Battery pack module for a power tool, power tool with at least one battery pack module and charger with at least one battery pack module

Abstract

Battery pack module (10) for a power tool (110), comprising a housing (12) with a connection section that can be connected to a counterpart connection section of the power tool (110) to which the battery pack module (10) is assigned, and to a counterpart connection section of a charger (210) to which the battery pack module (10) is assigned;- wherein the connecting section has several connecting contacts, at least one subgroup of several connecting contacts being suitable for contacting a respective connecting contact from several mating connecting contacts of the mating connecting section of the power tool (110) when the connecting section and the mating connecting section are connected to each other in a power tool coupling state of the battery pack module (10), and at least one subgroup of several connecting contacts being suitable for contacting a respective connecting contact from several mating connecting contacts of the mating connecting section of the charger (210) when the connecting section and the mating connecting section are connected to each other in an alternative charger coupling state of the battery pack module (10); - several individual battery cells arranged inside the housing (12);- a battery management circuit (16) arranged within the housing (12) and connected to the individual battery cells; - wherein the battery cells are suitable for providing electrical energy to operate the power tool (110) via associated contacts of the connection section, and are suitable for receiving electrical energy to be charged by means of the charger (210) via associated contacts of the connection section; characterized in that the battery management circuit (16) is suitable for performing active cell balancing between the battery cells of the battery pack module (10), which comprises transferring electrical energy from a single battery cell with a higher state of charge to at least one other single battery cell with a lower state of charge.;

Description

The present invention relates to a battery pack module for a power tool and a power tool equipped with at least one battery pack module, and a charger equipped with at least one battery pack module. The power tool according to the present invention is preferably a handheld, cordless power tool used by tradespeople or for private use in DIY projects. Examples of such handheld, cordless power tools are electric drills, electric saws, electric grinders, electric hammer drills, and the like. Handheld, cordless power tools have become widely used in recent years, primarily due to their advantage of being cordless. There is no need to connect an electrical cable or worry about it while working with these tools. Instead, a separate battery pack module can be charged with electrical energy and then connected (mechanically and electrically) to the power tool, as is generally known. The combined unit, consisting of the power tool and the battery pack module, is held by hand by the user during operation. However, providing battery pack modules that efficiently store as much electrical energy as possible to extend the time until the next necessary recharging of the battery pack module remains a challenge. It is therefore an object of the present invention to provide a battery pack module, a combination of a battery pack module and a power tool, and a combination of a battery pack module and a charger that make it possible to further increase the electrical capacity of the battery pack module, extend the service life of the battery pack, and improve the efficiency of storing electrical energy in the battery pack module. This problem is solved by a battery pack module, a combination of a battery pack module and a power tool, and a combination of a battery pack module and a charger, each having the features of claims 1, 18, and 19. Further features of the present invention are set forth in the dependent claims. The present invention provides a battery pack module for a power tool, wherein the battery pack module comprises a housing with a connecting section that can be connected to a mating connection section of a power tool to which the battery pack module is assigned, and to a mating connection section of a charger to which the battery pack module is assigned;- wherein the connecting section has several connecting contacts, at least one subgroup of which is suitable for contacting a corresponding mating contact of several mating contacts of the mating section of a power tool when the connecting section and the mating section are connected to each other in a power tool coupling state of the battery pack module, and at least one subgroup of which is suitable for contacting a corresponding mating contact of several mating contacts of the mating section of the charger when the connecting section and the mating section are connected to each other in an alternative charger coupling state of the battery pack module; - several individual battery cells arranged inside the housing;- a battery management circuit arranged within the housing and connected to the individual battery cells; - wherein the battery cells are capable of providing electrical energy for operating the power tool via associated contacts of the connection section, and of receiving electrical energy for charging by means of the charger via associated contacts of the connection section; and - wherein the battery management circuit is capable of performing active cell balancing between the battery cells of the battery pack module, comprising the transfer of electrical energy from a single battery cell with a higher state of charge to at least one other single battery cell with a lower state of charge.; The battery pack module according to the present invention has the following advantages: Maximized capacity: Balanced cells ensure that the battery pack can achieve its maximum rated capacity. This is because the overall performance is determined by the weakest cell in the pack. Extended lifespan: By preventing overcharging or over-discharging of individual cells, cell balancing extends the lifespan of the entire battery pack. Increased safety: Proper cell balancing reduces the risk of thermal runaway, a condition in which cells overheat and may catch fire or explode. Improved efficiency: Active balancing methods, in which energy is redistributed from more heavily charged cells to less heavily charged cells, are more efficient and can significantly improve the overall performance of the battery pack.Reduced downtime: Continuous balancing eliminates the need for dedicated downtime for cell balancing, ensuring that the battery pack always operates at maximum efficiency. The battery cells are preferably lithium-ion cells. Other types of battery cells can also be used if necessary. Optionally, the supply of electrical energy to operate the power tool can be carried out via associated contacts of the connection section via the battery management circuit. Optionally, the battery pack module can also be charged via the charger using the associated contacts of the connection section via the battery management circuit. The improvement according to the invention aims to provide a new type of battery management system. It not only expands the cell configuration by using different openings for the position of the nickel strips to achieve universality of the battery pack, but also integrates efficient active and passive balancing mechanisms and uses LED lights with integrated driver chips to indicate the status. The efficient balancing solution can utilize four ETA3006 units (an active balancing chip) to form an active balancing circuit providing a balancing current of over 1 A. Simultaneously, the T035 (a digital input chip with integrated battery voltage detection circuitry and a passive balancing circuit) can be used to implement the passive balancing function. When the active balancing circuit is activated, the passive balancing automatically deactivates to conserve energy. Cell-to-cell balancing can transfer excess energy stored in one cell to neighboring cells if they have less stored energy. Active balancing can be activated if the difference between cells is greater than 50 millivolts AND the voltage of the single cell with the highest value in the entire battery pack is greater than 4 V AND the voltage of the single cell with the lowest value in the entire battery pack is greater than 3.0 V. If the balancing process reaches a point where the difference between cells is close to 20 millivolts and the voltage difference does not change over a long period (more than 30 minutes), passive balancing is activated to further balance the unbalanced cells. The ETA3006 active balancing chip, which can be used in the battery pack, only balances two adjacent cells. Therefore, it is not possible to balance every cell to the same voltage. A passive balancing chip can be used to further balance cells that have already been brought very close to each other by the active balancing. This fully utilizes the energy-saving and highly efficient properties of active balancing as well as the passive balancing's ability to balance cells to the smallest possible voltage difference. The intelligent status indicator can use smart LED lights. These LEDs have integrated driver chips and can display corresponding colors or flashing patterns depending on the different battery states, making it easy for users to intuitively recognize the battery's condition. In summary, this improvement according to the invention provides a multi-mode battery management system. It features the highly efficient regulatory capability of active balancing and, as a backup, a passive balancing function implemented by the T035. Furthermore, it is characterized by a structural design suitable for different cell specifications and an intuitive LED status feedback system, thus providing a more flexible, efficient, and safer battery management solution. The battery pack module according to the invention enables the implementation of a method for cell balancing between several individual battery cells of a battery pack module, which is suitable for supplying energy to an associated power tool and being charged by an associated charger. The method comprises the implementation of active cell balancing between battery cells of the battery pack module, which includes the transfer of electrical energy from an individual battery cell with a higher state of charge to at least one other individual battery cell with a lower state of charge. The method advantageously includes performing passive cell balancing between the battery cells of the battery pack module. This passive cell balancing between the battery cells of the battery pack module can advantageously be carried out in a manner comprising at least one of the following procedures: a) balancing the state of charge between battery cells by consuming electrical energy from a respective individual battery cell with a higher state of charge than at least one other battery cell, and b) diverting electrical energy during a charging cycle with respect to a respective individual battery cell with a higher state of charge than at least one other battery cell, such that less electrical energy is charged into that respective individual battery cell. This passive cell balancing can include the consumption of electrical energy taken from a particular individual battery cell with a higher state of charge by providing a controlled short circuit via an electronic short-circuit arrangement, preferably comprising a transistor or a resistor. This passive cell balancing can also include the circuit diversion of electrical energy during the charging cycle via a path parallel to the respective individual cell. The method can only provide active cell balancing in groups for several groups of battery cells from the several individual battery cells or / and only between adjacent cells of the several individual battery cells. Advantageously, the method can include activating and deactivating active cell balancing as well as activating and deactivating passive load balancing depending on the states of the battery pack and its individual battery cells. In this context, it is proposed to activate active cell balancing when 1) the voltage difference between the cells is greater than a predefined first voltage difference of preferably about 50 mV, and 2) the voltage of a single battery cell exceeds an upper threshold of preferably about 4 V, wherein this battery cell is a battery cell that has a higher state of charge, preferably the highest state of charge of all battery cells, and 3) the voltage of no other battery cell is below a lower threshold of preferably about 3 V. Furthermore, it is proposed to deactivate the active cell balancing when a voltage difference between the cells subjected to active cell balancing of less than a second voltage difference of preferably about 20 mV is reached and maintained for a predetermined time interval, preferably for more than 30 minutes. Advantageously, passive cell balancing can be activated after active cell balancing has been deactivated to further balance the state of charge between the battery cells of the battery pack module. The method may further include indicating at least one status message and / or warning states relating to the battery pack module and its battery cells by means of a display arrangement or indicator light arrangement of the battery pack module. If desired, at least the status message and / or warning message relating to the power tool and / or the charger may be indicated by the display arrangement or indicator light arrangement of the battery pack module. The method may further include performing wireless communication, e.g., according to the Bluetooth standard, to transmit current or stored status, warning, and error information relating to the battery pack module from the battery pack module to an external device, such as a user device like a smartphone, tablet, or laptop. Visual or audible signaling from the battery pack module can also be triggered by the external device. An exemplary embodiment of the present invention is described below with reference to the accompanying drawings, in which: Fig. 1 shows a schematic block diagram of an embodiment of the battery pack module according to the present invention; Fig. 2 shows a schematic block diagram of an embodiment of the combination of a battery pack module and a power tool according to the present invention; Fig. 3 shows a schematic block diagram of an embodiment of the combination of a battery pack module and a charger according to the present invention; Fig. 4A, Fig. 4B show an embodiment of an active balancing circuit according to the present invention, wherein the balancing circuit is shown on two drawing sheets for the sake of graphical clarity; Fig. 5A, Fig.Figures 5B show an embodiment of a passive balancing circuit according to the present invention, wherein the balancing circuit is shown on two drawing sheets for the sake of graphical clarity; Figures 6A-6D show an embodiment of a battery management and charging system according to the present invention, wherein the battery management and charging system is shown on four drawing sheets for the sake of graphical clarity, and the break line in Figure 6D is to be aligned with the break line located at the bottom right of Figure 6B; and Figures 7A-7C show an embodiment of an LED circuit, which is schematically represented for a battery pack status indicator according to the present invention, wherein the LED circuit is shown on two drawing sheets for the sake of graphical clarity. Figures 1, 2 to 3 schematically illustrate an exemplary embodiment of a battery pack module 10, which is suitable for supplying energy to an associated power tool 110 (schematically shown in Figure 2) and for being charged by an associated charger 210 (schematically shown in Figure 3). The battery pack module 10 has a housing 12 containing various elements, as described below. A positive-locking engagement section 14 with connecting contacts can engage with a counter-positive-locking engagement section 114 of the power tool 110 and with a counter-positive-locking engagement section 214 of the charger 210. In the engaged state, the counter-connecting contacts of the respective counter-positive-locking engagement section 114 or 214 are in contact with the corresponding connecting contacts of the positive-locking engagement section 14. A battery management and control circuit 16, comprising electronics 22 for active and preferably also passive cell balancing, and which may further comprise one or more or all of the following components: a microprocessor 24, a memory module 26, a Bluetooth module 28 and optionally further electronics 30. Preferably, the battery pack module 10 is provided with a display and / or indicator light arrangement 18 to show at least one status and / or warning message relating to the battery pack module 10. Advantageously, status and / or warning message relating to the power tool 110 and / or the charger 210 can also be displayed by means of the display and / or indicator light arrangement 18 of the battery pack module 10. The display and / or indicator light arrangement 18 is connected to the battery management and control circuit 16 via an electrical connection line arrangement 32b. The battery pack module 10 comprises an integrated battery cell arrangement 20, which includes several individual accumulator battery cells. In the schematically shown embodiment, the battery management and control circuit 16 is connected between the connection contacts of the positive-locking engagement section 14 and the battery cell arrangement 20 by means of an electrical connection line arrangement 32a (provided on the side of the positive-locking engagement section 14) and two electrical connection line arrangements 32b and 32d (provided on the side of the battery cell arrangement 20). Optionally, however, electrical connection lines can also be provided that connect the respective connection contacts of the positive-locking engagement section 14 directly to the battery cell arrangement 20. The circuit for active compensation shown in Fig. 4A and Fig. 4B works in principle as follows: Downward converter compensation (buck compensation): Using the U5 unit circuit as an example: When the MCU detects that the voltage 21V_IN is higher than the voltage 16V8_IN and exceeds the defined threshold, ETA_EN switches U5 on. 21V_IN supplies current to pin 8 of U5. The chip's internal PWM circuit, R35 and L2, steps down the voltage to charge 16V8_IN. Consequently, the voltage 21V_IN drops and the voltage 16V8_IN rises; the voltage difference between the two decreases and gradually equalizes, thus completing the balancing process. Step-Up Compensation (Boost): If the voltage at 16V8_IN is higher than the voltage at 21V_IN and exceeds the set threshold, 16V8_IN charges 21V_IN via L2, R35, and the internal PWM circuit of U5 pin 2 by increasing the voltage. The voltage (of 16V8_IN) decreases while the voltage of 21V_IN increases, gradually reducing and equalizing the pressure difference and completing the equalization process. Other units: The operating principles of the other chips U6, U7 and U8 are identical. Efficiency: Since this circuit charges the lower voltage cell using energy from the higher voltage cell, it is more of an energy transfer than a loss, resulting in higher energy utilization efficiency. The passive balancing circuit shown in Figures 5A and 5B works in principle as follows: The MCU sets PWR_ON to a high level, switching on U1 so that it begins operation. When U1 detects that the B+ voltage is higher than the 16.8V voltage, exceeding the threshold, it switches on the internal discharge circuit, which connects U1 pin 2 and U1 pin 3. The B+ voltage continuously dissipates B+ power through R6, U1 pin 2, U1 pin 3, and R8. The voltage difference between B+ and 16.8V gradually decreases and equalizes, thus ending the balancing process. The balancing principles for the remaining 16V8, 12V6, 8V4 and 4V2 are the same as described above. The battery management and charging system shown in Figs. 6A - 6D has, in principle, the following structure and function: System structure: The battery management and charging circuit on the side of the battery pack mainly comprises U3 (Fig. 1), U1 (Fig. 2) and a charging communication circuit (consisting of R24, Q4, R3 and R10). Function: U1 acquires information on battery voltage and temperature and communicates with U3 to transmit the acquired battery data. U3 communicates bidirectionally with an external charger via the charging communication circuit. With the exception of the aforementioned battery management and charging communication circuits, the remaining circuits of the charging system are located on the charger's circuit board. The following describes the LED circuit shown in Figures 7A-7C, which schematically serves to indicate the status of the battery pack: The MCU controls the on / off state and color of LEDs 1-12 using LD_G pulses. The MCU performs the corresponding LED displays according to the current battery capacity and balance status. Light codes for charging status: Charge fully extinguished (Off) Temperature error, red flashing Battery error: Red / green alternating flashing light Total voltage of the battery pack > 19.5 V Green pulsating light Tolerance ±0.25 V 19.5 V > Total voltage of the battery pack > 18.5 V Orange pulsating light Tolerance ±0.25 V 18.5 V > Total voltage of the battery pack. Red pulsating light. Tolerance ±0.25 V There is no special LED light code indicator during battery balancing. Reference symbol list 10 Battery pack module 12 Housing 14 Positive locking section with connecting contacts 16 Battery management and control circuit 18 Display and / or indicator light assembly 20 Battery cell assembly with multiple individual accumulator battery cells 22 Electronics for active and passive cell balancing 24 Microprocessor 26 Memory module 28 Bluetooth module 30 Optionally, further electronics 32a, 32b, 32c and 32d Electrical connecting cable assembly 110 Power tool 114 Mutual positive locking section with mating connection contacts 115 Mutual positive locking and contact relationship 210 Charger 214 Mutual positive locking section with mating connection contacts 215 Mutual positive locking and contact relationship

Claims

Battery pack module (10) for a power tool (110), comprising a housing (12) with a connection section that can be connected to a counterpart connection section of the power tool (110) to which the battery pack module (10) is assigned, and to a counterpart connection section of a charger (210) to which the battery pack module (10) is assigned;- wherein the connecting section has several connecting contacts, at least one subgroup of several connecting contacts being suitable for contacting a respective connecting contact from several mating connecting contacts of the mating connecting section of the power tool (110) when the connecting section and the mating connecting section are connected to each other in a power tool coupling state of the battery pack module (10), and at least one subgroup of several connecting contacts being suitable for contacting a respective connecting contact from several mating connecting contacts of the mating connecting section of the charger (210) when the connecting section and the mating connecting section are connected to each other in an alternative charger coupling state of the battery pack module (10); - several individual battery cells arranged inside the housing (12);- a battery management circuit (16) arranged within the housing (12) and connected to the individual battery cells; - wherein the battery cells are suitable for providing electrical energy to operate the power tool (110) via associated contacts of the connection section, and are suitable for receiving electrical energy to be charged by means of the charger (210) via associated contacts of the connection section; characterized in that the battery management circuit (16) is suitable for performing active cell balancing between the battery cells of the battery pack module (10), which includes transferring electrical energy from a single battery cell with a higher state of charge to at least one other single battery cell with a lower state of charge.; Battery pack module (10) according to claim 1, wherein the battery management circuit (16) is further suitable for performing passive cell balancing between the battery cells of the battery pack module (10). Battery pack module according to claim 2, wherein the battery management circuit (16) is suitable for performing passive cell balancing between the battery cells of the battery pack module (10) in a manner comprising at least one of the following procedures: a) balancing the state of charge between battery cells by consuming electrical energy from a respective individual battery cell that has a higher state of charge than at least one other of the battery cells, and b) diverting electrical energy during a charging cycle with respect to a respective individual battery cell that has a higher state of charge than at least one other of the battery cells, such that less electrical energy is charged into that respective individual battery cell. Battery pack module (10) according to claim 3, wherein the battery management circuit (16) is suitable for enabling the consumption of electrical energy from a respective individual battery cell with a higher state of charge by providing a controlled short circuit via an electronic short-circuit arrangement, which preferably comprises a transistor or a resistor. Battery pack module (10) according to claim 3 or 4, wherein the battery management circuit (16) is suitable to provide a diversion of electrical energy via a path parallel to the respective individual cell during the charging cycle. Battery pack module (10) according to one of claims 1 to 5, wherein the battery management circuit (16) is suitable to provide active cell balancing only in groups for several groups of battery cells of the several individual battery cells or / and only between adjacent cells of the several individual battery cells. Battery pack module (10) according to one of claims 1 to 6, wherein the battery management circuit (16) is suitable for activating active cell balancing when 1) the voltage difference between the cells is greater than a predefined first voltage difference of preferably about 50 mV and 2) the voltage of a single battery cell exceeds an upper threshold of preferably about 4 V, wherein this battery cell is a battery cell that has a higher state of charge, preferably the highest state of charge of all battery cells, and 3) the voltage of no other battery cell is below a lower threshold of preferably about 3 V. Battery pack module (10) according to claim 7, wherein the battery management circuit (16) is suitable for deactivating the active cell balancing when a voltage difference between cells subjected to cell balancing of less than a second voltage difference of preferably about 20 mV is reached and maintained for a predetermined time interval, preferably for more than 30 minutes. Battery pack module (10) according to claim 8, wherein the battery management circuit (16) is further suitable for activating passive cell balancing after deactivation of active cell balancing in order to further balance the state of charge between the battery cells of the battery pack module (10). Battery pack module (10) according to one of claims 1 to 9, wherein the battery pack module (10) comprises a positive-lock engagement section (14) which includes or realizes the connection section, and which can be positively engaged with a counter-positive-lock engagement section (114) of the power tool (110) to which the battery pack module (10) is assigned, and which can be positively engaged with a counter-positive-lock engagement section (214) of the charger (210) to which the battery pack module (10) is assigned, wherein the counter-positive-lock engagement section (114) of the power tool (110) and the counter-positive-lock engagement section (214) of the charger (210) each realize or comprise the respective counter-connection section. Battery pack module (10) according to any one of claims 1 to 10, comprising a display arrangement (18) or a display light arrangement (18) arranged on or in an outer surface of the housing (12) to indicate status information and / or warning conditions relating to the battery pack module (10) and its battery cells. Battery pack module (10) according to any one of claims 1 to 10 or according to the preamble of claim 1, comprising a display arrangement (18) or indicator light arrangement (18) arranged on or in an outer surface of the housing (12) to display status information and / or warning information regarding the power tool (110) in the power tool coupling state of the battery pack module (10), or / and to display status information and / or warning information regarding the charger (210) in the charger coupling state of the battery pack module (10). Battery pack module according to claim 12, wherein the connecting section has at least one connecting contact suitable for coming into contact with a corresponding mating contact of the mating section of the power tool (110) or the charger (210) in order to enable the reception of signals which represent the status or warning information from the power tool (110) or the charger (210). Battery pack module (10) according to one of claims 1 to 13, comprising a microprocessor arrangement (24) belonging to the battery management circuit (16) and suitable for controlling the active cell balancing and, if present, the passive cell balancing. Battery pack module (10) according to claim 14, wherein the battery pack module (10) comprises a memory (26) associated with the microprocessor (24), wherein the microprocessor (24) is suitable for storing status information and / or warning information and / or error information relating to the battery pack module (10) in the memory (26). Battery pack module (10) according to claim 14 or 15, wherein the microprocessor (24) further comprises a communication circuit of the battery pack module (10) which is connected to the display arrangement (18) or the indicator light arrangement (18), wherein the microprocessor (24) is suitable for controlling the display arrangement (18) or the indicator light arrangement (18) to display the status information or the warning information. Battery pack module (10) according to claim 16, wherein the communication circuit comprises a wireless connection module such as a Bluetooth module (28) which enables the transmission of current or stored status information, warning information and error information relating to the battery pack module (10) to an external device such as a user device, for example a smartphone, a tablet or a laptop, and / or which enables the external device to wirelessly trigger a visual or acoustic signaling by the battery pack module (10). Combination of at least one battery pack module (10) according to one of the preceding claims 1 to 17 with a power tool (110) which can be supplied with energy by the battery pack module (10). Combination of at least one battery pack module (10) according to one of the preceding claims 1 to 17 with a charger (210) suitable for charging the battery pack module (10).

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