Abstract:
Conventional internal combustion engine technology has been around for decades and historically has been the primary power source for virtually all industrial equipment. It relies on carbon-based fuels, is loud, polluting, and the machines it powers are expensive to operate and maintain. A self-contained, rechargeable battery system is provided that possesses improved power than comparable diesel and gas engines and it generates zero emissions, is virtually maintenance free, is quiet, and recharges overnight via a standard electrical outlet. The rechargeable battery power system can be installed in new and used construction equipment and may be used wherever a source of power is required including smart grid application. It can be safely used indoors, in neighborhoods and other locations sensitive to the side effects of internal combustion engines. There is a battery management system that controls sequential shutdown system and a power reserve system to control operation of the battery.

Description:
BACKGROUND 
       [0001]    Energy is in constant need for powering equipment of all types and kinds. Recently, there has been a trend to power a plurality of different machines, for example automobiles, motorcycles, and construction equipment with electric. Typically these electrically powered devices will carry a power source in the form of a battery to power them. 
         [0002]    However, there are needs for improved battery designs that have a more universal applicability so that the battery is capable of powering devices from light towers to bulldozers. 
       SUMMARY 
       [0003]    There is provided a rechargeable battery power system having a battery with multiple uses. The rechargeable battery power system provides for a clean and quiet power source that includes a self-contained battery that does not require active cooling and that can be used in a plurality of different applications that require electric power. 
         [0004]    In particular, there is a battery assembly that comprises a battery housing and a battery, and the battery is disposed in the battery housing. The battery is a multiple use battery because it may be used in a plurality of different applications ranging from a stand-alone power source to a power source for powering equipment, lights and virtually any other machine that has a need for electrical power, for example machines traditionally powered by fossil fuels, such as diesel. 
         [0005]    The battery housing has a base wall joined to first and second side walls and the base wall joined to opposed first and second end walls. There is a housing cover that is releasable joined to the first and second opposed side walls and the opposed first and second end walls such that the cover is disposed opposite the base wall. 
         [0006]    The first sidewall includes a metal layer and first and second foam layers and a plastic sheet such that the first foam layer abuts against and is joined with the metal layer, and the first foam layer abuts against and is joined with the second foam layer. The second foam layer abuts against and is joined with the plastic sheet. 
         [0007]    The second side wall is structurally identical to the first side wall. 
         [0008]    The cover has opposed exterior and interior sides and a service disconnect extends from the exterior side. Joined to the interior side of the cover is a plastic sheet, and a foam cover sheet is joined to the plastic sheet such that the plastic sheet is disposed between the interior side of the cover and the foam cover sheet. The first end wall is joined to a first end wall foam sheet and the second end wall is joined to a second end wall foam sheet, and the second end wall has an exterior end wall surface and a current sensor is mounted to the second end wall. 
         [0009]    The base wall of the battery housing has a metal base wall sheet having opposed interior and exterior metal base wall surfaces, and joined to the interior metal base wall surface is a base wall plastic sheet that is joined to a base wall rubber sheet. 
         [0010]    As previously mentioned, disposed internal to the battery housing is the battery. The battery has first and second module banks Each of the first and second module banks is made of from groups of modules, and each module is made of individual cells. In one preferred embodiment each module has eight (8) cells that are electrically connected to one another, and the modules are electrically connected to one another to form the groups of modules. The first and second module banks may be electrically connected to one another such that together they can output power. In addition, a separator support plate separates the first and second module banks from one another. The separator support plate is part of the battery housing. The separator support plate provides for structural integrity and a thermal barrier between the first and second module banks. 
         [0011]    In one of the preferred embodiments, the battery assembly is installed in an excavator or other piece of equipment, for example heavy construction equipment, during the manufacturing process of the excavator or other piece of equipment. 
         [0012]    In another preferred embodiment there is provided a method for taking a used piece of equipment, for example a used excavator, and removing its engine. Then, the engine compartment is re-configured to house the battery assembly. There is provided a battery management system, a variable frequency driver and a variable frequency brushless electric motor or other suitable motor the shaft of which is connected to a hydraulic pump in order to complete the conversion from gas/diesel power to electric power. 
         [0013]    The rechargeable battery power system also includes a battery sequential shutdown system that allows the battery, for example when installed in a piece of equipment, to be shut down in a in a series of steps. This sequential shutdown prevents damage to the components of the rechargeable battery and drive motor systems. 
         [0014]    In addition, the rechargeable battery power system also includes a reserve power reserve system under the control of the battery management system that provides for a reserve of battery power. The battery reserve system will provide power to the piece of equipment, for example an excavator such that it can be driven to a location where the battery can be recharged. This prevents equipment from becoming inoperable and stranded while in the field. In one of the preferred embodiments a person having authority, for example a foreman, is the only one that can access the power reserve system. 
         [0015]    The rechargeable battery power system also includes a DC/AC inverter and an AC outlet is mounted on the piece of equipment. This provides workers with access to AC power and can be used to power equipment, for example drills and saws. A key switch is provided on the piece of equipment and it allows a user to turn on the AC power. 
         [0016]    In another preferred embodiment there is a light tower comprising a tower frame and the tower frame may be mounted on wheels. The light tower is telescopic and has a base portion that houses an extendable portion wherein the extendable portion can be raised and lowered. A battery assembly is provided and is supported by and connected to the tower frame. Lead lines extend from the battery assembly to a tower inverter that converts DC power from the battery to AC power, and inverter lead lines that extend from the tower inverter to the light array and the light array includes the light bulbs. The light bulbs are light emitting diodes (LEDs) in one of the preferred embodiments. The light tower also has a charger. 
         [0017]    The light tower has a housing with a control panel door  446 , and the housing supports a charging port so that the battery may be charged. The control panel door allows access to light switches to control the light array, a timer switch, a visual display that displays battery information, for example the percent of charge remaining in the battery and a low battery warning light. The timer switch automatically shuts of the systems after a predetermined amount of time passes to eliminate the possibility of the battery being over-discharged. The timer switch also serves as the main power switch, such that in order to turn the light tower on the user must set the time switch in advance. Also mounted on the light tower housing are convenience outlets that allow a user to run devices in need of electric power. The convenience outlet is powered by the same DC/AC inverter  440  that powers the LEDs. The battery management system will shut down the DC/AC tower inverter to protect the battery in the event a system fault or low battery condition. 
         [0018]    In the rechargeable battery system used in all embodiments, such as the excavator and light tower, there are limits set on the battery charge and discharge voltage levels that are narrower as compared to maximum and minimum safe levels, and this provides for an added safety margin against overcharge and discharge, significantly longer battery life. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
         [0019]      FIG. 1  is a system block diagram of a first embodiment of a rechargeable battery power system. 
           [0020]      FIG. 2  is a perspective view of an assembled battery assembly for use in the rechargeable battery power system. 
           [0021]      FIG. 3  is an expanded view of the battery assembly shown in  FIG. 2 . 
           [0022]      FIG. 4  is a diagrammatic view of a module and cells. 
           [0023]      FIG. 5  is a system block diagram of another embodiment of a rechargeable battery power system for use with a piece of equipment, for example a hydraulic excavator. 
           [0024]      FIG. 6  is a schematic of a shutdown sequencer. 
           [0025]      FIG. 7  shows a battery capacity indicator wherein the battery capacity includes a battery reserve capacity. 
           [0026]      FIG. 8  is a system block diagram that includes an inverter for use of the rechargeable battery power system of  FIG. 5 . 
           [0027]      FIG. 9  shows a hydraulic excavator powered by an internal combustion engine such as a gas or diesel engine. 
           [0028]      FIG. 10  is a perspective view of a hydraulic excavator modified such that it has a rechargeable battery power system. 
           [0029]      FIG. 11  is another perspective view of a hydraulic excavator modified such that it has the rechargeable battery power system. 
           [0030]      FIG. 12  is a perspective view of a hydraulic motor of the hydraulic excavator wherein a removable door is show allowing access to the hydraulic motor. 
           [0031]      FIG. 13  is a perspective view of another preferred embodiment wherein a light tower is provided having a rechargeable battery power system. 
           [0032]      FIG. 14  is a block diagram depicting a service provider entity and customer relationship. 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    At the outset, it is to be understood that like reference numerals are intended to identify the same structural elements, portions or surfaces consistently throughout the several drawing figures, such at elements, portions or surfaces that may be further described or explained by the entire written specification, of which this detailed description is a part. Unless otherwise indicated, the drawings are intended to read (that is, cross-hatching, arrangement of parts, proportion, degree, et cetera) together with the specification, and are considered to be a portion of the entire written description. As used in the description, the terms “horizontal,” “vertical”, ‘left, right,” “up,” “down,” as well as adjectival and adverbial derivatives thereof (for example, “horizontally”, “rightwardly”, “upwardly,” et cetera) refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms “inwardly” and “outwardly” generally refer the orientation of a surface relative to its axis of elongation, or axis of protestation, as appropriate. 
         [0034]    Turning now to  FIG. 1 , shown therein is a system block diagram of a rechargeable battery power system  10  having a battery assembly  48 . The battery assembly  48  includes a battery  50  having multiple uses and includes a battery housing  54  that houses the battery  50 . The rechargeable battery power system  10  has an alternating current (hereinafter referred to as AC) electric motor  12  and may be embodied as other types of motors in other preferred embodiments, a variable frequency motor driver  14 , a battery management system (sometimes referred to herein as BMS)  16  and the battery  50 . The battery  50  is a lithium-ion battery that may be of several types, including but not limited to lithium nickel manganese cobalt oxide (NMC), a lithium cobalt (LCO), a lithium iron phosphate (LFP); a lithium manganese oxide (LMO); and, a lithium nickel cobalt aluminum (NCA). The rechargeable battery power system  10  also includes a visual display  22 . 
         [0035]      FIG. 2  is a perspective view of the battery assembly  48 , and  FIG. 3  shows an exploded view of the battery assembly  48 . As shown in  FIG. 3  the battery  50  has first and second module banks  61 ,  63  that are substantially identical. The first module bank  61  is made from a first group of modules  55 , and the second module bank  63  is made from a second group of modules  57 . In turn, the first and second groups of modules  55 ,  57  are each made from individual modules commonly designated  53 , and each module  53  has individual cells commonly designated  51 . The cells  51  are embodied as rechargeable electrochemical cells in one of the preferred embodiments and are for storing electrical energy. In one preferred embodiment each module  53  has eight (8) cells  51  that are electrically connected to one another, and the modules  53  are electrically connected to one another to form the groups of modules  55 . In other preferred embodiments each module  53  may have more or less than eight cells  51 . The first module bank  61  is electrically connected to a bus bar  136  for allowing current to flow to the terminal boxes  96 . And, there are connector bus bars  138  that connect the first and second module banks  61 , 63   
         [0036]    As shown in  FIG. 4 , the there is a module  53  that has a module case  67  and the cells  51  are stacked together and supported in the module case  67 . Module terminals  69  extend from the module case  67  and the module terminals  69  may be electrically connected to other modules  53 . 
         [0037]    The electric motor  12  shown in  FIG. 1  is embodied as a three phase AC induction motor, but in other preferred embodiments other electric motor types may be used. The AC motor has a rotor  30 , a stator  32 , and an output shaft  34  that delivers output rotary power to a driven object, for example a hydraulic pump. As shown in  FIG. 1 , the AC induction motor  12  receives first, second and third drive lines  36 ,  38 ,  40 , one for each phase, and the first, second and third drive lines  36 ,  38 ,  40  are driven by the variable frequency motor driver  14 . It is pointed out that in other preferred embodiments other electric motors may be used, for example a permanent magnet AC (PMAC) motor may be used. The rotation speed of the AC induction motor  12  ranges from zero to 8,000 (or more) revolutions per minute. In one of the preferred embodiments the AC induction motor  12  is air cooled. 
         [0038]    The variable frequency motor driver  14  receives power from first and second direct current (DC) voltage lines  44 ,  46  from a battery  50 , and then it converts electrical power into three phase AC voltage provided on the first, second and third drive lines  36 ,  38 ,  40 . In addition, the variable frequency motor driver  14  is able to change the frequency and amplitude characteristics of the voltage on each of the first, second and third drive lines  36 ,  38 ,  40  so as to be able to control rate of rotation and/or output torque of the AC induction motor  12 . 
         [0039]    The battery  50  is a lithium-ion type battery The battery  50  is connected to the battery management system  16  on battery lines  52 . The battery  50  stores electrical energy provided by the battery management system  16  and provides electrical energy to the variable frequency motor driver  14 . The battery management system  16  has a battery management interface  17  for connection to an external power source, such that when the battery management system  16  is connected to an external power source through the battery management interface  17 , power is delivered over the battery lines  52  to charge the battery  50 . 
         [0040]    As shown in  FIGS. 2 and 3  and as previously mentioned, the battery housing  54  of the battery assembly  48  includes opposed first and second side walls  56 ,  58  and opposed first and second end walls  60 ,  62  and a base wall  64 . The first and second opposed side walls  56 ,  58  and the opposed first and second end walls  60 ,  62  extend from and are joined to the base wall  64 . The battery housing  54  also has a housing cover  66  that is joined to the first and second opposed side walls  56 ,  58  and the opposed first and second end walls  60 ,  62  such that it is opposite the base wall  64 . The cover  66 , the first and second opposed side walls  56 ,  58 , the opposed first and second end walls  60 ,  62  and base wall  64  may be connected by any suitable method, for example with nuts and bolts, screws, welds, and the like. 
         [0041]    As shown in  FIG. 3 , the first sidewall  56  is layered and includes a metal layer  68  and first and second foam layers  70 ,  72 , and a plastic sheet  74 . The plastic sheet  74  in other preferred embodiments is a polycarbonate resin sheet, or a thermoplastic sheet. The polycarbonate resin sheet can be a sheet of LEXAN®. LEXAN® is a registered trademark of Sabic Innovative Plastics IP B.V. having a business address of Plasticslaan 1, 4612 PX, Bergen OP Zoom, Netherlands and LEXAN® is commercially available and well known to those having ordinary skill in the art. The first foam layer  70  abuts against and is joined with the metal layer  68 , and the first foam layer  70  abuts against and is joined with the second foam layer  72 . The second foam layer  72  also abuts against and is joined with the plastic sheet  74 . 
         [0042]    The second side wall  58  is structurally identical to the first side wall  56  and includes a metal layer  68   a , first and second foam layers  70   a ,  72   a , and a plastic sheet  74   a . The first foam layer  70   a  abuts against and is joined with the metal layer  68   a , and the first foam layer  70   a  abuts against and is joined with the second foam layer  72   a , and the second foam layer  72   a  abuts against and is joined with the plastic sheet  74   a . The metal layer  68 , the first foam layer  68 , the second foam layer  72  and the plastic sheet  74  are joined with an adhesive. 
         [0043]    The cover  66  of the battery housing  54  has opposed exterior and interior sides  78 ,  80  and a service disconnect  82  is joined to and extends from the exterior side  78 . The service disconnect incapacitates the battery  50 , preventing the possibility of electric shock to a service technician, or damage to the battery during service or repair. Joined to the interior side  80  is a plastic sheet  84  and a foam cover sheet  86  is joined to the plastic sheet  84 , such that the plastic sheet  84  is disposed between the interior side  80  and the foam cover sheet  86 . In other preferred embodiments the plastic sheet  84  is embodied as a polycarbonate resin sheet, a thermoplastic sheet or sheet of LEXAN®. 
         [0044]    The first end wall  60  is joined to a first end wall foam sheet  88 , and the second end wall  62  is joined to a second end wall foam sheet  90 . The second end wall  62  has an exterior end wall surface  92  and a current sensor  94  is mounted to the second end wall  62  and abuts the exterior end wall surface  92 . In addition, terminal boxes  96  are mounted to the second end wall  62  and abut the exterior end wall surface  92 . Terminals  98  and a monitor wiring inlet  100  are mounted to the second end wall  62 . 
         [0045]    The base wall  64  has a metal base wall sheet  102  having opposed interior and exterior metal base wall surfaces  104 ,  106 . Joined to the interior metal base wall surface  104  is a first base wall plastic sheet  108  that is joined to a second base wall rubber sheet  110 . In other preferred embodiments the plastic sheet  108  is embodied as a polycarbonate resin sheet, a thermoplastic sheet or sheet of LEXAN®. 
         [0046]    The battery housing  54  of the battery assembly  48  is mounted on a pair of brace members  112   a ,  112   b  that have channel-shaped cross sections. In particular, isolation mounts  114  are threaded to the base wall  64  and the brace channel  112   a ,  112   b  such that they isolate the battery housing  54  from a surface that supports the brace channels  112   a ,  112   b.    
         [0047]    As previously described, the battery  50  has first and second module banks  61 ,  63  that are substantially identical and that are disposed internal to the battery housing  54 . As shown in  FIG. 3  a gap  128  extends from the first module bank  61  to the second module bank  63  and disposed in the gap  128  are first and second separator foam sheets  130 ,  134 . Disposed between the first and second separator foam sheets  130 ,  134  is a separator support plate  132 . The separator support plate  132  is made of metal in one of the preferred embodiments so that the battery housing  54  is strong and durable and capable of withstanding various external loads imposed thereon, and the separator support plate serves as a thermal barrier between first and second module banks  61 . 63 . 
         [0048]    It is pointed out that the battery  50  does not need an active cooling system to be cooled because of its configuration and will not overheat when used in connection with the applications and embodiments to be described presently. Thus, the battery  50  can be completely sealed from the environment, protecting against intrusion of water or other contaminants common in harsh environments. In addition, the battery  50  has a high energy density and thus can provide a long run time on a single charge and can be used in construction applications. 
         [0049]    As shown in  FIG. 1 , the visual display  22  is connected to the variable frequency motor driver  14  by a first visual display line  140 , and the battery management system  16  is connected to the visual display  22  by a second visual display line  142 . The visual display  22  receives inputs (battery data  59  and variable frequency motor driver data  14   a ) by way of the first and second visual display lines  140 ,  142 , and displays the battery data  51  and variable frequency motor driver data  14   a  that pertains to the operation of the variable frequency motor driver  14  and the battery  50 . 
         [0050]    Use of the rechargeable battery power system  10  having a battery  50  with multiple uses begins with connecting the rechargeable battery power system  10  to the battery  50  by way of the interface  17 , the battery management system  16  detects the connection made to the interface  17  and controls the flow of power through the interface  17  to charge the battery  50 . Power continues to flow from the external electrical power source through the interface  17  and to the battery  50  until the battery  50  is fully charged. It is pointed out that the interface  17  may be disconnected from the external electrical power source prior completely charging the battery  50 . The external electrical power is most commonly the power grid, but may be a generator, for example a portable diesel powered generator. 
         [0051]    The AC induction motor  12  is typically mounted on a surface or on a vehicle frame. The output shaft  34  is coupled to a drive object or driven shaft prior to actuating the AC induction motor  12 . When the AC induction motor  12  is actuated the variable frequency motor driver  14  causes electrical power to flow from the battery  50  to the AC induction motor  12 . In particular, the variable frequency motor driver  14  causes a sinusoidal voltage to flow in each of the first, second and third drive lines  36 ,  38 ,  40 . The variable frequency motor driver  14  controls the frequency and amplitude of the voltage in the first, second and third drive lines  36 ,  38 ,  40  in order to control the speed and power output of the AC induction motor  12 . The visual display  22  provides an active display of operating information from the variable frequency motor driver  14 . Then, when the charge in the battery  50  is depleted, the interface  17  is reconnected to the electrical power source in order to recharge the battery  50  as described. 
         [0052]    It is pointed out that the battery  50  is adaptable for use in virtually any application requiring electrical power including vehicles, machines, homes, businesses and the like. In other words, the applications wherein the battery  50  may by employed and used is without limit. 
         [0053]      FIGS. 5-8  show a second embodiment wherein there is a machine rechargeable battery power system  200  provided for use in a piece of equipment  298  that requires a source of power, for example an excavator  300  shown in  FIGS. 10-12 . 
         [0054]    Turning now to  FIG. 5 , the machine rechargeable battery power system  200  has the main components that include a variable frequency AC induction motor  210 , a variable frequency motor driver  230  and a battery management system  260 . There is also a battery  280  that is structurally identical to the previously described battery assembly  48  having a battery  50 , and the battery  280  may be otherwise embodied, for example the battery  280  can be made more powerful by the addition of identical third and fourth banks of module banks Battery lines  271  extend from the battery  280 . The machine rechargeable battery power system  200  further includes a screen  240 , a throttle  270 , and a voltage converter  274 . Outputs  241  generated by the battery management system  260  are displayed on a screen  240 . The outputs  241  displayed on the screen  240  include battery charge data. For example, the percentage of the charge remaining in the battery  280  is displayed, or the remaining battery life is displayed as a percentage. A low battery warning  243  that may be, for example, a low battery warning light  243   a  or flashing light is displayed on the screen  240  when the battery  280  has been discharged and reaches a predetermined level of discharge, for example when the battery  280  is 90% discharged. The operator (not shown) can take action to recharge the battery  280 . For example, the operator can drive the piece of equipment  298  (or excavator  300 ) to a location where it may be recharged. In addition, in one of the preferred embodiments there are multiple levels of low battery warnings  243 . For example, when a predetermined level of charge is remaining in the battery  280  a low battery light turns on and is displayed on the screen  240 . Then, when even a lower predetermined amount of charge is remaining a pulsing buzzer  244  is activated and emits sounds and the low battery warning light  243   a  remains on. The pulsing buzzer  244  and the low battery warning light  243   a  remain on until the battery  280  is fully depleted, causing all power to the variable frequency AC induction motor  210  and a hydraulic pump  301  (to be described presently) to be cut. 
         [0055]    The variable frequency AC induction motor  210  is a three phase AC induction motor, and in other preferred embodiments an electric motor of other types may be used. The variable frequency AC induction motor  210  has a rotor  211 , a stator  215 , and an output shaft  212  that delivers output rotary power to a driven object. Variable frequency AC induction motors are commercially available and are well known to those having ordinary skill in the art and are therefore not described herein in greater detail. The variable frequency AC induction motor  210  receives three drivelines  214   a ,  214   b  and  214   c , one for each phase. The variable frequency AC induction motor driver  230  drives the drivelines  214   a ,  214   b  and  214   c . The variable frequency AC induction motor  210  also contains a temperature sensor  217  that measures the temperature of the variable frequency AC induction motor  210 , and a sensor  218  that measures the speed of the rotor  211 . The variable frequency AC induction motor  210  also includes a cooling system  214  that is an air cooled system in one embodiment and may be a liquid cooling system in other preferred embodiments. Cooling a motor with air or liquid is well known to those having ordinary skill in the art and is therefore not described in greater detail herein. 
         [0056]    The variable frequency motor driver  230  receives power from the first and second DC voltage lines  250   a ,  250   b  and converts electrical power into three phase AC voltage provided on the drive lines  214   a ,  214   b  and  214   c . Variable frequency motor drivers are commercially available, and are well known to those having ordinary skill in the art and therefore they are not described in greater detail herein. The variable frequency motor driver  230  is able to change the frequency and amplitude characteristics of the voltage on each of the drive lines  214   a ,  214   b  and  214   c  so as to control the rotation rate and/or output torque of the variable frequency AC induction motor  210 . A databus interface  232  is a controlled area network (CAN) Bus interface, however, other bus interfaces may be used as well. The databus interface  232  receives and transmits information, commands, status, faults, and other similar information utilized by the machine rechargeable battery system  200 . The variable frequency motor driver  230  also has analog controls from the battery management system  260 . The power received by the variable frequency motor driver  230  from DC voltage bus lines  250   a ,  250   b  is provided by the battery  280 . The variable frequency motor driver  230  contains the databus interface  232 . The databus interface  232  allows the variable frequency motor driver  230  to transmit and receive operating information, commands, statuses, and faults within and used by the machine rechargeable battery system  200 . The variable frequency motor driver  230  also has a driver cooling system  234  that is air cooled in a preferred embodiment, and other preferred embodiments the driver cooling system  234  is a liquid cooling system. The variable frequency motor driver  230  also has a driver temperature sensor  236  for measuring the temperature of the variable frequency motor driver  230 . The variable frequency motor driver  230  also has a driver controller  237  that in one of the preferred embodiments is a logic based controller such as a microcontroller/microprocessor/CPU/FPGA/CPLD, that may be programmed to cause the variable frequency motor driver  230  to properly control the voltage and/or power on the drive lines  214   a ,  214   b  and  214   c    
         [0057]    The throttle  270  is connected to the variable frequency motor driver  230  and provides variable frequency motor driver  230  information pertaining to a user&#39;s desired operating parameters. In particular, the throttle  270  consists of a voltage varying device  270   a  coupled to a manual controller  270   b , thus providing the variable frequency motor driver  230  with a voltage level that represents the desired speed or torque provided by the variable frequency AC induction motor  210 . The throttle  270  may be a variable resistor or may also be a Hall effect sensor, or other device capable of controlling a voltage level to the variable frequency motor driver  230 . In particular, the Hall effect sensor is sealed and contains no contacts, and the use thereof as the voltage varying device  270   a  eliminates problems arising from dust, water, and long term use. The throttle  270  is embodied as a knob  270   b  that controls the voltage varying device  270   a . In addition, the knob  270   b  is easy to implement and is easier to use for the operator compared to a lever actuated throttle. The variable frequency motor driver  230  is coupled or otherwise joined to both the battery  280  through the first and second DC voltage lines  250   a ,  250   b . A safety switch  281  is connected to the variable frequency motor driver  230 . In one of the preferred embodiments the safety switch  281  is disposed in the safety bar  327  (shown in  FIG. 10 ) that the operator moves upon exiting the piece of equipment  298 . Upon movement of the safety bar  327  power to the variable frequency AC induction motor  210  is cut off. This results in safety and energy savings as the AC induction motor  210  cannot be inadvertently be left on, thus eliminating the possibility of draining the battery  280 , for example overnight or during a weekend. 
         [0058]    As shown in  FIGS. 5, 6 and 10 , a key switch  284  is provided. The throttle  270 , the safety switch  281  and the key switch  284  are located on an analog control bus  285 . The key switch  284  can be rotated to one of three positions, an “Off” position  284   a , a “Run” position  284   b , and an AC position  284   c . When in the “Off” position  284   a  no electricity is delivered to either the variable frequency AC induction motor  210  or the hydraulic pump  328 . When in “Run” position  284   b  electric power is delivered to the variable frequency AC induction motor  210  and the hydraulic pump  328  (shown in  FIG. 10 ). When in the AC position  284   c  electric power is made available to an outlet  312  disposed on the excavator  300  (see  FIG. 11 ). 
         [0059]    As shown, a current sensor  264  on the first voltage line  250   a  and the current sensor  264  measures the flow of current in and out of the battery  280 . A fuse  286  is located within the battery  280  and is capable of stopping electric current flow in the event the current flow is too high. 
         [0060]    As described above, the battery  280  may be embodied to be identical to the previously described battery  50  and has modules  53  of having cells  51  that are embodied as lithium-ion batteries. The cells  51  may be arranged in a 28 serial by 13 parallel array in one of the referred embodiments. Other lithium iron type batteries are also suitable for use. The cells  51  in the battery  280  and the battery  50  are commercially available. Additionally, lithium-ion batteries are well known to those having ordinary skill in the art and therefore are not described in greater detail herein. It is pointed out that the battery  280  and battery  50  may have cells from a different battery provider and may have a different cell arrangement in order to provide different voltage, capacity, maximum current, or battery housing envelope characteristics. Battery  280  is connected to the battery management system  260  via battery lines  271 . The battery  280  stores electrical energy provided by the battery management system  260  and provides electrical energy to the variable frequency motor driver  230 . 
         [0061]    The battery management system  260  may be used in connection with any embodiment mentioned herein. Battery management systems are commercially available and are well known to those having ordinary skill in the art and therefore not described in greater detail herein. The battery management system  260  has a battery management interface  278  for connection to an external electrical power source, for example the power grid or a generator. When the battery management system  260  is connected to the external power source through the battery management interface  278 , power is delivered over battery lines  271  in order to charge the battery  280 . The battery management system  260  also contains a management system controller  261  for providing logic control for charging and monitoring the battery  280  and communicating with other system components over a management system data bus interface  262 . The battery management system  260  also contains a charger  263  that converts voltages and provides current to the battery  280  while recharging. The battery management system  260  controls current provided by the charger  263  and further includes voltage sensors  255 , current sensor  264  and thermistors for controlling the charging process of the battery pack  280 . 
         [0062]    The voltage converter  274  is coupled to the battery management system  260  through first and second converter lines  276   a ,  276   b  and is also connected to first and second voltage lines  250   a ,  250   b  that are DC. The voltage converter  274  provides efficient voltage conversion from one voltage to another. In particular, the voltage converter  274  is capable of stepping down the voltage of the battery pack  280  to twelve volts (hereinafter referred to as 12V) that is needed by logic management components in the battery management system  260  and other 12V components of the machine electric motor system  200 . The voltage converter output may range from 12V to about 13.5V. 
         [0063]    Battery Sequential Shutdown System 
         [0064]    As shown in  FIGS. 5, 6 and 10 , the machine rechargeable battery power system  200  also includes a sequential shutdown system  287  so that when the key switch  284  is moved into the “Off” position  284   a  the sequential shutdown a sequential shutdown system  287  controls the shutdown process for the piece of equipment  298 , for example the excavator  300 . There is an analog battery management shutdown line  287   a  that extends from the sequential shutdown system  287  to the battery management system  260 . In particular, when the key switch  284  is moved to the “Off” position  284   a  the sequential shutdown system  287  commands the driver controller  237  of the variable frequency motor driver  230  to stop powering the variable frequency AC induction motor  210 , then commands the driver controller  237  to shut down after a time delay. The purpose is to assure that there is no current flowing through the battery lines  271  and main contactor  297  the contactor opens. Opening the contactor with current flowing can cause damage to the contactor and/or the driver controller  237 . As shown in  FIG. 6 , the variable frequency motor driver  230  includes two inputs, a power input  288  and an interlock  289 . The power input  288  provides a signal commanding the driver controller  237  to turn on. The interlock input  289  provides a signal commanding the driver controller  237  to allow current to flow to the variable frequency AC induction motor  210 . If the interlock input  289  is turned off, current will stop flowing to the variable frequency AC induction motor  210 , but the driver controller  237  will stay on, and this will keep the main contactor closed. Disconnecting the power input  288  will shut down the driver controller  237 , causing the main contactor to open immediately. 
         [0065]    The sequential shutdown system  287  includes a power relay  290  and an interlock relay  291  and a time delay circuit  292 . Inputs  290   a ,  291   a  to both the power and interlock relays  290 ,  291 , respectively, are powered when the key switch  284  is turned to “Run” position  284   b , providing 12V DC power to the power and interlock relays  290 ,  291  via the key power line  293 . The battery management system  260  controls the interlock relay  291  via the relay control line  295  that extends from the battery management system  260 . When the software of the battery management system  260  allows the battery  280  to discharge, the relay control line  295  of the battery management system  260  is connected to a 12V ground  294 , allowing the interlock relay input  291   a  to be powered via the key power lines  293 . This allows the software of the battery management system  260  to command the driver controller  237  to cut power to the AC induction motor  210  if there is a battery fault or the battery state of charge reaches zero. 
         [0066]    The time delay circuit  292  maintains power to the power relay input  290   a  and the power relay  290  for about one (1) second after the key switch  284  is turned to the “Off” position  284   a . The time delay circuit  292  may comprise any circuit that stores energy to power the power relay  290 , such as a resistor-capacitor circuit or an integrated circuit timer (not shown). Timer circuits and time delay circuits are well known to those having ordinary skill in the art and therefore are not described in greater detail herein. If the key switch  284  is turned to the “Off” position  284   a , the interlock relay  291  opens immediately, removing power from the interlock input  291   a  and stopping current flow to the AC induction motor  210 . The power relay  290  opens about one (1) second later, shutting down the motor driver controller  237  and opening the main contactor. This greatly reduces the possibility of the contactor  297  and other components of the machine and rechargeable battery power system  200  being damaged during shutdown. 
         [0067]    Battery Reserve Feature 
         [0068]    In normal use, the battery management system  260  commands the driver controller  237  to cut power to the AC induction motor  210  when the battery state-of-charge (hereinafter referred to as SOC) and designated by reference number  296  in  FIG. 7 , the total voltage of the battery  280 , or a cell  51  within the battery  280  reach a set or predetermined lower limit. This would result in other machines currently in use becoming inoperable and stranded, and thus unable to drive back onto a trailer or to a charging location. 
         [0069]    In order to resolve the problem of the excavator  300  or other piece of equipment becoming stranded or shutting down at an undesirable time or location, the there is a power reserve system  306  under the control of the battery management system  260  that provides for a reserve of battery power. The power reserve system  306  allows the piece of equipment  298  to operate for a short time after the BMS  260  normally commands the driver controller  237  to cut power to the AC induction motor  210 . The power reserve system  306  is activated with a reserve switch  307  accessible by use of a reserve key  308 . The use of a reserve key  308  is used so that machine operators (not shown) do not normally have access to the power reserve system  306 . In other preferred embodiments the power reserve system  306  could be controlled remotely, for example with a wireless device connected to the Internet. 
         [0070]    In order for the a power reserve system  306  to operate, the battery  280  has to have some usable energy remaining after the battery management system  260  first commands the driver controller  237  to cut power to the AC induction motor  210 . As shown in  FIG. 7 , this is accomplished by setting the normal SOC  296  lower limit at some percentage above zero, and individual cell  51  voltage lower limits above the lowest voltage that will not damage the cells  51 . The total battery  230  voltage lower limit may also be set higher than the lowest allowable battery  230  voltage (defined as the lowest cell voltage multiplied by the number of cells  51  in series). 
         [0071]    As shown in  FIG. 7 , the high voltage and SOC  296  upper limit exists when the battery  280  is fully charged. As shown, if the lowest allowable voltage is 2.8V of the cell  51 , the normal lower limit voltage may be set to 3.1V and the battery is empty as far as the operator of the excavator is concerned. When the power reserve system  306  is activated, the battery management system  260  allows the piece of equipment  288  to continue discharging the battery  280  until it reaches a new cell voltage lower limit, for example 2.8V. These voltage limits are set such that the battery reserve  309  indicated in  FIG. 7  provides enough run time to return the piece of equipment  298  to a trailer or charging location. The battery management system  260  will then again commands the driver controller  237  to cut power to the AC induction motor  210  the when a cell  51 , battery  230 , and/or SOC  296  have reached the new lower limits set by the power reserve system  306 . 
         [0072]    The battery display  240  will read zero or “empty” when the normal SOC  296  or voltage limits are reached. When the power reserve system  206  activates the battery reserve function the display  240  will continue to read zero. When the battery  280  is charged the battery display  240  will reset to normal operation. 
         [0073]    It is pointed out that in order for the reserve function of the power reserve system  306  to operate as described above, the battery management system  260  must commands the driver controller  237  to cut power to the AC induction motor  210  before the battery  280  has reached the absolute safe lower voltage limit. This reduces the normal usable capacity of the battery  280 . However, raising the lower voltage limit of the cell  51  has other advantages, namely it increases the cycle life of the cells  51  and also serves as a safety buffer such that damage to the battery  280  is less likely should there be a malfunction in any protection systems. Thus, using lower limits to SOC  296  and voltage that are higher than the lowest safe limits have a plurality of advantages which work in unison, but are weighed against a loss in usable capacity. 
         [0074]    Inverter For AC Power 
         [0075]    As shown in  FIGS. 8 and 10  the machine rechargeable battery system  200  also includes a DC/AC inverter  310  that makes use of a cooling system  314 . Lead lines  312   a ,  312   b  extend from the DC/AC inverter  310  to an AC outlet  315  disposed on, for example the excavator  300  as shown in  FIGS. 11 and 12 . The key switch  284  is turned to the AC position  284   c  in for power to be supplied to the AC outlet  315 . An inverter relay  316  is provided and is in communication with the key switch  284 , the DC/AC inverter  310  and the battery management system  260 . The battery management system  260  uses the inverter relay  316  to cut power to the DC/AC inverter  310  when the battery reaches a low voltage or SOC  296 . Thus, the piece of equipment  298  also provides a source of AC power for example to power drills and saws. 
         [0076]    Rebuild Of Used Machines 
         [0077]      FIG. 9  shows another preferred embodiment the piece of equipment  298  is embodied as an excavator that has been used and powered by an internal combustion engine  320 , for example a gas or diesel engine, and having an engine cooling system  321 , and a hydraulic pump  322 . There is also a frame  323  that supports the engine  320  on frame support bars  324  that are supported by the frame  323 . Mounting engines on frames is well known to those who have ordinary skill in the art and therefore not described in greater detail herein. 
         [0078]    As shown in  FIGS. 10-12 , the excavator  300  is modified to include the machine above-described rechargeable battery power system  200  including the sequential shutdown system  287 , power reserve system  306 , the inverter  310  and the other features described above. 
         [0079]    First the internal combustion engine  320  and associated engine cooling system  321  are removed, along with the frame support bars  324 , and this results in a battery recess  325  being formed in the excavator  300 . In addition, a fuel tank and other components necessary for the operation of an internal combustion engine (not shown) are removed from the excavator  300 . Then, a battery support plate  330  is welded or otherwise joined to the frame  323 . After installation of the battery support plate  330  the previously described battery  50  or battery  280  in is placed on battery support plate  330 . Disposed on the battery  280  is a charger  333  for providing DC current to charge the battery  280 . In particular, in the previously described a brace members  112   a ,  112   b  contact the battery support plate  330  and are secured to the battery support plate  330  with isolation mounts  114 . 
         [0080]    In addition, as shown there is the variable frequency motor driver  230  that controls the variable frequency AC induction motor  210 , that in, turn rotates and spins a hydraulic pump  328 . A metal frame  251  is provided and it supports the variable frequency AC induction motor  210 , the hydraulic pump  328 , the cooling system  214  and other components that facilitate servicing and cleaning these drive components. In addition, the variable frequency AC induction motor  210  is mounted on the frame  323  with motor isolation mounts  250  and the hydraulic pump  328  are mounted on the frame  323  with motor isolation mounts  250  and this isolates these components from the moving components of the excavator  300  or piece of equipment  298 . This has a plurality of advantages, for example the variable frequency AC induction motor  210  and the hydraulic pump  328  are subjected to less stress because they are allowed to move freely and independently relative to the frame  323 , and the excavator  300  runs more quietly because vibrations from the variable frequency AC induction motor  210  and the hydraulic pump  328  are transferred to the frame  323  to a much lesser degree. This is because the frame  323  acts as a resonator if the variable frequency AC induction motor  210  and the hydraulic pump  328  are directly mounted thereon. The variable frequency motor driver  230  is attached to the frame with isolation mounts  248  that are independently isolated relative to the variable frequency AC induction motor  210 , the hydraulic pump  328 , and the frame  323  and this isolates the drive controller  237  from vibrations that could damage the internal components over time. 
         [0081]    A pump cooling system  332  cools the hydraulic fluid pumped by the hydraulic ump  328 . The variable frequency motor driver  230 , hydraulic pump  328  and pump cooling system  332  have been relocated as compared to their location in when employed in connection with a combustion engine. The previously described battery management system  260  is also provided and disposed on the excavator  300 . The throttle  270  and visual display  240  are disposed in the cab  334  of the excavator  300 . 
         [0082]    In addition, as shown in  FIGS. 11 and 12  the excavator  300  further includes a battery cover  360  that is removable. There is a motor housing  362  that provides cover to the variable frequency AC induction motor  210  and hydraulic pump  328 . A removable access door  364  is mounted to the motor housing  362  that provides for easy access to the above-described components. The access door  364  is also provided with vents  366 . The motor housing  362  further includes an outlet panel  368  on which is mounted the AC outlet  315  and a charging port  370 , and a charging light indicator  372  that emits light when the battery  280  is being charged. Also shown is a charging cord  374  that can be plugged into a power source to supply power to the charger  333  that serves to charge the battery  280 . 
         [0083]    In addition, the variable frequency AC induction motor  210  is connected to the hydraulic pump  322 , and the variable frequency AC induction motor  210  turns the hydraulic pump  322  to pressurize a hydraulic system  326  of the excavator  300 . The variable frequency AC induction motor is connected to the battery  280  by way of the variable frequency motor driver  230 . Previously the engine  320 , typically a diesel engine, turned the hydraulic pump  322 . 
         [0084]    It is pointed out that the used excavator already has a counterweight. The weight of the battery  280  also serves as a counterweight. 
         [0085]    In another preferred embodiment the piece of equipment  298  or excavator  300  is newly manufactured and constructed to have the machine rechargeable battery power system  200  and features described immediately above, in which case there is no need to modify the excavator  300 . 
         [0086]    Thus, the present machine rechargeable battery power system  200  provides for a method of rebuilding excavators  300  comprising the acts of: 
         [0087]    providing an excavator  300  powered by an internal combustion engine  302 ; 
         [0088]    extracting the engine from the excavator  300 ; 
         [0089]    modifying the frame  310  of the excavator  300  such that it is capable of supporting a support plate  320  and fitting a support plate  320  on the frame  310  for supporting the battery  280 ; 
         [0090]    providing a battery  280  and fixedly supporting the battery  280  on the support plate  320 ; 
         [0091]    installing a variable frequency motor driver  230  and the variable frequency AC induction motor  210  such that they are supported on the support structure  332  affixed on the frame  310 ; 
         [0092]    providing the hydraulic pump  328  and a pump cooling system  330  for cooling the hydraulic fluid pumped by the hydraulic pump  328 , which are relocated from their placement in the internal combustion engine  302 ; and, 
         [0093]    providing the battery management system  260  and disposing the battery management system  260 , the throttle  270  and the visual display  240  in the cab  334  of the excavator  300 . 
         [0094]    The above-described method of rebuilding a piece of used equipment  298 , for example excavators  300  that have been used, provides for a method of generating income. For example and as shown in  FIG. 14 , there is a service provider entity  400  such as a service store, rebuild company, or a manufacturer that is capable of replacing internal combustion engines  302  with the battery  50 ,  280  and other power system components. A customer entity or business commonly designated  402  provides a piece of equipment  298  that has been used to the service provider entity  400 , or the service provider entity  400  purchases a piece of equipment  298  that has been used, and the service provider entity  400  replaces the internal combustion engine  302  with a the battery  50 ,  280  and other system components as described above. The service provider entity  400  then charges a fee to the customer entity  402  for labor and cost of the battery  50 ,  280  and system, or the service provider entity  400  re-sells the piece of equipment  298  to generate income. In other preferred embodiments, the service provider entity  400  makes pieces of equipment  298  that are new with the battery  50 ,  280  and system components built into the piece of equipment  298  and sells the piece of equipment  280  and to generate a profit. 
         [0095]    It is pointed out that the machine rechargeable battery power system  200  and the rechargeable battery power system  10  are not limited to just excavators  300 , but they may be used in virtually all construction equipment  298 , for example, new and used paving machines, rollers, graders, paving machines, loaders, tractors and trucks and other machines that require a power source. Thus, virtually any piece of equipment  298  having an internal combustion engine  302 , for example a gas or diesel engine, and having the engine cooling system  304 , and a hydraulic pump  301  may be modified to accept the machine rechargeable battery power system  200  and be equipped with the machine rechargeable battery power system  200 . First, the internal combustion engine  302  and associated engine cooling system  304  are removed, and that results in a battery recess  309  being defined in the piece of equipment  298 . Then the support plate  320  is welded or otherwise joined to the frame  310  of the piece of equipment. Next, a battery  280  is moved into the battery recess  309  and mounted to the frame  310  of the piece of equipment  298 . After installation of the battery support plate  320  the battery  50  or battery  280  is placed on battery support plate  320  that is supported on the pair of brace members  112   a ,  112   b.    
         [0096]    Light Tower 
         [0097]      FIG. 13  shows another preferred embodiment wherein there is a light tower  400  having a light tower housing  401  wherein a light tower housing  401  is shown prior to installation on a tower frame  402 , with arrow Z designating the direction the light tower housing  401  is to be moved. The tower frame  402  is mounted on wheels  404  and a tongue  406  extends from the tower frame  402 . A retractable tongue support  408  extends from the tongue  406  and supports the tower frame  402  on the ground  405  when in an extended position as shown. The tongue  406  is for towing the light tower  400  after the retractable tongue support  408  is moved into a retracted position. 
         [0098]    There is also a light tower  420  that is supported on the frame  402 , and the light tower  420  is telescopic and has a base portion  423  that houses an extendable portion  421  that can be raised and lowed in the directions of arrows X and Y, respectively. The extendable portion  421  can be manually raised and lowered with, for example, a hand crank  430 . The raising and lowering light towers in well-known to those having ordinary skill in the art and therefore is not described in greater detail herein. The extendable portion  421  supports a light array  432  that includes four light fixtures  434  with light bulbs  435 . In one of the preferred embodiments the lights bulbs  435  are embodied as LED&#39;s  435   a  and in other embodiments the may be incandescent light bulbs. 
         [0099]    Supported on and joined to the tower frame  402  is a battery assembly  48  and in particular the battery housing  54  that holds the battery  50 . A service disconnect  450  extends from the battery  50  and incapacitates the battery  50  for storage or maintenance. Lead lines extend from the battery  50  to a tower inverter  440  that converts DC power from the battery  50  to AC power. Inverter lead lines  442  extend from the tower inverter  440  to the light bulbs  435 . There is also a method of increasing voltage while reducing current flow to the LEDs  435   a  by way of DC/AC tower inverter  440  along with an AC/DC inverter located within each of the four light fixtures  434 . This arrangement reduces resistive power losses and allows for smaller gauge, lighter and less expensive wire to be used. 
         [0100]    The light tower housing  401  also supports a control panel door  446 , and supports a charging port  448  so that the battery  50  may be charged from virtually any power source via a light tower charger  444 . The control panel door  446  allows access to light switches  452  to control the light array  432 , a timer switch  454 , a visual display  458  that displays battery information, for example the percent of charge remaining in the battery  50 , and a low battery warning light. The timer switch  454  automatically shuts of the systems after a predetermined amount of time passes to eliminate the possibility of the battery  50  being over-discharged. The timer switch  454  also serves as the main power switch, such that in order to turn the light tower  420  on the user must set the time switch  454  in advance. The light tower  420  is silent and this will force the user to set the timer switch  454 . In addition, each of the four light fixtures  434  may be turned on or off. Also mounted on the light tower housing  401  are convenience outlets  460  that allow a user to run devices in need of electric power. The convenience outlet  460  is powered by the same DC/AC inverter  440  that powers the LEDs  435   a . The battery management system  260  will shut down the DC/AC tower inverter  440  to protect the battery  50  in the event a system fault or low battery condition. In addition, there are limits set on the battery charge and discharge voltage levels that are narrower as compared to maximum and minimum safe levels, and this provides for an added safety margin against overcharge and discharge, significantly longer battery  50  life cycles at the expense of a small reduction in useable capacity, extra capacity at the end of discharge which enables the reserve power feature (described above). 
         [0101]    The battery  50  for use with the light tower  420  is designed such that it only has a first module bank  61  and the separator support plate  132  is not present. This is due to the fact that the light tower  420  will not have a need for such a large amount of power in some preferred embodiments. 
         [0102]    It is pointed out that the use of the machine rechargeable battery power system  200  and the rechargeable battery power system  10  are provide for power with no pollution at a work, job or activity site, a minimal amount of noise at such sites, and no fuels need at the sites. In addition, because there is no noise and there is no messy odiferous fuels used at the sites the rechargeable battery power system  10  and rechargeable battery power system  200  can be used day or night. Thus, workers can work throughout the night without disturbing the neighborhood or city in which they are working. Additionally, the machine rechargeable battery power system  200  and the rechargeable battery power system  10  can be used indoors, whereas toxic emissions from an internal combustion engine  302  would prohibit it from being used indoors. In addition, the above-described battery  50  can be used by itself to supply electric power. 
         [0103]    In addition, the method of assembling the battery  280  may include more than 1000 cells  51  and includes quality control checks at all stages of assembly. 
         [0104]    It will be appreciated by those skilled in the art that while the rechargeable battery power system  10  and the machine rechargeable battery power system  200  and methods for providing rechargeable battery systems have been described in connection with particular embodiments and examples, the rechargeable battery power system  10  and the machine rechargeable battery power system  200  methods associated therewith are not necessarily so limited and that other examples, uses, modifications, and departures from the embodiments, examples, and uses may be made without departing from the rechargeable battery power system  10  and the machine rechargeable battery power system  200 , and all these embodiments are intended to be within the scope and spirit of the appended claims.