Patent Description:
Battery-powered appliances, such as cordless power tools, power equipment, cordless vacuum cleaners, and cordless lawn equipment (e.g., electric blowers, lawn mowers, etc.), typically include a battery or battery pack that supplies power to the battery-powered appliance. Some battery packs are removable from the appliance, for example, to allow a depleted battery pack to be replaced with a charged battery pack.

Some battery-powered appliances include battery packs having different power capacities. However, many of these battery-powered appliances typically require that the battery pack have a common size, shape, and/or form factor to connect to a battery receptacle of the appliance. As a result, battery packs having lower power capacities are often made larger than otherwise required to conform with the common form factor of high power capacity batteries.

Additionally, many appliances require that the battery pack be precisely aligned with the battery receptacle and associated electrical contacts to connect the battery pack to the appliance. Such connection systems are less than optimal for battery-powered appliances worn by a user during use (e.g., backpack vacuum cleaners) because the user generally needs to remove the appliance to connect or exchange a battery pack, resulting in additional down time and energy expended by the user.

This Background section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below.

The invention is defined by a battery pack according to claim <NUM>.

In an aspect, a battery pack includes a housing, at least one battery cell enclosed within the housing, a printed circuit board (PCBA) enclosed within the housing, a gauge electrically connected to the PCBA and including a plurality of lights, and a depressible button. The housing has a main body and a handle extending from the main body, and the handle defines an aperture sized and shaped to receive one or more of a user's fingers therein. The handle includes an outer surface positioned opposite and facing away from the aperture. The gauge and depressible button are located on the outer surface of the handle. The button and the plurality of lights are arranged linearly along the handle. Actuation of the button activates the gauge to illuminate a number of the plurality of lights that corresponds to a charge level of the at least one battery cell.

In another aspect, a battery pack includes a housing, at least one battery cell enclosed within the housing, a printed circuit board (PCBA) enclosed within the housing, a gauge electrically connected to the PCBA and including a plurality of lights, and an actuator attached to the housing. The housing has a main body and a handle extending from the main body in a first direction, and the handle defines an aperture sized and shaped to receive one or more of a user's fingers therein. The gauge is located on an outer surface of the handle. Actuation of the actuator activates the gauge to illuminate a number of the plurality of lights that corresponds to a charge level of the at least one battery cell. Each of the plurality of lights is visible from a first viewing direction that is parallel to and opposite the first direction, a second viewing direction orthogonal to the first viewing direction, and a third viewing direction that is parallel to and opposite the second viewing direction.

Various refinements exist of the features noted in relation to the above-mentioned aspects. Further features may also be incorporated in the above-mentioned aspects as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to any of the illustrated embodiments may be incorporated into any of the above-described aspects, alone or in any combination.

<CIT> discloses a power tool which includes a housing configured to house a motor, the housing defining a body axis and having a hand grip for a user, wherein the hand grip is positioned between a first end and a second end of the housing. The power tool further includes a tool element positioned at the first end of the housing and a battery connection port adapted to receive a battery pack. The battery connection port defines a removal axis for the battery pack and includes a first portion located at one end of the removal axis and a second portion located at an other end of the removal axis opposite the first portion. The second portion is positioned closer to the tool end than the first portion.

<CIT> discloses a battery assembly including a battery pack having a battery pack housing, an upper modular housing portion coupled to the battery pack housing positioned at a first end of the battery pack housing, a lower modular housing portion coupled to the battery pack housing positioned at a second end of the battery pack housing, and a handle formed as part of the upper modular housing portion. The battery assembly further includes multiple battery cells disposed within the battery pack housing, a mating feature including multiple ports electrically connected to the multiple battery cells and structured to supply power from the multiple battery cells through the ports and is structured to selectively connect the battery assembly with a receptacle of at least one of a piece of power equipment and a charging station.

<CIT> discloses a battery pack for selective attachment to a receptacle includes a housing enclosing a battery, a handle extending from the housing and defining an aperture between the housing and the handle, and a latching arrangement coupled to the housing and engageable with the receptacle for inhibiting the battery pack from being removed from the receptacle. The latching arrangement includes a latch member and an actuator movable relative to the housing from a first position to a second position to move the latch member from a latched position to and an unlatched position. The actuator is at least partially located within the aperture when the actuator is in the first position.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

<FIG> is a perspective view of an example portable, battery-powered appliance <NUM>, illustrated in the form of a cordless backpack vacuum cleaner. Although the appliance <NUM> is shown and described herein with reference to a backpack-mounted vacuum cleaner, battery-powered appliances consistent with this disclosure may be embodied in other types and in other combinations including, for example and without limitation, wet/dry vacuum cleaners, canister vacuum cleaners, upright vacuum cleaners, blowers, sprayers, and power tools and equipment (e.g., power threading machines, pipe saws, pipe beveling machines, and drain cleaning machines).

In the example embodiment, the appliance <NUM> includes a vacuum cleaner assembly <NUM> that is carried on a user's back via a harness or backpack assembly <NUM>, and a vacuum conduit <NUM> connected to the vacuum cleaner assembly <NUM>. The vacuum conduit <NUM> may generally include any suitable conduit for directing suction and/or forced air generated by the appliance <NUM>, including, for example and without limitation, vacuum hoses, vacuum wands or tubes, surface cleaning tools, and combinations thereof. In the illustrated embodiment, the vacuum conduit <NUM> includes a hose <NUM> extending from a top of the vacuum cleaner assembly <NUM>, a vacuum cleaner wand <NUM> connected to the hose <NUM>, and a vacuum cleaner floor tool <NUM> connected to a distal end of the wand <NUM>.

The backpack assembly <NUM> is sized and shaped to be worn by a user of the appliance <NUM> (e.g., on the user's back or shoulders) to facilitate carrying the appliance <NUM> during use. In the illustrated embodiment, the backpack assembly <NUM> includes two shoulder straps <NUM> and a waist belt <NUM> for securing the backpack assembly <NUM> and appliance <NUM> to the torso of a user. In other embodiments, the backpack assembly <NUM> may have any suitable configuration that enables the appliance <NUM> to function as described herein.

With additional reference to <FIG> and <FIG>, the vacuum cleaner assembly <NUM> includes a housing <NUM>, a suction unit <NUM> enclosed within the housing <NUM>, a controller <NUM>, and a power source <NUM>. The components and connections shown in <FIG> are a functional example only. Other embodiments may include different components, more or fewer components, components connected to different components, and/or different polarity connections.

The housing <NUM> defines an inlet <NUM>, at least one exhaust or outlet <NUM>, and a debris chamber <NUM> connected in fluid communication between the inlet <NUM> and the outlet <NUM>. In the example embodiment, the inlet <NUM> is defined at a top of the housing <NUM>, and the housing <NUM> includes two outlets <NUM> defined adjacent a bottom of the housing <NUM>. In other embodiments, the inlet <NUM> and the outlet(s) <NUM> may be defined at any suitable portion of the appliance <NUM> that enables the appliance <NUM> to function as described herein. Further, the appliance <NUM> may include more than or fewer than two outlets <NUM>.

In the illustrated embodiment, the housing <NUM> includes an access door or lid <NUM> that provides access to the debris chamber <NUM>, for example, to empty debris collected within the debris chamber <NUM>. The inlet <NUM> is defined in the lid <NUM> in the example embodiment. Further, the example housing <NUM> is adapted to receive a filter <NUM> within the debris chamber <NUM> to filter out fine debris and small particles from the air flow through the housing <NUM>. In the illustrated embodiment, the filter <NUM> is a bag filter, although the appliance <NUM> may be operable with other types of filters, including, for example and without limitation, cartridge filters.

The suction unit <NUM> is operable to generate airflow (indicated by arrows in <FIG>) through the housing <NUM> from the inlet <NUM> to the outlet <NUM> so as to draw debris into the debris chamber <NUM> through the inlet <NUM> by way of the vacuum conduit <NUM> (shown in <FIG>). The suction unit <NUM> includes a fan or impeller <NUM> and a motor <NUM> operatively connected to the impeller <NUM> (collectively referred to herein as a "motor assembly") to drive the impeller <NUM> and generate airflow through the housing <NUM>. The motor assembly is connected to the housing <NUM> and positioned adjacent the debris chamber <NUM> such that the impeller <NUM> receives airflow through an impeller inlet <NUM> defined by the housing <NUM>. In certain embodiments, the motor assembly may also be adapted to operate in a "reverse" mode in which the motor assembly generates airflow from the outlet <NUM> to the inlet <NUM>, so as to enable the appliance <NUM> to operate as a blower.

The controller <NUM> is generally configured to control one or more operations or processes of the appliance <NUM>. In some embodiments, for example, the controller <NUM> receives user input from a user interface <NUM> of appliance <NUM>, and controls one or more components of appliance <NUM> in response to such user inputs. In some embodiments, for example, the controller <NUM> controls the supply of power from the power source <NUM> to the vacuum suction unit <NUM> based on user input received from the user interface <NUM>. For example, the controller <NUM> operates the motor <NUM> in response to user input received from a power switch <NUM> and a speed selection switch <NUM> of the user interface <NUM>. The controller <NUM> may regulate or control electrical power supplied to appliance <NUM>, such as from power source <NUM>. For example, the controller <NUM> of the appliance <NUM> may include one or more power converters or regulators configured to control or regulate the electrical power supplied to components of the appliance <NUM>, such as the motor <NUM> of vacuum suction unit <NUM>. In some embodiments, for example, the controller <NUM> may include one or more DC power converters or regulators configured to control or regulate DC power supplied by the power source. Such power converters and regulators may be incorporated or integrated within components of the appliance <NUM>, such as the vacuum suction unit <NUM> and/or within the motor <NUM>. The controller <NUM> may also display information about the appliance <NUM> to the user through a display <NUM> of the user interface <NUM>.

The controller <NUM> may generally include any suitable computer and/or other processing unit, including any suitable combination of computers, processing units and/or the like that may be operated independently or in connection within one another. The controller <NUM> may include one or more processor(s) <NUM> and associated memory device(s) <NUM> containing instructions that cause the processor <NUM> (i.e., "configure the processor" or "program the processor") to perform a variety of computer-implemented functions (e.g., performing the calculations, determinations, and functions disclosed herein). As used herein, the term "processor" refers not only to integrated circuits, but also refers to a controller, a microcontroller, a microcomputer, a programmable logic controller (PLC), an application specific integrated circuit, and other programmable circuits. Additionally, the memory device(s) <NUM> of controller <NUM> may generally be or include memory element(s) including, but not limited to, computer readable medium (e.g., random access memory (RAM)), computer readable non-volatile medium (e.g., a flash memory), a floppy disk, a compact disc-read only memory (CD-ROM), a magneto-optical disk (MOD), a digital versatile disc (DVD) and/or other suitable memory elements. Such memory device(s) <NUM> may generally be configured to store suitable computer-readable instructions that, when implemented by the processor(s), configure or cause the controller <NUM> to perform various functions including, but not limited to, controlling appliance <NUM>, controlling operation of vacuum suction unit <NUM>, receiving inputs from user interface <NUM>, providing output to an operator via user interface <NUM>, and/or various other suitable computer-implemented functions.

The controller <NUM> includes a communications interface <NUM>. Communications interface <NUM> allows the appliance <NUM> (and more particularly, the controller <NUM>) to communicate with remote devices and systems as part of a wired or wireless communication network. Wireless network interfaces may include a radio frequency (RF) transceiver, a Bluetooth® adapter, a Wi-Fi transceiver, a ZigBee® transceiver, a near field communication (NFC) transceiver, an infrared (IR) transceiver, and/or any other device and communication protocol for wireless communication. (Bluetooth is a registered trademark of Bluetooth Special Interest Group of Kirkland, Washington; ZigBee is a registered trademark of the ZigBee Alliance of San Ramon, California. ) Wired network interfaces may use any suitable wired communication protocol for direct communication including, without limitation, USB, RS232, I2C, SPI, analog, and proprietary I/O protocols. Moreover, in some embodiments, the wired network interfaces include a wired network adapter allowing the computing device to be coupled to a network, such as the Internet, a local area network (LAN), a wide area network (WAN), a mesh network, and/or any other network to communicate with remote devices and systems via the network. Controller <NUM> transmits and receives communications over the communication network using messages formatted according to an appropriate network communication protocol. In some embodiments, the network communication protocol is an Ethernet communication protocol or an Institute of Electrical and Electronics Engineers (IEEE) <NUM> based communication protocol. In some embodiments, the communications interface <NUM> includes wired and wireless communications interfaces. In some embodiments, the communications interface <NUM> includes a wired communication interface for communicative connection to a communication interface in an automobile.

The communications interface <NUM> may be used, for example, for communicating diagnostics information, providing the serial number of the appliance <NUM>, providing maintenance performed information, providing firmware version information, receiving firmware updates and reprogramming, and providing motor <NUM> operation/fault status information to a diagnostic/monitoring device, or the like.

The controller <NUM> and/or components of controller <NUM> may be integrated or incorporated within other components of the appliance <NUM>. In some embodiments, for example, controller <NUM> may be incorporated within the vacuum suction unit <NUM> or the motor assembly.

The power source <NUM> is configured to supply electrical power to components of the appliance <NUM>, such as the motor <NUM> and the controller <NUM>, and may generally include any suitable power source that enables the appliance <NUM> to operate as described herein. Suitable types of power sources include, for example and without limitation, DC power sources, such as battery packs, and AC power sources, such as mains AC electricity from a household or commercial wall outlet.

The illustrated appliance <NUM> is a "cordless" vacuum cleaner that includes a portable power source, shown in the form of a battery pack <NUM> removably connected to a battery receptacle <NUM> defined by the housing <NUM>. The battery pack <NUM> of the example embodiment is a direct current (DC) source battery configured to supply direct current to the appliance <NUM>. The battery pack <NUM> may have any suitable DC battery construction that enables the appliance <NUM> to function as described herein. For example, the battery may include, without limitation, one or more lithium-ion batteries, nickel-metal hydride batteries, lead-acid batteries, lithium-metal batteries, supercapacitors or other capacitor-based voltage sources, lithium nickel manganese cobalt oxide batteries, lithium nickel cobalt aluminum oxide batteries, and any other suitable DC battery construction that enables the appliance <NUM> to function as described herein. In this embodiment, the battery pack <NUM> is a rechargeable lithium-ion battery that includes a plurality of lithium-ion cells.

The appliance <NUM> may also include a power cord (not shown) for supplying AC power, converted to DC, to charge the battery, to supply power to operate the motor <NUM>, and/or to power other operational components of the appliance <NUM>. Thus, the appliance <NUM> may be selectively operated in a cordless mode, in which the battery pack <NUM> is electrically connected to the appliance <NUM>, and a corded mode, in which a power cord is electrically connected to the appliance <NUM> and supplies AC power to the appliance <NUM> (e.g., from a wall outlet). Other embodiments may be operated only from a battery or only from AC power.

<FIG> are various views of first and second battery packs <NUM>, <NUM> suitable for use as the battery pack <NUM> of <FIG>. <FIG> is a perspective view of the first battery pack <NUM>, <FIG> is another perspective view of the first battery pack <NUM>, <FIG> is a side view of the first battery pack <NUM>, <FIG> is an end view of a first end of the first battery pack <NUM>, and <FIG> is an end view of a second end of the first battery pack <NUM>. <FIG> is a perspective view of the second battery pack <NUM>, <FIG> is another perspective view of the second battery pack <NUM>, <FIG> is a side view of the second battery pack <NUM>, <FIG> is an end view of a first end of the second battery pack <NUM>, and <FIG> is an end view of a second end of the second battery pack <NUM>.

The first and second battery packs <NUM>, <NUM> are DC source batteries configured to supply direct current to the appliance <NUM>. The first and second battery packs <NUM>, <NUM> may have any suitable DC battery construction that enables the appliance <NUM> to function as described herein, including any of the DC battery constructions described above. Additionally, the first battery pack <NUM> and the second battery pack <NUM> may have any suitable output or operating voltage that enables the appliance <NUM> to function as described herein. In some embodiments, for example, the battery <NUM> has a DC output voltage of between <NUM> volts DC (VDC) and <NUM> VDC, between <NUM> VDC and <NUM> VDC, between <NUM> VDC and <NUM> VDC, between <NUM> VDC and <NUM> VDC, between <NUM> VDC and <NUM> VDC, between <NUM> VDC and <NUM> VDC, between <NUM> VDC and <NUM> VDC, between <NUM> VDC and <NUM> VDC, between <NUM> VDC and <NUM> VDC, between <NUM> VDC and <NUM> VDC, between <NUM> VDC and <NUM> VDC, between <NUM> VDC and <NUM> VDC, between <NUM> VDC and <NUM> VDC, between <NUM> VDC and <NUM> VDC, or between <NUM> VDC and <NUM> VDC. In the example embodiment, the first and second battery packs <NUM>, <NUM> have the same DC output voltage, although the first battery pack <NUM> and the second battery pack <NUM> may have different output voltages in other embodiments.

In the example embodiment, the second battery pack <NUM> has a greater power capacity (e.g., Amp-hours (Ah)) than the first battery pack <NUM> and, as shown in <FIG> and <FIG>, for example, has a generally larger profile (e.g., greater width) than the first battery pack <NUM> to accommodate additional components (e.g., battery cells) for a greater power capacity.

In some embodiments, the second battery pack <NUM> has a power capacity between <NUM> to <NUM> times greater than the first battery pack <NUM>. The first and second battery packs <NUM>, <NUM> may have any suitable power capacity that enables the appliance <NUM> to function as described herein. In one embodiment, the first battery pack has a power capacity of <NUM> Ah, and the second battery pack has a power capacity of <NUM> Ah. In another embodiment, the first battery pack has a power capacity of <NUM> Ah, and the second battery pack has a power capacity of <NUM> Ah. In another embodiment, the first battery pack has a power capacity in the range of <NUM> Ah to <NUM> Ah, and the second battery pack has a power capacity in the range of <NUM> Ah to <NUM> Ah.

As described further herein, the battery receptacle <NUM> of the appliance <NUM> is configured to accommodate and separately receive each of the first battery pack <NUM> and the second battery pack <NUM> such that battery packs with different power capacities and sizes can be used with the appliance <NUM>. Additionally, embodiments of the battery receptacle <NUM> and first and second battery packs <NUM>, <NUM> collectively form a battery pack connection system that facilitates insertion and connection of each of the first battery pack <NUM> and the second battery pack <NUM> into the battery receptacle <NUM>. Embodiments of the present disclosure facilitate "blind" insertion of battery packs into the battery receptacle <NUM> - i.e., inserting a battery pack into the battery receptacle <NUM> without looking or being able to see the battery pack or the battery receptacle <NUM>. This configuration is particularly suited for battery-powered appliances that are secured to a user's back, such as backpack vacuum cleaners, blowers, sprayers, etc., where a user is unable to see the battery receptacle while the appliance is secured to the user. Embodiments of the present disclosure thereby facilitate switching or exchanging battery packs without having to remove the appliance from the user's back, also referred to as "hot-swapping".

Referring to <FIG>, the first battery pack <NUM> includes a housing <NUM> extending longitudinally from a first end <NUM> to a second end <NUM>. The housing <NUM> includes a main body <NUM> and a handle <NUM> located at the first end <NUM> of the housing <NUM> end and extending from the main body <NUM> in a first direction, indicated by arrow <NUM> in <FIG>. The handle <NUM> defines an aperture <NUM> sized and shaped to receive one or more of a user's fingers therein to facilitate grasping and handling the first battery pack <NUM>.

The first battery pack <NUM> also includes an electrical connector <NUM> that is sized and shaped complementary to an electrical receptacle <NUM> (<FIG>) of the battery receptacle <NUM> such that the first battery pack <NUM> is mechanically and electrically connectable to the electrical receptacle <NUM> of the battery receptacle <NUM>. The electrical connector <NUM> includes a plurality of electrical contacts (not labeled in <FIG>) that connect to corresponding electrical contacts of the electrical receptacle <NUM> of the battery receptacle <NUM>. Suitable electrical contacts include, for example and without limitation, clips, clamps, pads, prongs, leads, and combinations thereof. The electrical contacts are electrically connected to at least one battery cell <NUM> (<FIG>) enclosed within an internal cavity <NUM> (<FIG>) defined by the first battery pack housing <NUM> to supply electrical power therefrom through the electrical contacts.

The first battery pack <NUM> also includes a plurality of guide sections to facilitate insertion and connection of the first battery pack <NUM> into the battery receptacle <NUM>. Specifically, in the illustrated embodiment, the first battery pack <NUM> includes a first guide slot <NUM>, a second guide slot <NUM>, and an electrical connector slot <NUM> that includes the electrical connector <NUM> at a terminal end thereof.

Each of the first guide slot <NUM>, the second guide slot <NUM>, and the electrical connector slot <NUM> extends longitudinally from the second end <NUM> of the first battery pack housing <NUM> towards the first end <NUM> of the first battery pack housing <NUM>, and terminates prior to the first end <NUM> of the first battery pack housing <NUM>. Each of the first guide slot <NUM>, the second guide slot <NUM>, and the electrical connector slot <NUM> is open at the second end of the first battery pack housing <NUM> to receive a corresponding rail of the battery receptacle <NUM> (described further herein). Additionally, each of the first guide slot <NUM>, the second guide slot <NUM>, and the electrical connector slot <NUM> is sized and shaped complementary to the corresponding rail of the battery receptacle <NUM> to facilitate engagement therewith.

The first guide slot <NUM> has a length L<NUM> extending in the longitudinal direction <NUM>, a width W<NUM> extending in a direction oriented perpendicular to the length L<NUM>, and a height H<NUM> extending in a direction oriented perpendicular to both the length L<NUM> and the width W<NUM>. The second guide slot <NUM> also has a length, a width, and a height, which are identical to the dimensions of the first guide slot <NUM> in the illustrated embodiment, and therefore not labeled. In other embodiments, one or more dimensions of the second guide slot <NUM> may be different from those of the first guide slot <NUM>.

The electrical connector slot <NUM> has a length L<NUM> extending in the longitudinal direction <NUM>, a width W<NUM> extending in a direction oriented perpendicular to the length L<NUM>, and a height H<NUM> extending in a direction oriented perpendicular to both the length L<NUM> and the width W<NUM>. In the illustrated embodiment, the electrical connector slot length L<NUM> is less than the length of each of the first guide slot <NUM> and the second guide slot <NUM>. As described further herein, the respective lengths of each slot is sized complementary to a corresponding rail of the battery receptacle <NUM>, and the longer length of the first and second guide rails facilitates engaging guide rails of the battery receptacle <NUM>, during insertion, with the first and second guide slots <NUM>, <NUM> prior to an electrical connection rail of the battery receptacle <NUM> engaging the electrical connector slot <NUM>.

The first battery pack housing <NUM> of the illustrated embodiment also includes a pair of opposing side rails <NUM> that extend laterally inwards into the electrical connector slot <NUM>. The side rails <NUM> are sized and shaped complementary to corresponding slots of the battery receptacle <NUM> to facilitate securing the first battery pack housing <NUM> within the battery receptacle <NUM>.

As shown in <FIG>, the first battery pack <NUM> of the illustrated embodiment has a generally rectangular or pseudo-rectangular cross-section within a plane oriented perpendicular to the longitudinal direction <NUM>. The first battery pack housing <NUM> includes a first side <NUM>, an opposing second side <NUM>, a third side <NUM> (also referred to as a "top" of the housing <NUM>) extending between the first side <NUM> and the second side <NUM>, and a fourth side <NUM> (also referred to as a "bottom" of the housing <NUM>) opposite the top <NUM> and extending between the first side <NUM> and the second side <NUM>. The top <NUM> and bottom <NUM> are oriented generally parallel to one another and perpendicular to each of the first side <NUM> and the second side <NUM>.

In the illustrated embodiment, the first guide slot <NUM> is defined along the top <NUM> of the housing <NUM>, the second guide slot <NUM> is defined along the bottom <NUM> of the housing <NUM>, and the electrical connector slot <NUM> is defined along the first side <NUM> of the housing <NUM>. In other embodiments, the first guide slot <NUM>, the second guide slot <NUM>, and the electrical connector slot <NUM> may be located at any suitable position on the first battery pack housing <NUM> that enables the first battery pack <NUM> to function as described herein.

The second battery pack <NUM> has a configuration substantially similar to that of the first battery pack <NUM>, except the second battery pack <NUM> has a greater capacity and generally larger profile (e.g., a greater width) than the first battery pack <NUM>, as noted above.

In particular, the second battery pack <NUM> includes a housing <NUM> extending longitudinally from a first end <NUM> to a second end <NUM>. The housing <NUM> includes a main body <NUM> and a handle <NUM> located at the first end <NUM> of the housing <NUM> end and extending from the main body <NUM> in a first direction, indicated by arrow <NUM> in <FIG>. The handle <NUM> defines an aperture <NUM> sized and shaped to receive one or more of a user's fingers therein to facilitate grasping and handling the second battery pack <NUM>.

The second battery pack <NUM> also includes an electrical connector <NUM> that is sized and shaped complementary to the electrical receptacle <NUM> (<FIG>) of the battery receptacle <NUM> such that the second battery pack <NUM> is mechanically and electrically connectable to the electrical receptacle <NUM> of the battery receptacle <NUM>. The electrical connector <NUM> includes a plurality of electrical contacts (not labeled in <FIG>) that connect to corresponding electrical contacts of the electrical receptacle <NUM> of the battery receptacle <NUM>. Suitable electrical contacts include, for example and without limitation, clips, clamps, pads, prongs, leads, and combinations thereof. The electrical contacts are electrically connected to at least one battery cell enclosed within an internal cavity (not shown in <FIG>) defined by the second battery pack housing <NUM> to supply electrical power therefrom through the electrical contacts.

The second battery pack <NUM> also includes a plurality of guide sections to facilitate insertion and connection of the second battery pack <NUM> into the battery receptacle <NUM>. Specifically, in the illustrated embodiment, the second battery pack <NUM> includes a first guide slot <NUM>, a second guide slot <NUM>, and an electrical connector slot <NUM> that includes the electrical connector <NUM> at a terminal end thereof.

Each of the first guide slot <NUM>, the second guide slot <NUM>, and the electrical connector slot <NUM> extends longitudinally from the second end <NUM> of the second battery pack housing <NUM> towards the first end <NUM> of the second battery pack housing <NUM>, and terminates prior to the first end <NUM> of the second battery pack housing <NUM>. Each of the first guide slot <NUM>, the second guide slot <NUM>, and the electrical connector slot <NUM> is open at the second end <NUM> of the second battery pack housing <NUM> to receive a corresponding rail of the battery receptacle <NUM> (described further herein). Additionally, each of the first guide slot <NUM>, the second guide slot <NUM>, and the electrical connector slot <NUM> is sized and shaped complementary to the corresponding rail of the battery receptacle <NUM> to facilitate engagement therewith.

In some embodiments, such as the embodiments illustrated in <FIG>, the width W<NUM> of the guide slots <NUM>, <NUM> on second battery pack <NUM> may be greater than width W<NUM> of the guide slots <NUM>, <NUM> on the first battery pack <NUM>. For example, where the second battery pack <NUM> substantially fills or occupies the battery receptacle <NUM>, the guide slots <NUM>, <NUM> of second battery pack <NUM> may be wider to provide more play or tolerance to make insertion of the second battery pack <NUM> easier because the size and shape of the battery receptacle <NUM> will have a natural tendency to align the second battery pack <NUM> with the battery receptacle <NUM>. The narrower guide slots <NUM>, <NUM> of the smaller first battery pack <NUM> ensure proper alignment and prevent or inhibit movement, shifting, and/or misalignment of the first battery pack <NUM> in a direction perpendicular to the insertion direction.

The electrical connector slot <NUM> of the second battery pack <NUM> has a length L<NUM> extending in the longitudinal direction <NUM>, a width W<NUM> extending in a direction oriented perpendicular to the length L<NUM>, and a height H<NUM> extending in a direction oriented perpendicular to both the length L<NUM> and the width W<NUM>. In the illustrated embodiment, the electrical connector slot length L<NUM> is less than the length of each of the first guide slot <NUM> and the second guide slot <NUM>. As described further herein, the respective lengths of each slot is sized complementary to a corresponding rail of the battery receptacle <NUM>, and the longer length of the first and second guide slots <NUM>, <NUM> facilitates engaging guide rails of the battery receptacle <NUM>, during insertion, with the first and second guide slots <NUM>, <NUM> prior to an electrical connection rail of the battery receptacle <NUM> engaging the electrical connector slot <NUM>.

The second battery pack housing <NUM> of the illustrated embodiment also includes a pair of opposing side rails <NUM> that extend laterally inwards into the electrical connector slot <NUM>. The side rails <NUM> are sized and shaped complementary to corresponding slots of the battery receptacle to facilitate securing the second battery pack housing <NUM> within the battery receptacle <NUM>.

As shown in <FIG>, the second battery pack <NUM> of the illustrated embodiment has a generally rectangular or pseudo-rectangular cross-section within a plane oriented perpendicular to the longitudinal direction <NUM>. The second battery pack housing <NUM> includes a first side <NUM>, an opposing second side <NUM>, a third side <NUM> (also referred to as a "top" of the housing <NUM>) extending between the first side <NUM> and the second side <NUM>, and a fourth side <NUM> (also referred to as a "bottom" of the housing <NUM>) opposite the top <NUM> and extending between the first side <NUM> and the second side <NUM>. The top <NUM> and bottom <NUM> are oriented generally parallel to one another and perpendicular to each of the first side <NUM> and the second side <NUM>.

In the illustrated embodiment, the first guide slot <NUM> is defined along the top <NUM> of the housing <NUM>, the second guide slot <NUM> is defined along the bottom <NUM> of the housing <NUM>, and the electrical connector slot <NUM> is defined along the first side <NUM> of the housing <NUM>. In other embodiments, the first guide slot <NUM>, the second guide slot <NUM>, and the electrical connector slot <NUM> may be located at any suitable position on the second battery pack housing <NUM> that enables the second battery pack <NUM> to function as described herein.

With reference to <FIG> and <FIG>, the first battery pack <NUM> has a width W<NUM> measured from the first side <NUM> to the second side <NUM>, and the second battery pack <NUM> has a width W<NUM> measured from the first side <NUM> to the second side <NUM>. The second battery pack width W<NUM> is greater than the first battery pack width W<NUM> in the illustrated embodiment because the second battery pack <NUM> has a greater power capacity (and therefore larger and/or a greater number of battery cells) than the first battery pack <NUM>. The battery receptacle <NUM> is sized and shaped to separately receive each of the first battery pack <NUM> and the generally larger second battery pack <NUM>.

The first and second battery packs <NUM>, <NUM> have a common cross-sectional profile in a plane oriented perpendicular to the longitudinal direction, as shown in <FIG> and <FIG>. The common cross-sectional profile of the first and second battery packs <NUM>, <NUM> is shaped complementary to a portion of the battery receptacle <NUM> (e.g., a keyed section <NUM> of the battery receptacle <NUM>, described further herein) to facilitate alignment and insertion of each of the first and second battery packs <NUM>, <NUM> into the battery receptacle <NUM>.

The first and second battery packs <NUM>, <NUM> can include other features to facilitate connecting and disconnecting the first and second battery packs <NUM>, <NUM> from the battery receptacle <NUM>. As illustrated in <FIG>, for example, the second battery pack <NUM> of the illustrated embodiment includes a keyed lockout feature <NUM>, a latch-receiving slot <NUM>, and ejector pins <NUM> (one visible in <FIG>).

The keyed lockout feature <NUM> is sized and shaped complementary to a corresponding keyed feature (not shown) of the battery receptacle <NUM> to permit only certain battery packs to connect to the battery receptacle <NUM>. In some embodiments, for example, the appliance <NUM> may require a battery with certain characteristics (e.g., a certain battery voltage or ampacity) for proper operation. In such embodiments, battery packs that have the required characteristics can include the keyed lockout feature <NUM> such that the battery packs can be inserted into and connected to the receptacle <NUM>. Battery packs that do not include the keyed lockout feature <NUM> will be prevented from being fully inserted into and connected to the receptacle <NUM> because the keyed feature of the receptacle <NUM> will engage the housing of the battery pack and inhibit full insertion of the battery pack. In the illustrated embodiment, the keyed lockout feature <NUM> is a rectangular notch or recess defined in the housing <NUM> at the second end <NUM> of the housing <NUM> adjacent the electrical connector slot <NUM>. In other embodiments, the keyed lockout feature can have any other suitable size, shape, configuration, and position that enables the battery packs to function as described herein. Moreover, although only the second battery pack <NUM> is illustrated with the keyed lockout feature <NUM>, the first battery pack <NUM> may also include a keyed lockout feature <NUM>.

The latch-receiving slot <NUM> is sized, shaped, and positioned to receive a depressible latch <NUM> (shown in <FIG> and <FIG>) of the battery receptacle <NUM> to retain the battery pack <NUM> within the battery receptacle <NUM>. The latch-receiving slot <NUM> is positioned on the same side of the battery pack <NUM> as the electrical connector slot <NUM> in the illustrated embodiment, although in other embodiments the latch-receiving slot <NUM> may be positioned at any suitable location on the battery pack <NUM> that enables the battery pack <NUM> to function as described herein. The latch-receiving slot <NUM> is generally sized and shaped to cooperatively engage the latch <NUM> of the battery receptacle <NUM> to prevent the battery pack <NUM> from being removed from the battery receptacle <NUM> without the latch <NUM> being first disengaged. The latch-receiving slot <NUM> of the example embodiment is rectangular, although the latch-receiving slot <NUM> can have any other suitable shape that enables the battery pack <NUM> to function as described herein, including, for example and without limitation, square, triangular, polygonal, round, elliptical, or circular.

The ejector pins <NUM> are configured to facilitate removal of the battery pack <NUM> from the battery receptacle <NUM>. More specifically, the ejector pins <NUM> bias or urge the battery pack <NUM> out of the battery receptacle <NUM> when the battery pack <NUM> is connected to the battery receptacle <NUM> such that, when the latch <NUM> is disengaged from the battery pack <NUM>, the ejector pins <NUM> force or urge the battery pack <NUM> out of the battery receptacle <NUM> so less force is required from a user to remove the battery pack <NUM> from the battery receptacle <NUM>.

Each ejector pin <NUM> of the example embodiment is a spring-loaded pin that is biased towards a first or undepressed position (shown in <FIG>) by a spring (not shown) compressed between the ejector pin <NUM> and a portion of the battery pack housing <NUM>. The ejector pins <NUM> are positioned to engage a portion of the battery receptacle <NUM>, when the battery pack <NUM> is connected to the battery receptacle <NUM>, that causes the ejector pins <NUM> to be depressed to a second or depressed position (not shown). In this position, the ejector pins <NUM> engage and press against a portion of the battery receptacle <NUM> to bias or urge the battery pack <NUM> out of the battery receptacle <NUM>. The force exerted by the ejector pins <NUM> on the battery receptacle <NUM> reduces the amount of user-applied force needed to remove the battery pack from the battery receptacle <NUM> when the latch <NUM> is disengaged from the battery pack <NUM>. In some embodiments, the force from the ejector pins <NUM> can be sufficient to advance the battery pack <NUM> at least partially out of the battery receptacle <NUM> when the latch <NUM> is disengaged from the battery pack <NUM>.

In the illustrated embodiment, the battery pack <NUM> includes two ejector pins <NUM> located on opposite sides of the electrical connector slot <NUM>. In other embodiments, the battery pack <NUM> can include more than or less than two ejector pins <NUM>, and the ejector pins <NUM> can be located at any other suitable location on the battery pack <NUM> that enables the battery pack <NUM> to function as described herein.

The first battery pack <NUM> can include the same or similar latch-receiving slot <NUM> and ejector pins <NUM> as the second battery pack <NUM> as shown, for example, in <FIG> and <FIG>.

Referring again to <FIG>, the battery receptacle <NUM> of the illustrated embodiment is located at a bottom or base of the appliance housing <NUM>, though it should be understood that the battery receptacle <NUM> may be located at any suitable portion of the appliance housing <NUM> that enables the appliance <NUM> to function as described herein. Further, in the example embodiment, the battery receptacle <NUM> is oriented to receive a battery pack (e.g., first battery pack <NUM> and second battery pack <NUM>), when positioned on a user's back, in an insertion direction from right to left, as indicated by arrow <NUM> in <FIG>. In other embodiments, the battery receptacle <NUM> may be configured to receive a battery pack in any suitable direction that enables the appliance <NUM> to function as described herein.

<FIG> is a perspective view of the battery receptacle <NUM> of <FIG>, illustrating the first battery pack <NUM> being inserted into the battery receptacle <NUM>. <FIG> is another perspective view of the battery receptacle <NUM>, <FIG> is an end view of the battery receptacle <NUM> from an insertion end of the battery receptacle <NUM>, <FIG> is an end view of the battery receptacle <NUM> from a terminal end of the battery receptacle <NUM>, and <FIG> is a side view of the battery receptacle <NUM>.

The battery receptacle <NUM> includes an electrical receptacle <NUM> that electrically connects to the electrical connector <NUM>, <NUM> of each of the first and second battery packs <NUM>, <NUM>. The electrical receptacle <NUM> includes a plurality of electrical contacts (not shown in <FIG>) that connect to corresponding electrical contacts of the electrical connectors <NUM>, <NUM> of the first and second battery packs <NUM>, <NUM>. Suitable electrical contacts include, for example and without limitation, clips, clamps, pads, prongs, leads, and combinations thereof. The electrical contacts of the electrical receptacle <NUM> are electrically connected, directly or indirectly, to an electrical load of the appliance <NUM> (e.g., motor <NUM>, controller <NUM>) to supply electrical power from one of the first and second battery packs <NUM>, <NUM>.

As illustrated in <FIG>, the battery receptacle <NUM> defines an elongate passage <NUM> that extends longitudinally from an insertion end <NUM> to a terminal end <NUM>. The battery receptacle <NUM> defines an insertion opening <NUM> at the insertion end <NUM>, and a terminal opening <NUM> at the terminal end <NUM>. The elongate passage <NUM> is sized and shaped to separately receive each of the first and second battery packs <NUM>, <NUM> therein. For example, the battery receptacle <NUM> includes a keyed section <NUM> having a cross-sectional profile shaped complementary to the common cross-sectional profile (e.g., pseudo-rectangular) of the first and second battery packs <NUM>, <NUM>. Additionally, the battery receptacle <NUM> includes a reserve section <NUM> that is sized and shaped to receive or accommodate a portion <NUM> (e.g., a widthwise extension) of the second battery pack <NUM> therein, indicated by broken lines in <FIG>. Thus, the reserve section <NUM> of the battery receptacle <NUM> is unoccupied by the first battery pack <NUM> when the first battery pack <NUM> is connected to the electrical receptacle <NUM>, as shown in <FIG>, and is occupied by a portion of the second battery pack <NUM> (e.g., a widthwise extension <NUM>) when the second battery pack <NUM> is connected to the electrical receptacle <NUM>.

The battery receptacle <NUM> also includes a plurality of guide sections that cooperatively engage the guide sections of the first and second battery packs <NUM>, <NUM> to facilitate insertion of the first and second battery packs <NUM>, <NUM> into the elongate passage <NUM>.

Specifically, the battery receptacle <NUM> includes a first guide rail <NUM>, a second guide rail <NUM>, and an electrical connector rail <NUM>. The electrical connector rail <NUM> extends longitudinally within the elongate passage <NUM> and includes the electrical receptacle <NUM>. The electrical connector rail <NUM> is sized and shaped complementary to the electrical connector slots <NUM>, <NUM> of the first and second battery packs <NUM>, <NUM> such that the electrical connector rail <NUM> is insertable into each of the electrical connector slots <NUM>, <NUM>. The first guide rail <NUM> extends longitudinally within the passage <NUM>, and is sized and shaped to cooperatively engage the first guide slots <NUM>, <NUM> of each of the first and second battery packs <NUM>, <NUM>. The second guide rail <NUM> extends longitudinally within the passage <NUM>, and is sized and shaped to cooperatively engage the second guide slots <NUM>, <NUM> of each of the first and second battery packs <NUM>, <NUM>. In the example embodiment, the second guide rail <NUM> is positioned generally opposite the first guide rail <NUM> within the elongate passage <NUM>, although the first and second guide rails <NUM>, <NUM> may have any suitable relative positioning that enables the appliance <NUM> to function as described herein.

In the illustrated embodiment, each of the first and second guide rails <NUM>, <NUM> is positioned closer to the insertion opening <NUM> than the electrical connector rail <NUM>. As a result, the first and second guide rails <NUM>, <NUM> engage the first and second battery packs <NUM>, <NUM> (specifically, the first guide slots <NUM>, <NUM> and the second guide slots <NUM>, <NUM>) before the electrical connector rail <NUM> engages the electrical connector slots <NUM>, <NUM>. Additionally, as illustrated in <FIG>, the elongate passage <NUM> is outwardly flared at the insertion end <NUM>. The outward flare of the elongate passage <NUM> facilitates insertion of the first and second battery packs <NUM>, <NUM> by permitting a certain degree of misalignment as the battery pack (e.g., first battery pack <NUM>) is initially inserted into the elongate passage <NUM>. As the battery pack is inserted, the flared shape of the elongate passage <NUM> will gradually align the battery pack with the elongate passage <NUM> such that the first and second guide rails <NUM>, <NUM> of the battery receptacle <NUM> will be aligned with corresponding guide slots of the battery pack.

As illustrated in <FIG>, the battery receptacle <NUM> of the illustrated embodiment has a generally rectangular or pseudo-rectangular cross-section within a plane oriented perpendicular to the insertion direction <NUM>. The battery receptacle <NUM> includes a first wall <NUM> (also referred to as a "top" of the battery receptacle <NUM>), a second wall <NUM> (also referred to as a "bottom" of the battery receptacle <NUM>) positioned opposite the first wall <NUM>, a first side wall <NUM> extending between the first wall <NUM> and the second wall <NUM>, and a second side wall <NUM> positioned opposite the first side wall <NUM> and extending between the first wall <NUM> and the second wall <NUM>. The top <NUM> and bottom <NUM> are oriented generally parallel to one another and perpendicular to each of the first side wall <NUM> and the second side wall <NUM>. The electrical connector rail <NUM> protrudes from the first side wall <NUM>, the first guide rail <NUM> protrudes from the first wall <NUM>, and the second guide rail <NUM> protrudes from the opposing second wall <NUM>. In other embodiments, the first guide rail <NUM>, the second guide rail <NUM>, and the electrical connector rail <NUM> may be located at any suitable location within the battery receptacle <NUM> that enables the appliance <NUM> to function as described herein.

With reference to <FIG>, in operation, the first battery pack <NUM> is inserted into the elongate passage <NUM> of the battery receptacle <NUM> by positioning the second end <NUM> of the first battery pack <NUM> adjacent the insertion end <NUM> (e.g., within the insertion opening <NUM>) of the battery receptacle <NUM>. The user may grasp the first battery pack <NUM> by grabbing the first battery pack handle <NUM> to facilitate insertion of the first battery pack <NUM> into the battery receptacle <NUM>. The first battery pack <NUM> is then moved in the insertion direction <NUM> until the first and second guide rails <NUM>, <NUM> engage the first and second guide slots <NUM>, <NUM> of the first battery pack <NUM>. Engagement between the first and second guide rails <NUM>, <NUM> and the first and second guide slots <NUM>, <NUM> will align the first battery pack <NUM> within the elongate passage <NUM> both vertically and horizontally such that the electrical connector slot <NUM> of the first battery pack <NUM> is aligned with the electrical connector rail <NUM> of the battery receptacle <NUM>. Continued insertion of the first battery pack <NUM> in the insertion direction <NUM> will cause the electrical connector rail <NUM> to engage the electrical connector slot <NUM> of the first battery pack <NUM> to align the electrical connector <NUM> of the first battery pack <NUM> with the electrical receptacle <NUM> of the battery receptacle <NUM>. The first battery pack <NUM> is further inserted into the battery receptacle <NUM> until the electrical connector <NUM> of the first battery pack <NUM> engages and connects to the electrical receptacle <NUM>. The second battery pack <NUM> may be inserted into the battery receptacle <NUM> in a similar manner (e.g., after the first battery pack <NUM> is removed from the battery receptacle <NUM>).

In some embodiments, a battery pack may be inserted into and connected to the battery receptacle <NUM> while the appliance <NUM> is positioned on a user's back. For example, during use (i.e., while the appliance <NUM> is positioned on a user's back), a user may need to exchange a depleted battery pack (e.g., the first battery pack <NUM>) with another, charged battery pack (e.g., the second battery pack <NUM>). To do so, the user may first remove the first battery pack <NUM> from the battery receptacle <NUM> while the appliance <NUM> is on the user's back, and subsequently insert the second battery pack <NUM> into the battery receptacle <NUM> while the battery-powered appliance is on the user's back. To insert the second battery pack <NUM> into the battery receptacle <NUM>, the user may initially engage one or both of the first and second guide slots <NUM>, <NUM> of the second battery pack <NUM> with one or both of the first and second guide rails <NUM>, <NUM> of the battery receptacle <NUM> and, subsequently, engage the electrical connector slot <NUM> of the second battery pack <NUM> with the electrical connector rail <NUM> of the battery receptacle <NUM>. The user may then continue inserting the second battery pack <NUM> in the insertion direction <NUM> into the battery receptacle <NUM> until the electrical connector <NUM> of the second battery pack <NUM> engages and connects to the electrical receptacle <NUM> of the battery receptacle <NUM>.

As described above, the battery receptacle <NUM> of the present disclosure provides multiple rails to facilitate insertion and connection of different sized battery packs therein. In particular, the battery receptacle <NUM> includes a dual-rail locking system having two different types of rails - an electrical connector rail <NUM> and guide rails <NUM>, <NUM>. The electrical connector rail <NUM> guides the battery pack into electrical connectors within the battery receptacle <NUM>, and the secondary guide rails <NUM>, <NUM> facilitate guiding the battery pack blindly, as well as facilitate installation of different sized battery packs within the same size battery receptacle <NUM>.

The dual-rail system allows battery packs of different physical sizes to be installed in a common passage or aperture (e.g., elongate passage <NUM>) on a product or tool (e.g., appliance <NUM>). The guide rails <NUM>, <NUM> provide guidance for smaller battery packs installed in the battery receptacle <NUM> that do not occupy the entire width or space of the battery receptacle passage, and guide or lead the smaller battery packs into the electrical connection rail system to facilitate connection of the smaller battery pack to the electrical receptacle <NUM> of the battery receptacle <NUM>. Additionally, the use of two guide rails (e.g., guide rails <NUM>, <NUM>) provides additional strength to the connection between the battery receptacle <NUM> and the battery packs <NUM>, <NUM> as compared to rail systems that include a single guide rail or no guide rails.

Referring again to <FIG> and <FIG>, the first and second battery packs <NUM>, <NUM> of the illustrated embodiment each include a respective gauge <NUM>, <NUM> located on the handle <NUM>, <NUM>, respectively. The gauges <NUM>, <NUM> are generally configured to indicate a charge level of the respective battery pack <NUM>, <NUM>. While only the first battery pack gauge <NUM> is described below in detail, it should be understood that the second battery pack gauge <NUM> may have the same or similar construction as the first battery pack gauge <NUM> and operate in the same or similar manner as the first battery pack gauge <NUM>.

The gauge <NUM> of the first battery pack <NUM> is located on an outer surface <NUM> of the handle <NUM> (i.e., a surface positioned opposite and facing away from the aperture <NUM>) so that the gauge <NUM> is readily viewable by a user of the first battery pack <NUM>. The gauge <NUM> includes a plurality of lights <NUM> that are illuminated based on a charge level of the first battery pack <NUM>.

The gauge <NUM> of the illustrated embodiment includes <NUM> lights, although it should be understood that the gauge <NUM> may include any suitable number of lights that enables the gauge to function as described herein, including greater than or less than <NUM> lights. Additionally, in the illustrated embodiment, the lights <NUM> are light emitting diodes covered by a suitable cover (e.g., a light diffusing cover), though it should be understood that the lights <NUM> may include any suitable light emitting device that enables the gauge <NUM> to function as described herein. Moreover, while the gauge <NUM> in the example embodiment is described as illuminating a number of the plurality of lights <NUM> that corresponds to a charge level of the first battery pack <NUM>, it should be understood that the gauge <NUM> may use different modes of illumination to indicate a charge level. In some embodiments, for example, the gauge <NUM> can include a single light <NUM> that is illuminated upon activation of the actuator <NUM> to indicate a charge level of the battery pack <NUM>. The single light <NUM> can be illuminated, for example, for a number of pulses or a duration of time that corresponds to a charge level of the battery pack (e.g., <NUM> pulses to indicate a charge level greater than <NUM>%, <NUM> pulses to indicate a charge level between <NUM>% and <NUM>%, <NUM> pulses to indicate a charge level between <NUM>% and <NUM>%, and <NUM> pulse to indicate a charge level between <NUM>% and <NUM>%). Additionally or alternatively, the single light <NUM> can be illuminated different colors to indicate a state of charge. For example, the single light <NUM> can illuminate green to indicate a fully charged battery pack (e.g., greater than <NUM>%), yellow to indicate a medium state of charge of the battery back (e.g., between <NUM>% and <NUM>%), and red to indicate a low state of charge (e.g., less than <NUM>%).

With additional reference to <FIG>, the gauge <NUM> is electrically connected to a printed circuit board assembly (PCBA) <NUM> enclosed within an internal cavity <NUM> defined by the first battery pack housing <NUM> by one or more electrical conduits <NUM>. A portion of the first battery pack housing <NUM> is omitted from <FIG> to illustrate internal features of the first battery pack <NUM>. The PCBA <NUM> may be implemented as and/or include components of the controller <NUM>. Battery cells <NUM> of the first battery pack <NUM> are also enclosed within the internal cavity <NUM>. The PCBA <NUM> is electrically connected to the battery cells <NUM> to receive electrical power therefrom and/or control the supply of electrical power therefrom.

The gauge <NUM> is configured to illuminate a number of the plurality of lights <NUM> that corresponds to a charge level of the first battery pack <NUM> (specifically, a charge level of the battery cells <NUM>). For example, if a charge level of the battery cells <NUM> is at or near <NUM>% (e.g., greater than <NUM>%) all of the lights <NUM> (i.e., four lights) are illuminated when the gauge <NUM> is activated. When the charge level of the battery cells <NUM> is at or near <NUM>% (e.g., between <NUM>% and <NUM>%), only half of the lights <NUM> (i.e., two lights) are illuminated. In one particular embodiment, the gauge <NUM> is configured to illuminate a number of the plurality of lights <NUM> according to the following table:.

In the illustrated embodiment, the gauge <NUM> is activated by actuation of an actuator <NUM> attached to the first battery pack housing <NUM>, specifically on the handle <NUM>. In the illustrated embodiment, the actuator <NUM> is a depressible button, although it should be understood that the actuator <NUM> may include any suitable actuator that enables the gauge <NUM> to function as described herein. The button and the plurality of lights <NUM> are arranged linearly along the handle <NUM> in the illustrated embodiment, specifically along the outer surface <NUM> of the handle <NUM>.

Actuation of the actuator <NUM> activates the gauge <NUM> to illuminate a number of the plurality of lights <NUM> that corresponds to the charge level of the at battery cells <NUM>.

Additionally or alternatively, the gauge <NUM> may be activated based on detected motion or movement of the first battery pack <NUM>. For example, the first battery pack <NUM> may include an accelerometer that detects motion (e.g., when the battery pack is picked up), and automatically activates the gauge <NUM> based on the detected motion.

The gauge <NUM> illustrated in <FIG> and <FIG> is visible primarily from a viewing direction that is parallel to and opposite the direction in which the handle <NUM> extends from the main body <NUM> (i.e., the first direction <NUM>). In other embodiments, the gauge <NUM> may be visible from multiple orthogonal directions to facilitate visibility of the gauge <NUM>. <FIG>, for example, illustrate a gauge <NUM> that is visible from a first viewing direction <NUM> that is parallel to and opposite the direction in which the handle <NUM> extends from the main body <NUM> (i.e., a first direction), a second viewing direction <NUM> orthogonal to the first viewing direction <NUM>, and a third viewing direction <NUM> that is parallel to and opposite the second viewing direction <NUM>. In particular, in the embodiment illustrated in <FIG>, each light <NUM> extends or wraps around the handle <NUM> such that a first portion of each light <NUM> is visible from the second viewing direction <NUM> and a second portion of each light <NUM> is visible from the third viewing direction <NUM>. As a result, the gauge <NUM> can be viewed from multiple (e.g., three) orthogonal viewing directions to facilitate visibility of the gauge <NUM>.

When introducing elements of the present disclosure or the embodiment(s) thereof, the articles "a", "an", "the" and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," "containing" and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements. The use of terms indicating a particular orientation (e.g., "top", "bottom", "side", etc.) is for convenience of description and does not require any particular orientation of the item described.

Claim 1:
A battery pack (<NUM>) comprising:
a housing (<NUM>) having a main body (<NUM>) and a handle (<NUM>) extending from the main body, the handle defining an aperture (<NUM>) sized and shaped to receive one or more of a user's fingers therein;
at least one battery cell (<NUM>) enclosed within the housing;
a printed circuit board (PCBA) (<NUM>) enclosed within the housing;
a gauge (<NUM>) located on an outer surface (<NUM>) of the handle and electrically connected to the PCBA, wherein the gauge includes at least one light (<NUM>); and
an actuator (<NUM>) attached to the handle, wherein actuation of the actuator activates the gauge to illuminate the at least one light to indicate a charge level of the at least one battery cell.