BATTERY MANAGEMENT METHOD FOR MANAGING AUXILIARY AND MAIN BATTERY MODULES IN HYBRID VEHICLES

Abstract

A battery management method for managing an auxiliary battery module (33) and a main battery module (22) of a hybrid vehicle via a battery management processor (25), the method comprising: the battery management processor (25) receiving electrical energy from the auxiliary battery module (33) to switch on (102); determining (104) whether the battery management processor (25) was subject to a power loss prior to switching on at step (102); if the battery management processor (25) experienced a power loss prior to switching on, the battery management processor (25) reading the non-volatile memory (37) (108) to determine whether its stored data is intact;When the battery management processor (25) determines that the data stored in the non-volatile memory (37) is intact, the battery management processor (25) reads the non-volatile memory (37) (112) to identify data indicating a voltage drop in the auxiliary battery module (33) before power was applied to the battery management processor (25) in step (102), wherein the voltage drop data is written in the form of data patterns to specific voltage drop variable addresses of the non-volatile memory (37) to identify the specific voltage drop condition, wherein a first data pattern indicates that a start request has been received by the battery management processor (25) and an interruption of the start event occurred after the start request; a second data pattern indicates that the battery management processor (25) has detected unfiltered battery voltage transitions in the auxiliary battery module (33);a third data pattern indicates that the battery management processor (25) has determined that a request has been made for at least one high-current device to be powered by the starter (36) using electrical energy from the auxiliary battery module (33); and a fourth data pattern indicates that the battery management processor (25) has determined that a jump start has been requested; the battery management processor (25) receives an input signal from a voltage drop detector (44) of a smart device (44) electrically connected to the auxiliary battery module (33) (114) to detect a voltage drop condition in the smart device (42); when a voltage drop condition is detected in the smart device (42) or voltage drop data is identified in the non-volatile memory (37), the battery management processor (25) determines (118) that at least one trigger event has occurred;the battery management processor (25) increments a voltage drop counter by 1 (120); the battery management processor (25) compares the voltage drop counter with a predetermined voltage drop threshold (122) to determine whether the value in the voltage drop counter is greater than the predetermined voltage drop threshold, wherein if the value in the voltage drop counter is greater than the predetermined voltage drop threshold, the control module (26) activates a diagnostic trouble code (DTC) (124); and the battery management processor (25) instructs a battery management module (35) (128) to perform a jump start, charging the auxiliary battery module (33) with electrical energy from the main battery module (22), wherein, after execution of the jump start, a start event is triggered in response to an operator's key-turn instruction or in response to an auto-start instruction.

Description

The present disclosure relates to a method for managing additional batteries. Hybrid electric vehicles typically have an internal combustion engine and at least one electric machine, such as an electric motor-generator, for propulsion. These hybrid electric vehicles use two batteries; one is used to start the internal combustion engine and power vehicle accessories, and the other battery can be used to propel the vehicle. DE 10 2004 009 328 B4 discloses a method for monitoring the abnormality of a battery system that stores electrical energy by being charged and that delivers the stored energy to a load. The method comprises measuring the voltage and current of the battery system during each energy delivery to the load, determining the power recovery characteristics of the battery system relative to the discharge current based on the measured voltage and current, and monitoring at least the fluctuation of the recovering voltage immediately before or after the discharge to the load is complete. Based on the monitoring results, the abnormality of the battery system is then diagnosed. Further state of the art is described in US 2010 / 0 001 523 A1, DE 10 2011 012 316 A1 and DE 10 2013 200 763 A1. The object of the invention is to create a method by which it is possible to provide suitable battery management for a hybrid vehicle even in the event of a data error in the non-volatile memory of a battery management processor due to a power loss that occurred before switching on. The problem is solved by the subject matter of claim 1. It is advantageous to avoid an interruption of the starting event in a hybrid electric vehicle. An interruption of the starting event occurs when an internal combustion engine fails to start, even though an auxiliary battery module is electrically connected to a starter coupled to the internal combustion engine. Such an interruption of the starting event can occur because the auxiliary battery module may be discharged. The battery management method disclosed herein can be used to minimize the probability of an interruption of the starting event. To this end, the disclosed method can manage the operation of the auxiliary battery module and the main battery module of a hybrid vehicle. Fig. 1 is a schematic diagram of a hybrid vehicle; Fig. 2 is a schematic diagram of a portion of the hybrid powertrain of the hybrid vehicle shown in Fig. 1; Fig.Figure 3 is a flowchart of a procedure for initializing a battery management system; and Figure 4 is a flowchart of a procedure for managing the batteries of the hybrid vehicle. Referring to the drawings, in which identical elements are designated by the same reference numerals, Fig. 1 schematically shows a hybrid vehicle 10, such as a plug-in hybrid electric vehicle (PHEV) or an extended-range electric vehicle (EREV). In the embodiment shown, the hybrid vehicle 10 has a vehicle body 12 and a plurality of wheels 14, which are functionally coupled to the vehicle body 12. Each wheel 14 is coupled to a tire 16. The hybrid vehicle 10 also has a hybrid powertrain 29. The hybrid powertrain 29 has an internal combustion engine 18, which is functionally coupled to at least one of the wheels 14. The hybrid vehicle 10 also has a fuel source 19, such as a fuel tank, in fluid communication with the internal combustion engine 18. A line 21 fluidly couples the fuel source 19 to the internal combustion engine 18.The internal combustion engine 18 is therefore fluidly coupled to the fuel source 19. The fuel source 19 contains a fuel, such as gasoline, and can therefore supply fuel to the internal combustion engine 18 via line 21. During operation, the internal combustion engine 18 can burn the fuel supplied by the fuel source 19 to generate torque. The torque generated by the internal combustion engine 18 can be transmitted to the wheels 14 to propel the hybrid vehicle 10. The hybrid powertrain 29 additionally comprises at least one electric machine 20 and a main battery module 22, which is electrically connected to the electric machine 20. The main battery module 22 can comprise a single battery, a battery pack, a fuel cell, or any combination thereof, and can supply electrical energy to the electric machine 20. The main battery module 22 can be referred to as the high-voltage battery. In addition to the electrical connection with the main battery module 22, the electric machine 20 is functionally coupled to the internal combustion engine 18 and can therefore receive mechanical energy (e.g., torque) from the internal combustion engine 18. The electric machine 20 is also functionally coupled to at least one of the wheels 14 and can therefore be used to drive the wheels 14. The electric machine 20 can operate in a drive mode and a generation mode. In drive mode, the electric machine 20 can convert the electrical energy received from the main battery module 22 into mechanical energy (e.g., torque). When operating in drive mode, the electric machine 20 can transmit mechanical energy (e.g., torque) to the wheels 14 to propel the hybrid vehicle 10. In generation mode, the electric machine 20 can receive mechanical energy (e.g., torque) from the internal combustion engine 18 and convert this mechanical energy into electrical energy. The electrical energy generated by the electric machine 20 can then be transmitted to the main battery module 22. The hybrid powertrain 29 and the hybrid vehicle 10 can operate in a charge-depletion mode. In charge-depletion mode, the hybrid vehicle 10 uses only electrical energy from the main battery module 22. In other words, in charge-depletion mode, the hybrid powertrain 29 can only use energy from the main battery module 22 to propel the hybrid vehicle 10. Accordingly, the electrical energy stored in the main battery module 22 is depleted when the hybrid vehicle 10 is operated in charge-depletion mode. In other words, when operating in charge-depletion mode, the hybrid vehicle 10 uses only the electrical energy stored in the main battery module 22. For example, in charge-depletion mode, the hybrid powertrain 29 uses only power from the electric machine 20 to propel the hybrid vehicle 10.In another example, when the hybrid powertrain 29 operates in charge depletion mode, most of the power used to propel the hybrid vehicle 10 comes from the electric machine 20. The hybrid powertrain 29 and the hybrid vehicle 10 can also operate in a charge maintenance mode. In charge maintenance mode, the hybrid vehicle 10 uses only the energy from the fuel source 19, and therefore the electrical energy stored in the main battery module 22 is not depleted. As a result, the state of charge (SOC) of the main battery module 22 is maintained while the hybrid vehicle 10 operates in charge maintenance mode. In one example, in charge maintenance mode, the hybrid powertrain 29 uses only power from the internal combustion engine 18 to propel the hybrid vehicle 10. In another example, when the hybrid powertrain 29 operates in charge maintenance mode, most of the power used to propel the hybrid vehicle 10 comes from the internal combustion engine 18. The hybrid powertrain 29 and the hybrid vehicle 10 can also operate in a mixed mode. In mixed mode, the hybrid powertrain 29 uses power from the internal combustion engine 18 and the electric motor 20 to propel the hybrid vehicle 10. In other words, the hybrid powertrain 29 uses energy from the main battery module 22 and the fuel source 19 to propel the hybrid vehicle 10. The hybrid vehicle 10 also features an auxiliary battery module 33, such as a single 12-volt battery, which stores power for one or more vehicle accessories 40 (Fig. 2). As a non-limiting example, the vehicle accessories 40 include headlights, windshield wipers, central locking, electrically adjustable seats, a power steering pump, a water pump or air conditioning compressor, an audio system, and other vehicle accessories or devices. The auxiliary battery module 33 can be referred to as the low-voltage battery and can be recharged from the main battery module 22 via an auxiliary power module (not shown), which may be electrically connected to the auxiliary battery module 33. The auxiliary power module is a DC-DC power converter that converts power from the high voltage of the main battery module 22 to the low voltage required by the auxiliary battery module 33. The hybrid vehicle 10 further comprises a control module 26 in electronic communication with the electric motor 20 and the internal combustion engine 18. The terms "control module", "control", "controller", "control unit", "processor" and similar terms mean one or more combinations of one or more application-specific integrated circuit(s) (ASIC), electronic circuit(s), central processing unit(s) (preferably microprocessor(s)) and associated memory and storage (read-only, programmable read-only, direct access, hard disk drive, etc.) that execute one or more software or firmware programs or routines, combinational logic circuit(s), sequential logic circuit(s), input / output circuit(s) and devices, suitable signal conditioning and buffer circuits and other components that provide the described functionality.“Software,” “firmware,” “programs,” “instructions,” “routines,” “code,” “algorithms,” and similar terms mean any set of instructions executable by the controller that includes calibrations and lookup tables. The control module 26 includes at least one processor and at least one associated memory. As a non-limiting example, the control module 26 can be a powertrain control module that regulates the operation of one or more components of the hybrid powertrain 29. According to one embodiment, the control module 26 is equipped with on-board diagnostic (OBD) features that provide real-time data, such as that received from various sensors, including vehicle emission sensors, and supply a standardized set of diagnostic trouble codes (DTCs) that enable a technician to identify incidents in vehicle operation.In one embodiment, the control module 26 is a machine control module that controls the operation of the internal combustion engine 18. The internal combustion engine 18, the electric motor 20, the control module 26, the auxiliary battery module 33, and the main battery module 22 can be part of the hybrid powertrain 29. The hybrid powertrain 29 is configured to propel the hybrid vehicle 10. The hybrid powertrain 29 can also operate in a charge maintenance mode and a charge depletion mode, as discussed above with reference to the hybrid vehicle 10. The control module 26 is not necessarily part of the hybrid powertrain 29. The hybrid powertrain 29 also features a torque request actuator 23, similar to an accelerator pedal, which is functionally coupled to the control module 26. Thus, actuation of the torque request actuator 23 causes the control module 26 to instruct the hybrid powertrain 29 to generate additional output torque and transmit this additional output torque to the wheels 14. As a non-limiting example, the torque request actuator 23 can be an accelerator pedal that can be pressed to request additional output torque from the hybrid powertrain 29. The hybrid vehicle 10 can furthermore have a state-of-charge (SOC) sensor 31, which is functionally coupled to the main battery module 22. The SOC sensor 31 communicates electronically with the control module 26 and can determine the current SOC of the main battery module 22. During operation, the SOC sensor 31 can generate a signal indicating the current SOC of the main battery module 22. Furthermore, the SOC sensor 31 can send the generated signal to the control module 26. The hybrid vehicle 10 has at least one vehicle user interface 27 in communication (e.g., electronic communication) with the control module 26. The term "vehicle user interface" as used here encompasses any suitable form of electronic device, including both hardware and software components, that is arranged on the vehicle and enables a vehicle user to communicate with or through a component of the hybrid vehicle 10. The vehicle user interface 27 is capable of receiving an input from a user. In response to the user's input, the vehicle user interface 27 generates an input signal that is representative of the user's input. Furthermore, the vehicle user interface 27 can send the input signal to the control module 26. For example, the vehicle user interface 27 can be a touchscreen or at least a button that the user (e.g.,The driver or passenger can press the button to send an input signal to the control module 26. The hybrid vehicle 10 also features a battery management system (BMS) 35 that communicates with the main battery module 22 and the auxiliary battery module 33. During operation, the BMS 35 can control the operation of the main battery module 22 and the auxiliary battery module 33. With reference to Fig. 2, the BMS 35 includes at least one battery management controller 24, such as a microcontroller. The battery management controller 24 is specifically programmed to execute the steps of procedure 100 (Fig. 3) and procedure 200 (Fig. 4) and communicates (e.g., electronically) with the auxiliary battery module 33 and the main battery module 22. Accordingly, the battery management controller 24 can regulate the operation of the auxiliary battery module 33. In the embodiment shown, the battery management controller 24 includes a battery management processor 25, such as a microprocessor, and non-volatile memory 37 in communication with the battery management processor 25. The non-volatile memory 37 can store computer-readable instructions (e.g., software) and is a non-volatile storage medium. In one embodiment, the non-volatile memory 37 is random access memory (RAM).The battery management processor 25 can read the non-volatile memory 37 and execute the computer-readable instructions stored in the non-volatile memory 37. Furthermore, the battery management processor 25 communicates with smart devices 42. In the present disclosure, the term "smart device" refers to a vehicle device that includes a device processor 45 capable of executing computer-readable instructions (i.e., software). Each smart device 42 includes a voltage drop detector 44 configured to detect a voltage drop. The voltage drop detector 44 can be a voltage drop detector circuit capable of comparing the supply voltage with a predetermined fixed threshold.The battery management processor 25 communicates with the voltage drop detector 44 and can determine voltage drop conditions in the smart devices 42 based on inputs from the voltage drop detector 44. Each smart device 42 is electrically connected to the auxiliary battery module 33 and is therefore configured to receive electrical energy from the auxiliary battery module 33. The smart device 42 can be connected to the auxiliary battery module 33 via a wired or wireless connection. The hybrid powertrain 29 further comprises a starter 38 configured to receive electrical energy from the auxiliary battery module 33. In the illustrated embodiment, the starter 38 is a belt alternator starter (BAS), which combines a starter and an AC motor / alternator / generator and includes a belt (not shown) for driving vehicle accessories 40 and for starting the internal combustion engine 18. Accordingly, the starter 38 is functionally coupled to the auxiliary battery module 33 and the internal combustion engine 18. More precisely, the starter 38 can convert electrical energy from the auxiliary battery module 33 into mechanical energy to rotate the crankshaft (not shown) of the internal combustion engine 18, causing the internal combustion engine 18 to start running. Referring again to Fig. 1, the vehicle user interface 27 includes a jump-start input device 17, such as a virtual or physical button, configured to receive input from the user. For example, the user can press or slide the jump-start input device 17 to send a jump-start instruction to the battery management controller 24. Upon receiving the jump-start instruction, the battery management controller 24 instructs the main battery module 22 to electrically charge the auxiliary battery module 33. This can be accomplished by electrically connecting the main battery module 22 to the auxiliary battery module 33. For example, the user can press the jump-start input device 17 to send an input signal to the battery management controller 24.In response, the battery management controller 24 instructs the BMS 35 to electrically connect the auxiliary battery module 33 to the main battery module 22 in order to charge the auxiliary battery module 33 with electrical energy from the main battery module 22. Once the auxiliary battery module 33 is electrically charged, the user can turn the vehicle ignition switch 15 to start the internal combustion engine 18. The ignition switch 15 is configured to trigger a starting event by electrically connecting the starter 38 to the auxiliary battery module 33 in response to a key-turn instruction from the operator or in response to an auto-start instruction. It should be noted that before the starting event is triggered, the engine speed is 0 revolutions per minute (rpm), i.e., the engine is stopped and not rotating.The key-on machine start event is executed, for example, in response to a key-on instruction from the operator at the ignition switch 15 when an operator first enters a vehicle to begin a journey. It should be noted that a key-on machine start event includes a remote start event or similar operating sequences. An auto-start machine start event is executed in response to an instruction from the control module 26 to activate the ignition switch 15, for example, after an auto-stop instruction during ongoing vehicle operation. Alternatively, the starter 38 automatically starts the internal combustion engine 18 after the auxiliary battery module 33 has been electrically charged by the main battery module 22. Fig. 3 is a flowchart of a battery management method 100 for controlling the hybrid vehicle 10. More precisely, the method 100 can be executed by the battery management processor 25 to jump-start the hybrid vehicle 10 upon detection of an interruption of a start-up event. In the present disclosure, the term "jump-start" means electrically charging the auxiliary battery module 33 with electrical energy from the main battery module 22. During a jump-start, the main battery module 22 supplies electrical energy to the auxiliary battery module 33. After the hybrid vehicle 10 has performed a jump-start, a start-up event is triggered by electrically connecting the starter 38 to the auxiliary battery module 33 in response to a key-turn instruction from an operator or in response to an auto-start instruction from the control module 26.The term "starting event" refers to the transfer of mechanical power from the starter 38 to the crankshaft (not shown) of the internal combustion engine 18 to start the engine. A starting event is triggered when the auxiliary battery module 33 is electrically connected to the starter 38. An "interruption of a starting event" occurs when the engine 18 does not start, even after the auxiliary battery module 33 is electrically connected to the starter 38. Such an interruption of a starting event can occur if the auxiliary battery module 33 is discharged. Among other things, method 100 can be used to automatically initiate a jump start after identifying an interruption of a starting event. The inventive method 100 is used while the initialization of the BMS 35 begins with step 102, which includes switching on the battery management processor 25. As discussed above, the battery management processor 25 can be a microprocessor. The battery management processor 25 can be switched on in response to an instruction from the control module 26. To switch on, the battery management processor 25 receives electrical energy from the auxiliary battery module 33. After the battery management processor 25 is switched on, the method 100 continues with step 104. Step 104 involves determining whether the battery management processor 25 was subject to any power loss prior to power-up in step 102. As discussed above, the battery management processor 25 can receive electrical power from the auxiliary battery module 33. Prior to power-up, the battery management processor 25 may be in a standby mode or it may be completely powered off. In the standby state (or any other low-power mode), the battery management processor 25 operates at reduced power. This means that the power consumption of the battery management processor 25 in the standby state is less than the power consumption in a fully operational state.When the battery management processor 25 is supplied with power, it can identify, based on a loss of electrical power, whether it was operating in standby mode or whether it was completely switched off. In step 104, the battery management processor 25 determines whether it was subject to a loss of electrical power before being switched on. If the battery management processor 25 determines that it has not experienced any loss of electrical power before being switched on, then procedure 100 continues with step 106. At step 106, the battery management processor 25 continues with its normal wake-up process. If the battery management processor 25 determines that it experienced a loss of electrical power prior to power-up, the procedure 100 then proceeds to step 108. In step 108, the battery management processor 25 reads the non-volatile memory 37 to determine whether its stored data is intact (i.e., not corrupted). If the battery management processor 25 determines that the data stored in the non-volatile memory 37 is not intact (i.e., corrupted), then the procedure 100 proceeds to step 110. In step 110, the battery management processor 25 continues with its normal wake-up process. If the battery management processor 25 determines that the data stored in the non-volatile memory 37 is intact (i.e., not corrupted), then the procedure 100 proceeds to steps 112 and 114. In step 112, the battery management processor 25 reads the non-volatile memory 37 to identify data indicating a voltage drop in the auxiliary battery module 33 (i.e., voltage drop data) before the battery management processor 25 is powered on in step 102. As discussed above, a "brownout" or "voltage drop" is a decrease in voltage. The voltage drop data can be stored in the non-volatile memory 37 in several ways. As detailed below, the battery management processor 25 writes data patterns to the non-volatile memory 37 that specify different voltage drop conditions. These data patterns are written to specific voltage drop variable addresses to help identify the particular voltage drop condition.Thus, in step 112, the battery management processor 25 can read the non-volatile memory 37 to determine whether a data pattern is present in the voltage-drop variable address of the non-volatile memory 37. Alternatively, the battery management processor 25 can use flags that specify voltage drop conditions that occurred before the battery management processor 25 was powered on. In step 114, the battery management processor 25 receives an input signal from at least one of the voltage drop detectors 44 of the smart devices 44 to detect a voltage drop condition in at least one of the smart devices 42. As discussed above, the smart devices 42 have a voltage drop detector 44 and a device processor 45 capable of executing computer-readable instructions. In step 114, the battery management processor 25 determines the voltage drop conditions in the smart devices 42 based on the input signals from the voltage drop detectors 44. If no voltage drop conditions are detected in the smart devices 42 and no voltage drop data is identified in the non-volatile memory 37, the procedure 100 then proceeds to step 116. At step 116, the battery management processor 25 continues with its normal wake-up process. If either a voltage drop condition is detected in the smart devices 42 or voltage drop data is identified in the non-volatile memory 37, the method 100 then proceeds to step 118. In step 118, the battery management processor 25 determines that at least one trigger event occurs or has occurred. In the present disclosure, “trigger events” are events in the hybrid vehicle 10 that consume sufficient electrical energy from the auxiliary battery module 33 and (individually or collectively) cause an interruption of the starting event. As discussed above, an interruption of the starting event can occur if the auxiliary battery module 33 does not supply the starter 38 with sufficient electrical power to start the internal combustion engine 18. The trigger events can also be referred to as high-voltage events.Non-limiting examples of trigger events or indications include unfiltered battery voltage transitions in the auxiliary battery module 33, the use of high-current devices such as relays and electrical connectors, and a start request followed by an interruption of a start event. In the present disclosure, a "start request" relates to a request to trigger a start event. The term "high-current devices" relates to devices that require an electrical current greater than a predetermined current threshold to function as intended. After detection of a trigger event, the method 100 proceeds to step 120. In step 120, the battery management processor 25 increments a voltage drop counter by 1. Subsequently, the method 100 proceeds to step 122. In step 122, the battery management processor 25 compares the voltage drop counter to a predetermined voltage drop threshold to determine if the value in the voltage drop counter is greater than the predetermined voltage drop threshold. If the value in the voltage drop counter is greater than the predetermined voltage drop threshold, then procedure 100 proceeds to step 124. In step 124, the control module 26 activates a diagnostic trouble code (DTC) to allow a technician to identify the voltage drop condition of the auxiliary battery module 33. In other words, in step 124, the control module 26 activates a diagnostic code. After step 124 is completed, procedure 100 proceeds to step 126. If the value in the voltage drop counter is less than the predetermined voltage drop threshold, procedure 100 skips step 124 and proceeds directly to step 126.At step 126, the battery management processor 25 continues with its normal wake-up process. The battery management processor 25 then proceeds to step 128. In step 128, the battery management processor 25 instructs the BMS 35 to perform a jump start. As discussed above, the term "jump start" means electrically charging the auxiliary battery module 33 with electrical energy from the main battery module 22. To perform the jump start, the main battery module 22 is electrically connected to the auxiliary battery module 33. Additionally or alternatively, step 128 can include receiving a message for the vehicle user via the vehicle user interface 27 indicating that a jump start should be performed. The user can then manually initiate a jump start by activating the jump start input device 17. As discussed above, the hybrid powertrain 29 electrically charges the auxiliary battery module 33 with electrical energy from the main battery module 22 when the jump start input device 17 is activated.After a forced start, a start event can be triggered in response to a key-start instruction from the operator or in response to an auto-start instruction. With reference to Fig. 4, the battery management processor 25 can also periodically run a method 200 for identifying and recording the trigger events used in method 100 to jump-start the hybrid vehicle. Method 200 begins with step 202. In step 202, the battery management processor 25 determines whether it has received a start request from the ignition switch 15 or a control module, such as the control module 26. As discussed above, a “start request” is a request to initiate a start event. During a start event, the auxiliary battery module 33 supplies electrical power to the starter 38, and in response, the starter 38 applies torque to the crankshaft (not shown) to start the internal combustion engine 18. In step 202, the battery management processor 25 also determines whether the internal combustion engine 18 has started running after the start request.In other words, in step 202, the battery management processor 25 detects an interruption of a start-up event, for example, based on inputs from the control module 26. As discussed above, an “interruption of a start-up event” occurs when the internal combustion engine 18 fails to start, even after the auxiliary battery module 33 has been electrically connected to the starter 38. If a start-up request is received and an interruption of the start-up event is detected, the procedure 200 then proceeds to step 204. In step 204, the battery management processor 25 writes data indicating such a start request and an interruption of the start event to non-volatile memory 37. In step 204, the battery management processor 25 writes an initial data pattern (i.e., pattern A) to non-volatile memory 37. The initial data pattern indicates that a start request has been received by the battery management processor 25 and that an interruption of the start event occurred after the start request. Therefore, when the battery management processor 25 reads the initial data pattern during an initialization in procedure 100, it can detect that at least one trigger event (which in this case is the start request followed by the interruption of the start event) has occurred. After writing the initial data pattern to non-volatile memory 37, procedure 200 proceeds to step 206.If no start request has been received and no interruption of the start event has been detected, the battery management processor 25 then proceeds directly to step 206. In step 206, the battery management processor 25 determines whether unfiltered battery voltage transitions are present in the auxiliary battery module 33. The battery management processor 25 is electrically connected to the auxiliary battery module 33 and can therefore monitor the voltage of the auxiliary battery module 33 to detect unfiltered battery voltage transitions. Unfiltered battery voltage transitions can be detected, for example, if the absolute voltage of the auxiliary battery module 33 is outside a predetermined voltage range, the average voltage is outside a predetermined voltage range, or both. If the battery management processor 25 detects unfiltered battery voltage transitions in the auxiliary battery module 33, the procedure 200 then proceeds to step 208. In step 208, the battery management processor 25 writes data indicating the unfiltered battery voltage transitions to non-volatile memory 37. In step 208, the battery management processor 25 writes a second data pattern (i.e., pattern B) to non-volatile memory 37. This second data pattern indicates that the battery management processor 25 has detected unfiltered battery voltage transitions in the auxiliary battery module 33. Therefore, when the battery management processor 25 reads the second data pattern during initialization in procedure 100, it can detect that at least one trigger event, in this case the unfiltered battery voltage transitions, has occurred. After writing the second data pattern to non-volatile memory 37, procedure 200 proceeds to step 210.If no unfiltered battery voltage transition has been detected, the battery management processor 25 then proceeds directly to step 210. In step 210, the battery management processor 25 determines whether a request has been made for high-current devices, such as relays and electrical connectors, to be operated by the auxiliary battery module 33 (i.e., the "device operating request"). The term "high-current devices" refers to devices that require an electrical current greater than a predetermined current threshold to function as intended. Some of the vehicle accessory devices 40 (Fig. 2) may be high-current devices. Because the battery management processor 25 communicates with the control module 26 and the auxiliary battery module 33, it can receive inputs from the control module 26 and / or the auxiliary battery module 33 to determine whether a device operating request has been received.Accordingly, the battery management processor 25 can determine, based on inputs from the control module 26 and / or the auxiliary battery module 33, whether it has been requested that high-current devices be powered by electrical energy from the auxiliary battery module 33. If it has been requested that at least one high-current device be powered by electrical energy from the auxiliary battery module 33, then the procedure 200 continues with step 212. In step 212, the battery management processor 25 writes data specifying the device operation request to non-volatile memory 37. In step 212, the battery management processor 25 writes a third data pattern (i.e., pattern C) to non-volatile memory 37. The third data pattern indicates that the battery management processor 25 has determined that a request has been made for at least one high-current device to be powered by the starter 36 using electrical energy from the auxiliary battery module 33. Therefore, when the battery management processor 25 reads the third data pattern during initialization in procedure 100, it can detect that at least one trigger event, in this case the device operation request, has occurred. After writing the third data pattern to non-volatile memory 37, procedure 200 proceeds to step 214.If no device operation request has been detected, the battery management processor 25 then proceeds directly to step 214. In step 214, the battery management processor 25 determines whether a jump start has been requested. A jump start request can be initiated by the user or by the BMS 35 according to procedure 100. As discussed above, the term "jump start" means electrically charging the auxiliary battery module 33 with electrical energy from the main battery module 22. Since the battery management processor 25 communicates with the auxiliary battery module 33, it can determine whether the auxiliary battery module 33 has been electrically charged by the main battery module 22. More precisely, the battery management processor 25 can determine that a jump start has occurred or been initiated. If a jump start has occurred (or been initiated), procedure 200 then proceeds to step 216. In step 216, the battery management processor 25 writes data indicating a jump-start request. In step 216, the battery management processor 25 writes a fourth data pattern (i.e., pattern D) to non-volatile memory 37. The fourth data pattern indicates that the battery management processor 25 has determined that a jump-start has been requested. Therefore, when the battery management processor 25 reads the fourth data pattern during initialization in procedure 100, it can detect that at least one trigger event, in this case the jump-start request, has occurred. After writing the fourth data pattern to non-volatile memory 37, procedure 200 proceeds to step 218. In step 216, if the fourth data pattern has been written or another jump-start has been requested (either by the user or the BMS 35), the amount of time the hybrid vehicle 10 charges the auxiliary battery module 33 will increase.The longer charging time would make it more likely that the auxiliary battery module 33 has sufficient energy to start the internal combustion engine 18. If no jump-start request has been detected, the battery management processor 25 then proceeds directly to step 218. After either step 214 or step 216, procedure 200 continues with step 218. Procedure 200 ends at step 218.

Claims

Battery management method for managing an auxiliary battery module (33) and a main battery module (22) of a hybrid vehicle via a battery management processor (25), the method comprising: the battery management processor (25) receiving electrical energy from the auxiliary battery module (33) to switch on (102); determining (104) whether the battery management processor (25) was subject to a power loss prior to switching on at step (102); if the battery management processor (25) experienced a loss of electrical power prior to switching on, the battery management processor (25) reading the non-volatile memory (37) (108) to determine whether its stored data is intact;When the battery management processor (25) determines that the data stored in the non-volatile memory (37) is intact, the battery management processor (25) reads the non-volatile memory (37) (112) to identify data indicating a voltage drop in the auxiliary battery module (33) before power was applied to the battery management processor (25) in step (102), wherein the voltage drop data is written in the form of data patterns to specific voltage drop variable addresses of the non-volatile memory (37) to identify the specific voltage drop condition, wherein a first data pattern indicates that a start request has been received by the battery management processor (25) and an interruption of the start event occurred after the start request; a second data pattern indicates that the battery management processor (25) has detected unfiltered battery voltage transitions in the auxiliary battery module (33);a third data pattern indicates that the battery management processor (25) has determined that a request has been made for at least one high-current device to be powered by the starter (36) using electrical energy from the auxiliary battery module (33); and a fourth data pattern indicates that the battery management processor (25) has determined that a jump start has been requested; the battery management processor (25) receives an input signal from a voltage drop detector (44) of a smart device (44) electrically connected to the auxiliary battery module (33) (114) to detect a voltage drop condition in the smart device (42); when a voltage drop condition is detected in the smart device (42) or voltage drop data is identified in the non-volatile memory (37), the battery management processor (25) determines (118) that at least one trigger event has occurred;the battery management processor (25) increments a voltage drop counter by 1 (120); the battery management processor (25) compares the voltage drop counter with a predetermined voltage drop threshold (122) to determine whether the value in the voltage drop counter is greater than the predetermined voltage drop threshold, wherein if the value in the voltage drop counter is greater than the predetermined voltage drop threshold, the control module (26) activates a diagnostic trouble code (DTC) (124); and the battery management processor (25) instructs a battery management module (35) (128) to perform a jump start, charging the auxiliary battery module (33) with electrical energy from the main battery module (22), wherein, after execution of the jump start, a start event is triggered in response to an operator's key-turn instruction or in response to an auto-start instruction.

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