Patent Publication Number: US-2021194330-A1

Title: Gas engine replacement electronics modularity for feature expansion

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 62/951,775, filed Dec. 20, 2019, the entire content of which is hereby incorporated by reference. 
    
    
     FIELD 
     The present application relates to a gas engine replacement device and, more particularly, to input and/or output external electronics modules for adding features to the gas engine replacement device. 
     BACKGROUND 
     Outdoor power equipment (e.g., lawn and garden equipment) and construction equipment (e.g., concrete mixers, plate compactors), commonly referred to as power equipment, may include a gas engine to run the equipment. The gas engines may be small, single-cylinder or multi-cylinder gasoline engines. 
     SUMMARY 
     Gas engines produce emissions, require refueling, and are not readily configurable for particular applications of various types of equipment or preferences of users. There is a need to drive power equipment with reduced emissions and refueling requirements, and to allow expandable functionality for the sources that drive power equipment. 
     Embodiments described herein include gas engine replacement devices, also referred to as powerheads, that use, for example, lithium-ion battery packs and electric brushless motors provide several advantages over gas engines including eliminating emissions and a need to refuel with gasoline. Further, embodiments described herein include gas engine replacement devices that allow for expandable functionality. 
     In one embodiment, a method is provided for expanding features of a gas engine replacement device that drives power equipment. The method includes controlling, by an electronic processor of the gas engine replacement device, a power switching network to selectively provide power from a battery pack to rotate a motor of the gas engine replacement device. A power take-off shaft of the gas engine replacement device protrudes from a side of the housing and receives torque from the motor. The method further includes receiving an external electronics module by a module interface of the gas engine replacement device, and detecting a type of the external electronics module received by the module, configuring the gas engine replacement device based on the type of the external electronics module received by the module interface, and communicating with the external electronics module via the module interface, by an electronic processor of the gas engine replacement device. 
     In some embodiments, the method includes configuring, by the electronic processor, the gas engine replacement device for a specified method of communication via the module interface of the gas engine replacement device. 
     In some embodiments, the method includes operating, by the electronic processor, the gas engine replacement device to control the power equipment based on input received from the external electronics module, wherein the external electronics module includes at least one of a sensor, a user interface, or a power equipment interface. 
     In some embodiments, the method includes transmitting, by the electronic processor, performance information of the power equipment to the external electronics module for indication of the performance information by on a user interface of the external electronics module. 
     In another embodiment, a gas engine replacement device with feature expansion for driving power equipment is provided. The gas engine replacement device with feature expansion includes a housing, a battery receptacle coupled to the housing. The battery receptacle is configured to removably receive a battery pack. The gas engine replacement device also includes a motor located within the housing, a power take-off shaft that receives torque from the motor and protrudes from a side of the housing, a power switching network that is configured to selectively provide power from the battery pack to the motor, a module interface, and an electronic processor. The electronic processor is coupled to the power switching network, the module interface, and a memory. The memory stores instructions that when executed by the electronic processor configure the electronic processor to selectively provide power from the battery pack to rotate the motor. The electronic processor is also configured to receive an external electronics module by the module interface, detect a type of the external electronics module received by the module interface, configure the gas engine replacement device based on the type of the external electronics module received by the module interface, and communicate with the external electronics module via the module interface. 
     In some embodiments, the electronic processor is further configured to configure the gas engine replacement device for a specified method of communication via the module interface. 
     In some embodiments, the electronic processor is further configured to operate the gas engine replacement device to control the power equipment based on input received from the external electronics module, wherein the external electronics module includes at least one of a sensor, a user interface, or a power equipment interface. 
     In some embodiments, the electronic processor is further configured to transmit performance information of the power equipment to the external electronics module for indication of the performance information by a user interface of the external electronics module. 
     In another embodiment, a method is provided for expanding features of a gas engine replacement device that drives power equipment with an external electronics module. The method includes receiving, by a gas engine replacement device interface of an external electronics module, an interface of the gas engine replacement device, where the gas engine replacement device includes a motor driven by a battery. The method further includes communicating with the gas engine replacement device via the gas engine replacement device interface by an electronic processor of the external electronics module. 
     In some embodiments, the method includes receiving, by the electronic processor of the external electronics module, performance information relating to the power equipment driven by the gas engine replacement device, and transmitting a signal to the user interface to indicate the performance information by the user interface. 
     In some embodiments, the method includes receiving, via a user interface of the electronics module, input relating to the power equipment driven by the gas engine replacement device, and transmitting a signal based on the input received via the user interface via the gas engine replacement device interface to the gas engine replacement device. 
     In another embodiment, an external electronics module is provided for expanding features of a gas engine replacement device that drives power equipment. The external electronics module includes a gas engine replacement device interface. The gas engine replacement device interface is configured to receive an interface of the gas engine replacement device, where the gas engine replacement device includes a motor driven by a battery. The external electronics module also includes an electronic processor coupled to a memory. The memory stores instructions that when executed by the electronic processor configure the electronic processor to communicate with the gas engine replacement device via the gas engine replacement device interface. 
     In some embodiments, the external electronics module includes a user interface, where the electronic processor receives performance information relating to the power equipment driven by the gas engine replacement device and transmits a signal to the user interface to indicate the performance information by the user interface. 
     In some embodiments, the external electronics module includes a user interface, where the electronic processor receives input via the user interface. The input relates to the power equipment driven by the gas engine replacement device. The electronic processor transmits a signal based on the input received via the user interface via the gas engine replacement device interface to the gas engine replacement device for control of a motor of the gas engine replacement device. 
     In some embodiments, the external electronics module includes an input user interface, and an output user interface. The electronic processor receives input via the input user interface where the input relates to the power equipment driven by the gas engine replacement device. The electronic processor transmits a signal based on the input received via the input user interface to the output user interface for actuating an indication device. 
     In some embodiments, the external electronics module includes a sensor and the electronic processor receives output from the sensor and transmits a signal based on the output from the sensor to the gas engine replacement device via the gas engine replacement device interface for control of a motor of the gas engine replacement device. 
     In some embodiments, the external electronics module includes a motor and an accessory interface where the electronic processor receives output from the sensor and transmits a signal based on the output from the sensor to the motor to drive an accessory device. 
     In some embodiments, the external electronics module includes a user interface. The user interface includes at least one of an indicator, a switch, a display, a motor speed control selector; a speaker, a relay switch, a motor forward or reverse selector, an on-off switch, or a mode switch. 
     In some embodiments, the external electronics module includes a sensor. The sensor includes at least one of a float, a position sensor, an accelerometer, a gyroscope, a pressure sensor, or an air quality sensor. 
     In some embodiments, the external electronics module includes a gas engine replacement device interface, where the external electronics module receives power from a battery pack coupled to the gas engine replacement device via the gas engine replacement device interface. 
     In some embodiments, the gas engine replacement device interface includes a mechanical key for preventing unauthorized devices from attaching to the gas engine replacement device interface. 
     In some embodiments, the a gas engine replacement device interface includes a wireless transceiver for wirelessly communicating with the gas engine replacement device. 
     In some embodiments, the external electronics module includes a forward/reverse switch configured for selecting between forward and reverse rotation of the motor of the gas engine replacement device. 
     Before any embodiments are explained in detail, it is to be understood that the embodiments are not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. Embodiments described herein are capable of being practiced in or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limited. The use of “including,” “comprising” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “mounted,” “connected” and “coupled” are used broadly and encompass both direct and indirect mounting, connecting and coupling. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings, and can include electrical connections or couplings, whether direct or indirect. Additionally, as used herein with a list of items, “and/or” means that the items may be taken all together, in sub-sets, or as alternatives (for example, “A, B, and/or C” means A; B; C; A and B; B and C; A and C; or A, B, and C). 
     It should be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components may be utilized to implement embodiments described herein. Furthermore, and as described in subsequent paragraphs, the specific configurations illustrated in the drawings are intended as example embodiments and other alternative configurations are possible. The terms “processor” “central processing unit” and “CPU” are interchangeable unless otherwise stated. Where the terms “processor” or “central processing unit” or “CPU” are used as identifying a unit performing specific functions, it should be understood that, unless otherwise stated, those functions can be carried out by a single processor, or multiple processors arranged in any form, including parallel processors, serial processors, tandem processors or cloud processing/cloud computing configurations. 
     In addition, it should be understood that embodiments may include hardware, software, and electronic components or modules that, for purposes of discussion, may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art, and based on a reading of this detailed description, would recognize that, in at least one embodiment, the electronic-based aspects may be implemented in software (e.g., stored on non-transitory computer-readable medium) executable by one or more processing units, such as a microprocessor and/or application specific integrated circuits (“ASICs”). As such, it should be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components, may be utilized to implement the embodiments. 
     Other features and aspects will become apparent by consideration of the following detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a gas engine replacement device including interfaces for connecting electronics of an external electronics module, according to some embodiments. 
         FIG. 2  is a plan view of the gas engine replacement device of  FIG. 1  including interfaces for connecting electronics of an external electronics module, according to some embodiments. 
         FIG. 3  is a schematic view of the gas engine replacement device of  FIG. 1 , according to some embodiments. 
         FIG. 4  is a perspective view of a battery pack of the gas engine replacement device of  FIG. 1 , according to some embodiments. 
         FIG. 5  is a cross-sectional view of the battery pack of  FIG. 4 , according to some embodiments. 
         FIG. 6  is a cross-sectional view of a battery receptacle of the gas engine replacement device of  FIG. 1 , according to some embodiments. 
         FIG. 7  is a cross-sectional view of a motor of the gas engine replacement device of  FIG. 1 , according to some embodiments. 
         FIG. 8  is a schematic view of a motor, a gear train, and a power take-off shaft of the gas engine replacement device of  FIG. 1 , according to some embodiments. 
         FIG. 9  is a schematic view of the gas engine replacement device of  FIG. 1  including interfaces for connecting electronics of an external electronics module, according to some embodiments. 
         FIG. 10  is a schematic view of an external electronics module for attaching electronics to the gas engine replacement device of  FIG. 1 , according to some embodiments. 
         FIG. 11  is a diagram illustrating an external electronics module for attaching electronics to the gas engine replacement device of  FIG. 1 , which includes a user interface for providing feedback for power equipment that is attached to the gas engine replacement device, according to some embodiments. 
         FIG. 12  is a perspective view of a pump system attached to a gas engine replacement device with an external electronics module received by the gas engine replacement device, according to some embodiments 
         FIG. 13  is a flowchart of a method for interfacing one or more external electronics modules to the gas engine replacement device of  FIG. 1 , according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     As shown in  FIGS. 1 and 2 , a gas engine replacement device  10  for use with a piece of power equipment includes a housing  14  with a first side  18 , a second side  22  adjacent the first side  18 , a third side  26  opposite the second side  22 , a fourth side  28  opposite the first side  18 , a fifth side  30  extending between the second and third sides  22 ,  26 , and a sixth side  32  opposite the fifth side  30 . The gas engine replacement device  10  also includes a flange  34  coupled to the housing  14  on the first side  18 , an electric motor  36  located within the housing  14 , and a power take-off shaft  38  that protrudes from the second side  22  and receives torque from the motor  36 . As explained in further detail below, in some embodiments, the power take-off shaft  38  protrudes from the first side  18  and from the flange  34 . As shown in  FIG. 3 , the gas engine replacement device  10  also includes control electronics  42  positioned within the housing  14  and including wiring and a controller  46  that is electrically connected to the motor  36 . A similar gas engine replacement device  10  is described and illustrated in U.S. patent application Ser. No. 16/551,197, filed Aug. 26, 2019, the entire content of which is incorporated herein by reference. The gas engine replacement device  10  also includes one or more module interfaces  342   a,    342   b,    342   c  in the housing  14  for receiving external electronics modules  344  (e.g., external electronics modules). 
     As shown in  FIGS. 1-6 , the gas engine replacement device  10  also includes a battery pack  50  that is removably received in a battery receptacle  54  in the housing  14  to transfer current from the battery pack  50  to the motor  36  via the control electronics  42 . With reference to  FIGS. 4-6 , the battery pack  50  includes a battery pack housing  58  with a support portion  62  and a first terminal  66  that is electrically connected to a plurality of battery cells  68  supported by the battery pack housing  58 . The support portion  62  provides a slide-on arrangement with a projection/recess portion  70  cooperating with a complementary projection/recess portion  74  (shown in  FIG. 6 ) of the battery receptacle  54 . In the embodiment illustrated in  FIGS. 4-6 , the projection/recess portion  70  of the battery pack  50  is a guide rail and the projection/recess portion  74  of the battery receptacle  54  is a guide recess. A similar battery pack is described and illustrated in U.S. Patent Publication No. 2019/0006980 filed Jul. 2, 2018, the entire content of which is incorporated herein by reference. In some embodiments, the battery cells  68  have a nominal voltage of up to about 80 V. In some embodiments, the battery cells  68  have a nominal voltage of up to about 120 V. In some embodiments, the battery pack  50  has a weight of up to about 6 lb. In some embodiments, each of the battery cells  68  has a diameter of up to 21 mm and a length of up to about 71 mm. In some embodiments, the battery pack  50  includes up to twenty battery cells  68 . In some embodiments, the battery cells  68  are connected in series. In some embodiments, the battery cells  68  are operable to output a sustained operating discharge current of between about 40 A and about 60 A. In some embodiments, each of the battery cells  68  has a capacity of between about 3.0 Ah and about 5.0 Ah. 
       FIG. 6  illustrates the battery receptacle  54  of the gas engine replacement device  10  in accordance with some embodiments. The battery receptacle  54  includes the projection/recess portion  74 , a second terminal  78 , a latching mechanism  82 , and a power disconnect switch  86 . The projection/recess portion  74  cooperates with the projection/recess portion  70  of the battery pack  50  to attach the battery pack  50  to the battery receptacle  54  of the gas engine replacement device  10 . When the battery pack  50  is attached to the gas engine replacement device  10 , the second terminal  78  and the first terminal  66  are electrically connected to each other. The latching mechanism  82  protrudes from a surface of the battery receptacle  54  and is configured to engage the battery pack  50  to maintain engagement between the battery pack  50  and the battery receptacle  54 . Thus, the battery pack  50  is connectable to and supportable by the battery receptacle  54  such that the battery pack  50  is supportable by the housing  14  of the gas engine replacement device  10 . In some embodiments, the battery receptacle  54  is arranged on the housing  14  in a position to create a maximum possible distance of separation between the motor  36  and the battery pack  50 , in order to inhibit vibration transferred from the motor  36  to the battery pack  50 . In some embodiments, elastomeric members are positioned on the battery receptacle  54  in order to inhibit vibration transferred from the motor  36 , via the housing  14 , to the battery pack  50 . 
     In other embodiments (not shown), the latching mechanism  82  may be disposed at various locations (e.g., on a sidewall, an end wall, an upper end wall etc., of the battery receptacle  54 ) such that the latching mechanism  82  engages corresponding structure on the battery pack  50  to maintain engagement between the battery pack  50  and the battery receptacle  54 . The latching mechanism  82  includes a pivotable actuator or handle  90  operatively engaging a latch member  94 . The latch member  94  is slidably disposed in a bore  98  of the battery receptacle  54  and is biased toward a latching position by a biasing member  100  (e.g., a spring) to protrude through a surface of the battery receptacle  54  and into a cavity in the battery pack  50 . 
     The latching mechanism also  82  includes the power disconnect switch  86  (e.g., a micro-switch) facilitating electrical connecting/disconnecting the battery pack  50  from the battery receptacle  54  during actuation of the handle  90  to withdraw the latch member  94  from the battery pack  50 . The power disconnect switch  86  may act to electrically disconnect the battery pack  50  from the gas engine replacement device  10  prior to removal of the battery pack  50  from the battery receptacle  54 . The power disconnect switch  86  is actuated when the latch member  94  is moved from the latched position (i.e., when the latch member  94  is completely within the cavity of the battery pack  50 ) to an intermediate position. The power disconnect switch  86  is electrically connected to the controller  46  and may generate an interrupt to indicate that the battery pack  50  is being disconnected from the gas engine replacement device  10 . When the controller  46  receives the interrupt, the controller  46  begins a power down operation to safely power down the control electronics  42  of the gas engine replacement device  10 . A similar latching mechanism and disconnect switch is described and illustrated in U.S. Patent Publication No. 2019/0006980, which has been incorporated herein by reference. 
     As shown in  FIG. 7 , the motor  36  includes a motor housing  96  having an outer diameter  97 , a stator  99  having a nominal outer diameter  102  of up to about 80 mm, a rotor  103  having an output shaft  106  and supported for rotation within the stator  99 , and a fan  108 . A similar motor is described and illustrated in U.S. Patent Publication No. 2019/0006980, which has been incorporated herein by reference. In some embodiments, the motor  36  is a brushless direct current motor. In some embodiments, the motor  36  has a power output of at least about 2760 W. In some embodiments, the power output of the motor  36  may drop below 2760 W during operation. In some embodiments, the fan  108  has a diameter  109  that is larger diameter  97  of the motor housing  96 . In some embodiments, the motor  36  can be stopped with an electronic clutch (not shown) for quick overload control. In some embodiments, the motor  36  has a volume of up to about 443,619 mm 3 . In some embodiments, the motor has a weight of up to about 4.6 lb. The housing  14  includes an inlet vent and an outlet vent, such that the motor fan  108  pulls air through the inlet vent and along the control electronics  42  to cool the control electronics  42 , before the air is exhausted through the outlet vent. In the embodiment illustrated in  FIG. 7 , the motor  36  is an internal rotor motor, but in other embodiments, the motor  36  can be an outer rotor motor with a nominal outer diameter (i.e. the nominal outer diameter of the rotor) of up to about 80 mm. 
     With reference to  FIG. 8 , the motor  36  can transfer torque to the power take-off shaft  38  in a variety of configurations. In some embodiments, the output shaft  106  is also the power take-off shaft  38 , such that the motor  36  directly drives the power take-off shaft  38  without any intermediate gear train. For example, the motor  36  may be a direct drive high pole count motor. As shown in  FIG. 8 , in other embodiments, the gas engine replacement device  10  includes a gear train  110  that transfers torque from the motor  36  to the power take-off shaft  38 . In some embodiments, the gear train  110  can include a mechanical clutch (not shown) to discontinue the transfer of torque from the motor  36  to the power take-off shaft  38 . In some embodiments, the gear train  110  may include a planetary transmission that transfers torque from the output shaft  106  to the power take-off shaft  38 , and a rotational axis of the output shaft  106  is coaxial with a rotational axis of the power take-off shaft  38 . In some embodiments, the gear train  110  includes a spur gear engaged with the output shaft  106  of the rotor, such that the rotational axis of the output shaft  106  is offset from and parallel to the rotational axis of the power take-off shaft  38 . In some embodiments, the gear train  110  includes a bevel gear, such that the rotational axis of the output shaft  106  is perpendicular to the rotational axis of the power take-off shaft  38 . In other embodiments utilizing a bevel gear, the rotational axis of the output shaft  106  is not perpendicular, parallel, or coaxial to the rotational axis of the power take-off shaft  38 , and the power take-off shaft  38  protrudes from the flange  34 . 
     In some embodiments, the gas engine replacement device  10  includes ON/OFF indicators (not shown). In some embodiments, the gas engine replacement device  10  includes a filter (not shown) to keep airborne debris out of the motor  36  and control electronics  42 . In some embodiments, the filter includes a dirty filter sensor (not shown) and a self-cleaning mechanism (not shown). In some embodiments, the motor  36  will mimic a gas engine response when encountering resistance, such as slowing down or bogging. In some embodiments, the gas engine replacement device  10  includes a heat sink  202  in the housing  14  for air-cooling the control electronics  42  ( FIGS. 1 and 2 ). In some embodiments, the gas engine replacement device  10  is liquid cooled. 
     In some embodiments, the output shaft  106  of the rotor  103  has both forward and reverse capability as further described below. In some embodiments, the forward and reverse capability is controllable without shifting gears of the gear train  110 , in comparison to gas engines, which cannot achieve forward/reverse capability without extra gearing and time delay. Thus, the gas engine replacement device  10  provides increased speed, lower weight, and lower cost. Because the gas engine replacement device  10  has fewer moving parts and no combustion system, as compared with a gas engine, it also provides additional speed, weight, and cost advantages. 
     The gas engine replacement device  10  is able to operate in any orientation (vertical, horizontal, upside down) with respect to a ground surface for a prolonged period of time, giving it an advantage over four-cycle gas engines, which can only be operated in one orientation and at slight inclines for a shorter period of time. Because the gas engine replacement device  10  does not require gas, oil, or other fluids, it can run, be transported, and be stored upside down or on any given side without leaking or flooding 
     In operation, the gas engine replacement device  10  can be used to replace a gas engine system. Specifically, the gas engine replacement device  10  can be mounted to the piece of power equipment having a second bolt pattern by aligning a first bolt pattern defined by the plurality of apertures in the flange  34  with the second bolt pattern. In some embodiments, the flange  34  may include one or more intermediate mounting members or adapters arranged between the flange  34  itself and the flange of the piece of power equipment having the second bolt pattern, such that the adapter(s) couple the flange  34  to the piece of power equipment. In these embodiments, the adapter includes both the second bolt pattern and the first bolt pattern, such that the first bolt pattern of the flange  34  aligns with the first bolt pattern of the adapter and the second bolt pattern of the adapter aligns with the second bolt pattern defined in the piece of power equipment, thereby allowing the flange  34  of the gas engine replacement device  10  to be coupled to the piece of power equipment. 
     Alternatively, the gas engine replacement device  10  can be connected to a piece of power equipment using a belt system by providing a belt that operatively connects the power take-off shaft and an equipment bit. Thus, the power take-off shaft  38  of the gas engine replacement device  10  can be used to drive the equipment. 
     During operation, the housing  14  of the gas engine replacement device  10  is comparably much cooler than the housing of an internal combustion unit because there is no combustion in the gas engine replacement device  10 . Specifically, when a gas engine unit runs, the housing of the gas engine unit is 220 degrees Celsius or higher. In contrast, when the gas engine replacement device  10  runs, all of the exterior surfaces of the housing  14  are less than 95 degrees Celsius. Tables 1 and 2 below list with further specificity the temperature limits of different components on the housing  14  of the gas engine replacement device  10 . 
     Table 1 below lists the Underwriter&#39;s Laboratories (UL) temperature limits of different components typically used in power tools, with respect to whether those components are formed of metal, plastic, rubber, wood, porcelain, or vitreous. For example, at least in some embodiments, the plastic rated temperatures are never exceeded by the gas engine replacement device  10 . 
     
       
         
           
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                 Plastic/Rubber/ 
                 Porcelain/ 
               
               
                   
                 Metal 
                 Wood 
                 Vitreous 
               
               
                   
               
             
            
               
                 Casual Contact 
                 85° C. 
                 85° C. 
                 85° C. 
               
               
                 Handles and knobs that are 
                 55° C. 
                 75° C. 
                 65° C. 
               
               
                 continuously held 
                   
                   
                   
               
               
                 Handles and knobs that are only 
                 60° C. 
                 80° C. 
                 70° C. 
               
               
                 briefly held (i.e. switches) 
               
               
                   
               
            
           
         
       
     
     Table 2 below lists the UL temperature limits of different components of the battery pack housing  58  of the battery pack  50 , with respect to whether those components are formed of metal, plastic or rubber. For example, at least in some embodiments, the plastic rated temperatures are never exceeded by the gas engine replacement device  10 . 
     
       
         
           
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                   
                 Metal 
                 Plastic/Rubber 
               
               
                   
               
             
            
               
                 Casual Contact 
                 70° C. 
                 95° C. 
               
               
                 Handles and knobs that are continuously held 
                 55° C. 
                 75° C. 
               
               
                 Handles and knobs that are only briefly held  
                 60° C. 
                 85° C. 
               
               
                 (i.e. switches) 
               
               
                   
               
            
           
         
       
     
       FIG. 9  illustrates a simplified block diagram of the gas engine replacement device  10  according to one example embodiment. As shown in  FIG. 9 , the gas engine replacement device  10  includes an electronic processor  302 , a memory  306 , the battery pack  50 , a power switching network  310 , the motor  36 , a rotor position sensor  314 , a current sensor  318 , a user input device  322  (e.g., a trigger or power button), a transceiver  326 , indicators  330  (e.g., light-emitting diodes), a communications manager  340 , and one or more module interfaces  342   a,    342   b,    342   c.  Also shown in  FIG. 9  are one or more external electronics modules  344 A,  344 B,  344 C. In some embodiments, the gas engine replacement device  10  includes fewer or additional components than those shown in  FIG. 9 . For example, the gas engine replacement device  10  may include a battery pack fuel gauge, work lights, additional sensors, kill switch, the power disconnect switch  86 , etc. In some embodiments, elements of the gas engine replacement device  10  illustrated in  FIG. 9  including one or more of the electronic processor  302 , memory  306 , power switching network  310 , rotor position sensor  314 , current sensor  318 , user input device  322  (e.g., a trigger or power button), transceiver  326 , and indicators  330  (e.g., light-emitting diodes) form at least part of the control electronics  42  shown in  FIG. 3 , with the electronic processor  302  and the memory  306  forming at least part of the controller  46  shown in  FIG. 3 . 
     The memory  306  includes read only memory (ROM), random access memory (RAM), other non-transitory computer-readable media, or a combination thereof. The electronic processor  302  is configured to communicate with the memory  306  to store data and retrieve stored data. The electronic processor  302  is configured to receive instructions and data from the memory  306  and execute, among other things, the instructions. In particular, the electronic processor  302  executes instructions stored in the memory  306  to perform the methods described herein. 
     As described above, in some embodiments, the battery pack  50  is removably attached to the housing of the gas engine replacement device  10  such that a different battery pack  50  may be attached and removed to the gas engine replacement device  10  to provide different amount of power to the gas engine replacement device  10 . Further description of the battery pack  50  (e.g., nominal voltage, sustained operating discharge current, size, number of cells, operation, and the like), as well as the motor  36  (e.g., power output, size, operation, and the like), is provided above with respect to  FIGS. 1-8 . 
     The power switching network  310  enables the electronic processor  302  to control the operation of the motor  36 . Generally, when the user input device  322  is depressed (or otherwise actuated), electrical current is supplied from the battery pack  50  to the motor  36 , via the power switching network  310 . When the user input device  322  is not depressed (or otherwise actuated), electrical current is not supplied from the battery pack  50  to the motor  36 . In some embodiments, the amount in which the user input device  322  is depressed is related to or corresponds to a desired speed of rotation of the motor  36 . In other embodiments, the amount in which the user input device  322  is depressed is related to or corresponds to a desired torque. In other embodiments, a separate input device (e.g., slider, dial, or the like) is included on the gas engine replacement device  10  in communication with the electronic processor  302  to provide a desired speed of rotation or torque for the motor  36 . 
     In some embodiments, the user input device  322  may be a forward/reverse switch actuated by a user or a mode selection switch that allows the user to select a mode of operation. The user input device  322  provides a control signal to the electronic processor  302  to switch the direction of rotation of the motor  36  based on the actuation of the user input device  322 . In some embodiments, the input may be received from one or more sensors of the gas engine replacement device  10  or a power equipment coupled to the gas engine replacement device  10 . In some embodiments, the input may be received from, for example, a smart phone through the communication network  334 . 
     In response to the electronic processor  302  receiving a drive request signal from the user input device  322 , the electronic processor  302  activates the power switching network  310  to provide power to the motor  36 . Through the power switching network  310 , the electronic processor  302  controls the amount of current available to the motor  36  and thereby controls the speed and torque output of the motor  36 . The power switching network  310  may include numerous field-effect transistors (FETs), bipolar transistors, or other types of electrical switches. For instance, the power switching network  310  may include a six-FET bridge (see  FIG. 10 ) that receives pulse-width modulated (PWM) signals from the electronic processor  302  to drive the motor  36 . In some embodiments, the electronic processor  302  receives the drive request signal from an external electronics module  344  and the electronic processor  302  activates the power switching network  310  to provide power to the motor  36 . 
     The rotor position sensor  314  and the current sensor  318  are coupled to the electronic processor  302  and communicate to the electronic processor  302  various control signals indicative of different parameters of the gas engine replacement device  10  or the motor  36 . In some embodiments, the rotor position sensor  314  includes a Hall sensor or a plurality of Hall sensors. In other embodiments, the rotor position sensor  314  includes a quadrature encoder attached to the motor  36 . The rotor position sensor  314  outputs motor feedback information to the electronic processor  302 , such as an indication (e.g., a pulse) when a magnet of a rotor of the motor  36  rotates across the face of a Hall sensor. In yet other embodiments, the rotor position sensor  314  includes, for example, a voltage or a current sensor that provides an indication of a back electro-motive force (back emf) generated in the motor coils. The electronic processor  302  may determine the rotor position, the rotor speed, and the rotor acceleration based on the back emf signals received from the rotor position sensor  314 , that is, the voltage or the current sensor. The rotor position sensor  314  can be combined with the current sensor  318  to form a combined current and rotor position sensor. In this example, the combined sensor provides a current flowing to the active phase coil(s) of the motor  36  and also provides a current in one or more of the inactive phase coil(s) of the motor  36 . The electronic processor  302  measures the current flowing to the motor based on the current flowing to the active phase coils and measures the motor speed based on the current in the inactive phase coils. 
     Based on the motor feedback information from the rotor position sensor  314 , the electronic processor  302  can determine the position, velocity, and acceleration of the rotor. In response to the motor feedback information and the signals from the user input device  322 , the electronic processor  302  transmits control signals to control the power switching network  310  to drive the motor  36 . For instance, by selectively enabling and disabling the FETs of the power switching network  310 , power received from the battery pack  50  is selectively applied to stator windings of the motor  36  in a cyclic manner to cause rotation of the rotor of the motor  36 . The motor feedback information is used by the electronic processor  302  to ensure proper timing of control signals to the power switching network  310  and, in some instances, to provide closed-loop feedback to control the speed of the motor  36  to be at a desired level. For example, to drive the motor  36 , using the motor positioning information from the rotor position sensor  314 , the electronic processor  302  determines where the rotor magnets are in relation to the stator windings and (a) energizes a next stator winding pair (or pairs) in the predetermined pattern to provide magnetic force to the rotor magnets in a direction of desired rotation, and (b) de-energizes the previously energized stator winding pair (or pairs) to prevent application of magnetic forces on the rotor magnets that are opposite the direction of rotation of the rotor. 
     The current sensor  318  monitors or detects a current level of the motor  36  during operation of the gas engine replacement device  10  and provides control signals to the electronic processor  302  that are indicative of the detected current level. The electronic processor  302  may use the detected current level to control the power switching network  310  as explained in greater detail below. 
     The transceiver  326  allows for communication between the electronic processor  302  and an external device  338  (e.g., a smart phone, tablet, or laptop computer) over a wired or wireless communication network  334 . In some embodiments, the transceiver  326  may comprise separate transmitting and receiving components. In some embodiments, the transceiver  326  may comprise a wireless adapter attached to the gas engine replacement device  10 . In some embodiments, the transceiver  326  is a wireless transceiver that encodes information received from the electronic processor  302  into a carrier wireless signal and transmits the encoded wireless signal to the external device  338  over the communication network  334 . The transceiver  326  also decodes information from a wireless signal received from the external device  338  over the communication network  334  and provides the decoded information to the electronic processor  302 . 
     The communication network  334  provides a wired or wireless connection between the gas engine replacement device  10  and the external device  338 . The communication network  334  may comprise a short-range network, for example, a BLUETOOTH network, a Wi-Fi network or the like, or a long range network, for example, the Internet, a cellular network, or the like. 
     As shown in  FIG. 9 , the indicators  330  are also coupled to the electronic processor  302  and receive control signals from the electronic processor  302  to turn on and off or otherwise convey information based on different states of the gas engine replacement device  10 . The indicators  330  include, for example, one or more light-emitting diodes (“LEDs”), or a display screen. The indicators  330  can be configured to display conditions of, or information associated with, the gas engine replacement device  10 . For example, the indicators  330  are configured to indicate measured electrical characteristics of the gas engine replacement device  10 , the status of the gas engine replacement device  10 , the mode of the gas engine replacement device  10 , etc. The indicators  330  may also include elements to convey information to a user through audible or tactile outputs. In some embodiments, the indicators  330  include an eco-indicator that indicates an amount of power being used by the load during operation. 
     The connections shown between components of the gas engine replacement device  10  are simplified in  FIG. 9 . In practice, the wiring of the gas engine replacement device  10  is more complex, as the components of a gas engine replacement device are interconnected by several wires for power and control signals. For instance, each FET of the power switching network  310  is separately connected to the electronic processor  302  by a control line; each FET of the power switching network  310  is connected to a terminal of the motor  36 ; the power line from the battery pack  50  to the power switching network  310  includes a positive wire and a negative/ground wire; etc. Additionally, the power wires can have a large gauge/diameter to handle increased current. Further, although not shown, additional control signal and power lines are used to interconnect additional components of the gas engine replacement device  10 . 
     With reference to  FIGS. 1, 2, 9 and 10 , the housing  14  includes one or more module interfaces  342   a,    342   b,    342   c  that are configured to removably receive and support interchangeable modular electronic devices such as the external electronics module(s)  344 . In the illustrated embodiment, the housing  14  has three module interfaces  342   a,    342   b,    342   c  disposed on one side of the gas engine replacement device  10 . However, this configuration is merely exemplary, as the housing  14  may include more or less than three module interfaces  342   a,    342   b,    342   c,  and each side of the housing  14  may include more or less that three module interfaces  342   a,    342   b,    342   c.    
     With continued reference to  FIGS. 1, 2, 9 and 10 , each module interface  342   a,    342   b,    342   c  includes a communication interface and a coupling interface. The communication interface includes an electrical connector that may be disposed within a recess of the housing  14 . The electrical connector is configured to facilitate electrical communication and/or data communication between the external electronics module  344  and the gas engine replacement device  10 . The electrical connector may be any suitable type of input and/or output port. Additionally, in some embodiments the electrical connector may define separate power connectors and data connectors, which may similarly be any suitable type of power connectors and data connectors. In some embodiments, power from the battery pack  50  is supplied to an external electronics module  344  and is transmitted via a module interface  342   a,    342   b,    342   c  via an electrical connector. For example, to power the external electronics module  344 , a cable of 3 to 6 wires may be utilized in order to provide the communication lines and the voltage input with a ground for return. 
     The gas engine replacement device  10  may be configured to receive a variety of different external electronics modules  344  with the interface(s)  342   a,    342   b,    342   c.  In some embodiments, an external electronics module  344  may include a component that is designed for a particular piece of power equipment that is attached to and driven by the gas engine replacement device  10 . The specified external electronics module  344  may be received by the gas engine replacement device  10  via a module interface  342   a,    342   b,    342   c  or a set of interfaces configured to receive that particular external electronics module  344 . These external electronics modules  344  and module interfaces  342   a,    342   b,    342   c  allow users to add features to their gas engine replacement device  10  and/or to the power equipment driven by the gas engine replacement device  10  after they purchase their equipment. For example, when a concrete saw, pump, or compactor is attached to and/or driven by the gas engine replacement device  10 , an external electronics module  344  may include one or more performance indicators specified for the attached power equipment (see below for more details). 
     Alternatively, or in addition, various external electronics modules  344  may include one or more generic hardware component(s) (e.g., switches, relays, floats, position sensors, accelerometers, gyroscopes, pressure sensors, air quality sensors, displays, etc.) that can be interchangeably received by generic module interface(s)  342   a,    342   b,    342   c.  The generic external electronics modules  344  may be received by generic module interfaces  342   a,    342   b,    342   c  and signals may be routed to the electronic processor  302  and/or output to other external electronics module(s)  344  via other module interfaces  342   a,    342   b,    342   c.  For example, the output signals may be transmitted to external electronics modules  344  (e.g., to control displays, lights, LEDs, warnings, audible alerts, relays, or other feedback user interfaces). Generic external electronics modules  344  may be used by the OEM or end user and provide a more efficient and effective use of the gas engine replacement device  10  and attached power equipment since they may receive input and provide feedback tailored to a specific situation and usage. 
     The gas engine replacement device  10  includes a communications manager  340  that may be included in the electronic processor  302  or may be a separate processor component. The electronic processor  302  may receive signals from and/or transmit signals to the one or more external electronics modules  344  utilizing the communications manager  340 . In some embodiments, the electronic processor  302  receives a signal from a first external electronics module  344  and generates a signal for transmission based on the received signal. For example, the signal may be transmitted to the power switching network  310  to drive the motor  36  and/or control how the motor is driven based on input received from an external electronics module  344 . Alternatively, or in addition, the electronic processor  302  may transmit the output signal to a second external electronics module  344  based on the signal received from a first external electronics module  344 . In some embodiments, the communications manager  340  may translate received signals for communication with the electronic processor  302  or another external electronics module  344 . For example, a signal received from a first external electronics module  344  via a first module interface  342 A may be adapted for communication to a second external electronics module  344  via a second module interface  342 B and/or to a third external electronics module  344  via a third module interface  342 C. 
     The electronic processor  302  may be configured for receiving a particular type of external electronics module  344 . Moreover, the type of communication connections supported between the electronic processor  302  and an external electronics module  344  via a module interface  342   a,    342   b,    342   c  may be fixed, pre-defined (e.g., by an OEM), or may be user configurable. For example, a user may configure the electronic processor  302 , using an application on the external device  338 , for receiving a particular type of external electronics module  344  and/or for a communicating via one or more module interfaces  342   a,    342   b,    342   c  based on a specified communication method. The application on the external device  383  communicates configuration parameters to the electronic processor  302  via the transceiver  326  based on user input. The user may configure the gas engine replacement device  10  to receive an input from an external electronics module  344  in a specific way, such as with a specified type of data communications, a voltage level detected using an analog to digital converter of the electronic processor  302 , a resistance level, a standard digital I/O, etc. Output from the electronic processor  302  may be configured to be a PWM modification to the power switching network  310  to control the motor  36 , a signal to the module interface  342   a,    342   b,    342   c  including a general-purpose input/output (GPIO) state change, or another form of communication via the module interface  342   a,    342   b,    342   c.  Furthermore, various combinations of communication ports may be configured for the module interface(s)  342   a,    342   b,    342   c  and more than one output event may be generated. 
     In some embodiments, signals of various communication circuits, interfaces, or communications protocols (e.g., RS485, Universal Asynchronous Receiver/Transmitter (UART), Serial Peripheral Interface (SPI), Control Area Network (CAN bus), or Universal Serial Bus (USB) etc.) or voltage values that are detected by the electronic processor  302  via a module interface  342   a,    342   b,    342   c  from an external electronics module  344 , can be used by the electronic processor  302  to identify a particular external electronics module  344 . For example, when voltage levels are received from an external electronics module  344 , an analog to digital converter (ADC) of the electronic processor  302  may be used to determine which external electronics module  344  sent the voltage signal based on the voltage level being provided. The electronic processor  320  may identify the source of the signal using a signifier in a look-up table. Alternatively, or in addition, when a communication protocol is used, the electronic processor  302  may load-in operational information via the module interface  342   a,    342   b,    342   c  and configure the gas engine replacement device  10  with specified communication functions to be enabled and store information on how to load and/or save data from an external electronics module  344 . 
     Communication with the gas engine replacement device  10  by an external electronics module  344  may include connecting, based on the configured communication method, to either an internal or external communication buffer on the gas engine replacement device  10 . When exchanging information with the electronic processor  302 , the external electronics module  344  may provide a device ID so that the electronic processor  302  can configure a definition for the external electronics module  344  and unlock appropriate features to be accessed by or for the external electronics module  344 . Subsequent communications from the same external electronics module  344  may utilize the same device ID as packet identification such that the communications manager  340  can direct data received from the external electronics module  344  into an appropriate section of firmware. 
       FIG. 10  is a schematic view of an example of an external electronics modules  344  (e.g., one of the external electronics modules  344   a,    344   b,    344   c ) configured to attach to the gas engine replacement device  10 . The external electronics module  344  may include an electronic processor  1010 , a memory  1012 , a gas engine replacement device interface  1014  (or GER device interface  1014 ), a user interface  1016 , a power equipment/accessory interface  1018 , a sensor  1020 , and a motor  1022 . In the illustrated embodiment of  FIG. 10 , the external electronics module  344  includes elements  1010 ,  1012 ,  1014 ,  1016 ,  1018 ,  1020 , and  1022 . However, in some embodiments, the external electronics module  344  includes fewer or additional components than those shown in  FIG. 10 . For example, in some embodiments, the motor  1022  is not included, and in some embodiments, the sensor  1020  is not included. Further, in some embodiments, a load other than the motor  1022  is provided (e.g., one or more solenoid actuators that control power provided to yet another load). 
     The memory  1012  includes read only memory (ROM), random access memory (RAM), other non-transitory computer-readable media, or a combination thereof. The electronic processor  1010  is configured to communicate with the memory  1012  to store data and retrieve stored data. The electronic processor  1010  is configured to receive instructions and data from the memory  1012  and execute, among other things, the instructions. In particular, the electronic processor  1010  executes instructions stored in the memory  1012  to perform the methods described herein. In some embodiments, the external electronics module  344  may not include the electronic processor  1010  and/or the memory  1012  and may function based on hardware elements or circuitry of the external electronics module  344 . For example, input from one or more of the sensor(s)  1020 , the user interface  1016 , the GER device interface  1014 , and the power equipment/accessory interface  1018 , may be routed to one or more of the electronic processor  302  via the GER device interface  1014 , the user interface  1016 , or the power equipment/accessory interface  1018 . 
     The GER device interface  1014  may be disposed on a housing (e.g., the housing  1110  of  FIG. 11 ) of the external electronics module  344 . The GER device interface  1014  includes one or more interfaces that are configured to removably receive and support the module interface(s)  342   a,    342   b,    342   c  of the gas engine replacement device  10 , either directly or via a connector and cable to the module interface(s)  342   a,    342   b,    342   c  (e.g., the external electronics module  344  or a portion of the module may be handheld). In some embodiments, the module interface(s)  342   a,    342   b,    342   c  and/or the GER device interface(s)  1014  includes a mechanical key for guiding connection of the interfaces and preventing unauthorized or incompatible devices from attaching thereto. In some embodiments the module interface(s)  342   a,    342   b,    342   c  and/or the GER device interface(s)  1014  are configured with, for example, mechanical casings and/or electrical enclosures to protect the device or module electronics against intrusion, dust, accidental contact, and water damage, and may be ingress rated. Alternatively, or in addition, the GER device interface  1014  may include a wireless transceiver such that the electronic processor  1010  may communicate with the electronic processor  302  via the transceiver  326 . 
     The GER device interface  1014  may be coupled to the electronic processor  1010  of the external electronics module  344  such that the electronic processor  1010  of the external electronics module  344  is communicatively coupled to the electronic processor  302  of the gas engine replacement device  10  via the GER device interface  1014  of the external electronics module  344  and the module interface  342   a,    342   b,    342   c  of the gas engine replacement device  10 . 
     With continued reference to  FIGS. 1, 2, 9 and 10 , the GER device interface  1014  includes a communication interface and a coupling interface. The communication interface includes an electrical connector that corresponds to the module interface  342   a,    342   b,    342   c.  The electrical connector is configured to facilitate electrical communication and/or data communication between the external electronics module  344  and the gas engine replacement device  10 . The electrical connector may be any suitable type of input and/or output connector. Additionally, in some embodiments the electrical connector may define separate power connectors and data connectors, which may similarly be any suitable type of power connectors and data connectors. In some embodiments, power from the battery pack  50  is supplied to the external electronics module  344  and is transmitted via a module interface  342   a,    342   b,    342   c  and the electrical connector. For example, to power the external electronics module  344 , a cable of 3 to 6 wires may be utilized in order to provide the communication lines and the voltage input with a ground for return. 
     The user interface  1016  may be disposed on a housing (e.g., the housing the user interface  1016  of  FIG. 11 ) of the external electronics module  344  or may be separate from the housing and coupled by a cable or wirelessly (e.g. the interface may be hand held). The user interface  1016  is coupled to the electronic processor  1010 . The user interface  1016  may have input and/or output features to receive user input and/or provide feedback to users about the gas engine replacement device  10 , the external electronics module  344 , and/or the power equipment attached to the gas engine replacement device  10 . In some embodiments, the user interface  1016  may be similar to the user input device  322  and/or the indicators  330  of the gas engine replacement device  10 , or the user interface  1016  may be operated in place of the user input device  322  and/or the indicators  330 . For example, the user interface  1016  may include a trigger or power button such that when the user interface  1016  is depressed (or otherwise actuated), a signal is transmitted by the electronic processor  1010  to the electronic processor  302  and electrical current is supplied from the battery pack  50  to the motor  36  via the power switching network  310 . The user interface  1016  may be utilized to control a desired speed of rotation or applied torque of the motor  36  of the gas engine replacement device  10 . In some embodiments, the user interface  1016  may include a trigger pull, a slider, a dial, a display device (e.g., an interactive display), or the like. In some embodiments, the user interface  1016  includes a forward/reverse switch actuated by a user or a mode selection switch that allows the user to select a mode of operation of the gas engine replacement device  10 . 
     In some embodiments, the user interface  1016  includes an indicator and the electronic processor  1010  provides control signals to the user interface  1016  to turn on, turn off, or otherwise convey information based on different states of the gas engine replacement device  10  that may be received by the electronic processor  1010  from the electronic processor  302  of the gas engine replacement device  10 . The user interface  1016  may include, for example, one or more light-emitting diodes (“LEDs”) or a display screen. The user interface  1016  can be configured to display conditions of, or information associated with, the gas engine replacement device  10 , the external electronics module  344 , or the power equipment attached to the gas engine replacement device  10 . For example, the user interface  1016  may be configured to indicate measured electrical characteristics of the gas engine replacement device  10 , the status of the gas engine replacement device  10 , the mode of the gas engine replacement device  10 , etc. The user interface  1016  may also include elements to convey information to a user such as through displays, lights, LEDs, warnings, audible alerts, or other feedback user interfaces. In some embodiments, the user interface  1016  includes an eco-indicator that indicates an amount of power being drawn from the battery pack  50  and used by the load during operation. 
     In some embodiments, the external electronics module  344  may include a power equipment/accessory interface  1018  to connect to the power equipment (e.g., the pump system  1220  of  FIG. 12 ) or to an accessory (e.g., light, fan, vacuum, sprayer, speaker, etc.). The power equipment/accessory interface  1018  may connect directly, via a cable, or wirelessly (e.g., the power equipment/accessory interface  1018  may include a wireless transceiver) to the power equipment or the accessory. In some embodiments, the electronic processor  1010  of the external electronics module  344  may receive operational or performance data from the power equipment or accessory that may be utilized to provide feedback to a user via the user interface  1016 , for example. 
     In some embodiments, the external electronics module  344  includes one or more sensors  1020  (e.g., a level sensor, floats, position sensors, a temperature sensor, accelerometers, gyroscopes, pressure sensors, air quality sensors, a motor speed sensor, etc.). The sensor(s)  1020  may be configured to detect a condition or state of the external electronics module  344 , the gas engine replacement device  10 , and/or the surrounding environment. In some embodiments, the electronic processor  1010  receives an analog or digital signal from the sensor(s)  1020  and determines a responsive action. In some embodiments, the electronic processor  1010  is be configured to receive output from the sensor(s)  1020  and/or user input from the user interface  1016  and determine a responsive action using a look-up table. For example, in response to the sensor output and/or user input, the electronic processor  1010  may transmit a signal to the electronic processor  302  of the gas engine replacement device  10  to control the motor  36 , to transmit a signal to the user interface  1016  to indicate a condition or operation of the gas engine replacement device  10  or the power equipment attached to the gas engine replacement device  10 , or to transmit a signal via the power equipment/accessory interface  1018  to control the power equipment. 
     In some embodiments, the external electronics module  344  includes a motor  1022 . The motor  1022  may be controlled by the electronic processor  1010  via a power switching network (not shown) of the external electronics module  344 . The motor  1022  may drive an accessory (e.g., a fan, a vacuum, a sprayer, etc.) of the external electronics module  344 , the gas engine replacement device  10 , or the power equipment attached to the gas engine replacement device  10 . The electronic processor  1010  may drive the motor  1022  or actuate an accessory such as a light or speaker, based on input received from the electronic processor  302  of the gas engine replacement device  10 , from the power equipment via the power equipment/accessory  1018 , from the sensor  1020 , or user input received via the user interface  1016 . 
     In some embodiments, the user interface  1016  includes digital controls on a customizable user interface, such as a touch display or a combination of knobs and buttons. In some embodiments, the user interface  1016  can be modular, wired, or wireless and can be attachable to the gas engine replacement device  10  or be handheld. In some embodiments, the external electronics module  344  can be controlled with a remote control that includes status indicators for certain characteristics of the gas engine replacement device  10 , such as charge of the battery pack  50  and the temperature. In some embodiments, the external electronics module  344  can provide status indications with a remote programmable device. 
       FIG. 11  is a diagram illustrating an external electronics module  344  for attaching electronics to the gas engine replacement device of  FIG. 1 . The external electronics module  344  of  FIG. 11  includes a user interface  1016  for providing feedback for power equipment that is attached to the gas engine replacement device  10 . The power equipment is driven by the motor  36  of the gas engine replacement device  10 . As illustrated, the user interface  1016  of  FIG. 11  includes three components, including a level indicator  1128 , an eco-indicator  1130 , and a battery meter  1132 . However, in some embodiments, the user interface  1016  may include only two of the three components and, in other embodiments, the user interface  1016  may include only one of the three components or further components in addition to the three components. User perception of the operation of high-voltage battery-powered power equipment is different compared to typical gas engine device. The operator may not realize the amount of current being drawn from the battery pack  50  of the gas engine replacement device  10  to run the power equipment. This lack of recognition may result in inefficient operation of the power tool, leading to faster than normal discharge of the battery pack or slower completion of a workpiece operation. The user interface  1016  may provide useful feedback to the operator to allow improved efficiency and control of the power equipment. 
     The level indicator  1128  includes a center indicator  1134  and direction indicators  1136 . In the example illustrated, the center indicator  1134  is bar shaped and indicates whether the equipment driven by the gas engine replacement engine is level. For example, the center indicator  1134  indicates whether a rotational axis of the output shaft  140  is either parallel with the ground (i.e., horizontal, when the shaft is used in a sideways orientation) or perpendicular to the ground (i.e., vertical, when the shaft is used in an upright orientation). The center indicator  1134  may be illuminated to indicate to a user that the rotational axis is horizontal or vertical relative to the ground. The direction indicators  1136  include four indicators, one on each side of the center indicator  1134 . The direction indicators  1136  are shaped like arrows that point towards the center indicator  1134 . The direction indicators  1136  help the user in determining which direction to tilt or move the power equipment to align the rotational axis either parallel with or perpendicular to the ground. For example, the right direction indicator  1136  with the arrow pointing to the left may be illuminated when the power equipment is to be tilted or moved to the left. In one embodiment, the sensor  1020  (see  FIG. 10 ) includes an accelerometer configured to indicate position relative to Earth&#39;s gravitational pull, which the electronic processor  1010  receives and on which the electronic processor  1010  bases control signals sent to the level indicator  1128  to indicate the level of the gas engine replacement device  10 . 
     The eco-indicator  1130  is provided on the user interface  1016  to indicate an amount of power being used by the motor  36  of the gas engine replacement device  10  when the gas engine replacement device  10  is driving the power equipment (i.e., an amount of current being drawn from the battery pack  50  of the gas engine replacement device  10  to drive the motor  36 ). In the example illustrated, the eco-indicator  1130  includes five LED bars  1138 ,  1140 ,  1142 ,  1144 ,  1146 . The LED bars  1138 ,  1140 ,  1142 ,  1144 ,  1146  are distributed in a performance map that is segmented into a plurality of performance regions  1102 ,  1104 ,  1106  for operating the motor  36  of the gas engine replacement device  10  to drive the coupled power equipment. Illumination of the LED bars  1138 ,  1140 ,  1142 ,  1144 ,  1146  is based on control signals transmitted by the electronic processor  302  to the external electronics module  344 . For example, while the motor  36  is activated to drive the power equipment(e.g., based on user input to an input user interface  1016  on the an external electronics module  344 , or a trigger input on the power equipment), the electronic processor  302  receives output from the current sensor  318  and determines the current flowing to the motor  36 . The electronic processor  302  compares the detected motor current to a range of current thresholds to determine the current level. In one example, the current thresholds are 20%, 40%, 60%, 80%, and 100% of allowable current (e.g., a maximum current level) for driving the motor  36 . The thresholds may be mapped to the LED bars  1138 ,  1140 ,  1142 ,  1144 ,  1146  respectively. The allowable current may be a specified current level that the battery pack  50  can discharge without damaging the battery pack  50  or the power equipment. This specified or maximum battery current may be chosen as a maximum allowable motor current. The electronic processor  302  then generates signals to the external electronics module  344  to illuminate the appropriate LED bar  1138 ,  1140 ,  1142 ,  1144 ,  1146  according to the determined current level. 
     The battery meter  1132  of the user interface  1016  includes LED bars (for example, four LED bars) that are illuminated to indicate a state of charge of the battery pack  50  of the gas engine replacement device  10 . The LED bars of the battery meter  1132  are illuminated based on signals received by the external electronics module  344  from the electronic processor  302  of the gas engine replacement device  10  that indicate remaining charge level of the battery pack  50 . The LED bars of the battery meter  1132  may be illuminated according to corresponding charge level thresholds to indicate the level of charge remaining in the battery pack  50 . 
       FIG. 12  is a perspective view of a pump system  1220  attached to a gas engine replacement device  10  with an external electronics module  344  received by the gas engine replacement device  10 . The pump system  1220  includes a frame  1224  supporting the gas engine replacement device  10  and a pump  1228  with the gas engine replacement device  10  operable to drive the pump  1228 . A GER device interface  1114  (shown in  FIG. 10 ) of the external electronics module  344  is received by a module interface  342342342  of the gas engine replacement device  10  to connect the external electronics module  344  to the gas engine replacement device  10 . The illustrated pump  1228  (i.e., power equipment) is a centrifugal pump having an impeller positioned within a housing  1232  of the pump  1228  that is rotatable about an axis to move material from an inlet  1236  of the pump  1228  to an outlet  1240  of the pump  1228 . Specifically, the pump  1228  is a “trash pump” that includes enough clearance between the impeller of the pump  1228  and the housing  1232  (e.g., 8 millimeters) to provide a mixture of a liquid (e.g., water) and debris (e.g., solid material like mud, small rocks, leases, sand, sludge, etc.) to pass through the pump  1228  from the inlet  1236  to the outlet  1240  without the debris getting trapped within the pump  1228  and decreasing the performance of the pump system  1220 . 
     Typically, gas engine pumps include only one mode of operation. Particularly, the gas engine may rotate the motor only in one direction, which limits the functionality of the pump. In contrast, the pump system  1220  includes the gas engine replacement device  10  including a motor  36  that can be rotated in both the forward and reverse directions. Accordingly, the pump system  1220  is adapted to perform different functions based on the rotation direction of the motor. When the electronic processor  302  rotates the motor  36  in a first direction, the pump  1228  may drive the impeller in a forward direction to move material from an inlet  1236  of the pump  1228  to an outlet  1240  of the pump  1228 . When the electronic processor  302  rotates the motor  36  in a second direction, the pump  1228  may drive the impeller to clear jams or clear the pump  1228  if debris is stuck within the pump  1228  (without utilizing a transmission including a forward gear and a rearward gear). In some embodiments, the motor  36  may controlled by the electronic processor  302  to rotate at slower speed in the second direction than in the first direction to clear jams in the pump  1228 . For example, the electronic processor  302  may provide PWM signals to the FETs of the power switching network  310  with a higher duty ratio when driving in the first direction than the duty ratio when driving in the second direction, to rotate the motor  36  at a higher speed in the first direction compared to the second direction. 
     Pump sensors  1241 ,  1242  of the pump  1228  are in communication with the electronic processor  1010  of the external electronics module via the power equipment/accessory interface  1018 . The sensor  1241  detects an amount of liquid being moved through the pump  1228 . Based on output from the sensor  1241 , the electronic processor  1010  of the external electronics module  344  transmits a signal to the electronic processor  302  of the gas engine replacement device  10  to enable operation of the pump  1228  (e.g., drive the motor  36 ) if the amount of liquid is at or above a threshold level and automatically stop operation of the pump  1228  if the amount of liquid is below the threshold level. However, in other embodiments, the electronic processor  302  can simply monitor the current drawn by the motor  36  to determine whether to slow down or stop the motor  36 . 
     The sensor  1242  on the pump  1228  is connected to the electronic processor  1010  via the power equipment/accessory interface  1018  of the external electronics module  344  and is arranged in an impeller reservoir of the pump  1228 . The sensor  1242  monitors suction or fluid level in the impeller reservoir. The electronic processor  1010  receives output from the sensor  1242  and may output a signal to an indicator (e.g., an LED or display device) of the user interface  1016  when output of the sensor  1242  indicates that the pump  1228  is not adequately primed. In some embodiments, the electronic processor  1010  may transmit a signal to the electronic processor  302  of the gas engine replacement device  10  to automatically shut off the pump  1228  to protect the pump system  1220  based on the output of the sensor  1242 . Alternatively, or in addition, based on output from the sensor  1242 , the electronic processor  1010  may transmit a signal to the electronic processor  302  or directly to an electronically controlled valve  1243  on the pump  1228  to adjust an exhaust opening to support an auto-priming capability to protect the pump system  1220 . 
       FIG. 13  is a flowchart of a method  1300  for interfacing one or more external electronics modules  344  to the gas engine replacement device  10  of  FIG. 1 . The following method outlines a process for interfacing one external electronics module  344 , but may also be applied to interfacing additional external electronics module(s)  344  to the gas engine replacement device  10 . 
     In step  1302 , the gas engine replacement device  10  receives an external electronics module  344  at a module interface  342   a,    342   b,    342   c.  The external electronics module  344  includes electronics for feature expansion of the gas engine replacement device  10  and/or the power equipment driven by the gas engine replacement device  10 . A GER device interface  1114  of the external electronics module  344  (shown in  FIG. 10 ) is received by a module interface  342   a,    342   b,    342   c  of the gas engine replacement device  10  (shown in  FIG. 9 ) to connect the external electronics module  344  to the gas engine replacement device  10 . For example, with reference to the pump system  1220  of  FIG. 12 , the gas engine replacement device  10  includes a module interface  342   a,    342   b,    342   c  that receives the external electronics module  344 . In another example, the gas engine replacement device  10  is coupled to a different piece of power equipment, such as an agricultural sprayer, a concrete saw, a compactor, or the like. 
     In step  1304 , the electronic processor  302  of the gas engine replacement device  10  detects which type of external electronics module  344  is received by the module interface  342   a,    342   b,    342   c  and may establish communication with the received external electronics module  344  based on the configured method of communication for the receiving module interface  342   a,    342   b,    342   c.  For example, the electronic processor  302  may determine the type of attached external electronics module  344  based on a signal(s) sent to and/or received from to the module interface  342   a,    342   b,    342   c.  In some embodiments, the electronic processor  302  receives a device identifier (ID) from external electronics module  344 . Alternatively or in addition, the electronic processor  302  may determine the type of attached external electronics module  344  based on a voltage level or a resistance value detected using an ADC of the electronic processor  302  that is in communication with the GER device interface  1014 , or based on a type of communication protocol used. In some embodiments, the electronic processor  302  may retrieve information about the attached external electronics module  344  from a look-up table stored in the memory  306  (e.g., using data received or deduced from the external electronics module  344  as an index into the look-up table) or may determine the type of received external electronics module  344  based on information in the signal received from the external electronics module  344 . 
     For example, with reference to  FIG. 12 , the electronic processor  302  of the gas engine replacement device  10  in the pump system  1220  may determine that the external electronics module  344  attached to the module interface  342   a,    342   b,    342   c  is an external electronics module  344  for a pump system, which includes a power equipment/accessory interface  1018  (see  FIG. 10 ) that is configured to communicate with one or more of the sensor  1241 , the sensor  1242 , and the electronically controlled valve  1243  (e.g., via a wired connection). In some embodiments, the electronic processor  302  determines that the external electronics module  344  is an second type of external electronics module  344  for a pump system, which further (or instead) includes the user interface  1016  to provide feedback on operation of the gas engine replacement device  10 , and associated sensors  1020  used to generate the information displayed on the user interface  1016 . For example, the user interface  1016  may include one or more of the level indicator  1128 , eco-indicator  1130 , and battery meter  1132 , as illustrated in  FIG. 11 , and the sensors  1020  may include on or more of a current sensor, battery sensor, and accelerometer. 
     In another example, where the gas engine replacement device  10  is coupled to drive a pump motor of an agricultural sprayer, the electronic processor  302  may determine that the external electronics module  344  is an external electronics module  344  for a sprayer system, which includes a user interface  1016  with inputs including an activation switch and a pressure level control mechanism for user control of the sprayer (e.g., the user interface(s)  1016 ) and a supply level indicator to inform the user of the fluid level in a tank of the sprayer (e.g., indicating an amount of the fluid to be sprayed by the sprayer that is left in the tank). In another example, the gas engine replacement device  10  drives a propulsion motor of the sprayer (i.e., providing motive force to propel drive wheels of the sprayer), and the external electronics module  344  is determined to be a second type of external electronics module  344  for a sprayer that includes an output to a motor (e.g., motor  1022 ) that serves as a pump motor to pressurize and spray the fluid, as well as the other inputs and outputs as described with the first external electronics module  344  for a sprayer. 
     In another example, the gas engine replacement device  10  is coupled to power equipment and the electronic processor  302  determines that the external electronics module  344  is of the type shown in  FIG. 11 , or a generic external electronics module  344  configured to sense vibration (e.g., the sensor  1020  includes a vibration sensor), configured to receive a mode select input from a user via the user interface  1016 , configured to receive a control signal from the electronic processor  302  and provide an output to a solenoid actuator that is part of the external electronics module  344  or via the power equipment/accessory interface  1018 , or a combination thereof. 
     In step  1306 , the electronic processor  302  configures the gas engine replacement device  10  for interaction with the received external electronics module  344 . For example, the electronic processor  302  can determine a definition (e.g., defining a communication protocol, available features, operational ranges, and the like) for the external electronics module  344  and unlock appropriate features to be accessed by or for the external electronics module  344 . In some embodiments, a device ID is received from the received external electronics module  344  and is used as an index into a look-up table in the memory  306  to retrieve configuration data for the particular type of external electronics module  344 , and the electronic processor  302  then configures the definition for the specific external electronics module  344  based on the configuration data. Then, in subsequent communications with the same external electronics module  344 , the same device ID may be used as packet identification such that the communications manager  340  can direct data received from the received external electronics module  344  into an appropriate section of firmware. 
     For example, whereas in step  1304  the electronic processor  302  may determine that the external electronics module  344  coupled to the gas engine replacement device  10  is of a first or second type of external electronics module for a pump system, in step  1306 , the electronic processor  302  may access the memory  306  using a device ID to determine the various inputs, outputs, and/or other features of the external electronics module  344  and how to communicate and use these aspects. For example, certain firmware routines associated with the device ID may be enabled or retrieved to allow the electronic processor  302  to interact with the external electronics module  344 . 
     In step  1308 , the gas engine replacement device  10  and the received external electronics module  344  are operated based on the configuration from step  1306 . The electronic processor  302  may determine that the received external electronics module  344  is a type of module that receives input, provides output, or does both and operate accordingly. For example, the received external electronics module  344  may be an input module and may include a sensor  1020 , a user interface  1016 , or a power equipment/accessory interface  1018  to receive input. The electronic processor  1010  of the received external electronics module  344  may receive sensor input, user input, or input from power equipment attached to the gas engine replacement device  10  and communicate the input to the electronic processor  302  of the gas engine replacement device  10 . The electronic processor  302  may take an action based on the received input, such as, drive or control speed of the motor  36  or transmit a signal to activate the load  1022  or to control the user interface  1016  on a different external electronics module  344 . 
     In one example of the external electronics module  344  configured as an input module, the gas engine replacement device  10  having received the external electronics module  344  is attached to an agricultural sprayer (e.g., disposed on a vehicle or a walk-behind). The user interface  1016  of the received external electronics module  344  may have inputs including an activation switch and a pressure level control mechanism for a user to activate and control the intensity of the sprayer, respectively. In an example of step  1308 , the external electronics module  344  receives a pressure level (e.g., via a dial or selector of the user interface  1016 ) and actuation of the activation switch (e.g., via a push button or toggle of the user interface  1016 ). In response, the external electronics module  344  transmits a signal to the electronic processor  302  of the gas engine replacement device  10 . The electronic processor  302  then transmits a signal to the power switching network  310  to drive the motor  36  with power from the battery pack  50  based on actuation of the activation switch, and sets the PWM duty ratio for controlling the power switching network  310  based on the pressure level (e.g., the higher the pressure level, the higher the duty ratio). Alternatively, or in addition, the external electronics module  344  may include the sensor  1020  and the signal sent to the electronic processor  302  to indicate to activate the motor  36  may be based on output from the sensor  1020 . For example, the sensor  1020  may be an accelerometer or a tachometer that detects the speed of the gas engine replacement device  10  and sprayer (or the vehicle transporting them). A signal based on output from the sensor  1020  is transmitted to the electronic processor  302  from the external electronics module  344 , and the electronic processor  302  control the activation and/or the pressure level of the sprayer based on the speed or movement of the sprayer system. For example, the sprayer may be activated by the electronic processor  302  when the speed exceeds a first lower threshold (i.e., the motor  36  is controlled at a first lower duty ratio), and then the duty ratio increases as the speed increases (e.g., in 2, 5, or 10% increments mapped to corresponding incrementing speed thresholds). 
     In another example, the received external electronics module  344  is configured as an output module and the gas engine replacement device  10  having received the external electronics module  344  is again attached to an agricultural sprayer (e.g., disposed on a vehicle or a walk-behind). The external electronics module  344  includes a user interface  1016  that has audio and/or visual indicators that communicate performance or status of the gas engine replacement device  10  and/or power equipment attached to the gas engine replacement device  10 . An example of an external electronics module  344  that includes the user interface  1016  as an output device is described with respect to  FIG. 11 . As illustrated and described with respect to  FIG. 11 , the user interface  1016  includes one or more of the level indicator  1128 , the eco-indicator  1130 , and the battery meter  1132 . The electronic processor  302  may control the sprayer by driving the motor  36  and provide performance feedback to the user via the user interface  1016  of the external electronics module  344 . 
     Moreover, an external electronics module  344  may include both input and output components such that the electronic processor  302  controls the motor  36  based on input received by the external electronics module  344  and such that the electronic processor  302  controls the external electronics module  344  to provide user feedback. For example, with respect to the sprayer examples above, the external electronics module  344  may provide input signals to the electronic processor  302  (e.g., via the activation switch and pressure level) used to control the motor  36 , and may be controlled by the electronic processor  302  to provide output via the user interface  1016  (e.g., via indicators of the user interface  1016  illustrated in  FIG. 11 ). The input may be received by the electronic processor  302  of the gas engine replacement device  10  and the electronic processor  302  may provide feedback to the external electronics module  344  for display on the user interface  1016 . In some embodiments, the electronic processor  302  or the electronic processor  1010  may process input from the sensor  1020 , the user interface  1016 , or the power equipment/accessory interface  1018  and provide feedback to the user based via the user interface  1016  based on the input. 
     In some embodiments, the method  1300  is executed multiple times, once for each external electronics module  344  attached to the gas engine replacement device  10  (via respective module interfaces  342   a,    342   b,    342   c ). For example, with respect to the sprayer examples above, a first external electronics module  344  configured as an input module to provide input signals to the electronic processor  302  (e.g., via the activation switch and pressure level) used to control the motor  36  may be attached to a first module interface  342   a,    342   b,    342   c,  and then a second external electronics module  344  configured as an output module to be controlled by the electronic processor  302  to provide output via the user interface  1016  (e.g., via indicators of the user interface  1016  illustrated in  FIG. 11 ) is attached to a second module interface  342   a,    342   b,    342   c.  The method  1300  may be executed upon receipt of each external electronics module  344 . 
     The gas engine replacement device  10  may be coupled to and drive other power equipment such as a compactor, a rammer, a jetter, and a pump system, etc. 
     In some embodiments, the gas engine replacement device  10  is configured for utilizing a specified communication protocol to communicate with an external electronics module  344  via a module interface  342   a,    342   b,    342   c  (e.g., RS485, UART, SPI, CAN bus, USB, voltage or resistance levels, etc.). The configured communication protocol may be fixed for the life of the gas engine replacement device  10 , or may be configurable or reconfigurable. For example, the communication protocol may be pre-configured in the gas engine replacement by an OEM of the gas engine replacement device  10 . Alternatively or in addition, an OEM user or an end user may configure or reconfigure the communication protocol via a module interface  342   a,    342   b,    342   c.  Different module interfaces  342   a,    342   b,    342   c  may be configured for the same or different methods of communication. 
     In some embodiments, the external device  338  is used to configure or reconfigure the gas engine replacement device  10 . The external device  338  may be programmed with an application that generates a graphical user interface. The graphical user interface enables the user to select or define a communication protocol by the electronic processor  302  via one or more module interfaces  342   a,    342   b,    342   c.  The external device  338  then transmits information or communication parameters that are based on the user&#39;s selection to the electronic processor  302  via the transceiver  326 , and the electronic processor  302  configures the gas engine replacement device  10  accordingly. In some embodiments, a look-up table in the memory  306  may include communication parameters for configuring the communication protocol via the module interface(s)  342 .