Battery protection circuit for use with a bidirectional power converter

Abstract

A battery that has: one or more battery cells electrically connected to a bidirectional power converter via a positive terminal and a negative terminal, wherein the one or more battery cells are formed: output a discharge current via a first electrical path between the one or more battery cells and the bidirectional power converter, the first electrical path comprising (i) a positive electrical path between the one or more battery cells and the positive terminal and (ii) a negative electrical path between the one or more battery cells and the negative terminal, and receive a charging current via the first electrical path from the bidirectional power converter; a first overcurrent protection device; a second overcurrent protection device electrically connected in series with the first overcurrent protection device, wherein a series circuit of the first overcurrent protection device and the second overcurrent protection device is electrically connected between the one or more battery cells and the bidirectional power converter in the positive electrical path or the negative electrical path; a switching element which has: a first terminal electrically connected between a junction point between the first overcurrent protection device and the second overcurrent protection device, and a second terminal electrically connected to the corresponding other electrical path of the positive electrical path and the negative electrical path; and a battery management system communicatively connected to the switching element, wherein the battery management system is configured to: Monitoring one or more battery cells, Detecting a fault condition of one or more battery cells, Sending a first control signal to the bidirectional power converter to control the bidirectional power converter to cease operation in response to detecting the fault condition of the one or more battery cells, and Sending a second control signal to the switching element to close the switching element to cause a short circuit between the positive current path and the negative current path, wherein the short circuit between the positive current path and the negative current path causes at least the first overcurrent protection device to open to prevent current from flowing into or out of the one or more battery cells.

Description

Related applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 656,740, filed June 6, 2024, the entire contents of which are hereby incorporated by reference. Area

[0002] Some of the disclosed embodiments relate to a battery protection circuit for a battery electrically connected to a bidirectional power converter. overview

[0003] Electronic / electrical devices (such as a power tool, a power tool battery, a portable power source, and / or the like) may include one or more power converters to convert alternating current (AC) to direct current (DC) or vice versa. For example, a portable power source may include a power converter to convert alternating current from an AC source to direct current and charge a battery contained within the portable power source. Continuing this example, the portable power source may also include a power converter to convert direct current from the battery to alternating current for an AC load and to power the AC load. Traditionally, the charging and discharging functions of a battery (such as a battery pack for a power tool, the battery contained within the portable power source described above, etc.) are performed by a power converter.) by separate power converters with different power transfer capacities. Due to the use of two different power converters with different power transfer capacities, batteries typically have separate / different electrical charging and discharging paths, so separate / different charging and discharging protection circuits can be used to protect the battery cells (e.g., by preventing current flow) in the event of a fault (e.g., overcurrent, etc.).

[0004] In most applications, more power is typically transferred when discharging a battery than when charging (i.e., accepting charging current). Using separate / different current paths for charging and discharging reduces the requirements for protection devices in the charging current path, since less power is typically transferred in the charging current path than in the discharging current path. Accordingly, a fuse in the charging current path can be designed to open at a current less than the rated charging current of the battery to prevent current flow, thus providing a high degree of passive protection against overcurrent during charging. A separate fuse in the discharging current path can be designed to open at a current higher than the rated current of the fuse in the charging current path to prevent current flow, since the discharging current is often higher than the charging current and this is also desired.

[0005] However, when using a battery with a bidirectional power converter capable of transferring the same or similar high power / current in both directions (i.e., discharge current from the battery and charge current to the battery) over the same electrical path, there is only a single electrical path in which protection devices / circuits can be placed. Therefore, any protection circuit in the single electrical path should be designed to pass the full discharge current during normal operation, interrupt a full discharge fault current when a fault condition exists, and prevent battery cells from receiving charge current when a lesser fault condition (e.g., an overcurrent lower than the full discharge fault current) is detected during charging.

[0006] While such protection circuits are useful in situations where a battery is used with a bidirectional power converter that allows current to flow in both directions (e.g., a portable power source), such protection circuits can also be used when the bidirectional power converter is only used to allow current to flow in a single direction (e.g., in a power tool to provide DC power from a connected battery that is charged via a separate charger). In other words, the bidirectional power converter can be used in many different situations / applications / devices and can provide current flow in a first direction, current flow in a second direction opposite to the first direction, and / or current flow in both directions at different times.Regardless of whether the bidirectional power converter is used to provide current flow in both directions in a particular situation / application / device, its ability to do so over a single electrical path makes it useful for batteries used with the bidirectional power converter to provide a battery protection circuit configured to both pass full discharge current during normal operation, interrupt a full discharge fault current in the presence of a fault condition, and prevent battery cells from receiving charging current when a lesser fault condition (e.g., an overcurrent lower than the full discharge fault current) is detected during charging.

[0007] An embodiment provides a battery that may include one or more battery cells electrically coupled or connected to a bidirectional power converter via a positive terminal and a negative terminal. The one or more battery cells may be configured to output discharge current via a first electrical path between the one or more battery cells and the bidirectional power converter. The first electrical path may include (i) a positive electrical path between the one or more battery cells and the positive terminal and (ii) a negative electrical path between the one or more battery cells and the negative terminal. The one or more battery cells may also be configured to receive charge current via the first electrical path from the bidirectional power converter.The battery may also include a first overcurrent protection device and a second overcurrent protection device electrically connected in series with the first overcurrent protection device. A series connection of the first overcurrent protection device and the second overcurrent protection device may be electrically connected between the one or more battery cells and the bidirectional power converter in the positive electrical path or the negative electrical path. The battery may also include a switching element that may have a first terminal electrically connected between a junction between the first overcurrent protection device and the second overcurrent protection device. The switching element may also have a second terminal electrically coupled to the corresponding other terminal of the positive electrical path and the negative electrical path.The battery may also include a battery management system communicatively connected to the switching element. The battery management system may be configured to monitor the one or more battery cells and detect a fault condition of the one or more battery cells. The battery management system may be further configured to send a first control signal to the bidirectional power converter to control the bidirectional power converter to cease operation in response to detecting the fault condition of the one or more battery cells. The battery management system may be further configured to send a second control signal to the switching element to close the switching element to cause a short circuit between the positive current path and the negative current path.The short circuit between the positive current path and the negative current path may cause at least the first overcurrent protection device to open to prevent current from flowing into or out of the one or more battery cells.

[0008] In addition to any combination of the features described above, the first overcurrent protection device may be electrically connected between the one or more battery cells and the second overcurrent protection device. The second overcurrent protection device may be electrically connected between the first overcurrent protection device and the bidirectional power converter. The short circuit between the positive current path and the negative current path may cause the second overcurrent protection device to open if the current from the bidirectional power converter, caused by the short circuit, exceeds a current limit of the second overcurrent protection device. Opening the second overcurrent protection device may prevent current from being drawn from the bidirectional power converter.

[0009] In addition to any combination of the features described above, the first overcurrent protection device may be electrically connected or coupled between the one or more battery cells and the second overcurrent protection device. The second overcurrent protection device may be electrically connected between the first overcurrent protection device and the bidirectional power converter. The first overcurrent protection device may open in response to the current from the one or more battery cells due to the short circuit exceeding a current limit of the first overcurrent protection device.

[0010] In addition to any combination of the features described above, the battery management system may be configured to wait a predetermined period of time after sending the first control signal to the bidirectional power converter, determine that the bidirectional power converter has not ceased its operation within the predetermined period of time, and send the second control signal to the switching element to close the switching element to cause the short circuit between the positive current path and the negative current path in response to the determination that the bidirectional power converter has not ceased its operation.

[0011] In addition to any combination of the features described above, the battery management system may be configured to determine, before the expiration of the predetermined time period, that (i) the severity of the fault condition has increased, (ii) a second fault condition has been detected, or (iii) both (i) and (ii) apply. The battery management system may further be configured to send the second control signal to the switching element to close the switching element to cause the short circuit between the positive current path and the negative current path, before the expiration of the predetermined time period, if it is determined that (i) the severity of the fault condition has increased, (ii) the second fault condition has been detected, or (iii) both (i) and (ii) apply.

[0012] In addition to any combination of the features described above, the battery management system may be configured to wait a predetermined period of time after sending the first control signal to the bidirectional power converter, determine that the bidirectional power converter has ceased to operate within the predetermined period of time, and refrain from sending the second control signal to the switching element to close the switching element to cause the short circuit between the positive current path and the negative current path if it is determined that the bidirectional power converter has ceased to operate.

[0013] Another embodiment provides a battery that may include one or more battery cells electrically coupled to a bidirectional power converter. The one or more battery cells may be configured to output a discharge current via a first electrical path between the one or more battery cells and the bidirectional power converter. The one or more battery cells may be further configured to receive charge current from the bidirectional power converter via the first electrical path. The battery may further include a first overcurrent protection device electrically coupled between the one or more battery cells and the bidirectional power converter. The first overcurrent protection device may be electrically coupled to a positive or a negative side of the battery.The battery may further include a switching element having a first terminal electrically connected between a junction between the first overcurrent protection device and the bidirectional power converter. The switching element may further include a second terminal electrically coupled to the other of the positive and negative sides of the battery. The battery may also include a battery management system communicatively connected to the switching element. The battery management system may be configured to monitor the one or more battery cells and detect a fault condition of the one or more battery cells.The battery management system may be further configured to send a first control signal to the bidirectional power converter to control the bidirectional power converter to cease its operation in response to detecting the fault condition of the one or more battery cells. The battery management system may be further configured to send a second control signal to the switching element to close the switching element and cause a short circuit between the positive side and the negative side of the battery. The short circuit between the positive side and the negative side may cause the first overcurrent protection device to open to prevent current from flowing into or out of the one or more battery cells.

[0014] In addition to any combination of the features described above, the battery may include a second overcurrent protection device electrically connected in series with the first overcurrent protection device. A series connection of the first overcurrent protection device and the second overcurrent protection device may be electrically connected between the one or more battery cells and the bidirectional power converter on the positive or negative side of the battery. The first overcurrent protection device may be electrically connected between the one or more battery cells and the second overcurrent protection device, and the second overcurrent protection device may be electrically connected between the first overcurrent protection device and the bidirectional power converter. The junction may be arranged between the first overcurrent protection device and the second overcurrent protection device.The short circuit between the positive side and the negative side may cause the second overcurrent protection device to open in response to the current from the bidirectional power converter through the short circuit exceeding a second current limit of the second overcurrent protection device. Opening the second overcurrent protection device may prevent a current draw from the bidirectional power converter. The first overcurrent protection device may open in response to the current from the one or more battery cells through the short circuit exceeding a first current limit of the first overcurrent protection device.

[0015] In addition to any combination of the features described above, the battery management system may be configured to wait a predetermined period of time after sending the first control signal to the bidirectional power converter, determine that the bidirectional power converter has not ceased its operation within the predetermined period of time, and send the second control signal to the switching element to close the switching element to cause the short circuit between the positive side and the negative side in response to the determination that the bidirectional power converter has not ceased its operation.

[0016] In addition to any combination of the features described above, the battery management system may be configured to determine, before the expiration of the predetermined time period, that (i) the severity of the fault condition has increased, (ii) a second fault condition has been detected, or (iii) both (i) and (ii) apply. The battery management system may further be configured to send the second control signal to the switching element to close the switching element and cause the short circuit between the positive side and the negative side, before the expiration of the predetermined time period, if it is determined that (i) the severity of the fault condition has increased, (ii) the second fault condition has been detected, or (iii) both (i) and (ii) apply.

[0017] In addition to any combination of the features described above, the battery management system may be configured to determine that the bidirectional power converter has stopped operating and not send the second control signal to the switching element to close the switching element and cause the short circuit between the positive side and the negative side when it is determined that the bidirectional power converter has stopped operating.

[0018] In addition to any combination of the features described above, the battery may include a plurality of sensors configured to monitor the one or more battery cells. The plurality of sensors may be communicatively coupled to the battery management system.The plurality of sensors may include at least one sensor from a group consisting of: a current sensor configured to monitor the discharge current and the charge current; a temperature sensor configured to monitor a temperature of individual battery cells of the one or more battery cells and / or a temperature of the battery and / or an ambient temperature of an environment in which the battery is located, and / or combinations thereof; a voltage sensor configured to monitor a voltage of individual battery cells of the one or more battery cells, a total voltage of the one or more battery cells, or both the voltage of individual battery cells of the one or more battery cells and the total voltage of the one or more battery cells; and combinations thereof.

[0019] In addition to any combination of the features described above, the first overcurrent protection device may comprise a fuse, a positive temperature coefficient (PTC) element, a circuit breaker, or a blow-out device. The switching element may comprise a thyristor, a transistor, a relay, a contactor, or a thyratron.

[0020] In addition to any combination of the features described above, the battery may include a housing configured to house the one or more battery cells, the first overcurrent protection device, the switching element, and the battery management system. The housing may include at least one member selected from a group consisting of (i) a removable battery pack housing configured to be removably connected to a power tool device, (ii) a portable power source housing, (iii) a power tool device housing, and (iv) combinations thereof.

[0021] The battery may be used with a method for controlling the battery. The method may include outputting a discharge current through one or more battery cells of the battery in a discharge state via a first electrical path between the one or more battery cells and a bidirectional power converter. The method may also include receiving a charge current via the first electrical path through the one or more battery cells in a charge state. The method may also include monitoring the one or more battery cells of the battery with a battery management system of the battery while the one or more battery cells are in the discharge state and while the one or more battery cells are in the charge state. The method may also include detecting orDetecting a fault condition of the one or more battery cells with the battery management system. The method may further include sending a first control signal to the bidirectional power converter with the battery management system to control the bidirectional power converter to cease operation in response to detecting the fault condition of the one or more battery cells. The method may further include sending a second control signal with the battery management system to a switching element to close the switching element to cause a short circuit between a positive side and a negative side of the battery. The short circuit between the positive side and the negative side may cause a first overcurrent protection device to open to prevent current from flowing into or out of the one or more battery cells.

[0022] In addition to any combination of the features described above, the short circuit between the positive side and the negative side may cause a second overcurrent protection device to open to prevent current from being delivered from the bidirectional power converter. The second overcurrent protection device may be electrically connected in series with the first overcurrent protection device. A series connection of the first overcurrent protection device and the second overcurrent protection device may be electrically connected between the one or more battery cells and the bidirectional power converter on the positive or negative side of the battery.The first overcurrent protection device may be electrically connected between the one or more battery cells and the second overcurrent protection device, and the second overcurrent protection device may be electrically connected between the first overcurrent protection device and the bidirectional power converter. The short circuit between the positive side and the negative side may cause the second overcurrent protection device to open if the current from the bidirectional power converter through the short circuit exceeds a second current limit of the second overcurrent protection device. The first overcurrent protection device may open if the current from the one or more battery cells through the short circuit exceeds a first current limit of the first overcurrent protection device.

[0023] In addition to any combination of the features described above, the method may include waiting, with the battery management system, for a predetermined period of time after sending the first control signal to the bidirectional power converter. The method may also include determining, with the battery management system, that the bidirectional power converter has not ceased operation within the predetermined period of time. The method may also include sending the second control signal, with the battery management system, to the switching element to close the switching element to cause the short circuit between the positive side and the negative side in response to determining that the bidirectional power converter has not ceased operation.

[0024] In addition to any combination of the features described above, the method may include determining with the battery management system and before the expiration of the predetermined period of time that (i) the severity of the fault condition has increased, (ii) a second fault condition has been detected, or (iii) both (i) and (ii) are true. The method may also include sending the second control signal with the battery management system and before the expiration of the predetermined period of time to the switching element to close the switching element to cause the short circuit between the positive side and the negative side if it is determined that (i) the severity of the fault condition has increased, (ii) the second fault condition has been detected, or (iii) both (i) and (ii) are true.

[0025] In addition to any combination of the features described above, the method may include determining with the battery management system that the bidirectional power converter has ceased operation, and refraining from sending the second control signal to the switching element with the battery management system to close the switching element to cause the short circuit between the positive side and the negative side in response to determining that the bidirectional power converter has ceased operation.

[0026] In addition to any combination of the features described above, monitoring the one or more battery cells may include monitoring the one or more battery cells with a plurality of sensors. The plurality of sensors may be communicatively coupled to the battery management system.The plurality of sensors may include: a current sensor configured to monitor the discharge current and the charge current and / or a temperature sensor configured to monitor a temperature of individual battery cells of the one or more battery cells and / or a temperature of the battery and / or an ambient temperature of an environment in which the battery is located, and / or a combination thereof, and / or a voltage sensor configured to monitor a voltage of individual battery cells of the one or more battery cells, a total voltage of the one or more battery cells, or both the voltage of individual battery cells of the one or more battery cells and the total voltage of the one or more battery cells, and / or combinations thereof.

[0027] Before embodiments are explained in detail, it is to be understood that the embodiments are not limited in their application to the details of the construction and arrangement of the components set forth in the following description or illustrated in the accompanying drawings. The embodiments may be practiced or carried out in a variety of ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and not as limiting. The use of "having," "comprising," or "with," and variations thereof, is intended to include the elements listed thereafter and their equivalents, as well as additional elements. Unless otherwise specified or limited, the terms "mounted," "connected," "supported," and "coupled," and variations thereof, are used broadly and include both direct and indirect mounting, connecting, supporting, orHolding and pairing included.

[0028] Unless the context of use clearly requires otherwise, the articles "einer, eine, ein" and "der, die, das" should not be interpreted as "one" or "only one." Rather, these articles should be understood as "at least one" or "one or more." Similarly, when referring to a noun previously introduced by the indefinite article "ein" or "an," the terms "der" or "der genannte" mean "at least one" or "one or more," unless the context clearly indicates otherwise.

[0029] Furthermore, it should be noted that embodiments may include hardware, software, and electronic components or modules, which for purposes of explanation may be illustrated and described as if most components were implemented solely in hardware. However, one of ordinary skill in the art would recognize, based on this detailed description, that in at least one embodiment, the electronic aspects may be implemented in software (e.g., stored on a non-transitory, computer-readable medium) that may be executed by one or more processing units, such as a microprocessor and / or application-specific integrated circuits ("ASICs"). Therefore, it should be noted that a variety of hardware- and software-based devices, as well as a variety of different structural components, may be used to implement the embodiments.For example, “servers,” “computing devices,” “controllers,” “processors,” etc., described in the specification may include one or more processing units, one or more computer-readable media modules, one or more input / output interfaces, and various connections (e.g., a system bus) that connect the components.

[0030] Relative terms such as "about," "approximately," "substantially," etc., used in connection with an amount or condition, would be understood by one of ordinary skill in the art to include the stated value and to have the meaning given by the context (e.g., the term encompasses at least the degree of error associated with measurement accuracy, tolerances [e.g., in manufacture, assembly, use, etc.] associated with the particular value, etc.). Such terms should also be considered to disclose the range defined by the absolute values ​​of the two endpoints. For example, the phrase "from about 2 to about 4" also discloses the range "from 2 to 4." The relative terms can refer to plus or minus a percentage (e.g., 1%, 5%, 10%, or more) of a stated value.

[0031] It should be understood that while certain drawings depict hardware and software in particular devices, these depictions are for illustrative purposes only. Functions described herein as being performed by one component may be performed in a distributed manner by multiple components. Likewise, functions performed by multiple components may be consolidated and performed by a single component. In some embodiments, the depicted components may be combined or separated into separate software, firmware, and / or hardware. For example, rather than being housed and executed by a single electronic processor, logic and processing may be distributed among multiple electronic processors.Regardless of how hardware and software components are combined or separated, they may be located on the same computing device or distributed among different computing devices interconnected by one or more networks or other suitable communications links. Similarly, a component described as performing a particular function may also perform additional functions not described herein. For example, a device or structure "configured or arranged" in a particular manner is configured or arranged at least in that manner, but may also be configured or arranged in other ways not explicitly listed.

[0032] Accordingly, in the claims, for example, where an apparatus or system is claimed that includes a controller, an electronic processing unit, a computing device, a logic element, a module, a memory module, a communication channel or network, or any other element that is configured or arranged in a particular way, for example to perform multiple functions, the claim or claim element should be interpreted to mean one or more of those elements, each of the one or more elements being configured or arranged to perform one or more of the specified functions, such that the one or more elements as a group collectively perform the multiple functions.

[0033] Further aspects of the embodiments will become apparent from the detailed description and the accompanying drawings. Brief description of the drawings Fig. 1 is a simplified block diagram of an electronic / electrical device including a battery and a bidirectional power converter according to some embodiments. Fig. 2A-2C are perspective views of various electronic devices with the battery and the bidirectional power converter of Fig. 1 according to some embodiments. Fig. 3 is a simplified block diagram of an inverter bridge of the bidirectional power converter of Fig. 1 according to some embodiments. Fig. 4 shows a schematic diagram of the battery from Fig. 1, which according to some embodiments is connected to the bidirectional power converter of Fig. 1 is coupled. Fig. Figure 5 shows a flowchart of a method used by a battery management system of the battery Fig. 4 may be executed to protect the battery from faults in response to a fault condition detected according to some embodiments. Detailed description

[0034] Fig. 1 shows a simplified block diagram of an exemplary electronic (i.e., electrical) device 100. The electronic device 100 includes a battery system 110 (i.e., a battery 110), an alternating current (AC) power source or load 120, and a bidirectional power converter 130 electrically connected between the battery system 110 and the AC power source or load 120. The bidirectional power converter 130 is configured to convert direct current (DC) to alternating current and also to convert alternating current to direct current. For example, the bidirectional power converter 130 converts direct current from the battery system 110 to alternating current for the load 120 and converts alternating current from the AC power source 120 to direct current to charge the battery system 110. In some cases, the bidirectional power converter 130 may be incorporated into an electronic device 100 (e.g., aIn some cases, a power tool 100C discussed herein may be used to convert power in only one direction (e.g., from the battery system 110 to the load 120), although the bidirectional power converter 130 is capable of converting power in the opposite direction. In some cases, the bidirectional power converter 130 is configured to convert power in both directions (i.e., discharging power from the battery system 110 and charging power to the battery system 110) over the same electrical path 420 (see ). Fig. 4) at different times, rather than including a discharge current path that is separate / distinct from a charge current path, as previously discussed herein. The bidirectional power converter 130 may be referred to as a symmetrical bidirectional power converter 130 and / or a bidirectional power converter 130 with symmetrical power transfer capability.

[0035] Fig. 2A shows an example of an electronic device 100 in the form of a portable power source / power supply 100A. The portable power source 100A has a housing 205 for accommodating an internal battery system 210. The housing 205 also has an input / output panel 215. The input / output panel 215 has a power input 220 and a power output 225. The power output 225 is, for example, an AC output for powering AC electronic devices. The internal battery system 210 corresponds to the battery system 110. In some cases, the internal battery system has an integrated battery core that is not configured to be removable from the housing 205 by a user. The power input 220 and the outlet 225 correspond to the AC power source 120 and the AC load 120, respectively. The bidirectional power converter 130 is connected between the internal battery system 210, the power input 220, and the outlet 225.The bidirectional power converter 130 converts direct current from the internal battery system 210 to alternating current for power output 225. The bidirectional power converter 130 also converts the alternating current from the power input 220 to direct current for charging the internal battery system 210. As previously stated, (i) the direct current supplied from the internal battery system 210 to the bidirectional power converter 130, which is converted to alternating current, and (ii) the direct current supplied from the bidirectional power converter 130 to the internal battery system 210 for charging the internal battery system 210 each flow on the same current path 420 (see FIG. Fig. 4), but at different times. The portable power source 100A may include additional components not described or illustrated here. For example, the portable power source 100A may include additional power outputs 225 (e.g., both AC and DC), a display, and the like.

[0036] Fig. 2B shows an example of an electronic device 100 in the form of another portable power source / power supply 100B. The portable power source 100B includes a housing 230 with a first battery interface 235A and a second battery interface 235B. The first battery interface 235A and the second battery interface 235B are configured to each receive a first removable power tool battery pack 240A and a second removable power tool battery pack 240B. The first removable power tool battery pack 240A and the second removable power tool battery pack 240B, individually referred to as a removable power tool battery pack 240, are, for example, lithium-ion power tool batteries with a nominal voltage of 12 volts, 18 volts, 24 volts, 36 volts, 54 volts, 72 volts, 90 volts, 108 volts, or the like.The removable battery pack 240 can be used to power cordless indoor and outdoor power tools. The portable power source 100B also has a power input 245 and a power output 250. The power output 250 is, for example, an AC output for electronic devices powered by AC power. The removable battery packs 240 correspond to the battery system 110. The power input 245 and the power output 250 correspond to the AC power source 120 and the AC load 120, respectively. The bidirectional power converter 130 is connected between the removable battery packs 240, the power input 245, and the power output 250. The bidirectional power converter 130 converts DC power from the removable battery packs 240 for power tools to AC power for the power output 250.The bidirectional power converter 130 also converts the alternating current from the power input 245 to direct current for charging the removable power tool battery packs 240. As previously stated, (i) the direct current supplied from the power tool battery packs 240 to the bidirectional power converter 130 for conversion to alternating current and (ii) the direct current supplied from the bidirectional power converter 130 to the power tool battery packs 240 for charging the power tool battery packs 240 both flow on the same current path 420 (see FIG. Fig. 4), but at different times. The portable power source 100B may include additional components not described or illustrated here. For example, the portable power source 100B may include additional power outputs 250 (e.g., both AC and DC), a display, and the like.

[0037] Fig. 2C shows an example of an electronic device 100 in the form of a power tool 100C. In the illustrated example, the power tool 100C is a handheld core drill. The power tool 100C may include various types of indoor and outdoor, handheld, or mounted power tools, such as drills, saws, hammer drills, lighting equipment, sanders, or the like. The power tool 100C has a housing 255 that houses a motor and supports a removable power tool battery pack 240. The removable power tool battery pack 240 corresponds to the battery system 110, and the motor corresponds to the AC load 120. The bidirectional power converter 130 is connected between the removable power tool battery pack 240 and the motor.The bidirectional power converter 130 converts direct current from the power tool's removable battery pack 240 to alternating current for the motor. In some embodiments, the power tool 100C may further include a power cord for receiving alternating current. In these embodiments, the bidirectional power converter 130 also converts the alternating current from the power input or from the motor to direct current for charging the removable power tool battery pack 240. As previously stated, (i) the direct current supplied from the power tool battery pack 240 to the bidirectional power converter 130 for conversion to alternating current and (ii) the direct current supplied from the bidirectional power converter 130 to the power tool battery pack 240 for charging the power tool battery pack 240 both flow on the same current path 420 (see FIG. Fig. 4), but at different times. The 100C power tool may contain additional components not described or illustrated here.

[0038] Fig. Figure 3 shows a simplified block diagram of an inverter 300 that may be included in the bidirectional power converter 130. In the illustrated example, the inverter 300 has six switches arranged in an inverter bridge configuration. The switches include three high-side switches 310A, 310B, 310C, which are electrically connected between a positive terminal 320A of the battery system 110 and the AC power source or load 120. The switches also include three low-side switches 310C, 310E, 310F, which are electrically connected between a negative terminal 320B of the battery system 110 and the AC power source or load 120. The plurality of switches 310A-F are controlled by a controller using a gate driver to convert DC power from the battery system 110 to AC power for the AC load 120.

[0039] In one example, the plurality of switches 310A-F includes metal-oxide-semiconductor field-effect transistors (MOSFETs). In another example, the plurality of switches 310A-F includes wide-bandgap semiconductor FETs, i.e., gallium nitride (GaN) and / or silicon carbide (SiC)-based FETs. In another example, the plurality of switches 310A-F may include a combination of MOSFETs and wide-bandgap semiconductor FETs.

[0040] As previously explained, when using the battery 110 with the bidirectional power converter 130, which can transfer the same or a similar high level of power / current in both directions (i.e., discharge current from the battery 110 and charge current to the battery 110) over the same electrical path at different times, there is only a single electrical path in which to place protective devices / circuits. Therefore, each protective circuit in the single electrical path should be designed to both pass the full discharge current during normal operation, interrupt a full discharge fault current when a fault condition exists, and prevent battery cells from receiving charging current when a less severe fault condition (e.g., an overcurrent lower than the full discharge fault current) is detected during charging.

[0041] Fig. 4 shows a schematic diagram of the battery 110 coupled to the bidirectional power converter 130 according to some embodiments. As shown in Fig. 4, the bidirectional power converter 130 is connected between the AC power source or load 120 and the battery 110, as previously explained herein. The battery 110 has a positive terminal 405A and a negative terminal 405B electrically connected to the bidirectional power converter 130. The positive terminal 405A is electrically connected to a positive end of one or more battery cells 410. The negative terminal 405B is electrically connected to a negative end of the one or more battery cells 410. An electrical path between a positive end of the one or more battery cells 410 and the positive terminal 405A may be referred to as a positive electrical path 415A or positive side 415A of the battery 110.An electrical path between a negative end of the one or more battery cells 410 and the negative terminal 405B may be referred to as a negative electrical path 415B or negative side 415B of the battery 110.

[0042] A first electrical path 420 between the one or more battery cells 410 and the bidirectional power converter 130 includes the positive electrical path 415A and the negative electrical path 415B. As previously explained herein, in some cases, the first electrical path 420 may be the only electrical path through which a discharge current and a charge current flow at different times. In other words, (i) the direct current supplied by the one or more battery cells 410 to the bidirectional power converter 130 to be converted to alternating current and (ii) the direct current supplied by the bidirectional power converter 130 to the one or more battery cells 410 for charging the one or more battery cells 410 both flow on the same first electrical path 420, but at different times.The one or more battery cells 410 are configured to deliver discharge current to the bidirectional power converter 130 via the first electrical path 420. Additionally, the one or more battery cells 410 are configured to receive charge current from the bidirectional power converter 130 via the first electrical path 420.

[0043] In some cases, the battery 110 includes a first overcurrent protection device 425 and a second overcurrent protection device 430. The overcurrent protection devices 425, 430 may each include a fuse (e.g., a non-resettable fuse or a resettable fuse), a positive temperature coefficient (PTC) element, a power switch, a breakaway current path (e.g., an intentionally weak element) on a circuit board, and / or a semiconductor device that performs the same or a similar function as a fuse or the other elements listed above. As in Fig. 4, the second overcurrent protection device 430 may be electrically connected in series with the first overcurrent protection device 425. A series connection of the first overcurrent protection device 425 and the second overcurrent protection device 430 may be electrically connected between the one or more battery cells 410 and the bidirectional power converter 130 in the positive current path 415A or the negative current path 415B. In the Fig. In the example shown in Figure 4, the series connection of the first overcurrent protection device 425 and the second overcurrent protection device 430 is included in the positive current path 415A. In other cases, however, the series connection of the first overcurrent protection device 425 and the second overcurrent protection device 430 is included in the negative current path 415B.

[0044] In some cases, the battery 110 does not include the second overcurrent protection device 430. In such cases, the first terminal of the switching element 435 may be electrically connected between a junction between the first overcurrent protection device 425 and the bidirectional power converter 130.

[0045] In some cases, the battery 110 has a switching element 435, which may have a first terminal electrically connected between a junction 440 between the first overcurrent protection device 425 and the second overcurrent protection device 430. The switching element 435 may have a second terminal electrically connected to the corresponding other path of the positive electrical path 415A or the negative electrical path 415B (i.e., complementary to the one path of the positive electrical path 415A or the negative electrical path 415B on which the overcurrent protection devices 425, 430 are located). The switching element 435 may be an electronically controlled switch. For example, the switching element 435 may be a thyristor (e.g., a silicon controlled rectifier (SCR), a TRIAC, or the like); a transistor such as a bipolar transistor (BJT) (e.g.,of the Darlington type, a metal-oxide-semiconductor field-effect transistor (MOSFET), a junction field-effect transistor (JFET) or the like); a relay or contactor (e.g. of the latching or non-latching type in any suitable contact arrangement); a thyratron; and / or the like. In the device shown in . Fig. In the example shown in Figure 4, switching element 435 includes an SCR. In some cases, a third terminal (i.e., a control terminal) of switching element 435 is connected to a battery management system 445 of battery 110. Switching element 435 may be connected to battery management system 445 via a suitable drive circuit 450 (e.g., a driver, one or more resistors, and / or the like).

[0046] The battery management system 445 may include one or more circuit components (e.g., one or more integrated circuits) configured to provide the functionality described herein. In some cases, the battery management system 445 additionally or alternatively has an electronic processor that is part of, or functions as, the battery management system 445. The electronic processor may include a general-purpose single- or multi-chip processor (e.g., a microprocessor, a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, or discrete hardware components, or combinations thereof). The electronic processor may include or be coupled to memory, such as read-only memory ("ROM"), random-access memory ("RAM") (e.g.,B. Dynamic RAM ("DRAM"), Synchronous DRAM ("SDRAM"), etc.), Electrically Erasable Programmable Read Only Memory ("EEPROM"), Flash memory, a hard drive, an SD card, or other suitable magnetic, optical, physical, or electronic storage devices. The electronic processor may include and / or be electrically coupled to the memory and execute software instructions that can be stored in the memory. The software included in the implementation of the battery 110 may be stored in the memory. The software includes, for example, firmware, filters, rules, and / or other executable instructions. The electronic processor may be configured to, among other things, retrieve and execute instructions related to the control processes and methods described herein from the memory.

[0047] In cases where an electronic processor is included in the battery management system 445, the electronic processor that performs the actions and / or methods described herein may include one or more electronic processors located within the battery 110 or distributed among various devices and / or systems (e.g., the battery 110, the bidirectional power converter 130, etc.). For example, if the claims claim an apparatus or system that includes an electronic processor or other element configured in a particular manner, for example, to make multiple determinations, the claim or claim element should be interpreted to includeit means one or more electronic processors (or other elements), each of the one or more electronic processors (or other elements) configured as claimed, for example, to perform some or all of the plurality of determinations. To reiterate, these electronic processors and processing operations may be distributed.

[0048] As in Fig. 4, the battery management system 445 may be connected to the bidirectional power converter 130 via a communication link 452 to send and / or receive control commands, status information, and / or the like. For example, control signals between the battery management system 445 of the battery 110 and the bidirectional power converter 130 may include dedicated electrical signals transmitted over a communication channel such as one or a combination of RS232, RS485, a Controller Area Network (CAN) bus, Ethernet, and the like. In some cases, the bidirectional power converter 130 may have its own electronic processor to communicate with the electronic processor of the battery management system 445. In some cases, control signals from the battery management system 445 may only control switching elements (e.g.,similar to the switching element 435) of the bidirectional power converter 130, for example, to enable / disable the operation of the bidirectional power converter 130.

[0049] In some cases, the battery 110 includes a plurality of sensors configured to monitor the one or more battery cells 410. The plurality of sensors are in communication with the battery management system 445 so that the battery management system 445 can evaluate the data monitored by the plurality of sensors. The plurality of sensors may include one or more current sensors 455, one or more temperature sensors 460, one or more voltage sensors 465, and / or other types of sensors. In some cases, the current sensor 455 is configured to monitor the discharge current and the charge current. The current sensor 455 is in the negative current path 415B in Fig. 4. However, in other cases, the current sensor 455 may be disposed in the positive current path 415A. In some cases, the temperature sensor(s) 460 are configured to monitor at least one value from a group of values ​​consisting of a temperature of individual battery cells 410 of the one or more battery cells 410, a temperature of the battery 110, an ambient temperature of an environment in which the battery 110 is located, and combinations thereof. In some cases, the voltage sensor(s) 465 are configured to monitor a voltage of individual battery cells 410 of the one or more battery cells 410, a total voltage of the one or more battery cells 410, or both the voltage of the individual battery cells 410 of the one or more battery cells and the total voltage of the one or more battery cells 410.

[0050] Fig. 5 shows a flowchart of a method 500 that may be performed by the battery management system 445 of the battery 110 to protect the battery 110 from faults in response to a fault condition detected according to some embodiments. While in Fig. 5 a particular sequence of processing steps, reception of control signals and / or transmission of control signals is given as an example, the timing and order of these steps, receptions and transmissions may vary as needed without affecting the purpose and advantages of the examples described in detail later in this disclosure.

[0051] At block 505, the battery management system 445 monitors the one or more battery cells 410, for example, using at least one of the plurality of sensors 455, 460, 465 previously described herein. Because the first electrical path 420 is the only electrical path for both charging and discharging the one or more battery cells 410 via the bidirectional power converter 130, the battery management system 445 monitors the one or more battery cells 410 (at block 505) while the one or more battery cells are in the discharging state (i.e., while the one or more battery cells 410 are delivering a discharging current via the first electrical path 420) and in the charging state (i.e., while the one or more battery cells 410 are accepting a charging current via the first electrical path 420).

[0052] In block 510, the battery management system 445 determines whether a fault condition of the battery 110 has been detected. A fault condition is detected, for example, by the battery management system 445 when one or more of the battery cells 410 are operating outside a specified range (e.g., overtemperature, undertemperature, overvoltage, undervoltage, overcurrent, etc., and / or combinations thereof). If no fault condition is detected (in block 510), the method 500 returns to block 505 to repeat blocks 505 and 510 and monitor the one or more battery cells 410 for a fault condition. Conversely, if a fault condition is detected (in block 510), the method 500 proceeds to block 515.

[0053] At block 515, the battery management system 445 sends a first control signal to the bidirectional power converter 130 (via the communication link 452) to control the bidirectional power converter 130 to cease its operation in response to detecting the fault condition of the one or more battery cells 410. In many / most situations, the bidirectional power converter 130 will cease its operation (i.e., prevent current flow through the bidirectional power converter 130 regardless of the direction in which current is currently flowing through the bidirectional power converter 130) in response to the first control signal from the battery management system 445. However, in some cases, the bidirectional power converter 130 may remain active (i.e., continue to allow current flow) due to a failure / fault in the communication link 452, the bidirectional power converter 130, and / or the battery 110.As a fail-safe / backup shutdown method for this case, the battery management system 445 may take additional protective measures if it determines that the bidirectional power converter 130 has not gone offline after the battery management system 445 has transmitted the first control signal, as explained in more detail below.

[0054] At block 520, the battery management system 445 determines whether the bidirectional power converter 130 has ceased operation (e.g., the bidirectional power converter 130 may have ceased operation in response to receiving the first control signal sent by the battery management system 445 at block 515). In some cases, the battery management system 445 waits a predetermined period of time after sending the first control signal to the bidirectional power converter 130 before executing block 520. In some cases, the battery management system 445 determines that the bidirectional power converter 130 has not ceased operation within the predetermined period of time by noting that a monitored value (e.g., current) from one of the sensors has not decreased at all or has not decreased by a predetermined amount.For example, the battery management system 445 determines that the bidirectional power converter 130 has not ceased operation based on an equal or similar current flowing through the current sensor at the time blocks 515 and 520 are executed. In some cases, the bidirectional power converter 130 is configured to respond to the first control signal with an acknowledge signal or a non-acknowledge signal. If the acknowledge signal is not received or the non-acknowledge signal is received, the battery management system 445 may determine that the bidirectional power converter 130 has not ceased operation.In cases where the bidirectional power converter is configured to send the acknowledgement signal or the non-acknowledgement signal, the battery management system 445 may not wait the predetermined period of time between blocks 515 and 520 or may wait a shorter predetermined period of time.

[0055] If the battery management system 445 determines that the bidirectional power converter 130 has ceased operation (at block 520) (e.g., operation ceased in response to receiving the first control signal from the battery management system 445), the method 500 ends, and the battery 110 no longer supplies power to or receives power from the bidirectional power converter 130 until the fault condition is verified and the components of the battery 110 and the bidirectional power converter 130 are reset to undetect the fault condition. As in Fig. 5, in these cases, block 525 is not executed by the battery management system 445. In other words, the battery management system 445 may be configured not to send a second control signal to the switching element 435 to close the switching element 435 and cause a short circuit between the positive current path 415A and the negative current path 415B (in block 525) when it is determined that the bidirectional power converter 130 has ceased operation (in block 520). In some cases, the battery management system 445 may automatically reset after detecting no fault conditions of the battery 110 for a certain period of time.In some cases, the battery management system 445 may automatically send another control signal to the bidirectional power converter 130 to enable the bidirectional power converter 130 to operate normally after a certain period of time in which no fault conditions of the battery 110 have been detected.

[0056] If the battery management system 445 determines that the bidirectional power converter 130 has not ceased operation (at block 520) despite the first control signal being sent, the method 500 proceeds to block 525. At block 525, the battery management system 445 sends a second control signal to the switching element 435 to close the switching element 435 and cause a short circuit between the positive current path 415A and the negative current path 415B. In some cases, the battery management system 445 sends the second control signal in response to determining that the bidirectional power converter 130 is not turned off (at block 520). In some cases, the short circuit between the positive current path 415A and the negative current path 415B causes at least the first overcurrent protection device 425 to open to prevent current from flowing into or out of the one or more battery cells 410.

[0057] For example, as in Fig. 4, the first overcurrent protection device 425 is electrically connected between the one or more battery cells 410 and the second overcurrent protection device 430. Accordingly, when the switching element 435 is closed, the first overcurrent protection device 425 is in the short circuit path between the positive electrical path 415A and the negative electrical path 415B to cause the short circuit between the positive electrical path 415A and the negative electrical path 415B. The short circuit path between the positive current path 415A and the negative current path 415B of the battery 110 causes the one or more battery cells to briefly (e.g., almost instantaneously) deliver a high current that opens the first overcurrent protection device 425.The first overcurrent protection device 425 opens in response to the current from the one or more battery cells 410 due to the short circuit exceeding a current limit of the first overcurrent protection device 425. Once the first overcurrent protection device 425 is opened, current is prevented from flowing into or out of the one or more battery cells 410, for example, to or from the bidirectional power converter 130. Accordingly, the switching element 435 and the first overcurrent protection device 425 form a protection circuit (e.g., a crowbar circuit ora surge protector) that acts as a fail-safe to prevent current from flowing into or out of the one or more battery cells 410 if the bidirectional power converter 130 continues to operate after the battery management system 445 commands the bidirectional power converter 130 to cease operation (in block 515). The crowbar circuit may be activated (i.e., the switching element 435 may be controlled to close to cause a short circuit) while the battery 110 is being charged or while the battery 110 is being discharged. Activation of the crowbar circuit may eliminate the fault condition or at least prevent the fault condition from increasing in severity.

[0058] As in Fig. 4, in some cases, the second overcurrent protection device 430 is electrically connected between the first overcurrent protection device 425 and the bidirectional power converter 130. In some cases, the short circuit between the positive current path 415A and the negative current path 415B causes the second overcurrent protection device 430 to open in response to the current from the bidirectional power converter 130 exceeding a current limit of the second overcurrent protection device 430 due to the short circuit. For example, if the bidirectional power converter 130 supplies a sufficiently high amount of current when the switching element 435 is closed (i.e., when the crowbar circuit is activated), the second overcurrent protection device 430 opens. In some cases, a current limit of the first overcurrent protection device 425 may be the same as or different from the current limit of the second overcurrent protection device 430.In some cases, opening the second overcurrent protection device 430 prevents the battery 110 from drawing power from the bidirectional power converter 130. For example, the second overcurrent protection device 430 is configured to prevent the switching element 435, when closed, from causing a prolonged short circuit and high current draw on the DC side of the bidirectional power converter 130, thereby preventing a potential dangerous / fault condition (e.g., overcurrent, overtemperature, etc.) associated with the bidirectional power converter 130.

[0059] It is back on Fig. 5; if the battery management system 445 executes block 525 to cause the short circuit between the positive current path 415A and the negative current path 415B of the battery 110, the method 500 ends, and the battery 110 no longer supplies or receives power to the bidirectional power converter 130 until the fault condition is verified and the components of the battery 110 are reset to clear the fault detection. In some cases, after a certain period of time in which no fault conditions of the battery 110 are detected, the battery management system 445 may automatically reset itself (e.g., open the switching element 435 to allow normal battery operation again), and the overcurrent protection devices 425, 430 (e.g., PTC elements) may be automatically reset.

[0060] According to Fig. 5, fault conditions may be detected (in block 510) in any one or a combination of different ways. Additionally, a severity level of the fault conditions may be determined (in block 510 and / or thereafter), such that, in some cases, the battery management system 445 operates differently depending on the severity of one or more fault conditions.

[0061] In some cases, the battery management system 445 detects a fault condition by comparing a monitored value from one of the sensors to a threshold (e.g., an overcurrent threshold, an overvoltage threshold, an undervoltage threshold, an overtemperature threshold, an undertemperature threshold, and / or the like). If the monitored value exceeds the threshold, the battery management system 445 may detect a fault condition. In some cases, the battery management system 445 detects a fault condition when multiple monitored values ​​from different sensors exceed a respective threshold.

[0062] In some cases, the battery management system 445 determines a severity of the fault condition based on a number of monitored properties that have exceeded their respective thresholds (e.g., a larger number of monitored properties that are outside their desired operating range may indicate a more severe fault condition than a smaller number of monitored properties that are outside their desired operating range). Additionally or alternatively, the battery management system 445 may determine a severity of the fault condition based on a difference between a number of a monitored value that has exceeded the threshold and the threshold itself. For example, a monitored value (e.g., current) that has exceeded an overcurrent limit by a large amount may indicate a more severe fault condition than a monitored value (e.g.,current) that has exceeded the overcurrent limit by a smaller amount.

[0063] In some cases (e.g., if the fault condition is determined to be severe, or for certain applications regardless of the severity of the fault condition), the battery management system 445 may bypass block 520 of the method 500 and concurrently execute blocks 515 and 525 in response to detecting the severe fault condition (or any fault condition). In other words, in some cases, block 520 may not be included in the method 500.

[0064] In some cases, the predetermined period of time that the battery management system 445 waits after executing block 515 may be adjusted or interrupted depending on the severity of the detected fault condition. For example, the battery management system 445 may send the first control signal to the bidirectional power converter 130 to control the bidirectional power converter 130 to cease operation (in block 515) when a first fault condition is detected. Continuing this example, before the predetermined period of time expires, the battery management system 445 may determine that (i) the severity of the fault condition has increased (e.g., exceeded a second threshold that is higher than a first threshold that originally triggered detection of the fault condition), (ii) a second fault condition has been detected, or (iii) both (i) and (ii) apply.Additionally, before the predetermined time period expires, the battery management system 445 may send the second control signal to the switching element 435 to close the switching element 435 and cause the short circuit between the positive current path 415A and the negative current path 415B (in block 525) if it is determined that (i) the severity of the fault condition has increased (e.g., exceeded a second threshold that is higher than a first threshold that originally triggered detection of the fault condition), (ii) the second fault condition has been detected, or (iii) both (i) and (ii) are the case. As another example, the battery management system 445 may determine the predetermined time period to wait between blocks 515 and 520 based on a type of fault condition and / or a severity of the fault condition.For example, the battery management system 445 may wait a shorter predetermined period of time between blocks 515 and 520 when an overcurrent fault condition is detected than when an undervoltage fault condition is detected. As another example, the battery management system 445 may wait a shorter period of time when a more severe fault condition is detected (e.g., an overvoltage that exceeds the overvoltage threshold by a greater amount or a second, higher overvoltage threshold) than when a less severe fault condition is detected (e.g., an overvoltage that exceeds the overvoltage threshold by a lesser amount or only a first, lower overvoltage threshold).

[0065] With further reference to Fig.2A-2C, the battery 110, 210, 240 may include a housing (e.g., the housing 205 of the portable power source 100A, a power tool battery pack housing, etc.) configured to receive the one or more battery cells 410, the first overcurrent protection device 425, the second overcurrent protection device 430, the switching element 435, and / or the battery management system 445. The housing of the battery 110, 210, 240 may include (i) a removable battery pack housing configured to be removably connected to a power tool device 110C, and / or (ii) a portable power source housing 205, and / or (iii) a power tool device housing 255, and / or (iv) combinations thereof.

[0066] Although the disclosure is described in detail with reference to certain preferred embodiments, variations and modifications are possible within the scope and spirit of one or more independent aspects of the disclosure as described. Various features and advantages are set forth in the following claims. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 656,740

[0001]

Claims

[1] A battery that has: one or more battery cells electrically connected to a bidirectional power converter via a positive terminal and a negative terminal, wherein the one or more battery cells are formed: output a discharge current via a first electrical path between the one or more battery cells and the bidirectional power converter, the first electrical path comprising (i) a positive electrical path between the one or more battery cells and the positive terminal and (ii) a negative electrical path between the one or more battery cells and the negative terminal, and receive a charging current via the first electrical path from the bidirectional power converter; a first overcurrent protection device; a second overcurrent protection device electrically connected in series with the first overcurrent protection device, wherein a series circuit of the first overcurrent protection device and the second overcurrent protection device is electrically connected between the one or more battery cells and the bidirectional power converter in the positive electrical path or the negative electrical path; a switching element which has: a first terminal electrically connected between a junction point between the first overcurrent protection device and the second overcurrent protection device, and a second terminal electrically connected to the corresponding other electrical path of the positive electrical path and the negative electrical path; and a battery management system communicatively connected to the switching element, wherein the battery management system is configured to: Monitoring one or more battery cells, Detecting a fault condition of one or more battery cells, Sending a first control signal to the bidirectional power converter to control the bidirectional power converter to cease operation in response to detecting the fault condition of the one or more battery cells, and Sending a second control signal to the switching element to close the switching element to cause a short circuit between the positive current path and the negative current path, wherein the short circuit between the positive current path and the negative current path causes at least the first overcurrent protection device to open to prevent current from flowing into or out of the one or more battery cells. [2] The battery of claim 1, wherein the first overcurrent protection device is electrically connected between the one or more battery cells and the second overcurrent protection device, and wherein the second overcurrent protection device is electrically connected between the first overcurrent protection device and the bidirectional power converter; wherein the short circuit between the positive current path and the negative current path causes the second overcurrent protection device to open when the current from the bidirectional power converter due to the short circuit exceeds a current limit of the second overcurrent protection device; and wherein opening of the second overcurrent protection device prevents current from being drawn from the bidirectional power converter. [3] The battery of claim 1, wherein the first overcurrent protection device is electrically connected between the one or more battery cells and the second overcurrent protection device, and wherein the second overcurrent protection device is electrically connected between the first overcurrent protection device and the bidirectional power converter; wherein the first overcurrent protection device opens in response to a current flowing from the one or more battery cells through the short circuit exceeding a current limit of the first overcurrent protection device. [4] The battery of claim 1, wherein the battery management system is configured to: Waiting a predetermined period of time after sending the first control signal to the bidirectional power converter; Determining that the bidirectional power converter has not ceased operation within the predetermined period of time; and Sending the second control signal to the switching element to close the switching element to cause the short circuit between the positive current path and the negative current path in response to determining that the bidirectional power converter has not stopped operating. [5] The battery of claim 4, wherein the battery management system is configured to: Determining, before the expiration of the predetermined period of time, that (i) the severity of the fault condition has increased, (ii) a second fault condition has been detected, or (iii) both (i) and (ii) apply; and Sending, before the expiration of the predetermined period of time, the second control signal to the switching element to close the switching element to cause the short circuit between the positive current path and the negative current path when it is determined that (i) the severity of the fault condition has increased, (ii) the second fault condition has been detected, or (iii) both (i) and (ii) apply. [6] The battery of claim 1, wherein the battery management system is configured to: Waiting a predetermined period of time after sending the first control signal to the bidirectional power converter; Determining that the bidirectional power converter has ceased operation within the predetermined period of time; and Avoiding sending the second control signal to the switching element to close the switching element to cause the short circuit between the positive current path and the negative current path when it is determined that the bidirectional power converter has stopped its operation. [7] A battery that has: one or more battery cells electrically connected to a bidirectional power converter, wherein the one or more battery cells are configured to: Outputting a discharge current through a first electrical path between the one or more battery cells and the bidirectional power converter, and Receiving a charging current through the first electrical path from the bidirectional power converter; a first overcurrent protection device electrically connected between the one or more battery cells and the bidirectional power converter, the first overcurrent protection device electrically connected to a positive or a negative side of the battery; a switching element which has: a first terminal electrically connected between a junction point between the first overcurrent protection device and the bidirectional power converter, and a second terminal electrically connected to the corresponding other of the positive side and negative side of the battery; and a battery management system communicatively connected to the switching element, wherein the battery management system is configured to: Monitoring one or more battery cells, Detecting a fault condition of one or more battery cells, Sending a first control signal to the bidirectional power converter to control the bidirectional power converter to cease operation in response to detecting the fault condition of the one or more battery cells, and Sending a second control signal to the switching element to close the switching element to cause a short circuit between the positive side and the negative side of the battery, wherein the short circuit between the positive side and the negative side causes the first overcurrent protection device to open to prevent current from flowing into or out of the one or more battery cells. [8] The battery of claim 7, further comprising a second overcurrent protection device electrically connected in series with the first overcurrent protection device, wherein a series circuit of the first overcurrent protection device and the second overcurrent protection device is electrically connected between the one or more battery cells and the bidirectional power converter on the positive or negative sides of the battery; wherein the first overcurrent protection device is electrically connected between the one or more battery cells and the second overcurrent protection device, and wherein the second overcurrent protection device is electrically connected between the first overcurrent protection device and the bidirectional power converter; wherein the connection point is located between the first overcurrent protection device and the second overcurrent protection device; wherein the short circuit between the positive side and the negative side causes the second overcurrent protection device to open when the current from the bidirectional power converter through the short circuit exceeds a second current limit of the second overcurrent protection device; wherein the opening of the second overcurrent protection device prevents a current draw from the bidirectional power converter; and wherein the first overcurrent protection device opens when the current from the one or more battery cells due to the short circuit exceeds a first current limit of the first overcurrent protection device. [9] The battery of claim 7, wherein the battery management system is configured to: Waiting a predetermined period of time after sending the first control signal to the bidirectional power converter; Determining that the bidirectional power converter has not ceased operation within the predetermined period of time; and Sending the second control signal to the switching element to close the switching element to cause the short circuit between the positive side and the negative side in response to determining that the bidirectional power converter has not stopped its operation. [10] The battery of claim 9, wherein the battery management system is configured to: Determining, before the expiration of the predetermined period of time, that (i) the severity of the fault condition has increased, (ii) a second fault condition has been detected, or (iii) both (i) and (ii) apply; and Sending, before the expiration of the predetermined period of time, the second control signal to the switching element for closing the switching element to cause the short circuit between the positive side and the negative side when it is determined that (i) the severity of the fault condition has increased, (ii) the second fault condition has been detected, or (iii) both (i) and (ii) apply. [11] The battery of claim 7, wherein the battery management system is configured to: Determining that the bidirectional power converter has ceased operation; and Avoiding sending the second control signal to the switching element to close the switching element to cause the short circuit between the positive side and the negative side when it is determined that the bidirectional power converter has stopped its operation. [12] The battery of claim 7, further comprising a plurality of sensors configured to monitor the one or more battery cells, the plurality of sensors being communicatively coupled to the battery management system, and the plurality of sensors comprising: a current sensor configured to monitor the discharge current and the charging current; and / or a temperature sensor configured to monitor a temperature of individual battery cells of the one or more battery cells and / or a temperature of the battery and / or an ambient temperature of an environment in which the battery is located, and / or combinations thereof; and / or a voltage sensor configured to monitor a voltage of individual battery cells of the one or more battery cells, a total voltage of the one or more battery cells, or both the voltage of individual battery cells of the one or more battery cells and the total voltage of the one or more battery cells; and / or Combinations of these. [13] The battery according to claim 7, wherein the first overcurrent protection device comprises a fuse, a positive temperature coefficient (PTC) element, a power switch, or a burn-in conductor; and wherein the switching element comprises a thyristor, a transistor, a relay, a contactor, or a thyratron. [14] The battery of claim 7, further comprising a housing configured to receive the one or more battery cells, the first overcurrent protection device, the switching element, and the battery management system; wherein the housing comprises (i) a housing of a removable battery pack configured to be removably coupled to a power tool, and / or (ii) a housing of a portable power source, and / or (iii) a housing of a power tool device, and / or (iv) combinations thereof. [15] A battery, wherein the battery is designed to: Outputting, by one or more battery cells of the battery in a discharge state, a discharge current through a first electrical path between the one or more battery cells and a bidirectional power converter; Receiving, in the one or more battery cells in a state of charge, a charging current through the first electrical path; Monitoring, with a battery management system of the battery, the one or more battery cells of the battery while the one or more battery cells are in the discharge state and while the one or more battery cells are in the charge state; Detecting, with the battery management system, a fault condition of the one or more battery cells; Sending a first control signal to the bidirectional power converter with the battery management system to control the bidirectional power converter to cease operation in response to detecting the fault condition of the one or more battery cells; and Sending a second control signal with the battery management system to a switching element to close the switching element to cause a short circuit between a positive side and a negative side of the battery, wherein the short circuit between the positive side and the negative side causes a first overcurrent protection device to open to prevent current from flowing into or out of the one or more battery cells. [16] The battery of claim 15, wherein the short circuit between the positive side and the negative side causes a second overcurrent protection device to open to prevent current from being drawn from the bidirectional power converter; wherein the second overcurrent protection device is electrically connected in series with the first overcurrent protection device, and wherein a series circuit of the first overcurrent protection device and the second overcurrent protection device is electrically connected between the one or more battery cells and the bidirectional power converter on one side, the positive or negative sides, of the battery; wherein the first overcurrent protection device is electrically connected between the one or more battery cells and the second overcurrent protection device, and wherein the second overcurrent protection device is electrically connected between the first overcurrent protection device and the bidirectional power converter; wherein the short circuit between the positive side and the negative side causes the second overcurrent protection device to open when the current from the bidirectional power converter due to the short circuit exceeds a second current limit of the second overcurrent protection device; and wherein the first overcurrent protection device opens when the current from the one or more battery cells due to the short circuit exceeds a first current limit of the first overcurrent protection device. [17] The battery of claim 15, further comprising: Waiting, by means of the battery management system, a predetermined period of time after sending the first control signal to the bidirectional power converter; Determining, with the battery management system, that the bidirectional power converter has not ceased operation within the predetermined period of time; and Sending, with the battery management system, the second control signal to the switching element to close the switching element to cause the short circuit between the positive side and the negative side in response to determining that the bidirectional power converter has not stopped its operation. [18] The battery of claim 17, further comprising: Determining, with the battery management system and before the expiration of the predetermined period of time, that (i) the shear of the fault condition has increased, (ii) a second fault condition has been detected, or (iii) both (i) and (ii) apply; and Sending, with the battery management system and before the expiration of the predetermined period of time, the second control signal to the switching element to close the switching element to cause the short circuit between the positive side and the negative side when it is determined that (i) the severity of the fault condition has increased, (ii) the second fault condition has been detected, or (iii) both (i) and (ii) apply. [19] The battery of claim 15, further comprising: Determine, with the battery management system, that the bidirectional power converter has ceased operation; and by means of the battery management system, avoiding sending the second control signal to the switching element to close the switching element to cause the short circuit between the positive side and the negative side in response to determining that the bidirectional power converter has stopped operating. [20] The battery of claim 15, wherein monitoring the one or more battery cells comprises monitoring the one or more battery cells with a plurality of sensors, the plurality of sensors being communicatively coupled to the battery management system, and the plurality of sensors comprising: a current sensor designed to monitor the discharge current and the charging current; and / or a temperature sensor configured to monitor a temperature of individual battery cells of the one or more battery cells and / or a temperature of the battery and / or an ambient temperature of an environment in which the battery is located, and / or combinations thereof; and / or a voltage sensor configured to monitor a voltage of individual battery cells of the one or more battery cells, a total voltage of the one or more battery cells, or both the voltage of individual battery cells of the one or more battery cells and the total voltage of the one or more battery cells; and / or Combinations of these.

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