Patent Publication Number: US-2022228348-A1

Title: Electric braking power used for battery regeneration in a mobile work machine

Description:
FIELD OF THE DESCRIPTION 
     The present description relates to electrically powered work machines. More specifically, the present description relates to applying braking energy for battery regeneration in a battery powered work machine. 
     BACKGROUND 
     There are many different types of mobile work machines. Such work machines can include loaders, backhoes, excavators, graders, tracked crawlers, tractors, among others. Such mobile machines include a power supply that drives ground engaging elements, such as wheels or tracks. 
     In some mobile work machines, the power source is an electric power source (such as a battery) that is used to power one or more electric motors. The electric motors, in turn, drive the ground engaging elements through a transmission, which may be a direct connection transmission, or a geared and clutched transmission, or another type of transmission. Other mobile work machines are powered by hybrid systems which can use power from both an electric power source (such as a battery) and an engine, such as a gasoline or diesel fuel powered engine. 
     The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter. 
     SUMMARY 
     The available surge capacity of a battery is detected. The available steady state regeneration energy capacity of the battery is also detected. The available battery generation power, available from an electric motor, is detected as well. The generation power available from the electric motor is applied to regenerate (or recharge) the battery based upon the available surge energy capacity, and the available steady state capacity of the battery. 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the background. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a pictorial illustration of one example of a mobile work machine. 
         FIG. 2  is a block diagram of one example of the mobile work machine illustrated in  FIG. 1 . 
         FIG. 3  is a flow diagram illustrating how the mobile work machine operates to use braking energy to regenerate (or recharge) a battery. 
         FIG. 4  is a graphic illustration of one example of the operation of the mobile work machine in applying regeneration energy. 
         FIG. 5  is a block diagram of one example of a computing environment that can be used in the mobile work machine. 
     
    
    
     DETAILED DESCRIPTION 
     As discussed above, many mobile work machines are powered fully or partially using an electrical power source, such as a battery. The battery is used to power one or more electric motors. Battery life thus affects the timing and efficiency with which such work machines are able to perform operations. 
     In order to increase the operational life of the battery, such work machines can be configured so that, when the electric motor is braking, the braking energy generated by the electric motor is applied to the battery to regenerate or recharge the battery. However, this can present a number of different problems. The ability of a battery to accept recharging energy (also referred to as regeneration energy), such as that applied by a motor during electric braking, varies with the temperature of the battery. For example, a battery at 0° C. may only accept regeneration energy at 50% of the rate with which the battery can accept the regeneration energy when at 25° C. At −10° C., the same battery may only be able to accept regeneration energy at 15% of the rate with which the warmer battery can accept regeneration energy. 
     The same issues are present with a torque converter transmission driven by an electric motor, which needs a braking load for the motor to facilitate downshifting while at speed. Similar issues arise with electrically propelled direct drive transmissions, when they are performing reversals. These transmissions typically do not have a reversing clutch and instead depend on the electric motor to slow the machine down to a stop and then accelerating the motor in the opposite. During slowing of the machine, the electric motor can act as a generator as well. 
     Applying the regeneration energy to the battery may be desirable, as it increases the time that the mobile work machine can operate under battery power. However, if the battery is unable to accept the regeneration power, then if the regeneration power is applied to the battery, it can damage the battery. Therefore, when the rate of braking energy (regeneration energy) available from the electric motor (such as during down shifts) is too high, then alternative actions need to be taken, instead of downshifting the motor and applying the braking energy to the battery. For instance, in some systems, the operator uses service brakes to slow the machine down, in which case the regeneration energy is burned off as heat rather than being applied to the battery and stored for extending runtime. This can lead to operator confusion or frustration, because the mobile work machine must be operated differently when the battery is cold (the manual brakes must be applied more often) than when the battery is warm. 
     Another way to handle the problem is to oversize the battery so that, even in cold conditions, the battery can accept the maximum braking energy that will be generated by the motor during electric braking. However, oversizing the battery in this way may be extremely costly. Yet another way to address the problem may be to permanently divert the braking energy available from the motor, into another device, such as a brake resistor. However, this means that the braking energy will not be used to regenerate the battery, thus penalizing the operational battery life. 
     It is also known that batteries can accept regeneration energy at two different rates. Batteries are able to accept regeneration at one rate during steady state operation of the battery. However, batteries are also able to accept surges of regeneration energy for short periods of time. The power surge capacity may be significantly higher than the steady state energy capacity. The present description thus proceeds with respect to a system that receives an input from the battery, indicating how much power surge capacity is available, as well as the battery&#39;s current steady state energy capacity. A charging control system applies regeneration energy to the battery based upon the available power surge capacity and steady state energy capacity of the battery. The battery can thus be sized appropriately because the present system takes advantage of the power surge capacity of the battery as well as its stead state capacity. This increases the runtime of the battery, and makes the operation of the machine more consistent over a wider temperature range. 
       FIG. 1  is a pictorial illustration of one example of a mobile work machine  100 . In the example illustrated in  FIG. 1 , mobile work machine  100  is a loader that is powered (either in a hybrid system or a completely electrical system) by a power source located in power source compartment  102 . The power source illustratively includes a battery that can be used to drive an electric motor. The electric motor can be used to drive ground engaging elements (e.g., wheels)  104  through a transmission. The transmission may be a direct drive transmission, a geared transmission, a clutched transmission, or another type of transmission. It will also be noted that, while  FIG. 1  shows ground engaging elements  104  as wheels, they can be tracks or other ground engaging elements as well. 
       FIG. 1  also shows that mobile work machine  100  includes an operator compartment  106  that may have one or more operator interface mechanisms  108  that can be used for operator interaction. Machine  100  is also shown with an implement (such as a bucket  110 ) that may be actuated using one or more actuators  112 . 
       FIG. 2  is a block diagram showing portions of mobile work machine  100  in more detail. Some items shown in  FIG. 2  are similar to those shown in  FIG. 1 , and they are similarly numbered.  FIG. 2  shows that work machine  100  can include operator interface mechanism(s)  108 , one or more processors  114 , communication system  116 , control system  118 , controllable subsystems  120 , battery  122 , electric motor  124 , brake resistor  126 , transmission  128 , charging control system  130 , and it can include a wide variety of other work machine functionality  132 . In the example shown in  FIG. 2 , controllable subsystems  120  can include actuators  134  (which may include the actuators  112  illustrated in  FIG. 1  and other actuators), auxiliary loads  136 , an operator-actuated brake system  138 , and other controllable subsystems  140 . Auxiliary loads  136  can include fans  142 , air conditioners  144 , heaters  146 , electrical pumps  148 , an electrical pump  149  coupled to drive hydraulic fluid through a valve  151 , and a wide variety of other auxiliary loads  150 . Battery  122  can include surge capacity detector  152 , steady state capacity detector  154 , communication system  156 , rechargeable power storage  158 , and any of a wide variety of other battery functionality  160 . Charging control system  130  may include power surge capacity monitor  162 , steady state energy capacity monitor  164 , available regeneration energy monitor  166 , load demand detector  167 , regeneration energy controller  168 , and it can include other items  170 . Before describing the overall operation of mobile work machine  100  in applying regeneration energy to battery  122 , a brief description of some of the items in machine  100 , and their operation, will first be provided. 
     Communication system  116  can be any of a wide variety of different types of communication systems that facilitate communication among the items on mobile work machine  100 . For instance, it can be a controller area network (CAN) communication system that controls a CAN bus so that items in machine  100  can communicate with one another. Communication system  116  can also include a communication system that facilitates communication with remote systems, that are remote from machine  100 , such as a cellular communication system, a near field communication system, a local area network communication system, a wide area network communication system, or any of a wide variety of other communication systems or combinations of systems. 
     Operator interface mechanisms  108  can include mechanisms that are provided for interaction by an operator  172 . The operator interface mechanisms  108  can include a steering wheel, joysticks, levers, linkages, buttons, pedals, display screens, touch sensitive display screens, a microphone and speaker (such as a where speech recognition and/or speech synthesis functionality is provided), icons or links or other items that can be actuated using a touch gesture or a point and click device or in other ways, and/or any other audio, visual, or haptic device. 
     Actuators  134  can include any of a wide variety of different types of actuators on machine  100 . Actuators  134  can include electrical actuators, electro-hydraulic actuators, or other actuators that may be powered by battery  122 . There may be, of course, a wide variety of other actuators on machine  100  as well. 
     Auxiliary loads  136  are items that are powered by battery  122 , and that can be controllably activated, deactivated, or adjusted. Loads  136  can thus include electrically powered fans  142 , an air conditioner  144  that is used to air condition operator compartment  106 , one or more heaters  146 , and/or electrical pumps  148  that can be used to pump hydraulic fluid, water, coolant, or other fluids. The auxiliary load  136  can also include an electric pump (or electric motor)  149  that is configured to pump hydraulic fluid through a valve  151 . Valve  151  may have a hydraulic orifice so that motor  149  and valve  151  can be used to create a load similar to, or as an alternative to, break resistor  126  (described below). The auxiliary load  136  can be a wide variety of other electrical elements  150  that can be used to load battery  122 . 
     Operator actuated brake system  138  can be a system that receives an input from an operator interface mechanism  108  (such as a brake pedal or other operator input mechanism) and that, in response, actuates a braking system, such as a caliper, or another braking system that can be actuated to reduce the travel speed of mobile work machine  100 . Brake system  138  can be an electrically, pneumatically, or hydraulically assisted device as well. 
     Battery  122  may be used to power electric motor  124  and the electrically powered controllable subsystems  120 . Battery  122  may also be used to power electrically operated operator interface mechanisms  108  and communication system  116  and any other items that may be battery powered, on machine  100 . Battery  122  illustratively includes surge capacity detector  152  that detects the power surge capacity of battery  122 . The surge capacity detector  152  provides a power surge capacity indicator that indicates the capacity of power or regeneration energy that battery  122  can receive. Surge capacity detector  152  can provide the power surge capacity indicator in a variety of different ways, some of which are described in greater detail below with respect to  FIG. 3 . 
     Similarly, steady state capacity detector  154  generates an output indicative of the steady state capacity of battery  122 . The steady state capacity indicator indicates the amount of steady state regeneration energy that can be received by battery  122 . 
     Communication system  156  illustratively allows surge capacity detector  152  and steady state capacity detector  154  to output their respective indicators to charging control system  130 . Thus, communication system  156  may facilitate communication so detectors  152  and  154  output their respective indicators on a CAN bus that is arbitrated and controlled by a bus controller in communication system  116  or otherwise. Communication system  156  can facilitate the output of the power surge capacity indicator and the steady state capacity indicator in other ways as well. 
     Battery  122  also includes rechargeable power storage elements  158  that store the battery power that can be used to power the electrical elements of machine  100 . The power storage elements  158  are rechargeable so that when regeneration energy is applied to rechargeable power storage elements  158 , it regenerates those storage elements thus increasing the operational life of the battery  122 . 
     Electric motor  124  is powered by battery  122  and is used to drive transmission  128  which, in turn, drives the ground engaging elements  104 . As mentioned above, transmission  128  can be a direct drive transmission, a transmission that uses gears, a clutched transmission, or other transmissions. Electric motor  124  uses energy from battery  122  to drive transmission  128 . However, electric motor  124  can also be used to brake transmission  128  (such as during a downshift, or other electric braking operation), in which case electric motor  124  becomes a generator. The energy generated by motor  124  (such as during an electric braking operation) can be applied back to battery  122  to recharge the rechargeable power storage elements  158 . 
     However, the ability of battery  122  to receive the regeneration energy from electric motor  124  varies based on a number of different criteria. One of those criteria is battery temperature. When battery  122  is cold, its capacity to receive recharge energy may be diminished over that when it is warm. Also, the steady state capacity (the capacity of battery  122  to receive recharge energy in steady state operation) differs from, and is lower than, the power surge capacity of battery  122  (the rate at which battery  122  can receive regeneration energy momentarily, during surges). Power surge energy capacity monitor  162  monitors the power surge capacity indicator output by detector  152 . Steady state energy capacity monitor  164  monitors the steady state capacity indicator output by detector  154 . Available regeneration energy monitor  166  monitors the regeneration energy available from electric motor  124 , such as during electric braking operations. 
     Regeneration energy controller  168  then controls where the regeneration energy provided by electric motor  124  is applied. It will be noted that, in one example, charging control system  130  may be part of electric motor  124  or separate from electric motor  124 . In the example illustrated in  FIG. 2 , charging control system  130  is shown as being separate from electric motor  124 , but this is done by way of example only. To the extent that battery  122  can receive the regeneration energy without being damaged, either as a short surge, or steady state operation, then regeneration energy controller  168  controls the electric motor  124  to apply the regeneration energy to rechargeable power storage elements  158 . Where battery  122  cannot receive the regeneration energy (or all of the regeneration energy) without being damaged, then regeneration energy controller  168  diverts some or all of the regeneration energy away from battery  122 . For instance, regeneration energy controller  168  can provide signals to control system  118  to increase the auxiliary loads  136  (e.g., by turning on fans  142  or increasing fan speed, by turning on air conditioners  144  and/or heaters  146 , by increasing the output of electrical pumps  148  or  149 , by controlling the orifice on valve  151 , or other actuators  150 ). Increasing auxiliary loads  136  may consume enough of the regeneration energy that the remainder can be applied to the rechargeable power storage elements  158  in battery  122 . 
     In addition, regeneration energy controller  168  can control electric motor  124  to apply some or all of the recharge energy to brake resistor  126  where that energy can be dissipated as heat. It is first assumed that mobile work machine  100  has an electric motor  124 , and is operating. This is indicated by block  180  in the flow diagram of  FIG. 3 . At some point, electric motor  124  will become a generator so that regeneration power, such as during an electric braking operation, down shifting, etc. Therefore, there will be regeneration energy available from electric motor  124 . Available regeneration energy monitor  166  detects the amount of regeneration energy available from motor  124 . This is indicated by block  182 . For instance, it may be that the rate of electrical braking is indicative of the available regeneration energy. Thus, the rate of braking can be provided to available regeneration energy monitor  166  to indicate the amount of regeneration energy available. Electric motor  124  may output any of a wide variety of metrics that are indicative of the regeneration energy that is currently available at the output of the motor. 
     Steady state capacity monitor  164  also detects the steady state capacity indicator output by detector  154 , which is indicative of the steady state energy capacity of battery  122 . Detecting the battery steady state regeneration energy capacity is indicated by block  184  in the flow diagram of  FIG. 3 . In one example, the steady state regeneration energy capacity of battery  122  may be based upon the temperature of battery  122 . Thus, the indicator output by detector  154  may be a temperature output which is correlated, by steady state capacity monitor  164 , to a steady state regeneration energy capacity of battery  122 . The correlation can be done by accessing a lookup table, an energy/temperature curve, or a model, based upon the steady state capacity indicator output by detector  154 , which outputs an indicator of a steady state regeneration energy capacity. 
     Load demand detector  167  then detects the combined load demand of the various auxiliary loads  136  in controllable subsystems  120 . Detecting the combined load demand can be done by detecting the state of actuation, of the auxiliary loads  136 , the drain on battery  122  by the various auxiliary loads  136 , or in other ways. Detecting the auxiliary load demand is indicated by block  186  in the flow diagram of  FIG. 3 . 
     Regeneration energy controller  168  then determines whether the amount of regeneration energy available from motor  124  exceeds the battery steady state capacity and the auxiliary load demand. This is indicated by block  188  in the flow diagram of  FIG. 3 . 
     If the amount of regeneration energy that is available from electric motor  124  does not exceed the steady state capacity of battery  122  plus that being drawn by the auxiliary loads  136 , then regeneration energy controller  168  controls electric motor  124  to apply the available regeneration energy to the rechargeable power storage elements  158  to recharge them, as indicated by block  190  in the flow diagram of  FIG. 3 . 
     However, if, at block  188 , regeneration energy controller  168  determines that the amount of regeneration energy available from electric motor  124  does exceed the steady state capacity of batter  122  plus that being drawn by loads  136 , then power surge capacity monitor  162  provides an output to regeneration energy controller  168  indicating the current power surge capacity of battery  122 . Detecting the battery&#39;s power surge capacity is indicated by block  192  in the flow diagram of  FIG. 3 . In one example, the power surge capacity of battery  122  is output as a power surge capacity indicator by surge capacity detector  152 , as indicated by block  194  in the flow diagram of  FIG. 3 . 
     Surge capacity detector  152  can take a number of different forms. For instance, detector  152  may be an up/down counter that provides a counter value as the output. The up/down counter illustratively counts up, as the power surge capacity of battery  122  goes up, so that a value of one hundred indicates that the power surge capacity of battery  122  is at 100% of its rated power surge capacity (which may be a pre-defined value or a variable value that is determined based on capacity variation criteria). The up/down counter can be calibrated to battery  122  empirically, through testing, or in other ways. Using an up/down counter value to determine the available power surge capacity of battery  122  is indicated by block  196  in the flow diagram of  FIG. 3 . 
     Surge capacity detector  152  may also be a temperature or thermal detector, along with a thermal model or look-up table that receives the thermal input, indicating the temperature of battery  122 , and generates a value, where the power surge capacity is measured as follows: 
     
       
         
           
             
               
                 
                   
                     
                       I 
                       2 
                     
                     ⁢ 
                     T 
                   
                   
                     
                       I 
                       2 
                     
                     ⁢ 
                     T_rated 
                   
                 
               
               
                 
                   Eq 
                   . 
                   
                       
                   
                   ⁢ 
                   1 
                 
               
             
           
         
       
     
     Where I=the current being drawn from battery  122 ; 
     T is the temperature of the battery sensed by the thermal sensor; and 
     I 2 T_rated is a reference value of I 2 T for battery  122 . 
     The value of I 2 T is thus a measure of heat energy accumulated over a fixed span of time, such as the amount of heat energy accumulated in the last ten seconds. 
     A model or a lookup table or curve or other correlation structure can be used to generate an indication of power surge capacity based upon the value indicated by Equation 1. Detecting the battery power surge capacity based upon the input from a temperature sensor and correlation structure is indicated by block  198  in the flow diagram of  FIG. 3 . Detecting battery power surge capacity can be done in other ways as well, as indicated by block  200  in  FIG. 3 . 
     Regeneration energy controller  168  then determines whether the available power surge capacity for battery  122  is less than a threshold power surge capacity, as indicated by block  202  in the flow diagram of  FIG. 3 . For instance, it may be that the regeneration energy controller  168  will not apply the regeneration energy from electric motor  124  to battery  122  the regeneration energy exceeds fifty percent of the power surge capacity of battery  122 . In another example, the threshold value may be some value other than fifty percent, and the value may be pre-defined, set by the operator, or set in other ways. If, at block  202 , it is determined that the available power surge capacity for battery  122  is not less than the threshold power surge capacity value, then again regeneration energy controller  168  applies the regeneration energy from motor  124  to rechargeable power storage elements  158 , in battery  122 , to recharge battery  122 . Applying the available regeneration energy to the battery is indicated by block  190 . 
     However, if, at block  202  it is determined that the available power surge capacity of battery  122  is less than the threshold power surge capacity value, then regeneration energy controller  168  takes alternative actions, instead of simply applying all of the regeneration energy from electric motor  124  to battery  122 . In one example, regeneration energy controller  168  can provide an output to control system  118  so that control system  118  controls auxiliary loads  136  to increase the load placed on battery  122  by one or more of the auxiliary loads  136 . Controlling the controllable subsystems to increase the auxiliary load is indicated by block  204  in the flow diagram of  FIG. 3 . 
     In addition, depending on how far below the threshold value the available power surge capacity is, regeneration energy controller  168  can take additional steps as well. For instance, some of the regeneration energy generated by electric motor  124  can be diverted to brake resistor  126 . Adjusting the energy applied to brake resistor  126  is indicated by block  206  in the flow diagram of  FIG. 3 . Also, as discussed above, instead of, or in addition to, diverting energy to brake resistor  126 , energy can be diverted to pump  149  driving fluid through valve  151  or elsewhere. In one example, the amount of regeneration energy diverted to brake resistor  126  may vary inversely relative to the remaining power surge capacity of battery  122 . Where there is more power surge capacity remaining at battery  122 , then less of the regeneration energy is diverted to brake resistor  126  and more is applied to the rechargeable power storage elements  158  in battery  122 . Where less power surge capacity remains at battery  122 , then more of the regeneration energy output by electric motor  124  can be applied to brake resistor  126 . Varying the amount of energy applied to brake resistor  126  based upon the remaining power surge capacity in battery  122  is indicated by block  208  in the flow diagram of  FIG. 3 . In one example, the amount of energy applied to brake resistor  126  can be adjusted to ensure that the braking power by motor  124  remains at 100% of the rated braking power, as indicated by block  210 . The brake resistor  126  can be adjusted in other ways as well, as indicated by block  212 . 
     Even after the auxiliary loads  136  are adjusted, and brake resistor  126  is adjusted, some percent of the available regeneration energy available from electric motor  124  may still be applied to rechargeable power storage elements  158 , as indicated by block  214 . Therefore, the remaining power surge capacity of battery  122  can be taken advantage of, in order to recharge battery  122 , even where the remaining power surge capacity is less than 100% of the rated power surge capacity of battery  122 . 
     As the regeneration energy provided by electric motor  124  is applied to battery  122 , auxiliary loads  136 , and brake resistor  126 , the available regeneration energy at electric motor  124  is de-rated by available regeneration energy monitor  166  to indicate the current regeneration energy available at electric motor  124 . De-rating the available regeneration energy from motor  124  is indicated by block  216  in the flow diagram of  FIG. 3 . As long as machine  100  is still operating, processing then reverts to block  182 . This type of continuous operation is indicated by block  218  in the flow diagram of  FIG. 3 . 
       FIG. 4  is a graph further illustrating one example of how the regeneration energy controller  168  controls application of the regeneration energy generated by electric motor  124  during an electric braking operation.  FIG. 4  is illustrated with a power surge capacity threshold value of 50%. Therefore, when the power surge capacity remaining at battery  122  is above 50%, then none of the regeneration energy output by electric motor  124  is applied to the brake resistor. Instead, it may all be applied to the rechargeable power storage elements  158  in battery  122 , or to both elements  158  and to the auxiliary loads  136  in controllable subsystems  120 . 
     However, once the combination of the power surge capacity of battery  122  and the capacity of auxiliary loads  136  is less than 50% of the remaining power surge capacity of battery  122 , then recharge energy controller  168  begins to divert some of the regeneration energy provided by electric motor  124  to brake resistor  126 .  FIG. 4  also shows that, in one example, as the available power surge capacity for battery  122  falls below 10% of the maximum power surge capacity of battery  122 , then recharge energy controller  168  shifts a higher percentage of the regeneration energy provided by electric motor  124  to brake resistor  126 . This reduces the likelihood that the battery will be damaged based upon variation in sensor tolerances or other estimation inaccuracies, etc. 
     It can thus be seen that the present description takes advantage of the power surge capacity of battery  122  so that more regeneration energy can be applied to battery  122  than if the power surge capacity of battery  122  is not considered. Similarly, even under conditions where the steady state capacity or power surge capacity of battery  122  may be diminished (e.g., when battery  122  is cold) the system can still take advantage of the available power surge capacity in charging battery  122 , without damaging battery  122 . This increases the runtime of battery  122  and thus improves the efficiency and performance of work machine  100 . 
     The present discussion has mentioned processors and servers. In one example, the processors and servers include computer processors with associated memory and timing circuitry, not separately shown. They are functional parts of the systems or devices to which they belong and are activated by, and facilitate the functionality of the other components or items in those systems. 
     Also, a number of user interface displays have been discussed. They can take a wide variety of different forms and can have a wide variety of different user actuatable input mechanisms disposed thereon. For instance, the user actuatable input mechanisms can be text boxes, check boxes, icons, links, drop-down menus, search boxes, etc. They can also be actuated in a wide variety of different ways. For instance, they can be actuated using a point and click device (such as a track ball or mouse). They can be actuated using hardware buttons, switches, a joystick or keyboard, thumb switches or thumb pads, etc. They can also be actuated using a virtual keyboard or other virtual actuators. In addition, where the screen on which they are displayed is a touch sensitive screen, they can be actuated using touch gestures. Also, where the device that displays them has speech recognition components, they can be actuated using speech commands. 
     A number of data stores have also been discussed. It will be noted they can each be broken into multiple data stores. All can be local to the systems accessing them, all can be remote, or some can be local while others are remote. All of these configurations are contemplated herein. 
     Also, the figures show a number of blocks with functionality ascribed to each block. It will be noted that fewer blocks can be used so the functionality is performed by fewer components. Also, more blocks can be used with the functionality distributed among more components. 
     It will be noted that the above discussion has described a variety of different systems, components and/or logic. It will be appreciated that such systems, components and/or logic can be comprised of hardware items (such as processors and associated memory, or other processing components, some of which are described below) that perform the functions associated with those systems, components and/or logic. In addition, the systems, components and/or logic can be comprised of software that is loaded into a memory and is subsequently executed by a processor or server, or other computing component, as described below. The systems, components and/or logic can also be comprised of different combinations of hardware, software, firmware, etc., some examples of which are described below. These are only some examples of different structures that can be used to form the systems, components and/or logic described above. Other structures can be used as well. 
       FIG. 5  is one example of a computing environment in which elements of  FIG. 2 , or parts of it, (for example) can be deployed. With reference to  FIG. 5 , an example system for implementing some embodiments includes a computing device in the form of a computer  810  programmed to operate as described above. Components of computer  810  may include, but are not limited to, a processing unit  820  (which can comprise processors or servers from previous FIGS.), a system memory  830 , and a system bus  821  that couples various system components including the system memory to the processing unit  820 . The system bus  821  may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. Memory and programs described with respect to  FIG. 2  can be deployed in corresponding portions of  FIG. 5 . 
     Computer  810  typically includes a variety of computer readable media. Computer readable media can be any available media that can be accessed by computer  810  and includes both volatile and nonvolatile media, removable and non-removable media. By way of example, and not limitation, computer readable media may comprise computer storage media and communication media. Computer storage media is different from, and does not include, a modulated data signal or carrier wave. It includes hardware storage media including both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by computer  810 . Communication media may embody computer readable instructions, data structures, program modules or other data in a transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. 
     The system memory  830  includes computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM)  831  and random access memory (RAM)  832 . A basic input/output system  833  (BIOS), containing the basic routines that help to transfer information between elements within computer  810 , such as during start-up, is typically stored in ROM  831 . RAM  832  typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit  820 . By way of example, and not limitation,  FIG. 5  illustrates operating system  834 , application programs  835 , other program modules  836 , and program data  837 . 
     The computer  810  may also include other removable/non-removable volatile/nonvolatile computer storage media. By way of example only,  FIG. 5  illustrates a hard disk drive  841  that reads from or writes to non-removable, nonvolatile magnetic media, an optical disk drive  855 , and nonvolatile optical disk  856 . The hard disk drive  841  is typically connected to the system bus  821  through a non-removable memory interface such as interface  840 , and optical disk drive  855  are typically connected to the system bus  821  by a removable memory interface, such as interface  850 . 
     Alternatively, or in addition, the functionality described herein can be performed, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-programmable Gate Arrays (FPGAs), Application-specific Integrated Circuits (e.g., ASICs), Application-specific Standard Products (e.g., ASSPs), System-on-a-chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), etc. 
     The drives and their associated computer storage media discussed above and illustrated in  FIG. 5 , provide storage of computer readable instructions, data structures, program modules and other data for the computer  810 . In  FIG. 5 , for example, hard disk drive  841  is illustrated as storing operating system  844 , application programs  845 , other program modules  846 , and program data  847 . Note that these components can either be the same as or different from operating system  834 , application programs  835 , other program modules  836 , and program data  837 . 
     A user may enter commands and information into the computer  810  through input devices such as a keyboard  862 , a microphone  863 , and a pointing device  861 , such as a mouse, trackball or touch pad. Other input devices (not shown) may include a joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit  820  through a user input interface  860  that is coupled to the system bus, but may be connected by other interface and bus structures. A visual display  891  or other type of display device is also connected to the system bus  821  via an interface, such as a video interface  890 . In addition to the monitor, computers may also include other peripheral output devices such as speakers  897  and printer  896 , which may be connected through an output peripheral interface  895 . 
     The computer  810  is operated in a networked environment using logical connections (such as a controller area network—CAN, local area network—LAN, or wide area network—WAN) to one or more remote computers, such as a remote computer  880 . 
     When used in a LAN networking environment, the computer  810  is connected to the LAN  871  through a network interface or adapter  870 . When used in a WAN networking environment, the computer  810  typically includes a modem  872  or other means for establishing communications over the WAN  873 , such as the Internet. In a networked environment, program modules may be stored in a remote memory storage device.  FIG. 5  illustrates, for example, that remote application programs  885  can reside on remote computer  880 . 
     It should also be noted that the different examples described herein can be combined in different ways. That is, parts of one or more examples can be combined with parts of one or more other examples. All of this is contemplated herein. 
     Example 1 is a mobile work machine, comprising: 
     a ground engaging element; 
     a battery; 
     an electric motor that drives the ground engaging element; and 
     a charging control system that controls the application of regeneration energy, generated by the electric motor, to the battery based on a detected power surge capacity indicator, indicative of a power surge capacity of the battery. 
     Example 2 is the mobile work machine of any or all previous examples and further comprising: 
     a surge capacity detector that detects a variable indicative of the power surge capacity of the battery and generates the power surge capacity indicator. 
     Example 3 is the mobile work machine of any or all previous examples wherein the surge capacity detector comprises: 
     a thermal sensor that senses a thermal characteristic of the battery and generates the power surge capacity indicator based on the sensed thermal characteristic. 
     Example 4 is the mobile work machine of any or all previous examples and further comprising: 
     a steady state capacity detector that detects a variable indicative of steady state regeneration energy capacity of the battery and generates a steady state capacity indicator based on the detected variable indicative of the steady state regeneration energy capacity. 
     Example 5 is the mobile work machine of any or all previous examples wherein the charging control system comprises: 
     a regeneration energy monitor that detects available regeneration energy available from the electric motor. 
     Example 6 is the mobile work machine of any or all previous examples wherein the charging control system comprises: 
     a regeneration energy controller that determines whether the available regeneration energy available from the motor exceeds the steady state regeneration energy capacity of the battery and, if not, controls application of the regeneration energy to apply the regeneration energy from the electric motor to the battery. 
     Example 7 is the mobile work machine of any or all previous examples and further comprising: 
     an electrical load element that has a load capacity and wherein, if the regeneration energy controller determines that the available regeneration energy available from the motor exceeds the steady state regeneration energy capacity of the battery, the regeneration energy controller determines whether the regeneration energy from the electric motor exceeds the power surge capacity of the battery and, if so, controls application of the regeneration energy from the electric motor to apply the regeneration energy from the electric motor to the electrical load element. 
     Example 8 is the mobile work machine of any or all previous examples wherein the regeneration energy controller is configured to generate a load adjustment output to adjust the load capacity of the electrical load element based on whether the regeneration energy controller determines that the available regeneration energy available from the motor exceeds the power surge capacity of the battery. 
     Example 9 is the mobile work machine of any or all previous examples wherein the electric motor is configured to generate the regeneration energy while performing an electric braking operation and wherein the load element comprises: 
     a brake resistor; and 
     an auxiliary load element. 
     Example 10 is the mobile work machine of any or all previous examples wherein the regeneration energy controller is configured to control the auxiliary load element to adjust the load and to adjust application of the regeneration energy to the brake resistor and to the battery based on the power surge capacity of the battery. 
     Example 11 is the mobile work machine of any or all previous examples and further comprising: 
     a transmission, wherein the motor drives the ground engaging element through the transmission. 
     Example 12 is a method of controlling a mobile work machine, comprising: 
     initiating an electric motor that is powered by a battery to drive a set of ground engaging elements; 
     detecting a variable indicative of a power surge capacity of the battery; 
     generating a power surge capacity indicator indicative of the power surge capacity of the battery based on the detected variable; and 
     controlling application of regeneration energy, generated by the electric motor, to the battery, based on the power surge capacity indicator. 
     Example 13 is the method of any or all previous examples wherein detecting a variable indicative of the power surge capacity detector comprises: 
     sensing a thermal characteristic of the battery; and 
     generating the power surge capacity indicator based on the sensed thermal characteristic. 
     Example 14 is the method of any or all previous examples and further comprising: 
     detecting a variable indicative of steady state regeneration energy capacity of the battery; 
     generating a steady state capacity indicator based on the detected variable indicative of the steady state regeneration energy capacity; 
     detecting available regeneration energy available from the electric motor; 
     determining whether the available regeneration energy available from the motor exceeds the steady state regeneration energy capacity of the battery; and 
     if not, controlling application of the regeneration energy to apply the regeneration energy from the electric motor to the battery. 
     Example 15 is the method of any or all previous examples and further comprising: 
     if the available regeneration energy available from the motor exceeds the steady state regeneration energy capacity of the battery, determining whether the regeneration energy from the electric motor exceeds the power surge capacity of the battery; and 
     if so, applying the regeneration energy from the electric motor to an electric load element. 
     Example 16 is the method of any or all previous examples and further comprising: 
     generating a load adjustment output to adjust the load capacity of the electrical load element based on whether a determination that the available regeneration energy available from the motor exceeds the power surge capacity of the battery. 
     Example 17 is the method of any or all previous examples wherein generating a load adjustment output comprises: 
     controlling an auxiliary load element to adjust a load of the auxiliary load element to adjust application of the regeneration energy to a brake resistor and to the battery based on the power surge capacity of the battery. 
     Example 18 is a mobile work machine, comprising: 
     a ground engaging element; 
     a battery; 
     an electric motor that drives the ground engaging element; 
     a transmission, the motor driving the ground engaging element through the transmission; 
     a surge capacity detector that detects a variable indicative of a power surge capacity of the battery and generates a power surge capacity indicator based on the detected variable; and 
     a charging control system that controls the application of regeneration energy, generated by the electric motor, to the battery based on the power surge capacity indicator. 
     Example 19 is the mobile work machine of any or all previous examples and further comprising: 
     a steady state capacity detector that detects a variable indicative of steady state regeneration energy capacity of the battery and generates a steady state capacity indicator based on the detected variable indicative of the steady state regeneration energy capacity; 
     a regeneration energy monitor that detects available regeneration energy available from the electric motor; and 
     a regeneration energy controller that determines whether the available regeneration energy available from the motor exceeds the steady state regeneration energy capacity of the battery and, if not, controls application of the regeneration energy to apply the regeneration energy from the electric motor to the battery. 
     Example 20 is the mobile work machine of any or all previous examples and further comprising: 
     an electrical load element that has a load capacity and wherein, if the regeneration energy controller determines that the available regeneration energy available from the motor exceeds the steady state regeneration energy capacity of the battery, the regeneration energy controller determines whether the regeneration energy from the electric motor exceeds the power surge capacity of the battery and, if so, controls application of the regeneration energy from the electric motor to apply the regeneration energy from the electric motor to the electrical load element and generates a load adjustment output to adjust the load capacity of the electrical load element. 
     Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.