Abstract:
An electric vehicle battery recharging system is disclosed that is capable of generating an audible sound to indicate that the battery system of the vehicle is being recharged. The system includes an audible indicator that is connected or otherwise associated with a controller. The controller is configured to actuate the audible indicator in response to a voltage or current of a battery system rising a predetermined amount after recharging is initiated so as to provide audible confirmation to a recharging operator that the battery system is being recharged.

Description:
PRIORITY CLAIM 
     This application claims priority to and the benefit of U.S. Provisional Application No. 61/582,295 filed Dec. 31, 2011. 
    
    
     BACKGROUND 
     Embodiments relate to electric vehicles and the charging and recharging thereof. More particularly, but not exclusively, the embodiments relates to electric vehicles of the type which have traction batteries that need to be periodically recharged by connection to an external power source. 
     SUMMARY 
     In one aspect, the present invention provides an improvement on the way existing fleets of electric golf carts being recharged, such as a fleet of golf carts, battery recharging system that monitors for a rise in the voltage of an electric vehicle&#39;s battery after an attendant has connected the power cord to the vehicle charging port and then generates an audible confirmation once a sufficient rise in the battery voltage has been detected. 
     In one aspect, the present invention involves an improved battery recharging system that monitors a vehicle&#39;s battery after an attendant has successfully connected the vehicle to its charging system and then generates an audible confirmation once a sufficient rise in the battery voltage has been detected, thereby providing an audible confirmation that battery recharging is actually occurring. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Features of the invention will be better understood from the following detailed description when considered in reference to the accompanying drawings, in which: 
         FIG. 1  is a functional block diagram representing a vehicle according to an embodiment. 
         FIG. 2  is a functional block diagram representing another vehicle according to an embodiment. 
         FIG. 3  is a functional block diagram representing another vehicle according to an embodiment. 
         FIG. 4  is a flowchart illustrating an operation of a charging system according to an embodiment. 
         FIG. 5  is a schematic depiction of a fleet of electric vehicles being recharged according to an embodiment. 
         FIG. 6  is a block diagram of a vehicle charging system according to an embodiment. 
         FIG. 7  is a block diagram of a vehicle charging system according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a functional block diagram representing a vehicle according to an embodiment. In an embodiment, a vehicle  22  includes a rechargeable battery system  32  and an electric motor (not shown) and may be any variety of vehicle, such as a golf cart, utility vehicle, forklift, passenger vehicle or the like. In an embodiment, the battery system  32  serves as the sole source of the power to propel the vehicle, as in a traction battery pack for golf carts and utility vehicles, while in others the battery system  32  functions as a supplemental power source, as with a hybrid drive. In an embodiment, the battery system  32  can be a single battery, a bank of batteries, a bank of batteries with a dedicated controller, or the like. 
     Vehicle  22  includes a battery charging system  26 . Charging system  26  can be configured to recharge the battery system  32 . The charging system  26  can be a microprocessor based, solid state device, discrete electronics, or the like. Charging system  26  can be configured as an on-board charging system and can be connected to an external power source  10  by a charging cable. For example, charging cable  16  can have a connector  18  that mates with a corresponding connector  20  on the vehicle  22  to connect charging system  26  to an external AC power source  10 . In an embodiment, the making of this connection serves to commence the recharging of the battery system  32  by the system  26 . 
     The charging system  26  is coupled to a controller  36 . The controller  36  can be a motor controller for the vehicle. During operation of the vehicle  22 , the battery pack  32  can be configured to deliver power to the electric motor as directed by the motor controller  36 , for example, in response to received inputs (e.g. the operator depressing the accelerator). 
     In an embodiment, the controller  36  can be configured to actuate an audible indicator  38 . For example, when a transmission control or other equivalent directional control of the vehicle  22  is placed into a reverse setting, the controller  36  can be configured to actuate the audible indicator  38  to generate a beep. The controller  36  can be configured to actuate the same audible indicator  38  when the vehicle  22  is being recharged. 
     For example, a user can connect the connectors  18  and  20 , to supply power to the vehicle  22  from the power source  10 . The power source  10  can be any variety of power sources. For example, the power source  10  can be an alternating current (AC) power source. However, in other embodiments, the power source  10  can be a direct current (DC) power source. 
     The charging system  26  can be configured to generate a power connection signal. For example, the power connection signal can be a lockout signal used to prevent the vehicle  22  from moving, engaging the motor, or the like while connected to a power source  10 . The controller  36  can be configured to receive the power connection signal from charging system  26  and actuate the audible indicator  38  in response. In an embodiment, an audible signal can be generated when a connection is made. Accordingly, a user can receive positive feedback regarding the connection. 
     In addition or alternatively, an audible signal can be generated by the audible indicator  38  in response to a state of charging. As will be described in further detail below, a variety of techniques can be used to determine if the battery system is charging. 
     In an embodiment, the charging status can be used in combination with the connection status. For example, the connection signal can trigger an operation of determining if charging is occurring. As a result, the audible signal can be generated when the connection is made and charging has begun. In contrast, if power is restored after a power failure, an entire fleet of vehicles may begin charging. An audible signal from each vehicle  22  when charging resumes may not be desirable. Accordingly, the connection status can be used to filter changes in charging state from not-charging or discharging states to a charging state. However, in an embodiment, the audible signal can be generated based on the charging status without regard to the connection status. 
     Although the controller  36  has been used as an example of a system configured to actuate the audible indicator  38 , the audible indicator can be coupled to the charging system  26  as well. Thus, the charging system can be configured to actuate the audible indicator  38 . In a particular example, the charging system  38  can be configured to actuate a audible indicator  38  that is normally used to indicate that the vehicle is in a reverse mode. That is, an additional audible indicator  38  can, but need not be present as the existing audible indicator can be used. 
     Although the same audible signal can be used in both reverse and charging, in an embodiment, a different audible signal can be generated in association with charging than when the vehicle  22  is in reverse. For example, in reverse, a typical periodic beeping can occur. In contrast, the audible signal associated with charging can be a faster sequence of beeps that does not repeat. In another example, a different pitch can be used. In another example, a synthesized signal can be used. Any audible signal that can be distinguishable from a reverse signal can be used. 
     Although an audible indicator  38  has been described in association with charging, the audible signal can, but need not be the only technique used to communicate charging status. For example, a visual indicator  37  can also indicate the status. That is, the audible indication can be supplemental to other indications. However, in a busy environment, a visual indication may be overlooked, require direct line of sight, or the like for positive confirmation of charging. 
       FIG. 2  is a functional block diagram representing another vehicle according to an embodiment. In this embodiment, the controller  36  is coupled to the audible indicator  38  and the battery system  32 . The controller  36  can similarly be configured to determine a charging status of the battery system  32 . 
     However, in this embodiment, the vehicle  122  is configured to be coupled to an external charging system  126 . The external charging system  126  can be similarly coupled to a power source  10 . A connector  118  coupled to the charging system  126  can be connected to a connector  120  of the vehicle  122 . 
     In an embodiment, the controller  36  can be configured to receive a connection signal, such as a lockout signal, from the external charging system  126 . For example, a dedicated contact of the connectors  118  and  120  and corresponding conductors can propagate the connection signal to the controller  36 . 
     However, in another embodiment, the controller  36  can be configured to determine if a connection is made. For example, a switch can be used to detect if the connector  118  is mated with the connector  120 . In another example, electrical components within the connectors and/or the charging system  126  can affect an electrical parameter of a circuit coupled to the controller  36 . For example, a resistor in the connector  118  can change a voltage of a voltage divider coupled to the controller  36 . The controller  36  can sense the voltage and make a determination whether a connection is made based on the voltage. 
     In particular, in an embodiment, the vehicle  122  does not include the charging system  126 . Even if the external charging system  126  has determined that charging has begun, a fault can still occur. Furthermore, any signal, whether audible, visual, or otherwise, that is generated by the charging system  126  is conceptually associated with the charging system  126 . In contrast, as an on-board audible indicator  38  can be used to convey charging status, an indicator associated with the particular vehicle being charged can focus a user&#39;s attention to that vehicle, rather than a physically separate external charging system  126 . 
       FIG. 3  is a functional block diagram representing another vehicle according to an embodiment. In an embodiment, the charging components can be distributed between external components  227  and on-board components  226 . A connection signal can be generated in a variety of ways. For example, a lockout signal can still be transmitted from the on-board components  226 . Alternatively, the lockout signal can be merely propagated through or around the on-board components  226  from the external components  227 . 
       FIG. 4  is a flowchart illustrating an operation of a charging system according to an embodiment. In  300 , an initial power connection is monitored. For example, a lockout signal, connection signal, switch, change in an electrical parameter, or the like as described above, can be used to determine if a connection has been made in  302 . In one form, the controllers  26 ,  36  include software or applications that are configured to receive input signals, as set forth below, and take appropriate actions in response to those signals. 
     In this embodiment, voltage can be used to determine a charging state. In  304 , an initial voltage is recorded. The voltage can be stored in a memory, an energy storage device, or the like. 
     In  306 , the battery voltage is monitored. The battery voltage is compared with the recorded voltage in  308 . In particular, the current battery voltage can be compared to determine if the current voltage has exceeded the initial voltage by a threshold. For example, a 0.8 volt threshold can be used for a 48 V 100 Ah battery. 
     In an embodiment, the voltage threshold can be determined based on a particular time period. For example, the 0.8 V described above can correspond to a voltage increase that occurs in approximately 5-20 seconds for the associated battery system and charging system. Accordingly, the audible signal can be generated after approximately 5-20 seconds. For other batteries, battery systems, charging systems, or the like, a different voltage can be used. 
     If the voltage rise is detected in  308 , in  310  the audible signal can be generated. If not, a time limit is checked in  312  to determine if a threshold time has passed. If not, the battery voltage is again monitored in  306  and compared in  308 . 
     If the time has passed, processing can further continue in  316 . In general, The monitoring for the increase in battery voltage to generate the audible signal does not occur for further operations. However, if the power connection is interrupted, in  314 , the monitoring for the voltage rise can begin again in  300 . For example, if power has been lost, but the connection has not been disconnected, the voltage comparison does not begin again when power is restored. In contrast, if the power connection is disconnected then reconnected, the monitoring for the increase in the battery voltage can resume. 
     Although voltage has been used as an example of a technique to determine if the battery system is being charged, other techniques can be used. For example, a current monitor can sense that an initial current flow to the battery that is substantially zero, or indicates that the battery system is discharging. A current flow into the battery can indicate that the battery is charging. For example, a current threshold can be used to determine if the battery system is charging. 
     A time period can similarly be used as described above. For example, if the audible signal can be generated after a time period during which the current flow into the battery system meets or exceeds the threshold. In another example, an amount of energy transferred to the battery can be calculated, approximated, or the like. The audible signal can be generated in response to the amount of energy. Any parameter that changes based on the charging of a battery or battery system can be used in generated an audible signal. 
     Although a charging state has been described as associated with the audible signal, in an embodiment, the state of interest is that actual charging state of a battery. That is, whether the battery voltage is increasing, a supplied current is decreasing, an amount of energy has been transferred, or the like. As the monitored state used for determining whether charging is occurring is conceptually removed from the actual energy storage device, the potential for unresolved faults can increase. However, in other embodiments, the exact battery parameters can, but need not be used. Rather, proxies for the battery parameters, such as communicated sensed values, can be used. Furthermore, in an embodiment, parameters that are somewhat removed from the actual charging can be used, even if particular faults may not be detected. For example, a current flowing into an on-board charging system can be used. 
       FIG. 5  is a schematic depiction of a fleet of electric vehicles being recharged according to an embodiment. In an embodiment, multiple vehicles  22  can be charged in a location, such as a building  40 . The building  40  can be a garage, shed, awning, or the like. A power source  10  can be coupled to the vehicles through cables  16  and connectors  18  coupled to corresponding connectors on the vehicles  22 . 
     In operation, a user may be connecting many vehicles  22  to the power source  10 . During the hustle and bustle of a busy day, the user may neglect to verify that a visual indicator has illuminated, indicating that a particular vehicle  22  is charging. With the audible indication, a user can move on to connecting the next vehicle  22  to the power source  10  and, while finding the cable  16  for that next vehicle  22 , hear the audible indication confirming charging of the previous vehicle  22 . 
       FIG. 6  is a block diagram of a vehicle charging system according to an embodiment. Multiple ways can be used to sense how the connection is made by connectors  402  and  404 . For example, the controller  406  can be coupled to a sensor  412 . The sensor  412  can be a switch, circuit, such as the voltage divider described above, or the like. 
     The controller  406  can be coupled to the sensor  408 . The sensor  408  can be a voltage sensor, current sensor, output of the battery system  400 , or the like. Accordingly, the controller  406  can be configured to sense an electrical parameter associated with the battery system  400  to determine if the battery system  400  is charging. 
     The controller  406  can be any controller of the vehicle. For example, the controller  406  can be a dedicated, stand-alone controller. In another example, the controller can be part of the motor controller for the vehicle. In another example, the controller  406  can be part of a user interface for the vehicle. 
     Regardless, the controller  406  can be configured to generate an audible signal through the audible indicator  410 . Although a direct connection has been illustrated, the controller  406  can cause the audible signal to be generated through intervening systems. For example, the controller  406  can communicate to a motor controller to cause the motor controller to generate the audible signal. 
       FIG. 7  is a block diagram of a vehicle charging system according to an embodiment. The charging system  500  for the battery system  502  itself can be configured to determine if the connection is made between connectors  504  and  506 , and control the actuation of the audible indicator  508 . The charging system  500  can be a complete charging system that is configured to receive only power. In another example, the charging system  500  can be a part of system with onboard and external components. Regardless, the on-board charging system  500  can make a determination to actuate the audible indicator  508  as described above. That is, in an embodiment, the controller described above can be part of the charging system  500 . 
     An embodiment includes a computer-readable medium storing computer-readable code that when executed on a computer, causes the computer to perform the various techniques described above. In a particular example, an existing controller coupled to a audible indicator, such as a reverse audible indicator, can be retrofit with new firmware, software, or the like. Accordingly, the associated vehicle can be configured to generate an audible signal associated with charging as described above. 
     Although a lockout signal has been described above in association with determining if a power connection is made, the lockout signal is but one example of a signal that can be used to determine if the power connection is made. As described above, a variety of other signals can be used in combination with or separate from a lockout signal. 
     Although particular sequences of operations have been described above, in other embodiments, the sequences can occur as desired. 
     Although particular embodiments have been described above, the scope of the following claims is not limited to these embodiments. Various modifications, changes, combinations, substitution of equivalents, or the like can be made within the scope of the following claims.