Battery pack with integrated battery charger

Abstract

A battery pack includes a battery housing defining an interior cavity, a first positive terminal extending through the housing, a first negative terminal extending through the housing, a plurality of battery cells located within the interior cavity, and a battery charger located within the interior cavity. The plurality of battery cells are electrically connected with the first positive terminal and the first negative terminal. The battery charger is configured to charge a plurality of battery cells and includes a second positive terminal electrically connected with the first positive terminal within the housing and a second negative terminal electrically connected with the first negative terminal within the housing.

Description

Background Art

[0001] Battery packs may be used in a variety of equipment, including outdoor power equipment, vehicles, aerial man lifts, grounds care equipment, golf carts, forklifts and other industrial vehicles, grounds care equipment, recreational utility vehicles, industrial utility vehicles, lawn and garden equipment, and energy storage or battery backup systems. Outdoor power equipment includes lawn mowers, riding tractors, snow blowers, pressure washers, portable generators, cultivators, wood splitters, zero turn radius mowers, push mowers, riding mowers, and lawn equipment such as spreaders, sprayers, seeders, rakes, and blowers. For example, outdoor power equipment may use one or more electric motors to drive implements, such as the rotary blades of a lawn mower, the pump of a pressure washer, the auger of a snow blower, the alternator, and / or the drive train of the outdoor power equipment. Summary of the invention

[0002] At least one embodiment is directed to a battery pack including a battery housing defining an internal cavity, a first positive terminal extending through the housing, a first negative terminal extending through the housing, a plurality of battery cells within the internal cavity, and a battery charger within the internal cavity. The plurality of battery cells are electrically connected to the first positive terminal and the first negative terminal. The battery charger is configured to charge the plurality of battery cells and includes a second positive terminal within the housing electrically connected to the first positive terminal, and a second negative terminal within the housing electrically connected to the first negative terminal.

[0003] Another embodiment relates to a battery pack, comprising a battery housing defining an internal cavity, a first positive terminal, a first negative terminal, a plurality of battery cells located in the internal cavity, a temperature sensor mounted on the housing or the plurality of battery cells, and a battery charger located in the internal cavity. The plurality of battery cells are electrically connected to the first positive terminal and the first negative terminal. The battery charger is configured to dissipate energy to the housing when a temperature measurement value of the temperature sensor is below a threshold.

[0004] Another embodiment relates to outdoor power equipment, the equipment including a frame, a prime mover, wheels connected to the frame, and a rechargeable battery pack supported on the frame and configured to power the prime mover. The rechargeable battery pack includes a battery housing defining an internal cavity, a first positive terminal, a first negative terminal, a plurality of battery cells located in the internal cavity, and a battery charger located in the internal cavity. The plurality of battery cells are electrically connected to the first positive terminal and the first negative terminal. The battery charger is configured to charge the plurality of battery cells and includes a second positive terminal in the housing electrically connected to the first positive terminal and a second negative terminal in the housing electrically connected to the first negative terminal.

[0005] This summary is intended to be illustrative only and is not intended to be limiting in any way. Other aspects, novel features, and advantages of the devices or methods described herein will become apparent from the detailed description taken in conjunction with the accompanying drawings, in which like reference numerals refer to like elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The present disclosure will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which like reference numerals refer to like elements, and in which:

[0007] Figure 1 is a perspective view of a lawn mower according to some embodiments;

[0008] Figure 2 is a perspective view of a battery pack according to some embodiments;

[0009] Figure 3 yes Figure 2 a top front perspective view of a cross section of the battery pack shown, showing the battery module assembly (CMA) and charger;

[0010] Figure 4 yes Figure 2 A top front perspective view of a cross section of a battery pack is shown with the battery module assembly hidden;

[0011] Figure 5 yes Figure 4 a side and top perspective view of a cross section of the battery pack shown;

[0012] Figure 6 yes Figure 2 a perspective view of the base and charger of the illustrated battery pack;

[0013] Figure 7 yes Figure 2 a perspective view of the base, charger and frame of the battery pack shown;

[0014] Figure 8 yes Figure 2 A perspective view of the battery pack shown with the frame removed;

[0015] Fig. 9 According to some embodiments Figure 2 A block diagram of the energy balance of the battery pack shown;

[0016] Fig.10 yes Figure 2 a perspective view of the CMA of the illustrated battery pack;

[0017] Fig.11 yes Fig.10 A front view of the CMA shown;

[0018] Fig.12 yes Fig.10 A side view of the CMA shown;

[0019] Fig.13 is a perspective view of a battery pack according to some embodiments;

[0020] Fig.14 yes Fig.13 a front upper perspective view of a cross section of the battery pack shown, showing the CMA and charger;

[0021] Fig.15 yes Fig.13 A top front perspective view of a cross section of a battery pack shown with the housing hidden;

[0022] Fig.16 yes Fig.13 a side view of the CMA of the battery pack shown;

[0023] Fig.17 yes Fig.13 A top front perspective view of a cross section of the battery pack is shown with the CMA hidden;

[0024] Fig.18 yes Fig.13 a perspective view of the base and charger of the illustrated battery pack; and

[0025] Fig.19 yes Figure 2 or Fig.13 Schematic diagram of the battery management system of the battery pack shown. DETAILED DESCRIPTION

[0026] Before turning to the drawings, which specifically show some exemplary embodiments, it should be understood that the present disclosure is not limited to the details or methods described herein or shown in the drawings. At the same time, it should be understood that the terms used herein are only for descriptive purposes and should not be regarded as limiting.

[0027] Generally referring to the accompanying drawings, systems and methods for battery packs with integrated battery chargers are described herein. Certain battery packs (e.g., rechargeable battery packs) can receive charging from a dedicated charger (e.g., charger, battery charger, etc.) that is electrically connected to and configured to charge them. Conventional rechargeable battery packs typically receive charging power from a battery charger that is remote from the battery pack. In outdoor power equipment applications, there are typically several outdoor power equipment with different battery packs and different associated chargers. Therefore, the operator needs to correctly connect the battery pack to its associated charger, which presents the possibility of operator error (e.g., using an incompatible charger, using improper wiring, connecting the wrong wires or wiring in the wrong order, etc.).

[0028] During operation, a battery charger typically generates heat and dissipates that heat directly into the surrounding environment. Advantageously, the systems and methods described herein provide a battery pack with an integrated battery charger. The integrated battery charger simplifies the charging operation of the battery pack by eliminating the need for an operator to select a specific charger associated with the battery pack. In addition, the integrated charger can be used to selectively heat the interior of the battery pack under predefined operating conditions. Zero Turn Radius Mower

[0029] Reference Figure 1 , the outdoor power equipment is shown as a lawn mower 10. As shown, the lawn mower 10 is a zero turn radius riding lawn mower (ZTR). Although described in the context of a lawn mower 10, the battery pack and integrated battery charger system and method described herein are also applicable to other chores, including outdoor power equipment, indoor power equipment, light vehicles, aerial manlifts, ground care equipment, golf carts, forklifts and other industrial vehicles, recreational utility vehicles, industrial utility vehicles, and lawn and garden equipment. Outdoor power equipment may include lawn mowers, riding tractors, snowplows, high pressure washers, cultivators, wood splitters, push mowers, riding mowers, and lawn equipment such as spreaders, sprayers, seeders, rakes, and blowers. For example, outdoor power equipment may use one or more motors to drive implements, such as a rotary blade of a lawn mower, a pump of a high pressure washer, an auger of a snowplow, an AC generator, and / or a transmission system of an outdoor power equipment. Indoor power equipment may include floor sanders, floor polishers and waxers, vacuum cleaners, and the like.

[0030] As used herein, a "chore product" refers to any type of equipment, machine, or vehicle that can be used to perform certain chores (e.g., outdoor chores, indoor chores, lawn care, etc.). For example, a chore product may include a motor, pump, actuator, compressor, and / or other electrically powered device for driving a function of the chore product in order to perform chores. In some embodiments, chores refer to tasks performed by a user or automatically in or near a home, farm, agricultural facility, building, sidewalk, park, parking lot, forest, field, and / or lawn. In some embodiments, a chore product carries an operator and performs chores; in some embodiments, a chore product operates autonomously to perform chores without the operator physically / manually manipulating the chore product or the chore product.

[0031] In some embodiments, the lawn mower 10 includes a plurality of sensors 12 (e.g., visual sensors, camera sensors, IR emitters, IR cameras, thermal imaging cameras, position sensors, accelerometers, inductive sensors, etc.), one or more batteries (shown as battery pack 100 ), a controller 18 , one or more user interfaces 20 , and one or more input devices 22 .

[0032] In some embodiments, as shown, sensors 12 on lawn mower 10 can be arranged around lawn mower 10, or can be arranged at other locations as required by a particular configuration. Sensors 12 can all be of the same type, or can be a combination of different types of sensors. Sensors can include humidity sensors, rain sensors, air quality sensors, magnetic field sensors (such as compasses), temperature sensors, digital imaging sensors, motion detection sensors, rotation sensors, gyroscopes, chemical detection sensors, etc.

[0033] In some embodiments, the controller 18 can communicate with a home network, such as via Wi-Fi; in other embodiments, the controller 18 can communicate with a local communication hub or bridge device, such as a communication hub associated with a service vehicle. In other embodiments, the controller 18 can be configured to allow the lawn mower 10 to communicate directly with a central server or cloud server, such as via a cellular connection. In some embodiments, the controller 18 can be used to communicate with a user device capable of remotely controlling the lawn mower 10. Examples of user devices capable of remotely controlling the lawn mower 10 include a dedicated remote control, a smartphone, a tablet, a laptop, or any other user device capable of docking with the controller 18.

[0034] In some embodiments, the lawn mower 10 may also include multiple motors. In some embodiments, these motors are brushless DC motors. In other embodiments, these motors may be one of a brushed DC motor, an AC motor, a permanent magnet motor, etc., or a combination thereof. The lawn mower 10 may be provided with one or more traction motors 24 and / or one or more implement motors 28 (e.g., motors that perform chores). In some embodiments, each traction motor 24 and implement motor 28 is powered by and electrically connected to the battery pack 100. In some embodiments, the lawn mower 10 may be equipped with a traction motor 24 for each rear drive wheel 30. In further embodiments, such as Figure 1 As shown, the lawn mower 10 may include two or more non-traction wheels 26 (eg, hub wheels or casters). In some embodiments, the casters 26 may be positioned or locked in a particular position when the lawn mower 10 is operated in a particular mode.

[0035] The implement motor 28 may be used to drive one or more accessories connected to the mower 10. In some embodiments, the implement motor 28 may drive a cutting device, such as a rotary blade. In other examples, the implement motor 28 may be used to drive an accessory such as a spreader, blower, power rake, or other suitable accessory. In some embodiments, the accessory motor is located on the mowing deck 32. The mowing deck 32 may accommodate the implement motor 28 and one or more cutting blades connected to each accessory motor. In some embodiments, the implement motor 28 may be connected via a central bus. The central bus may be used to power and communicate with other devices such as the controller 18 and / or the battery pack 100; in some embodiments, the central bus may provide a single connection between the mowing deck 32 and the main body of the mower 10. The computing power used by the mower 10 may be distributed among all controllers 18 and controller modules. In addition, each controller or module receives and transmits data to each other in order to make decisions and perform actions, thereby achieving decentralized information processing among the controllers 18.

[0036] The mowing deck 32 may include one or more inserts to reduce noise emissions. The inserts may be made of one material or a combination of materials to reduce noise generated by accessories on the mowing deck 32, including the implement motor 28. For example, the inserts may be made of one or a combination of various foams, rubbers, polystyrene foams, gels, etc. The mowing deck may also be provided with one or more accessory rails to facilitate easy addition of other accessories to the mower 10. In some embodiments, the accessory rails may be configured to include power and / or data connections that can power additional accessories and / or communicate with components on the mower 10, such as the controller 18. Examples of accessories may include blowers, vacuums, collectors, etc.

[0037] In further embodiments, the mowing deck 32 may also have additional implement motors 28 for controlling other aspects of the mowing deck 32, such as a storage mode actuator, a mowing deck height adjustment device, a multi-directional discharge chute control device, etc. In some embodiments, the mower 10 may also have other implement motors 28, such as a seat adjustment motor, a suspension control motor, etc.

[0038] In some embodiments, the lawn mower 10 may include other features, such as a cup holder 34, an adjustable seat 36, etc. In some embodiments, the cup holder 34 may be powered by the battery pack 100 and include a heating and / or cooling element so that items placed in the cup holder 34 are heated or cooled. In some embodiments, the adjustable seat 36 may be connected to the battery pack 100 and configured to be adjusted via one or more electronic positioning devices. In further embodiments, the adjustable seat 36 may include one or more heating or cooling elements to improve operator comfort, the one or more heating or cooling elements being powered by the battery pack 100. Battery Pack

[0039] Reference Figures 2 to 18 According to some embodiments, the battery pack 100 is a rechargeable battery (e.g., a rechargeable battery, a rechargeable battery pack, a rechargeable battery array, a rechargeable energy storage device, etc.). In some embodiments, the battery pack 100 may be a rechargeable battery such as a lithium-ion battery. However, other battery types may also be used, such as nickel-cadmium, lead-acid, nickel-metal hydride (NiMH), or polymer lithium batteries. The battery pack 100 may be a lithium-ion battery that includes a plurality of lithium-ion cells arranged in various series (S) and parallel (P) arrangements. In some embodiments, the battery pack 100 provides approximately 1 kWh of energy (e.g., 800 Wh to 1.2 kWh). In some embodiments, the battery pack 100 is configured to be small enough, light enough, and easy to grasp so that a user can carry it manually. In other embodiments, the battery pack 100 is not configured to be small enough, light enough, or easy to grasp so that it cannot be carried manually by a user. For example, a user may need a lift, crane, or other handling equipment to move the battery pack 100. The battery pack 100 may also be interchangeable between different equipment or chore products (eg, between lawn tractors, vehicles, backup power supplies, stand-alone power supplies, portable generators, trolling motors, golf carts, etc.).

[0040] like Figures 2 to 3 As shown, the battery pack 100 includes a housing 102. The housing 102 is an external package for accommodating and protecting the internal components of the battery pack 100. For example, the housing 102 may define an internal cavity (e.g., an internal space, an internal volume, etc.), such as the internal cavity 104 shown in the figure, which can accommodate various electronic components of the battery pack 100. In some embodiments, part or all of the housing 102 can be made of metal, polymer, or composite material. In some embodiments, the housing 102 can be made of a thermally conductive material (e.g., a low thermal resistance material, a thermal conductivity of at least about 1ATM, metal, aluminum, aluminum alloy, aluminum copper alloy, copper alloy, or non-metallic thermal conductors such as graphite, etc.). In some embodiments, in order to facilitate heat conduction and heat dissipation of components within the housing 102, the thermal conductivity of the material of the housing 102 is at least about 1ATM, or at least approx. 1ATM. In some embodiments, when the housing 102 is used to support a larger battery system (e.g., a higher capacity, a larger volume, a heavier weight, a higher power, etc.), it is made of a material with a higher thermal conductivity, and the thickness of the material may be greater due to the increased load borne by the housing 102. In some embodiments, the housing 102 is made of a corrosion-resistant and rigid material such as an aluminum alloy. In some embodiments, part or all of the housing 102 is formed of a metal by a casting process or a drawing process (e.g., a deep drawing process).

[0041] In some embodiments, the housing 102 is connected to and supported on a base 108 (e.g., a bottom plate, a substrate, a bottom member, a bottom support, etc.). In some embodiments, the housing 102 is a battery pack case that includes one or more removable components to facilitate access to one or more components in the internal cavity 104. In the illustrated embodiment, the battery pack 100 includes a negative terminal 110, a panel-mounted data connection terminal 112, and a positive terminal 114. In some embodiments, the negative terminal 110 and / or the positive terminal 114 extend through the housing 102 and are accessible externally relative to the housing 102; in some embodiments, the data connection terminal 112 is located between the positive terminal 114 and the negative terminal 110 on the same side of the housing 102. In other embodiments, the data connection terminal 112 is disposed at other locations on the housing 102.

[0042] In some embodiments, the housing 102 is a single pentahedral package that covers the battery module assembly 116 (e.g., the battery module assembly (CMA) and the battery charger 120). In some embodiments, when the battery pack 100 is assembled, the CMA 116 is connected to the base 108, and the housing 102 covers and seals the CMA 116 within the internal cavity 104 to prevent or inhibit water or debris from entering the battery pack 100. The housing 102 can be adapted to CMAs 116 of different sizes and capacities. In some embodiments, the housing 102 of the battery pack 100 includes a user interface. For example, the battery pack 100 may include a display, a button, a camera, a microphone, a speaker, or other interface to facilitate interaction between the battery pack 100 and a user by displaying and / or receiving data about the battery pack 100.

[0043] In some embodiments, the panel mounted data connection terminal 112 of the battery pack 100 can provide short circuit protection between the positive terminal 114 and the negative terminal 110 of the battery pack 100; the panel mounted data connection terminal 112 can also include a foolproof pin for controlling different current capacities within a single connector. In some embodiments, the foolproof pin prevents the wrong component from being connected to the panel mounted data connection terminal 112.

[0044] In some embodiments, the positive terminal 114 may be or include one or more terminals, and the negative terminal 110 may be or include one or more terminals. In some embodiments, the positive terminal 114 and the negative terminal 110 may be located close to an electrical ground. For example, the positive terminal 114 and the negative terminal 110 may facilitate a user to connect a device through a connector having one or more plug layouts (e.g., two-pin, three-pin, Type-D, Type-F, Type-C, Type-D, Type-I, Type-L, Type-H, Type-E, Type-B, Type-G, Type-A, Type-K, various plugs, Anderson plugs, special plugs, etc.). In some embodiments, the positive terminal 114 and the negative terminal 110 may facilitate electrical connection with one or more external devices (e.g., a power output device, a power input device, a power storage device, etc.). For example, the positive terminal 114 may be connected to a connector or cable end of an external device. Such an external device may be or include another battery pack 100, electric outdoor power equipment, chore products, motors, computers, consumer devices, cell phones, electric drive systems, power input devices (e.g., solar panels, wind turbines, generators), or utility power sources (e.g., mains power, etc.). In some embodiments, the battery pack 100 includes one or more dedicated positive terminals 114 and negative terminals 110 for connection to one or more corresponding external devices.

[0045] In some embodiments, the battery pack 100 is configured to receive and / or supply at least one of alternating current (AC) power or direct current (DC) power. For example, the battery pack 100 may receive AC power through an AC input terminal (e.g., through connection to a grid, an AC power source, or a power station, etc.), may receive DC power through a DC input terminal (e.g., through connection to a non-inverting solar power source, a DC output of another battery pack 100, or a DC power source), may supply AC power through an AC output terminal (e.g., through connection to a CMA 116 via a DC to AC converter), and / or may supply DC power through a negative terminal 110 and a positive terminal 114 (e.g., through connection to a CMA 116). In some embodiments, the battery pack 100 is configured to be powered partially or entirely based on energy stored in the internal cavity 104. For example, the battery pack 100 may selectively access energy stored in the CMA 116 to achieve a target output characteristic (e.g., a target power characteristic) at the output end (e.g., the negative terminal 110 and the positive terminal 114) of the battery pack 100.

[0046] In some embodiments, the battery pack 100 may facilitate pass-through charging and / or may be configured to perform AC to DC and / or DC to AC power conversion for one or more power sources connected to the battery pack 100. For example, the battery pack 100 may receive DC power from a solar power source, then convert the DC power to AC power (e.g., via an inverter), and supply the resulting AC power directly to the output terminals of the battery pack 100 (e.g., via AC output terminals). In some embodiments, excess power (e.g., input power exceeds output power) may be applied to the CMA 116 to facilitate charging of the CMA 116. In some embodiments, when the CMA 116 is fully charged or charged at a limited rate, the battery pack 100 is configured to dissipate some or all of the excess power as heat. In some embodiments, the charger 120 is configured to perform AC to DC power conversion as well as power monitoring and conditioning, details of which will be further described below.

[0047] Reference Figures 3 to 7 , within the internal cavity 104, the base 108 is provided with a battery charger 120 (e.g., a recharger, a battery controller, a power controller, a battery management system, a battery manager, a charge manager, a charge controller). The charger 120 may be configured to supply energy to the CMA 116 based on the current flowing through at least a portion thereof. In some embodiments, the charger 120 is configured to receive and / or supply at least one of AC power or DC power. For example, the charger 120 may receive AC power through an AC input terminal (e.g., through connection with a power grid, an AC power source, or a power station), may receive DC power through a DC input terminal (e.g., through connection with a non-inverting solar power source, a DC output of another battery pack 100, or a DC power source), may supply AC power through an AC output terminal (e.g., through connection between a DC to AC converter (e.g., an inverter) and the CMA 116), and / or may supply DC power through a DC output terminal (e.g., through connection with the CMA 116). In some embodiments, the charger 120 is configured to receive AC power or DC power and selectively supply DC power to the CMA 116. In some embodiments, the charger 120 is configured to provide power to the output terminals (eg, the negative terminal 110 and the positive terminal 114 ) based in part or in whole on energy stored within the internal cavity 104 (eg, energy stored within the CMA 116 ).

[0048] In some embodiments, the charger 120 can regulate the power available at one or more terminals of the battery pack 100. For example, the charger 120 can limit the output power so that the amount of power available at the output terminals meets one or more thresholds. For example, excess power at the power input terminal can be applied to the CMA 116 to facilitate its charging and / or dissipated as heat. In some embodiments, the excess power at the power input terminal can be due to the power supply exceeding the output power limit (e.g., surge), the power supply exceeding the charging capacity of the CMA 116 (e.g., C-rate), and / or the power supply exceeding the demand at the power output terminal.

[0049] In some embodiments, the charger 120 may facilitate pass-through charging (e.g., simultaneously charging and discharging the CMA 116), and / or may be configured to perform AC to DC and / or DC to AC power conversion on power input to the battery pack 100. For example, the battery pack 100 may receive DC power from a solar power source, then convert the DC power to AC power (e.g., via an inverter and one or more power filtering devices), and supply the resulting AC power directly to the output terminals of the battery pack 100. In such an example, the power supply (e.g., power input to the charger 120) may be supplemented by power provided by the CMA 116, thereby increasing the output power to the desired power.

[0050] In some embodiments, the charger 120 is at least partially integrated into and / or supported on the base 108. The charger 120 can be connected to the base 108 by at least one of fasteners, adhesives, welds, bonds, thermally conductive materials, or other suitable connections, so that at least a portion of the heat generated by the charger 120 is transferred to the base 108. In some embodiments, the charger 120 is connected to the base 108 so that some or most of the components of the charger 120 are thermally connected to the base 108. For example, during the operation of the charger 120, its components can generate heat (e.g., intentionally by powering one or more resistive devices, or unintentionally due to inefficiencies in electrical devices), which can be transferred to the material of the base 108. In this way, the base 108 can thermally stabilize at least a portion of the charger 120.

[0051] In some embodiments, the charger 120 is at least partially integrated into the housing 102. The charger 120 can be connected to the housing 102 (e.g., fixed, bonded, press-fitted), so that part of the heat energy generated by the charger 120 is transferred to the housing 102 by thermal conduction (e.g., the connection does not include a thermal insulator that substantially prevents the transfer of heat energy between the charger 120 and the housing 102). For example, during the operation of the charger 120, its components may generate heat, which is deposited into the material of the housing 102. As a result, the housing 102 can thermally stabilize at least a portion of the charger 120.

[0052] Specific reference Figure 3 , the charger 120 is mounted within the interior cavity 104 in a portion of the area defined between the CMA 116 and the base 108, which is shown as a gap 122. The size and shape of the housing 102 and the CMA 116 can be designed to accommodate the gap 122, so that the CMA 116 and the charger 120 are spaced apart. In other words, the charger 120 can be arranged below the CMA 116, and the size of the housing 102 (e.g., increased height compared to a housing that does not accommodate the charger and CMA) is sufficient to accommodate the charger 120 and the CMA 116 mounted above the charger 120.

[0053] In some embodiments, when the battery pack 100 is assembled and in normal operation (e.g., Figure 2 1 ), the base 108 is lower than the housing 102 in the direction of gravity. In some embodiments, the base 108 may be lower than at least a portion of the CMA 116 in the direction of gravity. In such embodiments, the housing 102 may have a larger surface extending generally parallel to the direction of the gravity vector, thereby promoting natural convection.

[0054] The base 108 extends below at least a portion of the CMA 116. The footprint of the base 108 can be the same as or larger than the footprint of the CMA 116. In some embodiments, at least a portion of the CMA 116 can be mounted at a location that is gravitationally elevated from the base 108. In some embodiments, the housing 102 includes an edge whose interface with the base 108 is generally planar; in some embodiments, the base 108 includes one or more grooves, slots, ribs, and / or other suitable structures to facilitate forming a seal with the edge of the housing 102. In some embodiments, a sealant (e.g., silicone, etc.) can be applied along the interface between the housing 102 and the base 108 to facilitate or achieve a seal.

[0055] In some embodiments, the gap 122 is at least partially separated from the rest of the interior cavity 104 by a wall 124. In some embodiments, the wall 124 can isolate the charger 120 from other components within the interior cavity 104. In some embodiments, the wall 124 facilitates the exchange of fluid (e.g., gas, air, etc.) between the gap 122 and the rest of the interior cavity 104. In other embodiments, the wall 124 seals the gap 122 relative to the rest of the interior cavity 104, thereby inhibiting the exchange of fluid between the gap 122 and the rest of the interior cavity 104. In some embodiments, the wall 124 electrically, magnetically, and / or thermally shields the charger 120 from some or all components of the battery pack 100 within the interior cavity 104.

[0056] Reference Figure 4 , the charger 120 may be partially or completely arranged on a single board (e.g., a PCB board or circuit board). For example, the charger 120 may be or include one or more circuits configured as a system on a chip, wherein some or all of the circuits may be embedded on or in the charging board. In some embodiments, the charger 120 includes one or more input terminals and one or more output terminals that are connected to terminals within the internal cavity 104 or to terminals (e.g., positive terminal 114, negative terminal 110) passing through the housing 102. In some embodiments, the charger 120 may include an AC input terminal, a DC input terminal, an AC output terminal, and / or a DC output terminal. In some embodiments, the charger 120 includes an AC input terminal and a DC input terminal electrically connected to terminals extending through the housing 102 (e.g., the positive terminal 114, the negative terminal 110), a DC input terminal connected to the CMA 116 within the internal cavity 104, a DC output terminal connected to the CMA 116 (e.g., configured to output power to the CMA 116 to charge it), and an AC output terminal and a DC output terminal electrically connected to terminals extending through the housing 102 (e.g., the positive terminal 114, the negative terminal 110).

[0057] In some embodiments, the charger 120 may be configured to provide various charging curves suitable for charging the CMA 116; for example, the charger 120 may use the same or different charging curves for CMAs 116 of different sizes, capacities, compositions, and ages, and may be configured to implement new or traditional charging strategies (e.g., trickle charge, pre-charge, constant current charge, constant voltage charge, termination charge, etc.) to adapt to the current state of the battery pack 100. In some embodiments, the charger 120 may be configured to detect the state of the CMA 116 by acquiring information related to at least a portion of the CMA 116 (e.g., age, configuration, chemical composition, settings, arrangement, manufacturer specifications, capacity, temperature, rated voltage, rated current, historical operating data, etc.) and / or by acquiring information related to one or more connected devices (e.g., at least a portion of an external CMA 116 electrically connected to the battery pack 100, a solar charger, current consumption, etc.). In some embodiments, the battery pack 100 may be electrically connected to one or more other battery packs (e.g., via a jumper, one or more suitable electrical conductive devices), and the charger 120 may be configured to charge, manage, and maintain the one or more other electrically connected battery packs.

[0058] In some embodiments, the battery pack 100 may also be optionally provided as a kit, which includes the battery pack 100 and one or more additional energy storage devices. In such embodiments, the additional energy storage device (e.g., an external battery, a separate battery pack, an additional battery pack 100, etc.) may be monitored and maintained by the charger 120 of the battery pack 100 through a connection to the charger 120 (e.g., through a connection to the positive terminal 114, the data terminal 112, and / or the negative terminal 110). In some embodiments, the additional energy storage device may be configured to be charged by the charger 120. In some embodiments, the charger 120 may supplement or provide electrical energy at the output terminal of the battery pack 100 by drawing energy stored in the additional energy storage device.

[0059] Now refer to Figure 2 , Figure 3 and Figure 7 , the housing 102 includes a frame 130 that partially covers the housing 102. The frame 130 can be a rigid structure to support mechanical loads (e.g., forces) applied to the battery pack 100. For example, the frame 130 can be made of metal (e.g., titanium, aluminum, steel, etc.), metal alloys, composite materials, polymers, or any combination thereof, and can be connected to the base 108 by one or more permanent connection techniques (e.g., fusion, welding, riveting, etc.) or non-permanent connection techniques (e.g., fasteners, locking mechanisms, etc.).

[0060] In some embodiments, the frame 130 is connected to the base 108 and surrounds the housing 102 on at least three sides of the housing 102. For example, the frame 130 can extend around the right side 132, the left side 134, and the upper side 136 of the housing 102. In some embodiments, the frame 130 is assembled from two or more components that are formed separately and then assembled together. The frame 130 may include walls 138 connected together by a top plate 140. The frame 130 can be made of a thermally conductive material (e.g., a material with low thermal resistance). This allows heat energy to be transferred between the base 108 and the frame 130.

[0061] In some embodiments, the frame 130 includes one or more weight-reducing structures (e.g., holes, cutouts, shown as cutouts 142), mounting structures (e.g., mounting points, anchor points, tie-down points, crane connection points, lifting points, eyelets, etc., shown as mounting members 144), and one or more heat dissipation structures (e.g., heat sinks, ribs, heat dissipation pins, shown as heat sinks 146). In some embodiments, the thickness and rigidity of the frame 130 are sufficient to protect the housing 102 from impact (e.g., impact caused by external objects colliding with the battery pack 100). In some embodiments, the wall thickness of the housing 102 is relatively thin relative to the thickness of the base 108 and / or the frame 130. The frame 130 is configured to withstand forces that would otherwise be applied to the housing 102 (e.g., the weight of objects stacked above the battery pack 100, impact of objects, etc.). In this way, the frame 130 can protect the housing 102 from deformation due to loads, avoiding damage to components in the internal cavity 104 and / or breaking the seal between the housing 102 and the base 108.

[0062] In some embodiments, one or more walls 138 of the frame 130 taper inwardly toward the top 152 of the housing 102, and the footprint of the base 108 is larger than the footprint of the housing 102. In some embodiments, the frame 130 can be free-floating about the housing 102. For example, the frame 130 can surround the housing 102 without contacting or otherwise touching the housing 102 and be completely supported by the base 108.

[0063] Reference Figure 8 , the housing 102 has sufficient thickness and structural rigidity to enable it to support various loads (e.g., impact, weight, etc.) without the need to include a frame 130. The housing 102 can be made of a metal sheet through a deep drawing process. In some embodiments, the housing 102 includes a reinforcing structure (e.g., ribs, corrugations, bosses, etc., shown as ribs 148), which can enhance the rigidity of the housing 102. In some embodiments, the ribs 148 may include one or more bosses or structures configured to promote convective heat transfer.

[0064] In some embodiments, the housing 102 includes drainage structures (e.g., grooves, grooves, fluid conduits, etc.) configured to direct liquid and / or debris away from the housing 102. For example, the housing 102 may include one or more grooves 156 configured to prevent liquid (e.g., water) or debris (e.g., dust, dirt, grass clippings, etc.) from accumulating on the surface of the housing 102. The grooves 156 may be lower than the debris accumulation point in the direction of gravity (e.g., the lowest point of the concave surface in the direction of gravity) and extend downward in the direction of gravity, so that liquid and / or debris enter and pass through the grooves 156 under the action of gravity. In some embodiments, the grooves 156 can be used by the user to easily remove debris that would insulate the housing 102 (e.g., a layer of dirt or grass clippings that prevents ambient air from exchanging heat with the outer surface of the housing 102).

[0065] Reference Fig. 9 , the thermodynamic model of the battery pack 100 is shown as model 170. Model 170 is a simplified model based on various thermodynamic assumptions about the battery pack 100. In some embodiments, the charger 120 can use model 170 to make control decisions. For example, the charger 120 can determine the energy or power applied to the heating device (e.g., a resistor, a resistor bar, a ceramic heater, etc.) to achieve one or more target temperature values ​​of the battery pack 100 (e.g., according to the control logic of the controller). It should be noted that the thermodynamic model used by the charger 120 may be more complex than that shown in model 170, and may involve additional or different thermodynamic considerations and modeling techniques. For example, enthalpy (or negative entropy) is not described in detail in model 170, and transient and non-uniform internal characteristics are not described in detail in model 170. In addition, for illustrative purposes, it is assumed that the Biot number of the housing 102 is less than 0.1. Therefore, the housing 102 is modeled as an object with uniform temperature. In some embodiments, the Biot number of the housing 102 is not less than 0.1, and there are significant differences in its internal temperature. Additionally, the model 170 also illustrates lumped parameter assumptions (eg, lumped heat capacity approach) for the multiple components of the battery pack 100.

[0066] Reference Fig. 9, the battery pack 100 is configured so that it can be thermodynamically modeled as a closed system during its operation. For example, since the housing 102 is sealed to the base 108, the internal cavity 104 is isolated from the external environment, for example, by the housing 102. Therefore, the material transfer between the internal cavity 104 and the external environment can be ignored, and accordingly, the convection effect can be ignored (zero) when modeling. In some embodiments, the outer surface of the battery pack 100 (e.g., the outer surface of the housing 102 and the base 108, and optionally also the outer surface of the frame 130) may represent the thermodynamic boundary of the battery pack 100. This thermodynamic boundary can serve as a basis for defining an equilibrium state (e.g., mass balance, energy balance), which helps to determine one or more unknown variables of the model 170 (e.g., temperature value, heat transfer coefficient, energy value, target heat dissipation rate, etc.). In some embodiments, the structure of the housing 102 may be such that the thermodynamic boundaries of the battery pack 100 are assumed to have a fixed mass (sealed) and a fixed volume (eg, the housing 102 and base 108 are substantially rigid) to accommodate common applications of the battery pack 100 .

[0067] The model 170 may include a plurality of temperature nodes, illustrated as a temperature 180 of the CMA 116, a temperature 182 of the fluid within the internal cavity 104 (e.g., bulk temperature of air, gas, etc.), a temperature 184 of the housing 102, a temperature 186 of an interface between the charger 120 and the internal cavity 104, a temperature 188 inside the charger 120, a temperature 190 of an interface between the charger 120 and the base 108, a temperature 192 inside the base 108, a temperature 194 of an interface between the base 108 and an object 198 to which the battery pack 100 is mounted, a temperature 196 of the object 198, a temperature 200 of an interface between the fluid within the internal cavity 104 and the base 108, a temperature 202 of an interface between the external environment and the base 108, a temperature 204 of a boundary layer between the housing 102 and the external environment, a temperature 206 of a boundary layer between the base 108 and the external environment, a temperature 208 of the frame 130, and a temperature 210 of a boundary layer between the frame 130 and the external environment. Some or all of the temperature nodes 180 , 182 , 184 , 186 , 188 , 190 , 192 , 194 , 196 , 198 , 200 , 202 , 204 , 206 , 208 , 210 may be obtained by the charger 120 through measurement (e.g., through one or more temperature sensors) or may be approximately calculated based on a combination of thermodynamic differential equations and equilibrium models (e.g., mass balance, energy balance).

[0068] Model 170 schematically includes energy flows, illustrated as: convective energy transfer 212 between CMA 116 and the fluid within the internal cavity 104; convective energy transfer 214 between charger 120 and the fluid within the internal cavity 104; conductive energy transfer 216 between charger 120 and base 108; convective energy transfer 218 between the fluid within the internal cavity 104 and base 108; conductive energy transfer 220 between base 108 and object 198; conductive energy transfer 222 between base 108 and frame 130; convective energy transfer 224 between base 108 and the external environment; convective energy transfer 226 between frame 130 and the external environment; convective energy transfer 228 between housing 102 and the external environment; convective energy transfer 230 between the fluid within the internal cavity 104 and housing 102; and radiative energy transfer 232 between housing 102 and a heat source (e.g., the sun).

[0069] Conductive energy transfer (e.g., conductive energy transfer 216, conductive energy transfer 222, etc.) can be modeled according to Fourier's Law. For example, conductive energy transfer can be modeled as: Where q is the local heat flux density, k is the thermal conductivity of the material, is the temperature gradient (eg, the temperature gradient between example temperature nodes in the model 170 ).

[0070] Convective energy transfer (e.g., convection energy transfer 224, convection energy transfer 226, etc.) can be modeled according to Newton's Law of Cooling. For example, convection energy transfer can be modeled as: q 对流 =hA(T s -T ∞ ) Where q is the amount of heat lost from the object, h is the heat transfer coefficient, A is the heat transfer surface area, and T s is the surface temperature of the object, T ∞is the external ambient temperature. The heat transfer coefficient h may take into account a variety of fluid properties, including transport properties (such as viscosity of the fluid, thermal diffusivity, etc.), surface geometry of the object, and surface flow properties (e.g., laminar flow, turbulent flow, etc.). One or more convective heat transfers may determine values ​​associated with the boundary layer (e.g., temperature 208, temperature 204). The values ​​of the coefficients of convective heat transfer (e.g., heat transfer coefficient h) may be obtained through various approximations and engineering techniques (e.g., finite element analysis, numerical fluid mechanics, empirical relationships, numerical methods, simulations, etc.), thereby helping to determine appropriate values ​​for the model 170. This determination may involve the determination of various dimensionless parameters (π terms), such as Reynolds number, Prandtl number, Nusselt number, Biot number, Grashof number, and / or Rayleigh number. In some embodiments, the battery pack 100 is configured to maintain one or more temperature limits by estimating the maximum amount of heat transferred to the external environment under the assumption of natural convection (eg, when fluid is not forced to flow along the surfaces of the housing 102 and / or frame 130).

[0071] In some embodiments, radiative energy transfer (e.g., radiative energy transfer 232) can be modeled according to the Stefan-Boltzmann Law. For example, radiative energy transfer can be modeled as: q 辐射 =∈σT 4 A Where q is the heat transfer rate and σ is the Stefan-Boltzmann constant (i.e. ), A is the area of ​​the emitter, T is the temperature, and ∈ is the emissivity coefficient of the object. The value of the coefficient of radiative heat transfer (e.g., emissivity ε) can be obtained through various approximations and / or engineering techniques (e.g., finite element analysis, numerical fluid dynamics, empirical relationships, numerical methods, simulations, etc.), thereby helping to determine appropriate values ​​for model 170.

[0072] The exemplary energy transfers 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232 are each represented by arrows, the direction of which may represent the direction of energy flow based on the system state. In other embodiments, the direction of one or more energy transfers 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232 may be opposite to that shown. For example, the direction of the arrows indicates that when the battery pack 100 is in a state where the temperature of the charger 120 is elevated (e.g., the temperature 188 is relatively high), the temperature of the charger 120 is higher than the base 108 (e.g., the temperature 192), the fluid in the internal cavity 104 (e.g., the temperature 182), the housing 102 (e.g., the temperature 184), the object 198 (e.g., the temperature 196), and the external environment. Further, in this example, the temperature of the CMA 116 (e.g., the temperature 180 is relatively high) is higher than the temperature of the fluid in the internal cavity 104 (e.g., the temperature 182). In other words, in this example, each transfer arrow points to the direction of the temperature gradient decrease between each node (temperature node) (e.g., the temperatures 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210) in the model 170. This example can illustrate a situation where the battery pack 100 is in a powered state (e.g., turned on or inputting energy to the charger 120), and the charger 120 and the CMA 116 are dissipating heat.

[0073] In some embodiments, heat generated by the charger 120 and / or the CMA 116 may be transferred to the local environment of the charger 120 and the CMA 116. For example, heat generated by the charger 120 may be transferred to the base 108 and the fluid within the internal cavity 104. In some embodiments, the local environment (e.g., the environment within the internal cavity 104 near the CMA 116 and the charger 120) is below a temperature threshold required to perform one or more functions of the CMA 116 and / or the charger 120. In such embodiments, the charger 120 may direct electrical energy to a heating device (e.g., a resistive heating device, a resistor bank, etc.) to heat the battery pack 100 (e.g., to heat the internal cavity 104). For example, when the external environment is below freezing (e.g., during seasonal weather), the charger 120 may determine that the temperature of the battery pack 100 (e.g., within the internal cavity 104) is below a temperature threshold. In response to this determination, the charger 120 may direct energy to a heating element of the battery pack 100 to heat at least a portion of the battery pack 100. For example, the base 108 and / or the housing 102 may include one or more resistive elements connected to or embedded in the material thereof, which are configured to dissipate electrical energy in the form of heat when powered. In some embodiments, the resistive elements connected to or embedded in the material of the housing 102 may heat at least a portion of the housing 102 (e.g., the base 108, the housing 102), causing the heat to diffuse within the material, thereby facilitating the battery pack 100 to achieve dispersed and relatively stable heating.

[0074] In some embodiments, when part or all of the local environment is at the same or higher temperature than the CMA 116 and / or the charger 120 , the battery pack 100 may be configured to diffuse heat from the local environment throughout the battery pack 100 in order to maintain thermodynamic equilibrium within the battery pack 100 .

[0075] Reference Figures 10 to 12 , further details of the CMA 116 are shown according to some embodiments. The CMA 116 includes a top plate 318, a middle plate 310, an anti-twist plate 334, a spacer 309, a harness cutout 306, and mounting hardware 368. In some embodiments, the top plate 318 and the middle plate 310 (which is located between the top plate 318 and the base plate at the bottom of the CMA 116) are both made of aluminum. Each plate 310, 318 may have multiple harness cutouts 306 to facilitate the routing of cables in the internal cavity 104 of the battery pack 100. The harness cutouts 306 can be used to secure the harness of the CMA 116. In addition, the harness cutouts 306 in each plate of the battery pack 100 allow wires to be routed between layers without increasing the overall size of the battery pack 100. The battery pack 100 can be constructed using a series of lip seals with strap rails and locks.

[0076] The CMA 116 may include a plurality of vertically layered CMA sections 370, wherein a first layer is directly above a second layer and a third layer is above the second layer. Each CMA section 370 includes a top CMA battery support frame, a bottom CMA battery support frame, a top current collector plate (e.g., a positive current collector plate 366), a bottom current collector plate (e.g., a negative current collector plate 354), a plurality of battery cells 302, and a curable adhesive for bonding the battery cells 302 to the top CMA battery support frame and the bottom CMA battery support frame. The CMA sections 370 may be spaced apart from each other and located between the mid-plates 310, between the mid-plates 310 and the top plate 318, and / or between the bottom mid-plate 310 and the base 108 of the battery pack 100. Each layer of the CMA 116 may include two mid-plates 310 and a plurality of CMA sections 370. In some embodiments, in the CMA 116 , the mid-plate 310 is disposed between the positive terminals of the battery cells 302 within the CMA sections 370 .

[0077] In some embodiments, gaps exist between the battery cells 302 and the plates (e.g., top plate 318, mid-plate 310, housing 102, base 108, wall 124) that the CMA 116 assembles into each CMA section 370. These gaps in each layer of the battery pack prevent damage to the CMA 116 during a thermal event. Advantageously, as heat is dissipated from a damaged battery cell, the likelihood of a thermal event propagating (e.g., thermal runaway) to other battery cells 302 and causing more damage to the components of the CMA 116 is reduced.

[0078] The mounting hardware 368 may include fasteners that can be easily operated with a tool such as a wrench. In addition to providing structural support and stability for the entire battery pack 100, the mounting hardware 368 may also conduct heat along all structural components, plates, spacers, etc. of the battery pack 100. The spacers 309 between the layers of the CMA 116 may include compression stoppers 308. The compression stoppers 308 may be made of steel or aluminum, which is suitable for providing a thermal conduction path while maintaining electrical isolation between the layers.

[0079] In some embodiments, a battery cell 302 within a CMA section 370 in a battery pack 100 may be connected to a thermistor 317. In some embodiments, the thermistor 317 is secured to the battery cell 302 by a tape 316. In some embodiments, the thermistor 317 is mounted on the battery cell 302 using a closed cell foam adhesive. Each CMA section 370 within the battery pack 100 includes a thermistor 317 to monitor the temperature of the corresponding CMA section 370. The CMA 116 may also include resistive heating strips on each plate to uniformly heat the battery pack 100. In some embodiments, each layer has a heating strip, and the heating capacity of the heating strips of each layer is different from that of the heating strips of other layers. The resistance of the resistive heating element may change as its own temperature changes. For example, the variable resistance of the heating element may change based on the temperature of the heating element. Thus, when it is determined that a certain area of ​​the CMA 116 is hotter than other portions of the CMA 116 (e.g., the top layer of the battery pack 100 is near outdoor power equipment components that generate a lot of external heat), the resistive heating elements near that area may have a lower heating level than other resistive heating elements of the battery pack 100. For example, the resistive heating elements of the top layer of the battery pack 100 may have lower power than the resistive heating elements of the lower layers (e.g., the bottom layer). The resistive heating strips and thermistor 317 may communicate with the charger 120 to control the temperature within the battery pack 100.

[0080] In some embodiments, a layer of the battery pack 100 may include more resistive heating elements than other layers. In some embodiments, the resistive heating elements may have a positive or negative temperature coefficient to enhance the ability of the battery pack 100 to self-regulate thermally. In some embodiments, the charger 120 may receive and / or supply external power to drive one or more heating elements (e.g., resistive heating strips) using existing external terminals of the housing 102. As a result, the temperature of the battery pack 100 (e.g., the internal cavity 104, the charger 120, the CMA 116, the housing 102, etc.) may rise to a threshold temperature level without current flowing into or out of the battery pack 100 and the battery cells 302. In some embodiments, an internal circulation fan helps to create a uniform temperature inside the battery pack 100 without exchanging air with the outside of the housing 102 of the battery pack 100. Advantageously, by establishing a more uniform temperature level within the housing 102, the battery pack 100 can avoid a situation where the temperature of a particular area thereof is significantly higher than other components of the battery pack 100.

[0081] Each CMA section 370 of the battery pack 100 includes a plurality of battery cells 302 that can work together to output electricity to drive a vehicle or other device (e.g., a lawn mower 10). In some embodiments, the battery cells 302 are lithium-ion battery cells. For example, the battery cells 302 can be lithium-ion battery cells with a rated voltage of 3.6 volts and a rated capacity of 3 ampere hours. As shown, each of the 14 CMA sections 370 includes 32 battery cells 302, arranged in four rows, with eight battery cells in each row. The battery cells 302 are electrically connected to each other through wires, and the terminals of the wires are connected to each battery cell 302 and a common conductor (e.g., a positive current collector plate 366 or a negative current collector plate 354) (e.g., using wire bonding).

[0082] In some embodiments, the CMA 116 includes a battery management system 322 for regulating the current and / or voltage during the charging and discharging process to ensure that the battery cells 302 are not damaged or otherwise become a problematic charging state. In some embodiments, some or all of the functions and structures of the battery management system 322 are integrated into the charger 120. The battery management system 322 can block the current from being delivered to the battery cells 302 or block the current from being drawn from the battery cells 302 based on the current and voltage characteristics of the CMA section 370. In addition, the battery management system 322 can also implement control based on the temperature detected by the temperature sensor (e.g., thermistor 317) and adjust the operation of the CMA section 370 based on the detected overheating or overcooling conditions.

[0083] For example, the battery management system 322 may include a controller 390 having a processing circuit 392 having a processor 394 and a memory 396 (see Fig.19 ); the processing circuit 392 can be interconnected with the communication interface so that it and its components can send and receive data through the communication interface; the processor 394 can be implemented as a general-purpose processor, an application-specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGA), a group of processing components or other suitable electronic processing components.

[0084] The memory 396 (e.g., memory, storage unit, storage device, etc.) may include one or more devices (e.g., RAM, ROM, flash memory, hard disk storage, etc.) for storing data and / or computer code to complete or facilitate the various processes, levels and modules described in this application. The memory 396 may be a volatile or non-volatile memory. The memory 396 may include a database component, an object code component, a script component, or any other type of information structure to support the various activities and information structures described in this application. According to some embodiments, the memory 396 is communicatively connected to the processor 394 through the processing circuit 392 and includes computer code for executing (e.g., executed by the processing circuit 392 and / or the processor 394) one or more processes described herein. In some embodiments, the controller 390 performs the control functions of the battery management system 322 and / or the charger 120 described herein.

[0085] In some embodiments, the controller 390 is in communication with the CMA 116, the charger 120, one or more temperature sensors (e.g., thermistor 317 or other temperature sensors disposed within the housing 102), and the tape 316. The controller 390 is configured to detect the temperature within the housing 102 (e.g., within the internal cavity 104) and / or the battery cells of the CMA 116, and in response to the temperature within the housing 102 being below a threshold, instruct the charger 120 to dissipate heat (e.g., release electrical energy via a resistive heating element, the tape 316, or any other heating mechanism described herein).

[0086] Since the charger 120 and the battery management system 322 are both arranged in the battery pack 100, the battery pack 100 can be connected in series or in parallel. In some embodiments, the same charger 120 and the battery management system 322 can be used for the battery pack 100 with a nominal voltage of 24V, 36V, 48V, 96V or 120V respectively.

[0087] In some embodiments, the charger 120 is configured to output a nominal voltage between 24V and about 120V. In some embodiments, the charger 120 is configured to output at least one of 24V, 36V, 48V, 96V, or 120V when the CMA 116 is fully charged (e.g., as permitted by the battery management system 322) and / or connected to an external power source (e.g., via an AC power source connected to the AC input terminal of the battery pack 100). In some embodiments, the battery pack 100 has an energy storage capacity of at least 1 kWh. In some embodiments, the CMA 116 is configured to provide at least 1 kWh of energy when the plurality of battery cells are fully charged. In some embodiments, the CMA 116 is configured to nominally supply approximately 1 kWh, approximately 4 kWh, approximately 5 kWh, approximately 10 kWh, or approximately 35 kWh of energy when fully charged. Such capacities may support the power requirements expected for device operation. For example, in some embodiments, the lawn mower 10 is a commercial lawn mower equipped with a 50-inch mowing deck and is expected to consume approximately 35 kWh of energy during a full day of use.

[0088] As the CMA 116 ages, the maximum charge capacity of the cells 302 within the CMA segments 370 of the CMA 116 gradually decays over its useful life. This decay is caused by the battery pack 100 being cycled through discharge and recharge, temperature changes (e.g., high temperatures), and chemical degradation of the cells 302. A cycle refers to the transition of the battery pack from a fully charged state (charged by the charger 120 and permitted by the battery management system 322) to a partially or fully discharged state (also permitted by the battery management system 322). As the number of cycles increases during the life of the battery pack 100, its maximum charge capacity decreases. Similarly, as the number of cycles increases during the life of the battery pack 100, the efficiency of the CMA 116 decreases (e.g., due to chemical decomposition of the cells 302), and the heat generated by the CMA 116 per unit of power exchanged (e.g., per watt) increases.

[0089] In some embodiments, the battery management system 322 of the battery pack 100 may include an integrated data logger and may be programmed to store data related to the operation of the CMA segments 370 in a memory of the battery management system 322. The information recorded by the battery management system 322 may be used to determine the expected thermal load and service life measurement for each CMA. The service life measurement may be expressed as a percentage of life (e.g., a brand new CMA segment 370 is 100% life).

[0090] Reference Figures 10 to 12 and Fig.15, the battery management system 322 includes several connectors on one side thereof. The input and output components of the battery management system 322 can be fused to the battery management system 322 through resettable fuses. In some embodiments, a battery management system cover 324 is disposed around the battery management system 322. The battery management system cover 324 is used to protect the battery management system 322 and various wiring harness connectors and connections connected to the battery management system 322. In some embodiments, the battery management system cover 324 is a structural potting box with pressure resistance, impact resistance, and metal resistance, heat resistance, and electromagnetic interference (EMI) resistance. The battery management system 322 includes a thermistor connector 326 for monitoring the temperature of each CMA section 370 in the CMA 116. The battery management system 322 includes a CMA voltage connector 320 for receiving operation-related data of the battery cells 302 and the CMA sections 370 in the entire battery pack 100. In some embodiments, the measurement value read at the positive voltage tap 332 is transmitted to the battery management system 322 through the CMA voltage connector 320. Each connector of the battery management system 322 may be connected to a connection harness (eg, a shunt harness, etc.).

[0091] In some embodiments, the battery management system 322 includes a pre-charge circuit and a discharge circuit, both of which are integrated on the same circuit board of the battery management system 322. In some embodiments, the battery management system 322 is placed on the same circuit board as the charger 120. In some embodiments, the thermal impact of the battery management system 322 is relatively small (for example, it has fewer components with low thermal efficiency and does not generate a large amount of heat compared to the heat generated by the charging operation of the charger 120). In some embodiments, the battery management system 322 includes electrical components (for example, processors, solid-state electronic devices, etc.) that are particularly sensitive to temperature fluctuations, and these components will degrade when exposed to a certain temperature range (for example, 33 to 100 degrees Fahrenheit). In such embodiments, these sensitive electrical components can be kept at a certain distance from part or all of the charger 120. For example, the battery management system 322 can be mounted on the inner surface of the housing 102 or on the side of the CMA 116 away from the charger 120. In this way, the thermal impact of the heat generated by the operation of the charger 120 on the battery management system 322 is reduced. In other embodiments, the battery management system 322 is part of the charger 120. In some embodiments, the battery management system 322 is disposed on the same circuit board as the charger 120. In some embodiments, the charger 120 and the battery management system 322 are disposed within the same enclosure (e.g., a battery management system enclosure 324) within the interior cavity 104. In some embodiments, the battery management system 322 is mounted on the base 108 and adjacent to the charger 120. In some embodiments, part or all of the battery management system 322 is at least partially embedded within the housing 102. For example, the electrical components of the battery management system 322 and the charger 120 may be constructed on or within a portion of the base 108. In some embodiments, the base 108 is electrically isolated.

[0092] In some embodiments, the battery management system 322 performs current analysis on the battery pack 100 to detect which components are electrically connected to the terminals of the battery pack 100 (e.g., the positive terminal 114, the negative terminal 110, the data terminal 112, the AC input terminal, the AC output terminal, the DC input terminal, the DC output terminal, etc.). When an abnormal current curve of the battery pack 100 is detected, the battery management system 322 may issue an alarm to indicate the abnormal situation. In some embodiments, when the battery pack 100 is connected in parallel or in series with another battery pack, the battery management system 322 writes data to the adjacent battery management system 322 of the connected battery pack 100 to manage (e.g., update, restore, etc.) the firmware on the adjacent battery management system 322, and may replace the old firmware with a different firmware (e.g., a new firmware).

[0093] In some embodiments, the battery management system 322 may also be configured to update a charger or other energy source connected to the battery pack 100 with updated firmware, and may receive updated content of the updated firmware from the charger. For example, the battery management system 322 may be connected to a newly produced battery pack 100 (the battery management system 322 equipped with the battery pack is also newly produced and has different firmware), and based on the connection with the new battery management system 322, the old battery management system 322 may directly receive different firmware (e.g., by creating or otherwise obtaining a copy or mirror of the different firmware of the new battery management system 322) from the new battery management system 322 (e.g., via an API or one or more communication protocols).

[0094] In some embodiments, the battery management system 322 can operate in three different states: recharging, charging, and hybrid. In the hybrid state, the battery management system 322 can effectively charge the battery pack 100 even if it should be in a discharging state, regardless of whether communication is performed. In the charging state, the battery management system 322 can adopt adaptive charging limits. For example, when receiving regenerative charging, that is, when the battery pack 100 is replenishing its power, the battery management system 322 can reduce the maximum charging limit to avoid upper limit failures caused by regenerative charging. The decision of the battery management system 322 to reduce the maximum charging limit can be based on the frequency of failures.

[0095] The CMA 116 may also include a communication harness 336, a negative cable assembly 338, a contactor-to-contactor busbar 340, a positive cable assembly 342, a positive terminal-to-contactor busbar 344, a battery pack dual contactor 350, a contactor coil terminal 352, a CMA negative ground cable assembly 356, a series layer flexible busbar 358, a shunt isolator 362, and a CMA battery bracket 364. In some embodiments, the communication harness 336 connects the panel mounted data connection terminals 112 to the battery management system 322. The CMA negative ground cable assembly 356 may extend below the CMA 116 to the end of string mounting assembly 312 and, in a negative cabling manner, extend from the first CMA section 370 module to the ground terminal 372 of the last CMA section 370 module. In some embodiments, the CMA negative ground cable assembly extends from the first CMA segment 370 at the top layer of the battery stack 100, down through the front side of the CMA 116 to below the base plate of the battery stack 100, and then extends upward through the back side of the CMA 116 to connect with the last CMA segment 370 at the bottom layer of the CMA 116. The series layer flexible busbar 358 is used to electrically connect the various layers of the battery stack 100. In some embodiments, the CMA battery holder 364 is a bottom CMA battery holder frame that is connected to the negative terminal of the battery cell 302 in each CMA segment 370.

[0096] Reference Fig.10 , the contactor-to-contactor busbar 340 extends to a position near the top of the CMA 116 and can be connected to multiple CMA sections 370 at the same time. The positive cable assembly 342 extends to the positive terminal 114. The negative cable assembly 338 extends upward to the negative terminal 110. The communication harness 336 extends upward from the battery management system 322 to the data connection terminal 112. In some embodiments, the battery management system cover 324 and the top plate 318 constitute the top portion of the CMA 116. In other embodiments, the top plate 318 constitutes the top portion of the CMA 116.

[0097] Reference Fig.11 , the bottom of the CMA 116 includes a base plate 374 and a bottom current collector plate 376. Each bottom current collector plate 376 is connected to the bottom of each CMA section 370 in the battery pack 100. The CMA negative ground cable assembly 356 extends below the battery pack 100. In some embodiments, some of the bottom current collector plates 376 can be negative current collector plates connected to the negative terminals of the battery cells 302 in the CMA section 370. Other bottom current collector plates 376 are positive current collector plates connected to the positive terminals of the battery cells 302 in the CMA section 370 at the bottom of the battery module assembly.

[0098] Reference Fig.11 and Fig.12 , the battery management system 322 is located in the battery management system cover 324 and is placed on the CMA sections 370 of three different layers in the battery pack 100. The contactor 350, the positive terminal 114, the panel mount data connection terminal 112, the negative terminal 110, the positive cable assembly 342, the negative cable assembly 338, and the communication harness 336 are all located near the front side of the battery pack 100. In some embodiments, the dual contactors 350, the positive terminal 114, the negative terminal 110, and the panel mount data connection terminal 112 are aligned with the top layer of the battery pack 100. The tape 316 and the thermistor 317 are respectively connected to the battery cells 302 of the CMA section 370 in the battery pack 100. In some embodiments, each CMA section 370 of the battery pack 100 includes a thermistor 317 to monitor the current temperature level of each CMA section 370 in the battery pack 100. Thus, temperature changes throughout the battery pack 100 can be tracked and managed by the battery management system 322. In addition, the different layers of the battery pack 100 can be viewed from the front of the battery pack 100. In some embodiments, the battery pack 100 can have more or less than three CMA layers.

[0099] Refer again Figure 3, showing the three-layer structure of CMA 116. The charger 120 is located below the bottom layer of CMA 116. The charger 120 is connected to the positive cable assembly 342 and the negative cable assembly 338. In some embodiments, the negative cable assembly 338 includes a negative cable connecting the negative terminal 110 to the negative input terminal 380 of the charger 120, and a negative cable connecting the negative output terminal 382 of the controller to the CMA 116 (e.g., by connecting to the negative terminal of the battery management system 322). In some embodiments, the positive cable assembly 342 includes a positive cable connecting the positive terminal 114 to the input positive terminal 386 of the charger 120, and a positive cable connecting the positive output terminal 388 of the charger 120 to the battery module assembly (e.g., by connecting to the positive terminal of the battery management system 322). In some embodiments, the battery management system 322 is configured to be communicatively connected to the charger 120 (eg, via a wireless connection, a wired connection, a serial connection, etc.) such that the output of the charger 120 is responsive to instructions generated by the battery management system 322 .

[0100] Reference Figures 13 to 18 , shows a battery pack 100 according to some embodiments. Figures 13 to 18 The battery pack 100 and Figures 1 to 8 The battery pack 100 in FIG. 1 is similar to the battery pack 100 in FIG. 1 , and like features are identified with like reference numerals unless otherwise described herein or the difference is apparent from the drawings. Figures 13 to 18 As shown, the charger 120 is connected to the base 108 of the housing 102, and the charger 120 can occupy the space below the middle CMA of the CMA 116 and be adjacent to the inner surface of the front panel of the housing 102 (e.g., the panel including the negative terminal 110 and the positive terminal 114).

[0101] In some embodiments, the volume unit occupied by the charger 120 is equal to or similar to the volume unit occupied by the CMA section 370. The charger 120 can be close to the bottom layer of the CMA 116. For example, the charger 120 can occupy a portion of the internal cavity 104 that intersects the plane containing the CMA layer. In some embodiments, the charger 120 occupies less than 10% of the volume of the internal cavity 104.

[0102] In some embodiments, the CMA 116 at least partially surrounds the charger 120 by supporting one or more battery cells 302 on one or more sides of the charger 120. For example, in some embodiments, the CMA 116 may surround the charger 120 on one side of the charger 120. For example, in the interior cavity 104, the CMA 116 may surround the charger 120 on the top of the charger 120 (see, e.g., FIG. 1 ). Figure 3In some embodiments, the CMA 116 may surround the charger 120 on both sides of the charger 120. For example, the CMA 116 may surround the charger 120 on the top and back sides of the charger 120 (e.g., Fig.14 ). In some embodiments, the CMA 116 may surround the charger 120 on three sides of the charger 120. For example, the CMA 116 may surround the charger 120 on the top, left side, and right side of the charger 120. As another example, the CMA 116 may surround the charger 120 on the top, right side, and back side of the charger 120. In some embodiments, the CMA 116 may surround the charger 120 on four sides of the charger 120. For example, the CMA 116 may surround the charger 120 on the top, left side, right side, and back side of the charger 120. In some embodiments, the CMA 116 may surround the charger 120 on five sides of the charger 120. For example, the CMA 116 may surround the charger 120 on the top, left side, right side, back side, and front side of the charger 120.

[0103] Reference Fig.13 and Fig.14 According to some embodiments, the CMA 116 is connected to the base 108. The charger 120 is connected to the positive cable assembly 342 and the negative cable assembly 338. The negative cable assembly 338 includes a negative cable connecting the negative terminal 110 to the negative input terminal 380 of the charger 120, and a negative cable connecting the negative output terminal 382 of the controller to the CMA 116. The positive cable assembly 342 includes a positive cable connecting the positive terminal 114 to the positive input terminal 386 of the charger 120, and a positive cable connecting the positive output terminal 388 of the charger 120 to the CMA 116. The battery management system 322 is in communication with the charger 120. In some embodiments, all power entering and leaving the battery pack 100 is transferred through the charger 120. For example, all power entering the battery pack 100 (e.g., through the positive terminal 114, the negative terminal 110, and the data terminal 112) can be supplied to the input terminal of the charger 120 and processed (e.g., filtered, converted, boosted, bucked, transparently transmitted) by the charger 120. After processing, the input power can be output from the output terminal of the charger 120 arranged in the internal cavity 104, which is connected to at least one CMA 116 (for energy storage) or connected to the power output terminal of the battery pack 100 (e.g., the positive terminal 114, the negative terminal 110, the data terminal 112).

[0104] In some embodiments, the efficiency of the charger 120 is about 80% to about 90%. For example, if the charger 120 inputs 1 kW (1,000 watts) of electrical energy (e.g., at the input terminals of the charger 120), the charger 120 may output 0.8 kW to 0.9 kW of electrical energy at its output terminals, while the remaining input electrical energy is dissipated primarily as heat. In some embodiments, the charger 120 outputs 0 to about 0.6 kW of electrical energy at its output terminals. In some embodiments, the charger 120 outputs 0 to about 1 kW of electrical energy at its output terminals. In some embodiments, the charger 120 transfers about 100 watts to 150 watts of electrical energy into the housing 102 by conduction (e.g., by conductive heat transfer to the base 108).

[0105] In some embodiments, the charger 120 is configured to operate at less than its rated maximum efficiency, so that additional energy is dissipated in the battery pack 100 as heat. For example, the charger 120 can intentionally operate at an efficiency of about 0% to about 70%, heating the battery pack to above zero degrees Celsius. In some embodiments, most of the heat dissipated by the charger 120 is transferred to the housing by conduction. In some embodiments, most of the heat applied to the housing of the battery pack 100 (e.g., heat from the sun, heat generated by the CMA 116, heat generated by the charger 120, and heat generated by the connections and conduits in the internal cavity 104) is transferred from the outer surface of the battery pack 100 to a nearby ambient fluid (e.g., air) by at least one of natural convection (e.g., due to the buoyancy of the heated external fluid) or forced convection (e.g., due to airflow blowing or actively flowing through the outer surface of the battery pack 100). In some embodiments, the hottest components in the charger 120 (e.g., transformers, capacitors, semiconductors, etc.) are located near the housing 102. In some embodiments, the base 108 is isolated from some or all of the electrical energy entering and exiting the charger 120. For example, the base 108 can be electrically isolated from the input AC supplied to the charger 120.

[0106] Reference Figures 2 to 18According to some embodiments, the charger 120 is advantageously connected to the housing 102, and heat can be transferred into the housing 102. In this way, the thermal characteristics of the charger 120 are stabilized by exchanging thermal energy with the housing 102 and / or the base 108. For example, the base 108 can have a higher thermal capacity relative to the thermal capacity of some or all components of the charger 120, thereby effectively increasing the thermal capacity available to the charger 120 (e.g., when the temperature of the charger 120 exceeds the temperature of the base 108). Advantageously, the battery pack 100 helps improve the protection of the charger 120 from debris, water, other potential contaminants, and thermal disorders that may be detrimental to the performance of the charger 120, and provides a simplified and efficient application method for using the battery pack 100 to power outdoor power equipment. The battery pack 100 beneficially improves the user experience by reducing the required electrical connections and electrical equipment, thereby reducing the number of devices that the user needs to store, transport, maintain, and generally track in order to achieve one or more applications of the battery (e.g., the battery pack 100 powers the lawn mower 10).

[0107] With respect to the numerical ranges referred to herein, the terms "approximately," "approximately," "substantially," and similar terms generally refer to ±10% of the disclosed numerical values. When these terms are applied to structural features (e.g., describing their shape, size, direction, orientation, etc.), they are intended to cover minor deviations in structure that may occur during, for example, manufacturing or assembly, and are intended to have a broad meaning consistent with the common and recognized usage of ordinary technicians in the field to which the disclosed subject matter belongs. Therefore, these terms should be interpreted as indicating that insubstantial or insignificant modifications or changes to the described and claimed subject matter are considered to be within the scope of the disclosure as recorded in the appended claims.

[0108] It should be noted that the term "exemplary" and variations thereof used herein to describe various embodiments are intended to indicate that these embodiments are possible examples, representations, or illustrations (these terms are not intended to imply that these embodiments are necessarily unusual or optimal examples).

[0109] As used herein, the term "connected" and variations thereof refer to the direct or indirect connection of two components to one another. Such connection may be fixed (e.g., permanent or fixed) or removable (e.g., removable or releasable). Such connection may be achieved by directly connecting the two components to one another, by connecting the two components to one another using a separate intermediate component and any additional intermediate components that are connected to one another, or by connecting the two components to one another using an intermediate component that is integrally formed as a single unit with one of the two components. If "connected" or variations thereof are modified by other terms (e.g., "directly connected"), the above general definition of "connected" will be modified by the literal meaning of the additional term (e.g., "directly connected" means that the connection of the two components does not require any separate intermediate components), thereby producing a narrower definition than the above general definition of "connected". Such connection may be a mechanical connection, an electrical connection, or a fluid connection.

[0110] References to component positions herein (e.g., "top," "bottom," "above," "below") are only used to describe the orientation of various components in the drawings. It should be noted that the orientation of various components may be different according to other exemplary embodiments, and such variations are intended to be covered by the present disclosure.

[0111] To implement the hardware and data processing components used in the various processes, operations, example logic, logic modules, units and circuits described in the various embodiments of the present disclosure, a general-purpose single-chip or multi-chip processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete logic gates or transistor logic, discrete hardware components, or any combination of the above components can be used to implement or perform the functions described herein. A general-purpose processor can be a microprocessor, or any conventional processor, controller, microcontroller or state machine. The processor can also be implemented as a combination of multiple computing devices, such as a combination of a DSP and a microprocessor, a combination of multiple microprocessors, a combination of one or more microprocessors and a DSP core, or any other such configuration. In some embodiments, specific processes and methods can be performed by circuits for specific functions. A memory (e.g., memory, storage unit, storage device) may include one or more devices (e.g., RAM, ROM, flash memory, hard disk storage) for storing data and / or computer code to complete or facilitate the various processes, levels and modules described in the present disclosure. The memory may be or include volatile memory or non-volatile memory and may include database components, object code components, script components, or any other type of information structure that supports the various activities and information structures described in the present disclosure. According to an exemplary embodiment, the memory is communicatively connected to the processor via a processing circuit and includes computer code for executing (e.g., executed by the processing circuit or processor) one or more processes described herein.

[0112] The present disclosure relates to methods, systems and program products for implementing various operations on any machine-readable medium. The embodiments of the present disclosure can be implemented using an existing computer processor, or using a dedicated computer processor designed specifically for an appropriate system (whether integrated for this purpose or other purposes), or can be implemented by a hard-wired system. Implementations within the scope of the present disclosure include program products containing machine-readable media, which are used to carry or store machine-executable instructions or data structures. Such machine-readable media can be any available medium that can be accessed by a general or special-purpose computer or other device with a processor. For example, such machine-readable media can include RAM, ROM, EPROM, EEPROM or other optical disk storage, disk storage or other magnetic storage devices, or any other medium that can carry or store the required program code in the form of machine-executable instructions or data structures, and can be accessed by a general or special-purpose computer or other device with a processor. Combinations of the above various media are also included in the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data that enable a general-purpose computer, a special-purpose computer or a special-purpose processing device to perform a certain function or set of functions.

[0113] Although the drawings and description show a specific order of method steps, unless otherwise noted above, the order of these steps may be different from that shown and described. In addition, unless otherwise noted above, two or more steps may be performed simultaneously or partially simultaneously. For example, such variations may depend on the selected software and hardware systems and the designer's choice. All such variations are included within the scope of the present disclosure. Similarly, software implementations of the method can utilize standard programming techniques based on rule logic and other logic to complete various connection steps, processing steps, comparison steps, and decision steps.

[0114] It should be noted that the configuration and arrangement of the battery pack 100 shown in each exemplary embodiment are merely illustrative examples. In addition, any element disclosed in any embodiment may be combined or used with any other embodiment in the present disclosure. Although only examples of elements in a certain embodiment that may be combined or used in other embodiments are described above, it should be understood that other elements in each embodiment may also be combined or used with any other embodiment of the present disclosure.

Claims

1. A battery pack comprising: a housing defining an interior cavity; a first positive terminal extending through the housing; a first negative terminal extending through the housing; a plurality of battery cells within the internal cavity, the plurality of battery cells being electrically connected to a first positive terminal and a first negative terminal; as well as a battery charger located within the internal cavity, the battery charger configured to charge the plurality of battery cells and comprising: a second positive terminal electrically connected to the first positive terminal within the housing; and a second negative terminal electrically connected to the first negative terminal within the housing.

2. The battery pack according to claim 1, wherein: The housing comprises a base and a cover, wherein the cover is configured to be sealed and connected to the base.

3. The battery pack according to claim 2, wherein: The base is made of a thermally conductive material, the battery charger is connected to the base, and the battery charger is configured to transfer heat generated by the battery charger into the base.

4. The battery pack according to claim 3, wherein: The battery charger is connected to the base below the plurality of battery cells.

5. The battery pack according to claim 3, wherein: The battery charger is connected to the base below a first portion of the plurality of battery cells and adjacent to a second portion of the plurality of battery cells.

6. The battery pack according to claim 3, wherein: The plurality of battery cells are configured to output a nominal voltage between a first positive terminal and a first negative terminal, the voltage being between about 24 volts and about 120 volts.

7. The battery pack according to claim 3, wherein: The plurality of battery cells are configured to nominally supply at least 1 kilowatt-hour of energy.

8. The battery pack according to claim 3, wherein: The plurality of battery cells are configured to nominally supply at least 1 kilowatt-hour of energy when fully charged.

9. The battery pack according to claim 3, wherein: When the plurality of battery cells are fully charged, the energy they nominally supply is between about 1 kWh and about 35 kWh.

10. The battery pack according to claim 3, wherein: The plurality of battery cells are lithium-ion battery cells, and when the plurality of battery cells are fully charged, the energy they nominally supply is about 1 kWh, about 4 kWh, about 5 kWh, about 10 kWh, or about 35 kWh.

11. The battery pack according to claim 2, wherein: The battery charger is connected to the housing, and the battery charger is configured to transfer heat generated by the battery charger into the housing.

12. The battery pack according to claim 1, wherein: The housing includes one or more cooling structures formed therein for directing heat away from the interior cavity such that a temperature within the interior cavity remains below a threshold without the use of forced convection.

13. The battery pack of claim 12, further comprising a plurality of plates connected to the base, the plurality of plates partially surrounding the housing, and the plurality of plates are configured to receive heat from the base by conduction and dissipate heat by natural convection.

14. A battery pack comprising: a housing defining an interior cavity; first positive terminal; a first negative terminal; a plurality of battery cells within the internal cavity, the plurality of battery cells being electrically connected to a first positive terminal and a first negative terminal; a temperature sensor mounted on the housing or the plurality of battery cells; as well as A battery charger is located within the internal cavity, the battery charger being configured to dissipate energy into the housing when the temperature measurement of the temperature sensor is below a threshold.

15. The battery pack according to claim 14, wherein: The housing comprises a base and a cover, wherein the cover is configured to be sealed and connected to the base.

16. The battery pack according to claim 15, wherein: The base is made of a metal material, the battery charger is connected to the base, and the battery charger is configured to transfer heat generated by the battery charger into the base.

17. The battery pack according to claim 16, wherein: The plurality of battery cells are arranged into at least a first layer of battery module assemblies (CMA) and a second layer of CMAs, and the second layer of CMAs is separated from the base by the first layer of CMAs.

18. The battery pack according to claim 17, wherein: The battery charger is connected to the base below the second layer of CMA.

19. The battery pack of claim 17, wherein the battery charger is connected to the base below the second layer CMA and the first layer CMA.

20. Outdoor power equipment, including: frame; Prime mover; wheels connected to the frame; as well as a battery pack supported on the frame and configured to provide electrical energy to the prime mover, the battery pack comprising: a housing defining an interior cavity; first positive terminal; a first negative terminal; a plurality of battery cells within the internal cavity, the plurality of battery cells being electrically connected to a first positive terminal and a first negative terminal; and A battery charger is located within the internal cavity, the battery charger is configured to charge the plurality of battery cells, and includes: a second positive terminal electrically connected to the first positive terminal within the housing; and a second negative terminal electrically connected to the first negative terminal within the housing.

21. The outdoor power equipment of claim 20, wherein: The battery charger is configured to receive alternating current (AC) power and output direct current (DC) power through a second positive terminal and a second negative terminal to charge the plurality of battery cells.

22. The outdoor power equipment of claim 20, wherein: The plurality of battery cells are arranged into at least a first layer of battery module assemblies (CMA) and a second layer of CMAs, wherein the second layer of CMAs are separated from a base of the battery pack by the first layer of CMAs.

23. The outdoor power equipment of claim 22, wherein: The battery charger is connected to the base below the second layer of CMA.

24. The outdoor power equipment of claim 22, wherein: The battery charger is connected to the base below the second layer CMA and the first layer CMA.

25. The outdoor power equipment of claim 20, wherein: The battery charger is configured to dissipate energy into the housing when a temperature within the housing is below a threshold.

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