Mobile battery discharger for motor vehicles with mobile discharger

Abstract

Mobile battery (70) discharger, including: (i) a first electrical connection (20) for contacting (80) with a first electrical terminal (+) of a battery (70); (ii) a second electrical connection (30) for contacting (80) with a second electrical terminal (-) of a battery (70); and (iii) an electrical resistor (R1, R2, R3) which is electrically connected on one side to the first terminal (20) and on the other side to the second terminal (30), characterized by the fact that the discharger also includes: (iv) a first fluid connection (50) for connecting a fluid supply (90, 100); (v) a second fluid connection (40) for connecting a fluid drain (110, 120); and (vi) a fluid channel (60) which is connected to the first fluid port (50) and the second fluid port (40), wherein the fluid channel (60) is thermally coupled to the electrical resistance (R1, R2, R3).

Description

[0001] The present invention relates to a mobile discharger for battery modules for emergency or service use and to a motor vehicle for emergency or service use which is connected to the mobile discharger according to the invention. State of the art

[0002] In the event of servicing or an accident, the high amount of energy stored in the traction batteries of electric vehicles poses a risk. Discharging to a low state of charge (SOC) reduces the risk in case of an uncontrolled release of battery energy.

[0003] A safe and rapid discharge of batteries after an accident is usually not possible because the battery's contactors can no longer be closed: If the battery management system (BMS) is still functioning, it will prevent the contactors from closing, having previously detected a crash and any resulting defects. If the BMS is no longer functioning, the control unit for the contactors has failed, so the contactors also remain open. This open state is the fail-safe state for the battery. However, in the event of an accident, dangerous reactions can occur even in this state, for example, due to internal short circuits within the battery pack. Discharging the battery should mitigate the severity of these reactions.

[0004] Furthermore, contactors or switches may also have been rendered inoperable due to an accident.

[0005] Therefore, it is usually impossible today to discharge a damaged battery without complex disassembly and thus quickly restore it to a safe condition at the accident site. Transporting charged batteries is particularly risky, as movement of detached battery components or leaked coolant during transport can cause short circuits within the battery, leading to a fire. The aim should therefore be to discharge the battery directly at the accident site without moving it, before transporting it to a workshop.

[0006] WO 2003 / 041 208 A1 discloses a method for eliminating hazards associated with lithium-ion batteries using a heating resistor.

[0007] KR 10 2007 0 006 000 A discloses a fire suppression system for combating fires caused by accidents in modules of secondary batteries.

[0008] The state of the art in this regard is still the printed document DE 10 2009 050 125 A1. Disclosure of the invention

[0009] According to the invention, a mobile battery discharger is provided, comprising a first electrical connection, preferably a standard plug or a universal clamping contact for use with various pole geometries, for contacting a first electrical pole of a battery, a second electrical connection for contacting a second electrical pole of a battery, and an electrical resistor which is electrically connected on one side to the first connection and on the other side to the second connection, wherein the discharger further comprises a first fluid connection for connecting a fluid supply, a second fluid connection for connecting a fluid discharge, and a fluid channel which is connected to the first fluid connection and the second fluid connection, wherein the fluid channel is thermally coupled to the electrical resistor.

[0010] In the context of the present invention, a thermal coupling between resistor and fluid channel is preferably understood to be a connection such that preferably at least 80% of the waste heat from the resistor is absorbed by the fluid channel.

[0011] The invention offers the advantage that a large amount of energy can be dissipated safely in a very short time.

[0012] Lithium-ion battery cells or other high-energy cells are preferably considered as battery cells.

[0013] In accordance with the present invention, preferably the first fluid connection is a connection to a cooling water inlet and the second fluid connection is a connection to a cooling water outlet.

[0014] One resulting advantage is that cooling water is environmentally friendly and readily available.

[0015] In a preferred embodiment of the invention, the cooling water inlet includes a hydrant connection.

[0016] The advantage of this is that hydrant water has a high pressure, allowing for large volume flows of cooling water, which corresponds to a correspondingly large amount of energy to be dissipated.

[0017] It is also possible that the discharger has an additional resistor and another pair of terminals for contacting an additional battery.

[0018] The advantage of a discharger for discharging multiple batteries is the ability to discharge all affected batteries simultaneously in case of service, thus saving time compared to discharging in serial battery order.

[0019] It is also possible that the discharger has an electro-optical indicator designed to signal a battery status.

[0020] One advantage is the ability to influence the discharge behavior, for example to terminate the discharge or preferably to switch the discharge current on or off gradually in order to avoid arcing.

[0021] In a particular embodiment, the electro-optical display is a light-emitting diode that has a series resistor in order to be operated directly at different voltages.

[0022] This proves to be an advantage in achieving an optimal drive current for the light-emitting diode.

[0023] In a particularly preferred variant, the electrical resistance is a Zener diode, a transistor and / or an electrical resistor.

[0024] A resulting advantage is, in particular, the ability to set a threshold below which the light-emitting diode does not light up.

[0025] According to another aspect of the invention, a motor vehicle with a mobile unloader according to one of the aforementioned features is disclosed, wherein the motor vehicle comprises the mobile unloader and is connected to the unloader.

[0026] The advantage is the possibility according to the invention to optimize an emergency or service vehicle for unloading operations.

[0027] In a preferred embodiment, the motor vehicle includes a water tank which is connected to the first fluid connection of the mobile unloader.

[0028] One advantage achieved through this design is the ability to be location-independent of the cooling water supply, thus allowing the cooling water and the required cooling water pressure to be stored on the emergency or service vehicle. As an additional option, the top of the housing can preferably be equipped with attachment elements, such as shackles or eyelets.

[0029] This has the advantage of allowing it to be moved by standardized lifting equipment.

[0030] In one advantageous version, the mobile unloader is designed for passive driving, for example by means of swivel casters with a locking brake, and is also equipped with a handle that runs horizontally around the housing, so that it can be guided and held more easily by hand.

[0031] Preferably, the water channel in the device splits into several parallel channels and reunites the many channels into one channel before exiting the device.

[0032] It is also possible for the water channel to follow a meandering course through the device. The water channel is electrically isolated from the power resistor, but thermally well coupled. This can be achieved, for example, by using a thermally conductive plastic.

[0033] The power resistor for discharging the battery cells is designed so that a battery module can be discharged in just a few minutes. This requires discharge rates of typically 5C to 10C, allowing for complete discharge in 6 to 12 minutes. For the largest lithium-ion cells currently available, with a capacity of 60 Ah, discharge currents of 300 A to 600 A are therefore necessary. The power resistor is a wire-wound resistor with close thermal coupling to the water cooling channels.

[0034] With a module voltage of typically 60 V and a discharge current of 600 A, the total resistance is therefore typically 0.1 ohms. It can be achieved by preferably parallel-connected individual power resistors.

[0035] Preferably, a power semiconductor is used to activate the discharge process. Drawings

[0036] Exemplary embodiments of the invention are explained in more detail with reference to the drawings and the following description. The drawings show: Fig. 1 a mobile unloading device according to a preferred embodiment of the invention in a schematic perspective view, and Fig. 2 A mobile discharger connected to a battery according to a preferred embodiment of the invention in a schematic perspective view.

[0037] Fig. Figure 1 shows a three-dimensional schematic representation of a mobile unloading unit with a cuboid housing 130.

[0038] Inside the housing 130 are three high-performance electrical resistors R1, R2, R3, a cooling water channel 60 and electrical connecting lines 10 for supplying the resistors R1, R2 and R3.

[0039] The housing 130 preferably completely encloses the internal elements, which increases operational safety. The housing 130 is preferably electrically insulating.

[0040] On one or different outer sides of the housing 130 there is a wastewater connection 40, a cooling water connection 50, a first electrical connection pole 20 and a second electrical connection pole 30.

[0041] The cooling water channel 60 follows the longest possible, and therefore most winding, route in close proximity to the high-performance resistors R1, R2, and R3 to ensure good heat transfer from the resistors to the cooling water. The cooling water channel 60 is supplied via the cooling water connection 50 and emptied via the wastewater connection 40.

[0042] It is preferred that the jacket or outer wall of the cooling water channel 60 is thermally tightly but electrically insulated from the resistors R1, R2, R3.

[0043] Therefore, it is particularly preferred that the surface design of the cooling water channel 60 in the area of ​​resistors R1, R2, R3 has an extent corresponding to the shape of the resistors R1, R2, R3, in which the resistors R1, R2, R3 are embedded. This can advantageously improve the cooling efficiency.

[0044] Preferably, the power resistors R1, R2 and R3 are activated via a power transistor or (in a simplified version) a power contactor (possibly with series resistors), so that a large current does not flow immediately when the contacts are plugged in.

[0045] Fig.Figure 2 shows a three-dimensional schematic representation of a mobile discharger with a cuboid housing 130 connected to a battery 70.

[0046] A hydrant 90 supplies a cooling water hose 100, which is connected to the unloader. A wastewater hose 110 is connected to the unloader to drain the wastewater 120.

[0047] Two electrical terminals of a battery 70 are connected to the discharger by means of electrical connecting cables 80. Plugs or universal clamps are preferably used to connect the battery terminals.

[0048] The energy of the battery 70 being discharged remains in the wastewater 120.

[0049] In a preferred embodiment, a battery module with 13 cells in series (13s1p) is used.

[0050] In a preferred embodiment, the light-emitting diode of the electro-optical indicator is connected to an electrical resistor or a Zener diode to signal the state of charge. It is preferred that the light-emitting diode begins to illuminate at a module voltage of 20 V. If the light-emitting diode does not illuminate, this indicates a practically completely discharged battery module.

[0051] Preferably, the following operating concept is used for the display: Three light-emitting diodes and a push button with another light-emitting diode ("Discharging") are arranged side by side. Light-emitting diode 1 (red) indicates "out of range, use fewer cells!", meaning that the operator has connected too many cells and thus the voltage of the module to be discharged exceeds 60 volts. Preferably, the device is not designed for this. If the "Start Discharge" button is deactivated, this means that a discharge process cannot be started. The operator then moves the second contact by one cell and again observes the red light-emitting diode: This process is repeated until the lamp goes out, i.e., the voltage of the connected cells is below 60 volts. If light-emitting diode 2 (yellow) indicates that the voltage across the connected cells is between 20 volts and 60 volts.In this case, the discharge process can be started via the push button. After pressing the button, the light-emitting diode next to the button illuminates and indicates "Discharging". The power transistor (or a power contactor) is activated, allowing current to flow through the power resistors.

[0052] If the light-emitting diode 3 (green) is illuminated, it indicates that the voltage of the connected cells is below 20 volts. Therefore, with thirteen cells, this is significantly below 2 volts per cell, meaning the cells are deeply discharged and can no longer cause damage. The "Discharging" light-emitting diode is off.

Claims

[1] Mobile battery discharger (70), comprising: (i) a first electrical connection (20) for contacting (80) with a first electrical terminal (+) of a battery (70); (ii) a second electrical connection (30) for contacting (80) with a second electrical terminal (-) of a battery (70); and (iii) an electrical resistor (R1, R2, R3) which is electrically connected on one side to the first terminal (20) and on the other side to the second terminal (30), characterized by , that the discharger also includes: (iv) a first fluid connection (50) for connecting a fluid supply (90, 100); (v) a second fluid connection (40) for connecting a fluid drain (110, 120); and (vi) a fluid channel (60) which is connected to the first fluid port (50) and the second fluid port (40), wherein the fluid channel (60) is thermally coupled to the electrical resistance (R1, R2, R3). [2] Mobile unloading device according to claim 1, wherein the first fluid connection (50) is a connection to a cooling water inlet (100) and / or the second fluid connection (40) is a connection to a cooling water outlet (110, 120). [3] Mobile unloading device according to claim 2, wherein the cooling water inlet (100) comprises a hydrant connection (90). [4] Mobile discharger according to one of the preceding claims, wherein the discharger has a further resistor (R1, R2, R3) and a further pair of terminals for contacting (80) with an additional battery (70). [5] Mobile discharger according to one of the preceding claims, wherein the discharger has an electro-optical indicator configured to signal a charge level of a connected battery (70). [6] Mobile discharger according to claim 5, wherein the electro-optical indicator is a light-emitting diode. [7] Mobile discharger according to claim 6, wherein the light-emitting diode is connected to an electrical resistor. [8] Mobile discharger according to claim 7, wherein the electrical resistance is a Zener diode, a transistor and / or an ohmic resistor. [9] Motor vehicle with a mobile unloader according to any of the preceding claims, wherein the motor vehicle includes the mobile unloader and / or is connected to the unloader. [10] Motor vehicle according to claim 9, wherein the motor vehicle comprises a water tank which is connected to the first fluid connection (50) of the mobile unloader.

Images