Load dump protection method and device for starting battery and power supply equipment for new energy vehicles

Abstract

This invention provides a method for load dump protection of a starter battery. A control circuit is connected in series between the battery's total negative terminal and the battery bus negative terminal. The control circuit is connected in parallel with a load dump protection circuit and includes a series-connected energy storage unit and a control switch. The positive terminal of the energy storage unit is adjacent to the battery's total negative terminal relative to the negative terminal. The load dump protection method includes: when an overvoltage occurs during the charging process of the starter battery, outputting a first signal for conduction control to control the control switch to conduct; after the control switch completes its conduction action, outputting a second signal for disconnection control to control the charging switch of the control circuit to disconnect, so that the starter battery and the load dump protection circuit are connected in series to form a freewheeling circuit, and the energy storage unit absorbs energy, thereby stabilizing the voltage between the battery bus positive terminal and the battery bus negative terminal below a preset threshold; after the charging switch completes its disconnection action, outputting a first signal for disconnection control to control the control switch to disconnect.

Description

Technical Field

[0001] The invention relates to power supply equipment, in particular to load dump protection of a starting battery in the power supply equipment. Background Art

[0002] In order to replace lead-acid batteries for car starting, one technical route is to use supercapacitors, which have a wide operating temperature range, large charging current and short charging time, and have a certain ability to resist overcharging. The disadvantages are that the single-cell operating voltage is low, the internal resistance is large, a larger number of series connections are required, and the storage energy is limited. It is only suitable for short-term high-power output occasions. It usually needs to be used in parallel with a battery. It is expensive and there is an electrolyte leakage problem, and the overall application cost is high.

[0003] The second technical route is to use lithium-ion batteries (especially lithium iron phosphate batteries) as starting batteries. Lithium-ion batteries have the advantages of high energy density, small size, and long life, but they need to be equipped with protection boards to prevent overcharging and over-discharging. For example, after the vehicle is started, the on-board generator supplies power to the on-board equipment and charges the starting battery at the same time. When the output voltage of the on-board generator is greater than the threshold VH1 (for example, 29V) or there is a large inconsistency in the battery cell voltage, the starting battery may trigger the cell overvoltage protection and thus turn off the charging switch module. The existing starting battery and its protection board, due to the fixed protection time, are prone to false triggering of undervoltage protection and overcurrent protection at the moment of starting due to the drop in battery voltage caused by large current, resulting in the inability to reliably start the car, and even damage to the charging and discharging protection switch device; in addition, when the generator charges the starting battery, due to the inconsistent cell voltage, after the overcharge protection is generated, the charging switch module is disconnected at the moment, and an induced high voltage (up to 65V or more) will be generated between the output busbars P+ and P-, and the generator will dump load. The increase in the generator voltage affects the normal operation of the on-board equipment and even overvoltage damage.

[0004] Therefore, there is an urgent need for a circuit that can perform load dump protection on the starting battery in the new energy battery. Summary of the invention

[0005] The purpose of the present invention is to provide a load dump protection circuit for a starting battery and a power supply device for a new energy vehicle. The load dump protection circuit can turn on the load dump protection before the charging switch is disconnected, and provide load dump protection to the load side at the moment the charging switch is turned off, so that the voltage between the positive electrode of the battery bus and the negative electrode of the battery bus is stabilized below a preset threshold, which is safe, reliable and flexible to control.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a load dump protection method for a starting battery, wherein a control circuit is connected in series between the total negative electrode of the starting battery and the negative electrode of the battery bus, the control circuit includes a charging switch, and the control circuit is connected in parallel with a load dump protection circuit, the load dump protection circuit includes a series-connected energy storage unit and a control switch, the positive electrode of the energy storage unit is adjacent to the total negative electrode of the battery relative to the negative electrode; the load dump protection method comprises: when overvoltage occurs during the charging process of the starting battery, outputting a first signal for conduction control to control the control switch to be turned on; after the control switch completes the conduction action, outputting a second signal for disconnection control to control the charging switch to be turned off, so that the starting battery and the load dump protection circuit are connected in series to form a freewheeling loop, and the energy storage unit absorbs energy, thereby stabilizing the voltage between the positive electrode of the battery bus and the negative electrode of the battery bus below a preset threshold; after the charging switch completes the disconnection action, outputting the first signal for disconnection control to control the control switch to be turned off.

[0007] Preferably, in one solution, when the starting battery recovers from overvoltage protection and re-enters the charging process, the output also controls the control switch to be turned on for a preset time length to form a discharge loop between the energy storage unit and the control circuit, and complete the discharge of electrical energy in the energy storage unit.

[0008] Preferably, in another embodiment, the load dump protection circuit further includes a discharge branch connected in parallel with the energy storage unit, and a discharge switch is connected in series on the discharge branch. The discharge switch is a switch that performs opposite actions to the control switch. When the control switch is controlled to be disconnected, the discharge switch is simultaneously controlled to be closed to form a discharge loop between the energy storage unit and the discharge branch. When the control switch is controlled to be closed, the discharge switch is simultaneously controlled to be disconnected.

[0009] Preferably, in another embodiment, the load dump protection circuit further includes a discharge resistor connected in parallel with the energy storage unit, so that when the control switch is disconnected, a discharge loop is formed between the energy storage unit and the discharge resistor.

[0010] Preferably, outputting a second signal for disconnection control to control the charging switch to disconnect after the control switch completes the conduction action includes: delaying for a first time length from outputting the first signal for conduction control and then outputting the second signal for disconnection control to control the charging switch to disconnect.

[0011] Preferably, outputting a first signal for disconnection control to control the control switch to disconnect after the charging switch completes the disconnection action includes: delaying for a second time period from outputting the second information for disconnection control and then outputting the first signal for disconnection control to control the control switch to disconnect.

[0012] Specifically, the second time length is greater than the time length for the charging switch to complete the disconnection action.

[0013] More specifically, the second duration is 1 second.

[0014] Preferably, the energy storage unit is a supercapacitor or is formed by connecting a plurality of electrolytic capacitors in parallel;

[0015] Preferably, the control switch is a bidirectional switch.

[0016] Preferably, the control switch is a relay switch or is composed of a plurality of MOS tubes connected in series and parallel.

[0017] Wherein, the control circuit also includes a current detection circuit and a discharge switch connected in series with the charging switch.

[0018] The present invention also provides a load dump protection device for a starting battery, wherein a control circuit is connected in series between the total negative electrode of the starting battery and the negative electrode of the battery bus, the control circuit includes a charging switch, a load dump protection circuit, a processor and a memory, the load dump protection circuit is connected in parallel with the control circuit, and includes a series-connected energy storage unit and a control switch, the memory stores at least one operation instruction, and the processor can execute the operation instruction to implement the load dump protection method for the starting battery as described above.

[0019] The present invention also provides a power supply device for a new energy vehicle, comprising a starting battery, a control circuit, a battery management module and a load dump protection device, wherein a control circuit is connected in series between the total negative electrode of the starting battery and the negative electrode of the battery bus, the battery management module is connected to the control end of the control circuit, and the load dump protection circuit is the load dump protection device of the starting battery as described above.

[0020] Preferably, the processor of the load dump protection device is the processor of the battery management module; or, the processor of the load dump protection device is a processor different from the battery management module, and the processor of the load dump protection device is also connected to the signal output terminal of the processor of the battery management module for outputting the charging status.

[0021] Compared with the prior art, the load dump protection circuit of the present invention can connect the load dump protection circuit to the charging circuit of the rechargeable battery after the overvoltage protection is triggered and before the charging switch is disconnected, and then disconnect the charging switch, so that a freewheeling circuit is formed between the load dump protection circuit and the starting battery, and the energy storage unit absorbs energy, thereby stabilizing the voltage between the positive electrode of the battery bus and the negative electrode of the battery bus below a preset threshold, effectively solving the load dump problem that occurs during the disconnection of the charging switch. Furthermore, the present invention can flexibly control the timing of load dumping by controlling the control switch for load dump protection through system control, and can start the load dump protection when overvoltage protection is about to occur, and can turn off the load dump protection after the risk of load dumping has passed (for example, after the charging switch 21 is completed), thereby achieving flexible control. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a hardware structure diagram of the power supply equipment of the new energy vehicle in Example 1 of the present invention.

[0023] Figure 2 It is a flow chart of the load dump protection method of the present invention.

[0024] Figure 3 It is a structural block diagram of the power supply equipment of the new energy vehicle of the present invention.

[0025] Figure 4 It is a structural block diagram of a power supply device for a new energy vehicle in a preferred embodiment of the present invention.

[0026] Figure 5a to Figure 5d It is a process diagram of load dump protection performed by the power supply equipment of the new energy vehicle in Example 1 of the present invention.

[0027] Figure 6 This is a hardware structure diagram of the power supply equipment of the new energy vehicle in Example 2 of the present invention.

[0028] Figures 7a to 7d It is a process diagram of load dump protection performed by the power supply equipment of the new energy vehicle in Embodiment 2 of the present invention. DETAILED DESCRIPTION

[0029] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, the following is a detailed description in conjunction with the implementation methods and the accompanying drawings.

[0030] Embodiment 1:

[0031] refer to Figure 1, is the first embodiment of the present invention. In this embodiment, a power supply device for a new energy vehicle is disclosed, including a starting battery 30, a control circuit 20, a battery management module 40 and a load dump protection device. The control circuit 20 is connected in series between the battery total negative electrode B- of the starting battery 30 and the battery bus negative electrode P-. The control circuit 20 includes a charging switch 21, and the battery management module 40 is connected to the control end of the control circuit 20.

[0032] refer to Figure 1 The load dump protection device includes a load dump protection circuit 10, a processor 11 and a memory 12. The load dump protection circuit 10 is connected in parallel with the control circuit 20. The load dump protection circuit 10 includes a series-connected energy storage unit C and a control switch SK1. The positive electrode of the energy storage unit C is adjacent to the total negative electrode B- of the battery relative to the negative electrode. The memory 12 stores at least one operation instruction 13. The processor 11 can execute the operation instruction 13 to implement the load dump protection method of the starter battery 30.

[0033] The energy storage unit C is a supercapacitor or a plurality of electrolytic capacitors connected in parallel, such as two or more N-type enhanced MOSFETs connected in series and parallel. The control switch SK1 is a bidirectional switch. Specifically, the control switch SK1 is a relay switch or a plurality of MOS tubes connected in series and parallel.

[0034] The control circuit further includes a current detection circuit 23 and a discharge switch 22 connected in series with the charging switch 21. Of course, the control circuit may be only the charging switch 21, so that the load dump protection circuit 10 is directly connected in parallel with the charging switch 21 itself.

[0035] The preset threshold is 32 V. Of course, the preset threshold can also be fine-tuned by adjusting the parameters of the energy storage unit C.

[0036] Wherein, the starting battery 30 is a lithium-ion battery.

[0037] refer to Figure 2 The load dump protection method includes steps S11 to S14.

[0038] S11, when an overvoltage phenomenon occurs during the charging process of the starting battery 30, the overvoltage protection is triggered, and a first signal S1 for conduction control is output to control the control switch SK1 to be turned on.

[0039] S12, after the control switch SK1 completes the conduction action, the second signal S2 for disconnection control is output to control the charging switch 21 to be disconnected, so that the starting battery 30 and the load dump protection circuit 10 are connected in series to form a freewheeling loop, and the energy storage unit C absorbs energy, thereby stabilizing the voltage between the positive electrode P+ of the battery bus and the negative electrode P- of the battery bus below a preset threshold.

[0040] In step S12, the first time length is delayed from the output of the first signal S1 for conducting control, and then the second signal S2 for disconnection control is output to control the charging switch 21 to disconnect. The first time length is greater than or equal to the action time of the control switch SK1, and the difference between the first time length and the time for the control switch SK1 to complete the conduction action is less than a first preset threshold, for example, less than 0.2 seconds, to ensure that the control switch SK1 completes the conduction action and will not be delayed too long. Of course, other methods can also be used to ensure that the control switch SK1 completes the conduction action, not limited to being guaranteed by timing control.

[0041] Of course, when it is predicted that the overvoltage risk is high (for example, the output voltage is detected to be continuously greater than the second threshold, the second threshold is less than the first threshold, or the current output voltage is unstable), the first signal S1 for conduction control can be output to control the control switch SK1 to be turned on. At this time, the execution time of step S12 is: after the overvoltage phenomenon triggers the overvoltage protection and the control switch SK1 completes the conduction action, the second signal S2 for disconnection control is output to control the charging switch 21 to be turned off, thereby accelerating the response time of the overvoltage protection.

[0042] S13, after the charging switch 21 completes the disconnection action, outputting the first disconnection control signal S1 to control the control switch SK1 to be disconnected.

[0043] In step S13, the second time length is delayed from the output of the second information for disconnection control to the output of the first signal S1 for disconnection control to control the control switch SK1 to disconnect. Specifically, the second time length is greater than the time length for the charging switch 21 to complete the disconnection action, and the difference between the second time length and the time length for the charging switch 21 to complete the disconnection action is greater than the second preset threshold value, so that the control switch SK1 is still ensured to be closed for a period of time after the charging switch 21 is disconnected, to ensure that the voltage between the positive electrode P+ of the battery bus and the negative electrode P- of the battery bus is stable below the preset threshold value. In this embodiment, the second time length is 1 second, and the second time length can be set according to the action time of the charging switch 21 and the duration of the load dumping, and is not limited to 1 second. Of course, other methods can also be used to ensure that the charging switch 21 completes the disconnection action, not limited to timing control.

[0044] In order to facilitate the discharge of the energy storage unit C after completing the load dump protection, when the starting battery 30 recovers from the overvoltage protection and re-enters the charging process, the control switch SK1 is also output to control the preset conduction time. The preset time is to ensure that the starting battery 30 discharges to the preset power, and it is necessary to ensure that when the next overvoltage protection occurs, the energy storage unit C can quickly absorb enough energy to prevent load dumping.

[0045] refer to Figure 3 The processor 11 of the load dump protection device is the processor of the battery management module 40 , that is, the control software of the load dump protection device is directly loaded into the original battery control board (including the battery management module 40 ) of the starter battery 30 .

[0046] refer to Figure 4 Different from the above embodiment, in another preferred embodiment, the processor 11 of the load dump protection device is a processor different from the battery management module 40. This embodiment makes the load dump protection device an external device different from the original power supply device, which is easy to modify the existing power supply device.

[0047] refer to Figure 5a to Figure 5d , describing the working process of the power supply device of the present invention for load dump protection:

[0048] refer to Figure 5a After the vehicle is started, the on-board generator supplies power to the on-board equipment and charges the starting battery 30. At this time, the current I flows from the total negative electrode B- of the battery through the current detection circuit 23, the discharge switch 22 and the charging switch 21 to the negative electrode P- of the battery bus. The control circuit 20 and the starting battery 30 are connected in series to form a charging circuit. At this time, on the load dump protection circuit 10, the control switch SK1 is in the disconnected state, and the load dump protection circuit 10 is in the cut-off state.

[0049] refer to Figure 5b When the output voltage of the vehicle generator is greater than the first threshold VH1 (for example, 29V) or there is a large inconsistency in the battery cell voltage, the battery management module 40 triggers the cell overvoltage protection to pre-turn off the charging switch 21. Before turning off the charging switch 21, the first signal S1 for conduction control is output to the control end of the control switch SK1 to control the control switch SK1 to turn on.

[0050] refer to Figure 5cAfter controlling the first duration of the control switch SK1 to be turned on or ensuring that the control switch SK1 completes the conduction work by other means, the second signal S2 for disconnection control is output to control the charging switch 21 to be turned off. The current I flows from the total negative electrode B- of the battery through the energy storage unit C and the control switch SK1 to the negative electrode P- of the battery bus. The load dump protection circuit 10 is connected in series with the starting battery 30 to form a freewheeling loop, and the energy storage unit C begins to be charged, so as to stabilize the voltage between the positive electrode P+ of the battery bus and the negative electrode P- of the battery bus below the preset threshold.

[0051] refer to Figure 5d , starting from outputting the second information S2 for disconnection control, delaying for a second time length and then outputting the first signal S2 for disconnection control to control the control switch SK1 to be disconnected.

[0052] When the subsequent charging switch 21 is turned on and the starting battery 30 is recharged, the electricity in the energy storage unit C is gradually released from the control circuit 20 until the voltage difference across the energy storage unit C is equal to the extremely low voltage difference across the control circuit 20, and the electricity in the energy storage unit C is maintained at a very small value and can be ignored.

[0053] Embodiment 2:

[0054] refer to Figure 6 Different from the first embodiment, in the second embodiment, the load dump protection circuit 10a further includes a discharge branch connected in parallel with the energy storage unit C, and a discharge switch SK2 is connected in series on the discharge branch. The discharge switch SK2 is a switch that performs the opposite action to the control switch SK1. When the control switch SK1 is controlled to be disconnected, the discharge switch SK2 is controlled to be closed at the same time, so as to form a discharge loop between the energy storage unit C and the discharge branch. When the control switch SK1 is controlled to be closed, the discharge switch SK2 is controlled to be disconnected at the same time. In order to prevent the current of the discharge loop from being too large, a current limiting resistor can also be connected in series in the discharge loop. The size of the current limiting resistor is set according to actual needs. It is necessary to enable the energy storage unit C to achieve rapid discharge while preventing the discharge loop from overheating and burning related devices.

[0055] The discharge switch SK2 is a switch that is turned on and off by the system signal control, and can be a bidirectional switch, or a unidirectional switch set from the positive electrode of the energy storage unit C to the negative electrode of the energy storage unit C, and can be a semiconductor switch, or other electronically controlled switches, such as a relay switch. Of course, a discharge resistor can also be used instead of the discharge switch SK2, and the resistance of the discharge resistor is 1KΩ to 10KΩ. Of course, the resistance of the discharge resistor R is not limited to this, and can be set according to actual needs.

[0056] For the convenience of control, in this embodiment, the discharge switch SK2 and the control switch SK1 are the normally closed contact switch and normally open contact switch of the same contactor switch SK. In this embodiment, the discharge switch SK2 is a normally closed switch, and the control switch SK1 is a normally open switch. Of course, the discharge switch SK2 can also be set as a normally open switch, and the control switch SK1 can be set as a normally closed switch. The coil SK is the control coil of the contactor switch SK, which is controlled by the battery management module 40 or the control part of the load dump protection device.

[0057] refer to Figures 7a to 7d , describing the working process of the power supply device of the present invention for load dump protection:

[0058] refer to Figure 7a After the vehicle is started, the on-board generator supplies power to the on-board equipment and charges the starting battery 30. At this time, the current I flows from the total negative electrode B- of the battery through the current detection circuit 23, the discharge switch 22 and the charging switch 21 to the negative electrode P- of the battery busbar. The control circuit 20 and the starting battery 30 are connected in series to form a charging circuit. At this time, on the load dump protection circuit 10a, the system controls the control switch SK1 to be in the off state and controls the discharge switch SK2 to be in the on state, ensuring that the power in the energy storage unit C is discharged or kept in a very low state, and the load dump protection circuit 10a is in the off state.

[0059] refer to Figure 7b When the output voltage of the vehicle-mounted generator is greater than the first threshold VH1 (for example, 29V) or there is a large inconsistency in the battery cell voltage, the battery management module 40 triggers the cell overvoltage protection to pre-turn off the charging switch 21. Before turning off the charging switch 21, the first signal S1 for conduction control is output to the control end of the control switch SK1 to control the control switch SK1 to turn on, and at the same time control the discharge switch SK2 to turn off, and a very small part of the current begins to flow to the energy storage unit C to charge the energy storage unit C. Of course, since the voltage difference between the two ends of the control unit 20 is extremely low, the voltage difference between the energy storage units C is extremely low.

[0060] refer to Figure 7c After controlling the first duration of the control switch SK1 to be turned on or ensuring that the control switch SK1 completes the conduction work by other means, the second signal S2 for disconnection control is output to control the charging switch 21 to be turned off. The current I flows from the total negative electrode B- of the battery through the energy storage unit C and the control switch SK1 to the negative electrode P- of the battery bus. The load dump protection circuit 10 is connected in series with the starting battery 30 to form a freewheeling loop, and the energy storage unit C begins to be charged, so as to stabilize the voltage between the positive electrode P+ of the battery bus and the negative electrode P- of the battery bus below the preset threshold.

[0061] refer to Figure 7d, delaying the second time length from outputting the second information S2 for disconnection control, or delaying a load dumping protection time length after ensuring that the charging switch 21 is disconnected, and then outputting the first signal S2 for disconnection control to control the charging switch 21 to disconnect, completing the load dumping protection, at this time, the discharge switch SK2 is controlled to be turned on at the same time, the energy storage unit C and the discharge switch SK2 form a discharge loop, and the power of the energy storage unit C is quickly released through the discharge switch SK2, so as to perform the next round of load dumping protection.

[0062] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A load dump protection method for a starting battery, wherein a control circuit is connected in series between the total negative electrode of the starting battery and the negative electrode of the battery busbar, and the control circuit includes a charging switch, characterized in that: The control circuit is connected in parallel with a load dump protection circuit, which includes a series-connected energy storage unit and a control switch, wherein the positive electrode of the energy storage unit is adjacent to the total negative electrode of the battery relative to the negative electrode; the load dump protection method includes: When the overvoltage protection is triggered during the charging process of the startup battery, a first signal for conducting control is output to control the control switch to conduct; After the control switch completes the conduction action, a second signal for disconnection control is output to control the charging switch to be disconnected, so that the starting battery and the load dump protection circuit are connected in series to form a freewheeling loop, and the energy storage unit absorbs energy, thereby stabilizing the voltage between the positive electrode of the battery bus and the negative electrode of the battery bus below a preset threshold; After the charging switch completes the disconnection action, outputting a first signal for disconnection control to control the control switch to disconnect; The energy storage unit is a super capacitor or is formed by connecting a plurality of electrolytic capacitors in parallel.

2. The load dump protection method for a starting battery as claimed in claim 1, characterized in that: When the starting battery recovers from overvoltage protection and re-enters the charging process, the control switch is also output to control the preset conduction time to form a discharge loop between the energy storage unit and the control circuit, and the electric energy in the energy storage unit is discharged; or The load dump protection circuit further includes a discharge branch connected in parallel with the energy storage unit, a discharge switch is connected in series on the discharge branch, and the discharge switch is a switch that performs opposite actions to the control switch. When the control switch is controlled to be disconnected, the discharge switch is controlled to be closed at the same time to form a discharge loop between the energy storage unit and the discharge branch. When the control switch is controlled to be closed, the discharge switch is controlled to be disconnected at the same time; or, The load dump protection circuit further includes a discharge resistor connected in parallel with the energy storage unit, so that when the control switch is disconnected, a discharge loop is formed between the energy storage unit and the discharge resistor.

3. The load dump protection method for a starting battery as claimed in claim 1, characterized in that: Outputting a second signal for disconnection control to control the charging switch to disconnect after the control switch completes the conduction action includes: delaying for a first time length from outputting the first signal for conduction control and then outputting the second signal for disconnection control to control the charging switch to disconnect.

4. The load dump protection method for a starting battery as claimed in claim 1, characterized in that: Outputting a first signal for disconnection control to control the control switch to disconnect after the charging switch completes the disconnection action includes: delaying for a second time period from outputting the second information for disconnection control and then outputting the first signal for disconnection control to control the control switch to disconnect, and the second time period is greater than the time period for the charging switch to complete the disconnection action.

5. The load dump protection method for a starting battery as claimed in claim 4, characterized in that: The second duration is 1 second.

6. The load dump protection method for a starting battery as claimed in claim 1, characterized in that: The control switch is a bidirectional switch.

7. The load dump protection method for a starting battery as claimed in claim 1, characterized in that: The control switch is a relay switch or a combination of multiple MOS tubes connected in series and parallel; The control circuit also includes a current detection circuit and a discharge switch connected in series with the charging switch.

8. A load dump protection device for a starting battery, wherein a control circuit is connected in series between the total negative electrode of the starting battery and the negative electrode of the battery busbar, and the control circuit includes a charging switch, characterized in that: The method comprises a load dump protection circuit, a processor and a memory. The load dump protection circuit is connected in parallel with the control circuit and comprises a series-connected energy storage unit and a control switch. The memory stores at least one operation instruction. The processor can execute the operation instruction to implement the load dump protection method for the starting battery according to any one of claims 1 to 7.

9. A power supply device for a new energy vehicle, characterized in that: It includes a starting battery, a control circuit, a battery management module and a load dump protection device. A control circuit is connected in series between the total negative electrode of the starting battery and the negative electrode of the battery bus. The battery management module is connected to the control end of the control circuit. The load dump protection circuit is the load dump protection device of the starting battery as claimed in claim 8.

10. The power supply device according to claim 9, characterized in that: The processor of the load dump protection device is the processor of the battery management module; or, The processor of the load dump protection device is different from the processor of the battery management module, and the processor of the load dump protection device is also connected to the signal output terminal of the processor of the battery management module for outputting the charging status.

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