bank. The operator must reconnect by hand. This method cannot be applied to a three-pole battery with two switches and a priority. None of these is to solve the above problem.

[Summary of invention]

A first aspect of the invention provides a three pole battery system comprising an AUX battery for supplying an electrical auxiliary device, a CRA battery and an electrical auxiliary device connected to the AUX battery, and a device for connecting between two similar poles of the battery. In a vehicle electrical system, the device detects the charge state of the AUX battery, a conventional open switch (R1) that connects the AUX and CRA batteries, prevents overcharging and prevents cranking and auxiliary functions and charge state of the AUX battery. Sensing means for opening R1 to maintain each output to close R1 when reduced, such that the AUX battery is preferentially discharged as long as it still maintains a sufficient CRA battery charge state to start the vehicle. .

A second aspect of the invention provides a vehicle electrical system as described above, a device for connecting between similar poles of a battery, said device comprising

(a) a conventional open switch (R1) connecting the CRA and AUX batteries,

(b) a normally closed switch (R2) connecting the AUX to the electrical auxiliary device,

(c) detect the charge state of the AUX battery and any current from the AUX battery to the CRA battery, i) connect and disconnect the CRA and AUX batteries, ii) allow the system to charge the CRA and AUX batteries, and And sensing means for connecting the AUX battery to the electrical auxiliary device and for disconnecting the AUX battery from the electrical auxiliary device in order to respond to the load.

The switch provides an auxiliary battery protection device comprising a switch to disconnect the auxiliary device from the AUX battery in accordance with the charge state of the AUX battery.

The switch may be a latching relay. Such relays do not add any quiescent current drop on the battery. The state of charge may be evaluated by measuring both the current and voltage available in the AUX battery. Evaluation can be discussed based on main temperature, electrolyte concentration, battery life and internal resistance.

If fully charged, the voltage drop to 12.68V and then to 12.1V is small but hinders low current availability. Therefore, the switch must apply both values before connection or disconnection occurs. Alternatively, the rate of change of the voltage may be measured and used to operate the relay. Therefore, the auxiliary voltage is periodically sampled, and ΔV is used to drive a signal for operating the relay. The purpose is to maintain a charge of a useful size in AUX batteries. Extreme discharge quickly drains the battery.

Other device features of the present invention

(a) data storage means suitable for storing data indicating battery current, voltage, temperature, vehicle failure detection or engine start-up;

(b) data input means suitable for inputting data relating to battery current, voltage, temperature, vehicle fault detection or engine starting;

(c) comparison means for comparing the current available to the accessory to the state of charge of the AUX battery and for generating a signal to connect or disconnect the accessory to protect the state of charge,

Provides data for handling assemblies used in battery control devices.

The state of charge to be separated is preferably 10% of the maximum charge at a mild ambient temperature ie above 2 ° C. In colder climates, such as Canada, where winter temperatures drop to -35 ° C, the state of charge is set at 60% of full charge.

The comparison means also protects its state of charge by comparing the current flowing between the AUX and CRA batteries with the value of the data storage means to open or close the relays connecting the CRA and AUX batteries.

Providing a switch connected between two batteries having a CRA battery and an AUX battery of the present invention and the same two bars of test voltage applied to the more electrically positive side of the switch indicating that the driver wishes to start the vehicle and Where the switch engages a relay that is connected in response to detection on one side of the starter switch.

If the relay is disconnected in response to a voltage dropping to the set level on the AUX battery, improved switch operation is the result. Reconnection occurs when the voltage exceeds another set level.

Switch operation is also improved if the relay opens when the switch detects a current above the set maximum flowing from the AUX battery to the CRA battery.

The switch therefore connects and disconnects two batteries in response to voltage sensing, excessive current flow and detected startup conditions.

The invention also provides a switch incorporating a relay that opens in response to any of the above two conditions.

In the voltage sensing associated with this, the relay opens when the AUX battery voltage drops to a predetermined range lower than 12.55V. The reference voltage is delivered by the band gap generator to a comparator where the AUX battery compares the available voltage with the reference voltage and the synthesized signal drives the relay. The relay is closed at 12.9V and open at 12.55V by hysteresis in the circuit. This prevents unnecessary relay operation in response to small voltage drops caused by auxiliary devices such as direction indicators.

The signal voltage is derived from an insulated supply that is not related to the ground of the vehicle. A blocking diode is inserted between the ignition switch and the starter solenoid because there is a very low resistance path through the vehicle ground system from one side of the switch to the other.

When an isolated voltage supply is introduced to the conductor connecting the AUX anode to the ignition switch, the voltage normally sinks the auxiliary device but does not complete the circuit through the starter solenoid due to the blocking diode. The facility for insulated voltages and blocking diodes ensures that the relay is initially closed and therefore open for vehicle starting. This represents separating the output of the CRA battery cranking the cold motor from the output of the AUX battery to the hotspark facility.

The isolated voltage may instead be generated by the engine computer but the means is economical and effective since it performs control without causing minor disturbances to the vehicle electrical system and no redesign such as engine computer revision is required.

In other variations, the keyswitch itself is modified to make the isolation voltage supply independent, but this specification looks at the adaptive proposal rather than the redesign pathway.

Turning the key to the start position allows the relay to be latched in the connected state for 30 seconds, but the repeated connection circuitry is blocked when it detects that both batteries are charged and remains blocked for 6 seconds. Separation of the two batteries will provide a spark.

In fact, many charge / discharge states occur in the vehicle SLI battery and any of the three sensing states that provide input to the switch regarding the operation of the relay can ignore the other two operations. Key positions have priority only at the beginning. The device thus offers the advantages of a specialized system. No human interference is required.

Hereinafter, with reference to the accompanying drawings will be described in more detail the present specification.

Referring first to Figure 1, the CRA battery 2 is connected to the starter motor 4 via the pole 6 and the AUX battery 8 is connected by the conductor 10 from the pole 12 to the auxiliary device ( Not shown). The pole 14 serves both batteries. It is connected and disconnected by a relay R1 which receives a signal from the interface circuit of the SGS Thomson ST6220 microprocessor P (see FIG. 2) of the pseudo poles 6 and 12. FIG. The current flowing from the AUX battery to the CRA battery when R1 is closed is detected by the current sensor 16. The sensor is branched. The value (0 to 255) for the current magnitude is fed to the data entry bus at microprocessor μP.

Similar sensor 18 senses the AUX current in conductor 10. The voltage sensor 20 connected in parallel detects an auxiliary voltage. Battery voltages from the piezo disk 22 and the semiconductor LM 337 detector, which sense movement such as two different inputs, driver entry and engine travel, reach the bus in the microprocessor. These are input data for the microprocessor and are given in code of the following manner. The input range is shown in FIG.

R1 is normally open, the output signal from the microprocessor closes the relay and connects the batteries such that the battery output is added. R1 is open and closed continuously to charge both batteries during operation. R2 has a 0N coil and an OFF coil and is bistable so that a pulse of current changes state. R2 only opens to modify the state, which only tends to disable the discharge from time to time.

R2 operation is improved by providing transistor Q5 in parallel with the relay. When R2 is closed, transistor Q5 remains on, but when the vehicle is not running, no improvement is detected for 30 seconds, the power consumption of the auxiliary device drops below 2A, and no incoming charging current is detected. That is, the voltage at the AUX terminal saves 100mA by disconnecting R2 below the voltage of the auxiliary device, and transistor Q5 becomes a single conductor for the auxiliary device.

When the microcomputer detects that the AUX battery voltage falls to the predetermined attention level, the transistor Q5 is switched off to save the AUX battery. When the moment when the transistor Q5 is switched on is detected, the current increases or the voltage on the auxiliary device becomes equal to or higher than the AUX battery voltage and R2 is connected. Thus, transistor Q5 assists when the vehicle is not used and no heavy load is applied.

Referring to FIG. 2, μP consumes only mA and functions as an aid to engine operation.

4 shows an input for receiving:

1. (AUX) voltage

2. AUX Current

3. Current flowing from AUX to CRA

4. Temperature

5. Vehicle boarding

6. Engine operation

The output is as follows:

a. R1

b. R2 connection

c. Transistor Q5 not connected

The unit operation is as follows:

The vehicle is driven as AUX no-load and both AUX and CRA batteries are charged. The noise detector indicates that the vehicle is running. The driver parks the vehicle as AUX no load. R1 and R2 remain connected. The clock memory remains intact. R1 induces a current, is in a charged state, and R1 is cut out. If the driver switches on the amplitude light and R1 is not already cut out, and R1 is cut out, the microprocessor periodically samples the charge state of the AUX battery. If the state of charge is at a preset threshold (adjusted to temperature), ie 10% at 20 ° C, 25% at -10 ° C and 60% at -35 ° C, R2 blocks the AUX no-load. Therefore, the streetlight switches off the battery for the vehicle to start.

When the driver starts the vehicle, the piezo detector detects it and R2 is shut off to provide ignition, and the microprocessor guarantees a 30 second connection to start. If the AUX output is low, R1 is cut in to support ignition.

When running, R2 is connected for safety purposes regardless of the state of charge. If the vehicle does not start for the allowed 30 seconds, the microprocessor continuously samples the state of charge of the AUX battery and if he is at a preset threshold, R2 is cut out.

When the vehicle is started and driven, it charges the alternator CRA battery, and the microprocessor samples the same state of charge, calculating the state of charge to make a genuine product that takes into account temperature, current, voltage, battery capacity, and battery life. If the CRA battery must be fully charged, R1 is cut out to prevent overcharging. Destroyed fan belts create overheating problems that result from cooling water circulation failures faster than some of the accessories fail. The alternator must not run to keep the AUX charge low, R2 and R1 closed, and R1 and R2 remain closed until the vehicle finally stops due to lack of ignition voltage. Also, R2 never falls off while the car is in operation. If the internal switch fails, for example, if the AUX battery box needs to be charged at 13.5V based on the voltage at the AUX terminal, but the piezo detector does not indicate charging, the system will fail and the standby code will fail. It is assumed that R2 does not fall off. Batteries of this type tend to be used in military and commercial four-wheel drive vehicles and emergency vehicles and in ships where performance is a concern. Because the AUX battery begins discharging first, the CRA battery can still drive the motor and provide the ignition voltage even if the AUX battery drops to the lowest voltage too low to ignite in an emergency when both batteries are discharged. In ships where a motion sensor such as a piezo device is not available, a homogeneous switch is used to close R2 upon departure.

Inductive pick ups close to electrical components, such as spark plugs, detect operating conditions where piezo devices are not practical.

Advantages of the device described above are as follows.

a) R2 will never fall off while the vehicle is in motion;

b) Freezing of the battery does not occur well.

c) The output of AUX battery is maximized.

d) The battery has a longer life.

e) prevent overcharging;

f) Prolongs battery life by preventing excessive discharge of AUX batteries.

Referring first to FIG. 5, the CRA battery 2 is provided to the starter motor 4 via the pole 6. The AUX battery 8 is connected from the pole 12 to electrical auxiliaries by the conductor 10. The poles 6 and 12 are connected or disconnected by relay R1 to receive signals from the interface circuit of the microprocessor μP.

The cable 24 connects the pole 8 to the starter motor 4 via the starter solenoid 26. The lead 10 connects the AUX battery to the alternator A. The lead 10 also connects the AUX battery to another accessory, such as lights 30. The isolated signal voltage receives F at FEED IN and S is detected at SENSE. The blocking diode 32 is disposed close to the key switch 34. Diodes such as device 28 are components added to the vehicle circuit.

The two components are shown in FIG. The switch 28 lies on the lead of the battery. The starter solenoid 26 is connected to the key switch 34 by the lid 36. A push of the connector 38 comprising a diode lies between the solenoid 26 and the tag 40 at the end of the lead 36. It is connected to the ST position of the key switch 34.

[Voltage sensing]

Referring to FIG. 3, this means of operating relay R1 takes the lowest priority. Voltage detection detects the voltage of the AUX battery via R9 (10) and RU2. RU2 allows precise setting of a given switching point. The UIC is a voltage follower that buffers the input and sends about 1/10 of the AUX voltage to the comparator UID. The negative input of the comparator derives directly from the precision ref (Z1). When about one-tenth of the AUX voltage exceeds the ref voltage, the output of the UID rises and Q1 turns on by allowing current to flow through the relay to connect it. Hysteresis is provided to R12 and R13 to reduce noise and facilitate switching operation.

Thus, relays often operate in response to voltage sensing because the change in engine speed and the use of braces are constantly changing.

[Isolated voltage supply]

U4 556 looks like a dual oscillator, reducing the power consumption of the switch. U4B vibrates at about 6Hz and U4B vibrates at about 6KHz, providing the Q output of part B to the reset input of A. Therefore, based on Q3, a short explosion of 6 KHz arrives at the current amplifier.

T1 is an isolation transformer whose output is the bridge rectified by D1-4 and the output dc voltage is stored in capacitor C8. The generation of the isolated dc voltage is necessary to avoid low resistance paths to the normal battery source supplied when the light remains. U3 optocouplers are used as detection devices. When the key is turned to START it provides a negative impulse at the input to the comparator U2B.

R3, D5, C5 provide latching of these pulses. Key switch detection remains on for the time constant of R3-C5. U2A consists of a comparator that is biased such that the reference input of the comparator is close to one fifth of the crank voltage. As long as the voltage at the other input is higher than the reference voltage, the output is high, thus turning on Q1 and providing current through relay (R1) to connect the AUX battery to the CRA battery. These sources are separated from the current paths available in the auxiliary circuits, in that the direct current is not available in any of the available ground windings providing chassis and for example light and starter solenoids. The blocking diode 24 allows current to flow in only one direction.

If the driver's key is in the ST position, the voltage is detected and the opto-coupler R1 / R2 sends a short period of signal obtained by the amplifiers U2: 8 and U2: A. The amplified signal switches on transistor Q1 and relay R1 is closed. CRA batteries provide a cracking current. AUX activates the coil and starter solenoid. When the opto-coupler generates a simple voltage signal that indicates to the switch that the driver is starting the vehicle, the condenser C5 induces a delay so that a 5 second delay prevents the key switch from operating immediately again. This leaves the relay commanded by another sensor. The best starting condition exists if the auxiliary battery is discharged when the relay is open and both batteries are at their input, but the vehicle only starts if the CRA battery is connected to the coil via the relay.

[Overcurrent Protection]

It is to be understood that the AUX battery cannot support the CRA battery because of the different current levels. Regardless of whether the CRA battery is discharging for any reason, current flows from the secondary battery as soon as the relay is connected when charging. The transient sensor only monitors the current flowing from the AUX to the CRA battery (not reverse) and blocks currents above 40A.

The purpose of the current sensor is:

(a) Protection of relays from current damage

(b) Removing AUX and CRA Batteries at Startup to Hot Spark

A thick copper wire transition resistor 42 is connected between the two anodes 6, 8 in the switch 20. Excessive current protection only works in one direction, from AUX to CRA. Detection is a function of R16 that drops approximately 100mV at 50A. The differential amplifier 1B references the drop on the R16 transition 42. It is supplied to both inputs of comparator U2. The negative input of the comparator is supplied from the precision band difference reference point 21 via RV1 which is used to set the selected OCP destination. When the output of 1B is greater than the point set by RV1, the output of U2D rises and is fed through R45 to both inputs of the second comparator U2C. The negative input of the comparator U2C is biased by R17 and R18 at about a third crank voltage. If key switch detection is not active, D9 stops positive input above the negative input. This excessive current protection only works during key switch detection. When the output of U2C rises, it starts the delay caused by D10, C6, R19 which in turn supplies comparator U1B. This output drives Q2, which removes the voltage driving Q1, and the relay disconnects. The current sensor has priority on the voltage sensor and the key start sensor but is enabled by the start sensor.

[Installation Procedure]

1. The wiring mechanism is split by disconnecting the cable that supplies the starting motor from all accessories.

2. The alternator shall be on the AUX side of the apparatus.

3. The accessory is removed from the battery and the starting terminal is removed from the starting solenoid. The multimeter is used to verify that there is a direct path between them when the key is in ST. There is at least 10K ohm resistance between them.

4. Damiod 24 is included in the adapter at terminal 36 as shown in FIG.

[Operation of the sensor]

The car stops as the relay opens. Both batteries are charged. The key switch turns. The CRA battery cranks the motor. The AUX battery activates the coil. The motor starts and then goes idle. Auxiliary is switched on. The voltage drop is detected by the voltage sensor and the relay is closed. Charging continues. The vehicle stops. The relay opens. The light turns on. The AUX battery discharges but the CRA battery charges. When the key returns, the key operation takes priority and the relay closes, but the voltage sensor detects the low voltage of the AUX battery. With the relay closed, the CRA battery cranks the motor to activate the coil.

Claims (23)

A vehicle electrical apparatus comprising: a three pole battery comprising an AUX battery and a CRA battery for powering electrical auxiliary devices; For the connection between the same poles of the three-pole battery, (a) a normally open switch connecting the CRA and AUX batteries, (b) a normally closed switch connecting said AUX battery to an electrical auxiliary device; (c) sensing the state of charge of the AUX battery and all current from the AUX battery to the CRA battery, i) connecting and disconnecting the CRA battery and the AUX battery, and ii) causing the generator to allow the CRA battery and AUX And a connecting device including sensing means for connecting and disconnecting the AUX battery to the electrical auxiliary device to charge both sides of the battery so as to respond to the variable load, wherein the normally closed switch is a bistable relay. Vehicle electrical equipment. 2. The bistable relay of claim 1 wherein said bistable relay has a primary and a secondary coil and can be brought into a first state by a current pulse in said primary coil and by a current pulse in a secondary coil. Vehicle electrical apparatus characterized in that it can be. 2. The bistable relay of claim 1 wherein the bistable relay comprises a switch having a conducting state and a nonconducting state, the primary and secondary coils, wherein the switch is in the conducting state to the nonconductive state by a current pulse in the primary coil. And is converted from a nonconductive state to a conducting state by a current pulse in the secondary coil. A vehicle electrical apparatus comprising: a three pole battery comprising an AUX battery and a CRA battery for powering electrical auxiliary devices; For the connection between the same poles of the three-pole battery, (a) a normally open switch connecting the CRA and AUX batteries, (b) a normally closed switch connecting said AUX battery to an electrical auxiliary device; (c) detecting the state of charge of the AUX battery and all currents from the AUX battery to the CRA battery, i) connecting and disconnecting the CRA battery and the AUX battery, and ii) allowing the generator to generate the CRA battery and the AUX A connecting device comprising sensing means for connecting and disconnecting the AUX battery to the electrical auxiliary device to charge both sides of the battery so as to respond to a variable load, wherein the normally closed switch is configured to maintain the conduction state. It includes two current conductors in parallel that require a holding current, the current capacity of one conductor and the holding current are larger than the other conductor, and the sensing means can select which conductor is more economical for the current load. Vehicle electric device. 5. The vehicle according to claim 4, wherein the normally closed switch is a transistor and a relay connected in parallel, and when the normally closed switch is opened, the transistor is maintained to conduct current from the AUX battery to the electrical auxiliary device. Electrical devices. 6. The vehicle electrical apparatus of claim 5, wherein the relay conducts a current of 30 to 100 amps and has a static holding induction current of 10 to 1 amp. 6. The vehicle electrical apparatus of claim 5, wherein the transistor conducts a current of 3 to 30 amps and has a quiescent hold inductive current of 1 to 10 ma. In the vehicle electrical system, A three-pole battery comprising an AUX battery and a CRA battery for powering electrical auxiliary devices; For the connection between the same poles of the three-pole battery, (a) a normally open switch connecting the CRA and AUX batteries, (b) a normally closed switch connecting said AUX battery to an electrical auxiliary device; (c) detecting the state of charge of the AUX battery and all currents from the AUX battery to the CRA battery, i) connecting and disconnecting the CRA battery and the AUX battery, and ii) allowing the generator to generate the CRA battery and the AUX And a connecting device including sensing means for connecting and disconnecting an AUX battery to the electrical auxiliary device to charge both sides of the battery so as to respond to the variable load. The sensing means includes a battery current, a battery voltage, and Data storage means suitable for storing data indicative of current from a CRA battery to an AUX battery, data input means suitable for inputting data relating to the AUX battery current, AUX battery voltage, current from the CRA battery to an AUX battery, and Compare the input data with corresponding stored data and close the normal Vehicle electric unit comprising a comparing means for generating a signal for operating the signal and the normally open switch for controlling the operation of the position. 9. The vehicle electrical apparatus according to claim 8, wherein said data storing means, data input means and comparing means also process data related to battery electrolyte temperature. 9. The vehicle electrical apparatus of claim 8, wherein the sensing means includes a temperature recorder for recording a temperature and adjusting the state of the charge value at which the normally closed switch is disconnected from the immediately preceding cycle. 11. The vehicle electrical apparatus of claim 10, wherein the cycle is 1 to 7 days. 10. The vehicle electrical apparatus according to claim 9, wherein said data storing means, data input means and comparing means also process data associated with a vehicle failure indicative of vehicle operation. 9. The vehicular electric device according to claim 8, wherein said sensing means comprises a piezo device for detecting movement of the vehicle and closing said normally closed switch. 9. The vehicular electric apparatus according to claim 8, wherein said sensing means samples voltage and current 25 to 100 times per second. The vehicle electrical apparatus according to claim 8, wherein the sensing means detects an output voltage of the auxiliary electrical apparatus. 9. The vehicle electrical apparatus of claim 8, wherein the sensing means detects a current from the AUX battery to an electrical auxiliary device. The method of claim 8, wherein the sensing means, (a) when the CRA battery needs to be charged, and (b) when the AUX battery is discharged to a level at which the CRA battery provides current to the electric auxiliary device, closing the normally open switch using the input data. The method of claim 8, wherein the sensing means is configured to open the normally open switch using at least some of the input data when the current flowing from the AUX battery to the CRA battery is equal to or less than a predetermined value indicating an appropriate state of charge. Vehicle electrical equipment. The vehicle electrical apparatus of claim 8, wherein the sensing means opens the normally closed switch by using the input data when the charging of the CRA battery falls to a predetermined minimum value. The vehicle electrical apparatus of claim 8, wherein the sensing means is configured to close the normally closed switch using the input data when the electric system is started. 10. The vehicle electrical apparatus of claim 8, wherein the normally open switch is opened and the normally closed switch is closed when the vehicle's starting requirements are met and the state of charge of the CRA battery and the AUX battery is consistent with the data. . 10. The method of claim 8, wherein the normally open switch and the normally closed switch are closed when the vehicle's starting requirement is satisfied and the state of charge of the CRA battery is appropriate but the state of charge of the AUX battery is lower than a predetermined value in the data. Vehicle electrical system. The function of a CRA battery according to claim 8, wherein in the case of a charging failure, the normally open switch is intermittently opened and closed and the normally closed switch is closed, thereby providing an electric current to the electric assist device intermittently and starting the vehicle. And the AUX battery is first discharged to conserve.