Battery pack, system, and printed circuit board

Abstract

A battery pack, system, and printed circuit board, the battery pack including a housing, a battery cell within the housing, a power terminal and a temperature terminal within the housing, and a temperature integrated circuit in thermal contact with the power terminal and electrically connected to the temperature terminal. The temperature integrated circuit is configured to detect a temperature of the power terminal, compare the temperature of the power terminal to a temperature threshold, and pull the temperature terminal low in response to the temperature of the power terminal satisfying the temperature threshold.

Description

[0001] Cross-reference to related applications This application claims priority and benefit to U.S. Provisional Patent No. 63 / 666,557, filed July 1, 2024, the contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to battery packs, and more specifically to monitoring the terminal temperature of battery packs. Background Technology

[0003] A battery pack includes terminals that facilitate the transfer of power from individual battery cells within the pack to devices coupled to the pack. For example, a battery pack can be used to power power tools such as drills, saws, etc. To reduce cost and weight, battery packs are typically housed in plastic casings. At high temperatures, plastic is prone to melting or deformation. For example, when the battery pack terminals experience an overheating event, the battery pack casing (e.g., the casing surrounding the terminals) may melt. A melted casing can cause warping and, in extreme cases, may prevent the user from using the battery pack. Power tools can monitor the temperature of the individual battery cells at the battery pack terminals. However, monitoring the individual battery cell temperature may not prevent the battery pack casing from melting due to overheating of the battery terminals. Therefore, it would be advantageous to provide a battery pack with an integrated circuit that performs terminal temperature monitoring using minimal components and requires no additional firmware to keep the battery pack casing as compact as possible. Utility Model Content

[0004] The present invention provides a battery pack comprising a housing, individual battery cells within the housing, a power terminal, a temperature terminal, and a temperature integrated circuit that is thermally contacted with and electrically connected to the power terminal. The temperature integrated circuit is configured to detect the temperature of the power terminal, compare the temperature of the power terminal with a temperature threshold, and pull down the temperature terminal in response to the power terminal temperature meeting the temperature threshold.

[0005] Another embodiment of this invention provides a system including a battery pack and a power tool. The battery pack includes a device interface having a power terminal and a temperature terminal. The power tool includes a power input unit configured to connect to the device interface and a controller coupled to the power input unit. The controller is configured to determine the voltage at the temperature terminal, compare the voltage at the temperature terminal to a threshold voltage, and prevent the battery pack from discharging in response to determining that the voltage at the temperature terminal is less than the threshold voltage.

[0006] A further embodiment of this invention provides a printed circuit board. The printed circuit board includes a power terminal, a temperature terminal, and a temperature integrated circuit that is thermally contacted with and electrically connected to the temperature terminal. The temperature integrated circuit is configured to detect the temperature of the power terminal, compare the temperature of the power terminal with a temperature threshold, and pull down the temperature terminal in response to the temperature of the power terminal meeting the temperature threshold. Attached Figure Description

[0007] Figure 1 A battery pack for power tools is shown according to some embodiments.

[0008] Figure 2 The passage according to some embodiments is shown. Figure 1 Power tools powered by battery packs.

[0009] Figure 3 It is based on some implementation methods Figure 1 A 3D view of the battery pack's device interface.

[0010] Figure 4 This illustrates a configuration with the casing removed according to some embodiments. Figure 1 A 3D view of the battery pack.

[0011] Figure 5 The following are illustrated according to some embodiments. Figure 1 The printed circuit board of the battery pack.

[0012] Figure 6 It is based on some implementation methods Figure 1 A simplified block diagram of the battery pack.

[0013] Figure 7 It is based on some implementation methods Figure 1 A simplified block diagram of the temperature integrated circuit for the battery pack.

[0014] Figure 8 The following are illustrated according to some embodiments. Figure 6 The thermal diagram of the printed circuit board.

[0015] Figure 9 The following are illustrated according to some embodiments. Figure 6 The thermal diagram of the printed circuit board.

[0016] Figure 10 It is based on some implementation methods Figure 1 A simplified diagram of the battery pack.

[0017] Figure 11 A flowchart of a method for monitoring the temperature of battery pack terminals according to some embodiments is shown.

[0018] Figure 12 It is based on some implementation methods Figure 2 A block diagram of the controller for a power tool.

[0019] Figure 13 A flowchart of a method for monitoring the temperature of battery pack terminals according to some embodiments is shown.

[0020] Figure 14 This illustrates according to some embodiments. Figure 1 A graph showing the temperature-based output of the battery pack.

[0021] Figure 15 This illustrates according to some embodiments. Figure 1 A graph showing the temperature-based output of the battery pack.

[0022] Figure 16 This illustrates according to some embodiments. Figure 1 A graph showing the temperature-based output of the battery pack. Detailed Implementation

[0023] Before explaining any implementation in detail, the application of the implementation is not limited to the details of the configuration and arrangement of the components described in the following description or shown in the drawings. The implementation can be practiced or implemented in various ways. Furthermore, the wording and terminology used in this invention are for illustrative purposes and should not be considered restrictive. The use of "comprising," "including," or "having," and variations thereof, is intended to cover the items listed thereafter and their equivalents, as well as additional items. Unless otherwise stated or limited, the terms "mounted," "connected," "supported," and "coupled," and variations thereof, are used broadly and cover direct and indirect mounting, connection, support, and coupling.

[0024] Furthermore, implementations may include hardware, software, and electronic components or modules, which may be shown and described for the purposes of discussion as if most components were implemented solely in hardware. However, those skilled in the art, and based on this detailed description, will recognize that in at least one implementation, unless otherwise stated, the electronic aspects may be implemented in software (e.g., stored on a non-transitory computer-readable medium) executable by one or more processing units (such as microprocessors and / or application-specific integrated circuits (“ASICs”)). Therefore, it should be noted that these implementations may be implemented using a plurality of hardware and software-based devices and a plurality of different structural components. For example, “server,” “computing device,” “controller,” “processor,” etc., described in the specification may include one or more processing units, one or more computer-readable medium modules, one or more input / output interfaces, and various connectors (e.g., system buses) for connection components.

[0025] Related terms used in conjunction with quantities or conditions, such as “about,” “approximately,” “generally,” etc., will be understood by a person skilled in the art to include the value and have a meaning defined by the context (e.g., the term includes at least the degree of error associated with measurement accuracy, the tolerance associated with a particular value [e.g., manufacturing, assembly, use, etc.]). Such terms should also be considered to disclose a range defined by the absolute values ​​of two endpoints. For example, the expression “about 2 to about 4” also discloses a range of “2 to 4.” Related terms may refer to a percentage added to or subtracted from the indicated value (e.g., 1%, 5%, 10% or more).

[0026] Although some of the accompanying drawings show hardware and software located within a particular device, these depictions are for illustrative purposes only. Functions described in this invention as being performed by a single component can be performed by multiple components in a distributed manner. Similarly, functions performed by multiple components can be combined and performed by a single component. In some embodiments, the components shown can be combined or divided into separate software, firmware, and / or hardware. For example, logic and processing can be distributed among multiple electronic processors, rather than residing within and being performed by a single electronic processor. Regardless of how the hardware and software components are combined or divided, the hardware and software components can reside on the same computing device or can be distributed among different computing devices connected via one or more networks or other suitable communication links. Similarly, components described as performing specific functions can also perform additional functions not described in this invention. For example, a device or structure "configured" in a certain way is at least configured in that way, but can also be configured in a way not explicitly listed.

[0027] Figure 1 A diagram is shown for use with power tools (such as power tool 100). Figure 2 This is an exemplary embodiment of a battery pack 50 that provides power and communicates with it. The battery pack 50 includes a housing 55 and a device interface 60 for connecting the battery pack 50 to a power tool (e.g., power tool 100) or a charger. In the illustrated example, the housing 55 includes a vertical portion 65 and a horizontal portion 70. The housing 55 can be made from a hardened plastic material using, for example, injection molding, 3D printing, or other similar processes. In some examples, the housing 55 may be made from a modular half-housing joined together using fasteners. The device interface 60 is located on the top edge of the vertical portion 65 furthest from the horizontal portion 70. In some embodiments, the battery pack 50 may (e.g., in a lower capacity configuration) not include the horizontal portion 70.

[0028] Battery pack 50 may include one or more lithium-ion battery cells, such as battery cell 405 ( Figure 4In some embodiments, battery pack 50 may have different chemical compositions, such as nickel-cadmium, nickel metal hydride, etc. In some embodiments, battery pack 50 may include six "18650" battery cells having a nominal voltage of 3.6 volts ("V"), each battery cell configured as a 3S2P (two parallel strings of three battery cells connected in series). For example, three cells may be arranged in the vertical portion 65, and three cells may be arranged in the horizontal portion 70. In some embodiments, battery pack 50 may include three "18650" battery cells connected in series to form a lower capacity configuration, i.e., without the horizontal portion 70. In other embodiments, different configurations of one or more battery cells may be used. In some embodiments, the density of battery cells may be increased from a conventional density.

[0029] In the illustrated embodiment, battery pack 50 has a nominal output voltage of 10.8 V. In other embodiments, the output voltage level of battery pack 50 may be different. For example, battery pack 50 may be a 3.6 V battery pack, an 18 V battery pack, a 36 V battery pack, or other voltages. Battery pack 50 may also have various capacities (e.g., 1.2, 2, 3, 4, 5, 6, 8, or 12 ampere-hours).

[0030] Figure 2 An exemplary embodiment of power tool 100 is shown. In the example shown, power tool 100 is an electric handheld pruning machine or a portable chainsaw. The chainsaw 100 is powered by a rechargeable power tool battery pack 50. For example, the battery pack 50 shown is an interchangeable battery pack configured to connect to and power various tools other than the chainsaw 100.

[0031] See also Figure 2 The chainsaw 100 includes a housing 130. The housing 130 defines a handle housing portion 140, a motor housing portion 150, and a drive housing portion 160. In the illustrated embodiment, the handle housing portion 140 extends from both the drive housing portion 160 and the motor housing portion 150. In other embodiments, the handle housing portion 140 may extend from either the drive housing portion 160 or the motor housing portion 150. In the illustrated embodiment, the handle housing portion 140 includes a battery receiving portion 170 disposed opposite to the motor housing portion 150. At least a portion of the battery pack 50 may be coupled to the battery receiving portion 170. In other embodiments, the battery receiving portion 170 may be defined on or elsewhere within the housing 130.

[0032] See Figure 2The illustrated housing 130 further includes a handle guard 180 extending between the drive housing portion 160 and the battery receiving portion 170. The handle housing portion 140 includes at least one grip surface 190 for a user to grip when operating the chainsaw 100. The handle guard 180 may support a removable adjustment tool or button for adjusting settings on the chainsaw 100. A trigger 200 is positioned on the handle housing portion 140 for operating the chainsaw 100. As shown, the trigger 200 is an on / off trigger switch. In other embodiments, the trigger 200 may be a variable speed trigger switch, a dual-speed trigger switch, a button, or another suitable actuator.

[0033] Figure 3 A perspective view of a device interface 60 of a battery pack 50 according to some embodiments is shown. The device interface 60 includes a negative terminal port 305 and a positive terminal port 310. The negative terminal port 305 and the positive terminal port 310 facilitate communication between the battery receiving section 170 and the individual battery cells of the battery pack 50 via negative and positive terminals (such as negative terminal 420 and positive terminal 425). Figure 4 Electrical connection.

[0034] In addition to the negative terminal 305 and the positive terminal 310, the device interface 60 includes a temperature terminal (“T terminal”) 315, a first communication terminal 320, and a second communication terminal 325. The T terminal 315 provides a voltage to the power tool 100 that indicates the temperature of a battery cell or power terminals 420, 425. Based on the voltage at the T terminal 315, the power tool 100 determines whether to allow the battery pack 50 to discharge. When the T terminal 315 indicates a high-temperature condition, the power tool 100 can prevent the battery pack 50 from discharging. The first communication terminal 320 provides a battery cell tap to the power tool 100 between the battery cell with the lowest positive potential and an intermediate battery cell (e.g., in a 3S or 3S2P configuration), and the second communication terminal 325 provides a battery cell tap to the power tool between an intermediate battery cell and a battery cell with the highest positive potential.

[0035] Figure 4An exemplary embodiment of a battery pack 50 with the casing 55 removed is shown. In the example shown, the battery pack 50 includes a plurality of battery cells 405, a thermistor 410, and a printed circuit board (“PCB”) 415. Thermistor 410 senses the temperature of the battery cells 405, particularly the temperature of the first battery cell 405 among the battery cells 405. For example, the thermistor 410 is placed directly on the first battery cell 405 (e.g., the battery cell with the highest positive potential) to monitor the temperature of the first battery cell 405. Thermistor 410 may be positioned in physical contact with the first battery cell 405. Thermistor 410 is, for example, a negative temperature coefficient (“NTC”) thermistor, a positive temperature coefficient (“PTC”) thermistor, etc. The resistance of the thermistor 410 varies based on the ambient temperature—that is, the temperature of the battery cell 405. For example, when the temperature of the first battery cell 405 changes, the resistance of the thermistor 410 changes, resulting in a change in the current flowing through the thermistor 410 and the voltage across it. The temperature of the battery cell 405 is determined based on the change in current / voltage across the thermistor 410.

[0036] PCB 415 is disposed on the top portion of battery cell 405. For example, the top portion of battery cell 405 is physically close to device interface 60. Battery negative terminal 420 and battery positive terminal 425 are mounted on PCB 415. Battery negative terminal 420 and battery positive terminal 425 may be collectively referred to as power terminals 420, 425, and may be individually referred to as power terminals 420 and 425. In the example shown, power terminals 420, 425 are clamp-shaped and configured to receive blade terminals of power tool 100. In other examples, power terminals 420, 425 may be blade terminals received in clamp-shaped terminals of power tool 100. Thermistor 410 is electrically connected to PCB 415 at the opposite end of the physical connection between thermistor 410 and the first battery cell 405. See also Figure 5 PCB 415 is generally triangular and includes means mounted on a first side 510 of PCB 415. For example, a temperature integrated circuit (“IC”) 500, a battery negative terminal 420, and a battery positive terminal 425 are mounted on the first side 510 of PCB 415. A T-terminal 315, a first communication terminal 320, and a second communication terminal 325 are disposed along the front edge 515 of PCB 415. The temperature IC 500 is configured to be adjacent to the positive terminal 425 (e.g., in thermal contact with the power terminal 425).

[0037] Figure 6This is a simplified block diagram of battery pack 50. In the example shown, temperature IC 500 is electrically connected to thermistor 410 and T-terminal 315 within battery pack 50. Both temperature IC 500 and thermistor 410 can independently drive the voltage at T-terminal 315. Temperature IC 500 monitors the temperature of power terminals 420, 425 of battery pack 50. In some embodiments, temperature IC 500 engages (e.g., temperature IC 500 “trips”) when positive terminal 425 is above 130°C. When temperature IC 500 trips, it pulls T-terminal 315 low, regardless of the temperature of individual battery cell 405 monitored by thermistor 410. When temperature IC 500 does not trip, the voltage seen by power tool 100 at T-terminal 315 reflects the voltage driven solely by thermistor 410. Table 1 (below) shows an example of the relationship between the temperature of individual battery cell 405, the resistance of thermistor 410, and the voltage at T-terminal 315. In one example, when the temperature of the battery cell 405 is greater than or equal to 75°C, the resistance of the thermistor 410 is less than 1.5 kOhms, and the voltage at terminal T 315 is less than 0.4 V. The power tool 100 can detect this voltage at terminal T 315 (e.g., below 0.5 V) and stop / prevent the battery pack 50 from discharging until the voltage at terminal T 315 recovers (e.g., recovers to above 0.4 V) to operate the motor of the power tool 100. However, a small current can still be released to operate the controller 900 that monitors the voltage at terminal T 315 (see [link to relevant documentation]). Figure 9 ).

[0038]

[0039] Figure 7A simplified block diagram of an exemplary implementation of a temperature IC 500 is shown. In one example, the temperature IC 500 can be implemented using a temperature switch—such as the Texas Instruments part number TMP302D temperature switch. In the example shown, the temperature IC 500 includes a temperature threshold and hysteresis circuit 710, a comparator 720, and a built-in temperature sensor 730. The temperature IC 500 also includes a power supply voltage pin 740, a temperature setting pin 750, a hysteresis setting pin 760, and an output pin 770. The power supply voltage pin 740 receives an operating power supply for powering the components of the temperature IC. In one example, the nominal power supply voltage is 3.3 V. The temperature setting pin 750 and the hysteresis setting pin 760 are connected to the temperature threshold and hysteresis circuit 710. In the example shown, the temperature setting pin 750 includes two pins to receive, for example, two-bit inputs (e.g., power supply voltage = 1; ground = 0) to set the temperature threshold. Therefore, the temperature setting pin 750 can be used to set the temperature threshold to four different values. The hysteresis setting pin 760 can receive a single input to set the hysteresis, which is used to compare the detected temperature with a temperature threshold. In one example, the hysteresis can be set to 5°C (“C”) or 10°C based on a single input.

[0040] Temperature threshold and hysteresis circuit 710 receives a temperature setting from temperature setting pin 750 and a hysteresis setting from hysteresis setting pin 760, and provides a temperature threshold signal 780 to comparator 720. In one example, temperature threshold signal 780 includes a first temperature threshold signal providing a temperature threshold set using temperature setting pin 750 and a second temperature threshold signal set based on the temperature setting and hysteresis setting. Built-in temperature sensor 730 may be a thermistor similar to thermistor 410. Built-in temperature sensor 730 provides comparator 720 with a temperature signal 790 corresponding to the ambient temperature of temperature IC 500. Comparator 720 can operate in two states: (i) normal state; and (ii) tripped state. In the normal state, the comparator outputs high (e.g., power supply voltage) at output pin 770. In the normal state, comparator 720 compares temperature signal 790 with the first temperature threshold signal to compare the temperature with the set temperature threshold. When the temperature exceeds the temperature threshold, comparator 720 drives output pin 770 low (e.g., low voltage, ground, etc.) and enters a trip state. In the trip state, comparator 720 compares the temperature signal 790 with a second temperature threshold signal to resolve hysteresis. When the temperature falls below the hysteresis temperature threshold, the comparator drives output pin 770 high (e.g., power supply voltage) and enters a normal state.

[0041] Figure 8 and Figure 9An exemplary thermal diagram of PCB 415 is shown. As can be seen from the thermal diagram, the negative battery terminal 420 and the positive battery terminal 425 can generate heat during operation (e.g., during discharge). Heat is concentrated around the negative battery terminal 420 and the positive battery terminal 425. For example, the hottest areas of PCB 415 are concentrated around the negative battery terminal 420 and the positive battery terminal 425, and it cools radially with increasing distance from the negative battery terminal 420 and the positive battery terminal 425. This heat concentration at the negative battery terminal 420 and the positive battery terminal 425 can cause the housing 55 to heat up and, in some cases, melt. Temperature IC 500 is therefore... Figure 5 As shown, the temperature IC 500 is positioned adjacent to one of the power terminals 420 and 425 (i.e., in thermal contact with one of the power terminals 420 and 425), which allows the temperature IC 500 to effectively detect the temperature of the power terminals 420 and 425 using the built-in temperature sensor 730. The thermal contact between the temperature IC 500 and the power terminals 420 and 425 can be achieved by placing the temperature IC 500 adjacent to the power terminals 420 and 425, without requiring physical contact between the temperature IC 500 and the power terminals 420 and 425.

[0042] Figure 10 A schematic diagram of a battery pack 50 according to some embodiments is shown. In the illustrated example, the battery pack 50 includes an electrostatic discharge protection circuit 805, a low-dropout circuit 810 electrically connected to the positive terminal 425 of the battery, and a temperature IC 500 electrically connected to the T terminal 315. The low-dropout circuit 810 converts the voltage from the battery cell 405 into a power supply voltage 815 to supply other components of the battery pack 50, such as the temperature IC 500. In one example, the low-dropout circuit 810 converts the output voltage of the battery cell 405 to 3.3 V, which is supplied as the power supply voltage 815 to the temperature IC 500.

[0043] Battery pack 50 also includes additional circuitry that provides input to temperature IC 500. In the example shown, battery pack 50 is not a smart battery pack; that is, battery pack 50 does not include a controller (e.g., a microcontroller or microprocessor). Input to temperature IC 500 is provided using circuitry instead of from a controller. A supply voltage 815 from low-dropout circuitry 810 is provided to supply voltage pin 740 of temperature IC 500. In the example shown, a voltage divider is used to set temperature setting pin 750 high (e.g., supply voltage or ground voltage). Pin 760 is grounded to set the hysteresis to, for example, 5°C. Output pin 770 is coupled to terminal T 315 along with thermistor 410.

[0044] In one example, power from battery pack 50 is used to power the load of power tool 100 and an auxiliary power supply (housekeeping power supply) of the power tool through two current paths. The auxiliary power supply can provide power to certain sensing and / or control components (e.g., controllers) of power tool 100. A discharge FET can be placed between the power supply terminals and the load in power tool 100, but not between the power supply terminals and the auxiliary power supply. This terminates the discharge to the load when the discharge FET is turned on, but the auxiliary power supply can continue to power the control components in power tool 100. The auxiliary power supply can provide a voltage (e.g., 3.3 volts) at the device temperature terminal of the power tool, which is electrically connected to terminal T 315. The auxiliary power supply can be electrically connected to the device temperature terminal using a resistor, which forms a voltage divider at terminal T 315 with the thermistor 410. The voltage at device terminal T 315 is based on the supply voltage from the auxiliary power supply and presents the voltages shown in the table above. The voltage at terminal 315 is detected by a controller (e.g., controller 1205) to determine the temperature of the battery cells at power terminals 420, 425 and control the discharge FET accordingly. When the temperature of power terminals 420, 425 is below a temperature threshold, temperature IC 500 can provide a high signal or high impedance, which minimizes or eliminates the current flowing to temperature IC 500, and the temperature being detected is solely determined by thermistor 410. When the temperature of power terminals 420, 425 is above the temperature threshold, temperature IC 500 can provide a low signal or low impedance, which allows most or all of the current to bypass thermistor 410 and flow to temperature IC 500.

[0045] Figure 11 A flowchart of an exemplary method 1100 for monitoring the temperature of battery pack terminals is shown. Although the illustrated method 1100 includes specific steps, not all steps need to be performed or need to be performed in the order presented. In some embodiments, method 1100 is performed by the battery pack 50, and in particular by the temperature IC 500.

[0046] Method 1100 includes detecting the temperature of the power terminals 420, 425 of the battery pack using a built-in temperature sensor 730 (step 1110). As described above, the temperature IC 500 is positioned adjacent to one of the power terminals 420, 425 to detect the ambient temperature around the power terminals 420, 425. The built-in temperature sensor 730 provides a temperature signal 790 to the comparator 720 of the temperature IC 500 based on the ambient temperature around the temperature IC 500.

[0047] Method 1100 includes using temperature IC 500 to compare the temperature of the power supply terminal with a temperature threshold (step 1120). Comparator 720 of temperature IC 500 compares a temperature signal 790 from a built-in temperature sensor 730 with a temperature threshold set using a temperature setting pin 750. The temperature threshold is set, for example, to one of 110°C, 115°C, 120°C, 125°C, etc. In one example, it is based, for example, on a heatmap 800 (see...). Figure 8 The temperature threshold of the temperature IC 500 is selected to detect when power terminals 420 and 425 are at 130°C. Although the maximum setpoint for the temperature threshold is 125°C in the example above, the temperature IC 500 takes into account the hysteresis of tripping conditions. This allows the temperature to be compared with the selected temperature tripping threshold (125°C) plus a hysteresis (e.g., 5°C) to reach the tripping point of 130°C. Therefore, the temperature threshold can be set between 100°C and 135°C, and the hysteresis can be set between 5°C and 10°C.

[0048] Method 1100 includes using a temperature IC 500 to pull down terminal T 315 in response to the temperature of power supply terminals 420, 425 meeting a temperature threshold (in step 1130). The temperature of power supply terminals 420, 425 meets the temperature threshold, for example, when the temperature is equal to or greater than the temperature threshold. When the temperature of power supply terminals 420, 425 meets the temperature threshold, comparator 720 drives output pin 770 and thus drives terminal T low. In one example, "low" means that the voltage output at terminal T 315 is less than or equal to 0.7V.

[0049] Figure 12 This is a block diagram of a controller 1200 for a power tool 100 according to some embodiments. The controller 1200 is electrically and / or communicatively connected to various modules or components of the power tool 100. For example, the controller 1200 shown is connected to an indicator 1210 (e.g., an LED, a tactile indicator, an auditory indicator, etc.), a sensor 1215 (e.g., a current sensor, a voltage sensor, a torque sensor, a trigger pull sensor, a temperature sensor, etc.), a power input unit 1220, a switch network 1225, and a trigger switch 1235.

[0050] The controller 1200 includes a plurality of electrical and electronic components that provide power, operation control, and protection to components and modules within the controller 1200 and / or the power tool 100. For example, the controller 1200 particularly includes a processing unit 1240 (e.g., a microprocessor, electronic processor, electronic controller, microcontroller, or other suitable programmable device), a memory 1245, an input unit 1250, and an output unit 1255. The processing unit 1240 particularly includes a control unit 1265, an arithmetic logic unit (“ALU”) 1270, and a plurality of registers 1275 (in... Figure 12 The system is shown as a set of registers and is implemented using a known computer architecture (e.g., a modified Harvard architecture, von Neumann architecture, etc.). Processing unit 1240, memory 1245, input unit 1250, and output unit 1255, as well as various modules connected to controller 1200, are connected via one or more control and / or data buses (e.g., common bus 1260). For illustrative purposes, in... Figure 12 The diagram illustrates a control and / or data bus. Given the embodiments described herein, the use of one or more control and / or data buses for interconnection and communication between various modules and components will be known to those skilled in the art.

[0051] Memory 1245 is a non-transitory computer-readable medium, including, for example, a program storage area and a data storage area. The program storage area and data storage area may include combinations of different types of memory, such as ROM, RAM (e.g., DRAM, SDRAM, etc.), EEPROM, flash memory, hard disk, SD card, or other suitable magnetic, optical, physical, or electronic memory devices. Processing unit 1240 is connected to memory 1245 and executes software instructions that can be stored in RAM of memory 1245 (e.g., during execution), ROM of memory 1245 (e.g., on a substantially permanent basis), or another non-transitory computer-readable medium such as another memory or disk. Software included in an implementation of power tool 100 may be stored in memory 1245 of controller 1200. Software includes, for example, firmware, one or more applications, program data, filters, rules, one or more program modules, and other executable instructions. Controller 1200 is configured to retrieve from memory 1245 and execute instructions related to the control processes and methods described herein. In other embodiments, controller 1200 includes additional, fewer, or different components.

[0052] The motor 1230 is energized based on the state of trigger 200. Normally, the motor 1230 is energized when trigger 200 is activated and de-energized when trigger 200 is deactivated. In the illustrated embodiment, trigger 200 is coupled to trigger switch 1235, such that trigger switch 1235 is activated when trigger 200 is depressed and deactivated when trigger 200 is released.

[0053] Switching network 1225 allows controller 1200 to control the operation of motor 1230. Switching network 1225 includes a plurality of electronic switches (e.g., FETs, bipolar transistors, etc.) connected to form an active network that controls motor 1230 using pulse width modulation (“PWM”) signals. For example, switching network 1225 may include a six-FET bridge that receives PWM signals from controller 1200 to drive motor 1230. Generally, when trigger 200 is pressed as indicated by the output of trigger switch 1235, current is supplied from power input unit 1220 to motor 1230 via switching network 1225. When trigger 200 is not pressed, current is not supplied from power input unit 1220 to motor 1230.

[0054] When battery pack 50 is coupled to power tool 100, device interface 60 of battery pack 50 is coupled to power input unit 1220. Power input unit 1220 may include a battery pack interface having corresponding power and communication terminals (e.g., temperature terminals) that mate with corresponding power, temperature, and communication terminals of device interface 60 of battery pack 50. Power input unit 1220 includes active and / or passive components (e.g., voltage buck controller, voltage converter, rectifier, filter, etc.) to regulate or control the power received from controller 1200 through device interface 60. In some embodiments, controller 1200 determines a low voltage at T terminal 315 via power input unit 1220 and prevents discharge from battery pack 50. Power input unit 1220 may be electrically and communicatively coupled to terminals of power tool 100. For example, the power tool 100 may include a blade terminal or clamp terminal that mates with at least one of the T terminal 315, the first communication terminal 320, the second communication terminal 325, and the power terminals 420, 425 of the battery pack 50.

[0055] Figure 13 A flowchart of a method 1300 for monitoring battery pack temperature is shown. Although the illustrated method 1300 includes specific steps, not all steps need to be performed or need to be performed in the order presented. In some embodiments, method 1300 is performed by a power tool controller 1200.

[0056] Method 1300 includes determining the voltage at terminal 315 using power tool controller 1200 (step 1305). In some embodiments, power input unit 1220 senses the voltage output from terminal 315 of battery pack 50, and power tool controller 1200 determines the voltage value. In determination step 1310, power tool controller 1200 determines whether the voltage value at terminal 315 is less than a threshold. In some embodiments, the threshold is stored in memory 1245, and processing unit 1240 compares the voltage value at terminal 315 with the stored threshold. The threshold may be set, for example, to 0.5 V. When the voltage at terminal 315 is less than the threshold (yes in determination step 1310), method 1300 proceeds to step 1315. When the voltage at terminal 315 is not less than the threshold (i.e., the voltage at terminal 315 is greater than the threshold) (no in determination step 1310), method 1300 returns to step 1315.

[0057] In step 1315, the power tool controller 1200 prevents the battery pack 50 from discharging. In some embodiments, the power tool controller 1200 will not allow discharge until a voltage corresponding to the release temperature is detected at terminal T 315. For example, the release temperature may correspond to a 5°C hysteresis relative to a temperature threshold. Temperature IC 500 can provide the hysteresis release detected by the power tool controller 1200 at terminal T 315. For example, temperature IC 500 may set the release temperature threshold based on the hysteresis and the temperature threshold (i.e., 130°C - 5°C = 125°C). When the temperature of power terminals 420, 425 drops below the release temperature threshold, temperature IC 500 can drive terminal T 315 high (i.e., release terminal T 315). The power tool 100 may include a discharge FET connected to one of the positive or negative power terminals. The power tool controller 1200 can discharge from the battery pack 50 by turning on the discharge FET, which prevents any discharge current from flowing from the battery pack 50 to the power tool 100.

[0058] Figure 14This is a graph 1400 showing the temperature-based output of the T-terminal 315 according to some embodiments. The x-axis is the operating time of the battery pack 50 (i.e., measured in seconds), the first y-axis is the temperature of the battery cell 405 (i.e., measured in degrees Celsius (°C), and the second y-axis is the voltage of the T-terminal 315 (i.e., measured in volts (V)). As the temperature of the battery cell 405 increases (and subsequently the temperature of the positive terminal 425 increases), the voltage of the T-terminal 315 decreases. In some embodiments, the increase in the temperature of the battery cell 405 and the decrease in the voltage of the T-terminal 315 occur linearly. In some embodiments, the temperature IC 500 trips when the temperature of the positive terminal 425 exceeds a threshold. In some embodiments, discharge is prevented when the temperature IC 500 trips. In some embodiments, the voltage of the T-terminal 315 recovers after the temperature IC 500 hysteresis is released.

[0059] Figure 15 An example 1500 of a first temperature integrated circuit operation according to some embodiments is shown. In some embodiments, the temperature IC 500 will not affect the temperature communication of the battery cells 405 between the battery pack 50 and the power tool 100 based on the signal from the thermistor 410. In this example, when the temperature of the battery cell 405 is 10°C and the temperature of the positive terminal 425 is below 120°C, the power tool 100 (especially the power tool controller 1200) treats the voltage at the T terminal 315 as 2.2V. In response to the voltage at the T terminal 315 being 2.2V when the temperature of the battery cell 405 is 10°C and the temperature of the positive terminal 425 is below 120°C, the battery pack 50 is allowed to discharge. When the power tool 100, especially the power tool controller 120, treats the voltage at the T terminal 315 as 0V when the temperature of the battery cell 405 is 10°C and the temperature of the positive terminal 425 is above or equal to 120°C, the temperature IC 500 trips. When the temperature IC 500 trips, the battery pack 50 is not allowed to discharge. However, as mentioned above, a small amount of power can be released, for example, through power terminals 420, 425 or T terminal 315 to maintain the operation of controller 1200.

[0060] Figure 16An example 1600 of the operation of a second temperature integrated circuit is shown when the battery cell 405 is at room temperature (e.g., 25°C). The x-axis is the operating time of the battery pack 50 (i.e., measured in seconds), the first y-axis is the voltage at terminal 315 (i.e., measured in volts (V), and the second y-axis is the temperature of the battery cell 405 (i.e., measured in degrees Celsius (°C)). In some embodiments, the temperature IC 500 trips when a 120°C threshold is reached. For example, when power terminals 420, 425 are below 120°C, the voltage at terminal 315 may be 1.7 V. When the temperature IC 500 trips, the voltage at terminal 315 is pulled low. The voltage at terminal 315 recovers after a 5°C hysteresis.

[0061] Therefore, the embodiments described in this utility model particularly provide a battery pack with a temperature integrated circuit, which is used to transmit the temperature of the battery cells and battery pack terminals to the power tool.

Claims

1. A battery pack characterized by comprising: include: case; A battery cell, wherein the battery cell is located within the housing; Power terminals and temperature terminals; and A temperature integrated circuit, which is in thermal contact with and electrically connected to the power supply terminal, and is configured to: Detect the temperature of the power supply terminal. The temperature is compared with a temperature threshold, and In response to the temperature meeting the temperature threshold, the temperature terminal is pulled low.

2. The battery pack of claim 1, wherein, Pulling the temperature terminal down includes setting the voltage at the temperature terminal to below 0.7 V.

3. The battery pack of claim 1, wherein, It further includes a thermistor that is in thermal contact with the battery cell and electrically connected to the temperature terminal, and is configured to control the voltage at the temperature terminal independently of the temperature integrated circuit.

4. The battery pack of claim 3, wherein, When the temperature is greater than or equal to the temperature threshold, the temperature integrated circuit is configured to drive the temperature terminal, and wherein when the temperature is lower than the temperature threshold, the thermistor is configured to drive the temperature terminal.

5. The battery pack of claim 1, wherein, The power terminal is the positive power terminal of the battery pack, and the positive power terminal is configured to receive power from power tools.

6. The battery pack of claim 1, wherein, Further includes: The first communication terminal provides a battery cell tap between the battery cell with the lowest positive potential and the intermediate battery cell; and The second communication terminal provides a battery cell tap between the battery cell with the highest positive potential and the intermediate battery cell.

7. The battery pack of claim 1, wherein, The device further includes a printed circuit board, wherein the power terminal, the temperature terminal, and the temperature integrated circuit are mounted to the printed circuit board.

8. The battery pack of claim 7, wherein, It further includes a device interface configured to receive electronic devices, wherein the printed circuit board is disposed at the top portion of the battery cell and located between the battery cell and the device interface.

9. The battery pack as claimed in claim 1, characterized in that, The temperature integrated circuit includes a temperature setting pin and a built-in temperature sensor, wherein the temperature of the power supply terminal is sensed by the built-in temperature sensor, and the temperature integrated circuit is further configured to: The temperature threshold is set based on the input received at the temperature setting pin.

10. The battery pack of claim 9, wherein, The input is a first input, and the temperature integrated circuit includes a hysteresis setting pin, the temperature integrated circuit being further configured to: The hysteresis is set based on the second input received at the hysteresis setting pin. The release temperature threshold is determined based on the temperature threshold and the hysteresis. and The temperature terminal is released when the temperature meets the release temperature threshold.

11. The battery pack of claim 10, wherein, The temperature threshold is set between 100°C and 130°C.

12. The battery pack as claimed in claim 10, characterized in that, The hysteresis is set between 5°C and 10°C.

13. A system, characterized by include: The battery pack includes: Device interface, the device interface having power terminals and temperature terminals; and Power tools, the power tools comprising: A power input unit, configured to connect to the device interface, and A controller, coupled to the power input unit and configured to: Determine the voltage at the temperature terminal. The voltage at the temperature terminal is compared with a threshold value, and In response to determining that the voltage at the temperature terminal is less than the threshold voltage, the battery pack is prevented from discharging.

14. The system of claim 13, wherein, The controller prevents discharge until a voltage corresponding to the release temperature is detected at the temperature terminal.

15. The system of claim 14, wherein, The release temperature corresponds to a hysteresis between 5°C and 10°C relative to the threshold.

16. The system of claim 13, wherein, The threshold is 0.5 V.

17. The system of claim 13, wherein, The threshold is set between 100°C and 130°C.

18. A printed circuit board, characterized in that, include: Power terminals; Temperature terminals; and A temperature integrated circuit, wherein the temperature integrated circuit is in thermal contact with and electrically connected to the power supply terminal, and the temperature integrated circuit is configured to: Detect the temperature of the power supply terminal. The temperature is compared with a temperature threshold, and The temperature terminal is pulled down in response to the temperature of the power terminal meeting the temperature threshold.

19. The printed circuit board of claim 18, wherein, The temperature integrated circuit includes a temperature setting pin and a built-in temperature sensor, wherein the temperature of the power supply terminal is sensed by the built-in temperature sensor, and the temperature integrated circuit is further configured to: The temperature threshold is set based on the input received at the temperature setting pin.

20. The printed circuit board of claim 19, wherein, The input is a first input, and the temperature integrated circuit includes a hysteresis setting pin, the temperature integrated circuit being further configured to: The hysteresis is set based on the second input received at the hysteresis setting pin. The release temperature threshold is determined based on the temperature threshold and the hysteresis. and The temperature terminal is released when the temperature meets the release temperature threshold.

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