DE19952693A1 - Measurement, determination and display of condition of an automotive starter battery using one or more sensor for measuring charge, temperature, voltage, etc. to provided detailed information about current and future state, etc. - Google Patents

Abstract

Procedure for determination of battery (1) condition in which the battery charge, temperature, charging current, discharging current and or the steady current are measured and these are then used to determine battery state or condition. An Independent claim is made for a device for determining battery condition in which one or several sensors (13, R3, 23) are used to measure charge, temperature, charging current, discharging current and or the steady current in conjunction with an analysis circuit (2) that processes the measurement values from the sensors.

Description

The invention relates to a method and a device for determining, displaying and / or reading out the state of a battery, in particular a starter battery for a motor vehicle. It also relates to a method and a device for re gel the charge of a battery, especially a starter battery for a motor vehicle stuff. Finally, the invention relates to a battery, in particular a starter battery Series for a motor vehicle. The invention makes management both one Battery as well as several batteries possible.

Starter batteries provide the motor vehicles with the energy to start the engine. The associated energy loss is caused by the Power is supplied by a generator that is driven by the engine compared. However, a starter battery for a motor vehicle has a variety of influences sen and subjected to aging processes.

Proceeding from this, the object of the invention is a method and a device for determining the state, in particular the state of charge,  to propose a battery, in particular a starter battery for a motor vehicle gene.

According to the invention, this object is achieved in a method of the type mentioned at the outset in that the battery _voltage U _BATTERY , the battery temperature T _BATTERY , the charging current I _CHARGE , the discharge current I _DISCHARGE and / or the quiescent current I _{REST are detected} and from this the battery state is determined.

Advantageous further developments are described in the subclaims.

The internal resistance (ΛU / ΛI), the impedance, the battery voltage change per time (ΛU / Λt) is preferably used from the recorded value (s) (i.e. the battery voltage, the battery temperature, the charging current, the discharge current and / or the quiescent current), the current change per time (ΛI / Λt), the charge _amount (ΣQ _CHARGE ) and / or the discharge amount (ΣQ _DISCHARGE ) is determined. Individual, several or all of these determined values are used to assess the state of the battery, in particular the state of charge or the general state of the battery.

Another advantageous development is characterized in that from a individual, several or all recorded values and / or from individual, several or all determined values of the battery state of charge, the general battery stand (service life), the starting ability of the battery, the optimal charging voltage for the controller control of the battery and / or the charge and / or discharge balance of the Battery for the determination of the energy throughput also depending on the discharge depth is determined. This determination is preferably carried out as a function of the Battery temperature.

According to a further advantageous development, the battery voltage, the Battery temperature, the charging current, the discharging current and / or the quiescent current in constant and / or dynamically selected intervals recorded. The dynamic The intervals are preferably selected as a function of one or more or all of the detected and / or determined values. Determining the battery condition,  that is, the determination of the "determined values" is also preferably carried out at constant and / or dynamically selected intervals, preferably in the same intervals as the acquisition of the "acquired values".

It is advantageous if the recorded values and / or the determined values and / or Extreme values of the detected and / or determined values are stored and / or filtered and / or compressed (compressed or a data compression under to be thrown).

The "determined values" are preferably determined by means of an identifier field.

According to a further advantageous development, the battery voltage and the battery temperature are measured in idle phases. The measurement of the battery voltage and the battery temperature is preferably carried out in phases with extremely low discharge current or without load (stationary phases of the motor vehicle). In this way, a factor for estimating the state of charge can be obtained:

SOC = f (U ₀ , [T]), without load

Here mean:
SOC = State Of Charge = state of charge
U ₀ = no-load voltage; barely detectable in operation, since constantly
T = Quiescent current consumer active
T = battery temperature

A further advantageous development is characterized in that the charge and load currents are recorded and that the charge and discharge amounts (Ah), the charge / discharge power and the charge and discharge work (Wh) are cumulated. The energy throughput can be used to assess the service life. The charging factor can also be determined. The change in the charge factor can be used to assess the state of the battery or state of charge, also in connection with the change in battery voltage when the load changes:
LF _Ah = f (Σcharge current quantity [depending on T] / Σdischarge current quantity)
LF _Wh = f (Σcharge current work [depending on T] / Σdischarge current work)
LF _W = f (Σcharge power [load-dependent on T] / Σdischarge power)
SOH = f (ΛLF _{Ah / Wh} , Λt, T)

Here mean:
LF _Ah = charging factor of the current throughput
LF _Wh = load factor of the energy throughput
LF _W = load factor of the power
SOH = State Of Health = battery condition (lifespan)

Another advantageous development is characterized in that the battery voltage change is detected when the load changes as a function of time and temperature. This can be done in the following ways: Determination of inner resistance; When initializing / commissioning, the determined characteristic data are saved in the EEprom / flash memory to evaluate the change over the service life. The battery voltage drop under load is determined depending on the current level and temperature. The change in battery voltage during charging is determined as a function of the current level and temperature. The state of charge and the state of the battery are estimated:

SOC = f (ΛUdΛI, T)

SOH = f (ΛUdΛI, T, At)

Herein means:
LUdΛI = internal resistance (with a relatively large change in the current); if necessary, impedance measurement by electronic circuit

Another advantageous development is characterized in that one or several values are continuously recorded and that extreme values of the recorded Values are saved. The continuous recording can take place by that the values are recorded in recurring intervals, preferably in constant and / or dynamically selected intervals. It is done in this Meaning continuous measurements with acquisition and storage of extreme values to correct lifetime predictions, because under extreme loads the to expected life can be shortened.

A method for displaying and / or reading the state of a battery, ins a starter battery for a motor vehicle, according to the invention characterized in that the battery condition according to the inventive method is determined and that the determined battery status is displayed and / or exhausted will.

The invention further relates to a method for regulating the charge of a battery, in particular a starter battery for a motor vehicle, which according to the invention there is characterized in that the battery state according to the invention Procedure is determined and that one or more or all of the determined values is used to regulate the battery charge. Preferably the or the determined values used to regulate the charging process of the battery. This can be done in that the generator that charges the battery accordingly is controlled or regulated. For generator control, fol criteria used:

The charging voltage depending on the battery temperature and the battery condition improves the current consumption at low temperatures; when the battery is cold, the regulator voltage is increased to improve the current consumption:

U _controller = f (T, [SOC, SOH])

Herein means:
U _controller = charging voltage setting on the generator

It is advantageous if, depending on the battery state determined The load is switched off. Such a load switch-off preferably takes place at heavy load, with low state of charge and / or with a negative charge balance. The load switch-off is preferably carried out according to defined priorities. After that is it is possible to lock different consumers against each other. For example se this lock can be such that during the actuation of the elec trical seat adjustment in the vehicle, the seat heating can not be activated can. It is also possible to completely switch off individual consumers. At for example, the seat heating can be switched off or deactivated in this way until the state of charge and / or the charge balance is sufficient again Has reached value; then the seat heating is released again.

The following criteria can be used to switch off the load: Terminal 15 off (vehicle is without additional consumers): state of charge, battery voltage, temperature, quiescent current. Terminal 15 on, engine off (vehicle is stationary, but possibly with additional consumers): state of charge, battery voltage, battery temperature, quiescent current, discharge current (amount of discharge current). Terminal 15 on, engine on (vehicle is moving, additional consumers depending on convenience): state of charge, battery voltage, battery temperature, charging current, discharge current (level of discharge current), charge balance. The switching can be carried out according to a corresponding priority list or switch-off request via the CANbus in the vehicle electrical system.

A device of the type specified is known according to the invention draws through one or more sensors to detect the battery voltage, the battery temperature, the charging current, the discharging current and / or the quiescent current  and an evaluation circuit, in particular a microprocessor, for the Er average of the battery state from those detected by the sensor or sensors ten.

An advantageous development is characterized by measuring amplifiers for ver strengthen the sensor signals. In this way, the sensor signals can be switched off value circuit or the processor can be adapted. Furthermore, one or multiple A / D converters are available.

The evaluation circuit or the microprocessor is preferably to be carried out suitable or programmed for the inventive method.

The invention further relates to a display and / or readout device for display gene and / or reading the state of a battery, especially a starter battery of a motor vehicle, by an inventive device for Determine the battery status is marked. An inventive Re Gel device for regulating the charge of a battery or starter battery is ge characterized by an inventive device for determining the condition of the battery.

Finally, the invention relates to a battery, in particular a starter battery for a motor vehicle, which is determined by a device according to the invention, Indicating and / or reading the battery status is marked and / or by a regulating device for regulating the charge of the battery.

An embodiment of the invention will now be described with reference to the accompanying Drawing explained in detail. In the drawing shows the

only figure is a circuit diagram for a device for Ermit and display the status of a starter battery terie of a motor vehicle.  

The positive pole of starter battery 1 with a voltage of 12-36 volts, depending on the battery and vehicle, in the exemplary embodiment of +14 V is at terminal 30 . It is connected to the microcontroller system 2 via a resistor R1. The micro controller system 2 has an A / D converter 3 for several inputs at its input. It also has a real-time clock 4 , a system monitor (watchdog) 5 , a data memory 6 , which can be configured as a flash memory, a program memory 7 , which can be configured as EEprom, flash or the like, and several interfaces, namely a CAN -Bus 8 for bidirectional data exchange with an on-board computer, a first serial interface 9 for bidirectional data exchange with a service station, a calibration station and an upload / download station and other devices, a second serial interface 10 for data output to a display and an I / O interface 11 for the data delivery to a direct load shedding and to static displays and other devices.

The output of the resistor R1 connected to the A / D converter 3 is connected to the ground via a parallel connection of a further resistor R2 and a diode D1. R1, R2 and D1 form an interface module 12 for the battery voltage.

The negative pole of the battery 1 is connected to ground via a measuring device 13 for current measurement and a resistor R3. The charging current flows through the measuring device 13 in the direction from the battery 1 to the earth, that is to say in the direction of the arrow 14 . The discharge current flows in the direction of arrow 15 , that is in the opposite direction.

The magnetic field sensor is connected via line 16 to an input of an amplifier 17 . The other input of amplifier 17 is connected to the output of amplifier 17 via resistor R4 and to ground via resistor R5. Amplifier 17 and resistors R4 and R5 form an interface module 18 for the charge / discharge current in the measuring range from -100 A to +100 A.

The input of the resistor R3 is connected via a line 19 to a resistor R6, the other end of which is connected to an input of the amplifier 20 . This input of amplifier 20 is connected to the output of amplifier 20 via resistor R7. The output of shunt R3 is connected via line 21 to resistor R8, the other end of which is connected to the second input of amplifier 20 . Furthermore, the output of the resistor R8 is connected to ground via the further resistor R9. The resistors R6, R7, R8 and R9 and the amplifier 20 form an interface module 22 for the charge / discharge current in the measuring range from -1A to + 1A. Instead of the Runt R3, a ground strap or a magnetic field sensor could also be used.

The input of the temperature cooler (possibly NTC) 23 is connected to a reference voltage source U _ref . The output of the temperature sensor 23 is connected to the first input of an amplifier 24 ; it is also connected to ground via resistor R10. The other input of amplifier 24 is connected to the output of amplifier 24 via resistor R11 and to ground via resistor R12. The reference voltage source U _ref , the resistors R10, R11 and R12 and the amplifier R24 form an interface module 25 for the battery temperature in the measuring range from -50 ° C to + 80 ° C.

The interface modules 12 , 18 , 22 and 25 are connected to the A / D converter 3 of the micro controller system 2 . The I / O interface 11 of the microcontroller system 2 also has 2 further inputs, namely the "ignition on" input (terminal 15 ) and the "engine running" input.

In the data memory 6 of the microcontroller system 2 , the characteristic data of the built-in battery are stored (the energy throughput, the load profile and other values), furthermore the recorded data of the built-in battery (the charges, the discharges, the currents, the voltages, the temperatures, the times and other values). Furthermore, the data memory 6 contains an error memory for implausible data, defects and other data.

The program memory 7 of the microcontroller system 2 contains evaluation algorithms and functions for determining the state of charge, the state of the battery, the charge / discharge amounts, the ability to start and other values. It also contains programs for recording and processing the input variables (currents, voltages, temperatures, operating conditions, etc.).

Via the sensors 12 , 18 , 22 and 25 connected to the microcontroller system 2 via the measuring amplifiers or interface modules, sensors 13 , R3 and 23, the corresponding battery and peripheral values are detected in measured, dynamically selected intervals as required and in the microcontroller system 2 or a processor evaluated by a corresponding program (which can be stored in the program memory 7 ). The battery data to be recorded are the battery voltage, the battery temperature, the charging current, the discharge current and the quiescent current. The values to be determined are the internal resistance and / or the impedance ΛU / ΛI (internal resistance), ΛU / Λt, ΛI / Λt, ΣQ _CHARGE , ΣQ _DISCHARGE . Furthermore, "extreme values" are recorded and saved in order to be able to make statements about the load behavior.

Furthermore, the initialization data of the battery (that is, the data of the initial start-up) are held or stored in the memory 6 , in order to determine a change over time in this way and thus make predictions about the expected service life or the expected end of life of the battery to be able to do.

On the one hand, the evaluation includes data storage that corresponds to one appropriate algorithm performs data filtering and data compression. To the others are derived from the read-in measured values via further algorithms meaningful calculations are carried out, which are suitable to make statements about the current battery status with regard to charge status, startability, battery standing (service life) and optimal charging voltage depending on the temperature temperature (battery temperature).  

Furthermore, interfaces can be used to control displays via the be judged battery condition occur; These ads can be used as simple signals (Warning or indicator lamps) or via a graphic display with a legible display ge.

In addition, a control interface for the On-board electronics can be controlled. For example, the charge controller of the Generator according to the battery condition and the temperature of the battery in Charging voltage and charging current can be regulated.

In addition, under heavy load, with low charge and / or negative load balance, a load shutdown according to defined priorities.

A service interface enables the data to be read out e.g. B. for the workshop and reinitialization when replacing the battery in the vehicle.

The device comprises the following components:

• - A microcontroller system 2 for controlling the measurements, evaluation (algorithms) and output of the data and data storage; the microcontroller 2 comprises integrated A / D converters for direct or indirect measurement value acquisition.
• - Sensors: voltage measurement (measurement of the battery voltage; from the end poles of the battery); Temperature measurement (battery temperature; tap possibly at the end pole); Measurement of the charge and discharge current (voltage drop via shunt R3 or magnetic field sensor); Measurement of the quiescent current (voltage drop via shunt or magnetic field sensor, depending on the vehicle condition, ie with terminal 15 OFF = quiescent current measurement and reduced internal consumption of the entire circuit).
• - Measuring amplifier: adaptation of the quantities to be measured to the Interfaces of the microcontroller system.
• - Integrated real-time clock 4 : Documentation of the time of measurement, auxiliary variable for determining time-dependent variables such as loading and unloading quantities.
• - Interface to ads or displays.
• - Interface to fieldbus systems, e.g. B. CAN.
• - Interface to service devices, e.g. B. CAN or special fieldbus system for initialization, reset, workshop data output.
• - Interface for system communication, e.g. B. Up- and download of Software and data.
• - I / O interfaces for controlling actuators (relays or similar liches), e.g. B. for load shedding.

Due to the complex power requirements in the automobile, it is easy to balance the charge and discharge current quantities with charge factor correction or an assessment of the state of charge via the no-load voltage or only to a very limited extent possible. Rather, there must be a number of different factors Condition to be closed. The different ones occurring in the vehicle Load profiles and loads with their various characteristics must appear when they occur be measured and evaluated dynamically. In the first approach then these results are compared with a map and the condition is assessed become. The preferred criteria for different battery assessments are already explained at the beginning.  

The invention provides a device with correspondingly necessary sensors and associated amplifier circuits for determining battery voltage, La discharge and discharge current, quiescent current, battery temperature and internal resistance or Impedance of the battery to be assessed created. In the device or Device is created by appropriate algorithms using one or more processes sensors the respective battery charge status, battery status in general, the startable speed, the optimal charging voltage for controller control, charging and discharging balance of the Battery determined for determining the energy throughput. The results will be via appropriate interfaces either directly on a display or on display gene (lamps) or via corresponding fieldbuses, in the automotive Area mainly CANBus. In this way, a bat Teriemanagement-System created that also as a diagnostic device externally is settable.

Claims (19)

1. A method for determining the state of a battery, in particular a starter battery ( 1 ) for a motor vehicle, characterized in that
that the battery voltage, the battery temperature, the charging current, the discharge current and / or the quiescent current is detected
and that the battery condition is determined from this. 2. The method according to claim 1, characterized in that from or recorded values of internal resistance, impedance, battery voltage change  per time, the current change per time, the amount of charge and / or the discharge quantity is determined. 3. The method according to claim 1 or 2, characterized in that from the or the detected values and / or the values determined according to claim 2 the battery charge level, the general battery status (service life), the Startability of the battery, the optimal charging voltage for the controller control tion and / or the charge and / or discharge balance of the battery for the determination of the energy throughput is determined. 4. The method according to any one of the preceding claims, characterized shows that the battery voltage, the battery temperature, the charging current, the discharge current and / or the quiescent current in constant and / or dy Named intervals are recorded. 5. The method according to any one of the preceding claims, characterized records that the recorded values and / or the determined values and / or Ex trem values of the detected and / or determined values are stored and / or ge are filtered and / or compressed. 6. The method according to any one of the preceding claims, characterized indicates that the determined values are determined by a map. 7. The method according to any one of the preceding claims, characterized records that the battery voltage and the battery temperature at rest be measured. 8. The method according to any one of the preceding claims, characterized records that the charging and load currents are detected and that the charging and Unloading quantities and the loading and unloading work can be accumulated.   9. The method according to any one of the preceding claims, characterized records that the battery voltage change depending on the load change speed of time and temperature is detected. 10. The method according to any one of the preceding claims, characterized records that one or more or all values are continuously recorded and that extreme values of the detected values are stored. 11. Method for displaying and / or reading out the state of a battery, in particular a starter battery for a motor vehicle, characterized records that the battery state according to one of claims 1 to 10 is telt and that the determined battery status is displayed and / or read out will. 12. Method for regulating the charge of a battery, especially a starter Battery for a motor vehicle, characterized in that the battery was determined according to one of claims 1 to 10 and that one or ver or several or all of the determined values for regulating the battery charge is applied. 13. The method according to any one of the preceding claims, characterized records that depending on the determined battery condition The load is switched off. 14. Device for determining the state of a battery, in particular a starter battery for a motor vehicle, characterized by one or more sensors (13, R3, 23) for detecting the battery voltage, the battery temperature, the charging current, the discharge current and / or the quiescent current and an evaluation circuit ( 2 ), in particular a microprocessor, for determining the battery state from the values detected by the sensor or sensors. 15. The apparatus according to claim 14, characterized by measuring amplifier ( 12 , 18 , 22 , 25 ) for amplifying the sensor signals. 16. The apparatus according to claim 14 or 15, characterized by an evaluation circuit ( 2 ), in particular a microprocessor, for performing the method according to one of claims 1 to 13. 17. Display and / or readout device for displaying and / or reading out the State of a battery, especially a starter battery of a motor vehicle stuff, characterized by a device according to one of claims 14 until 16. 18. Control device for controlling the charge of a battery, in particular one Starter battery of a motor vehicle, characterized by a device according to one of claims 14 to 16. 19. Battery, in particular starter battery for a motor vehicle by a device according to one of claims 14 to 18.