Abstract:
Currently the most common method on the market to charge electric vehicles is to plug in the electric vehicle to a power source. Wireless charging technologies are also being developed and infrastructure has begun to be rolled out into the marketplace. Designing separate charging systems for wireless and wired systems may lead to drawbacks as not all chargers will be compatible with all vehicles. The invention described herein illustrates a system for bridging the gap between wired and wireless charging infrastructure through the use of a multi-mode electric vehicle charging system capable of delivering power through a plurality of transmission methods, where one of those methods is wireless power transfer.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a continuation of Patent Cooperation Treaty application No. PCT/CA2015/050736 filed 5 Aug. 2015 and entitled MULTI-MODE CHARGING SYSTEM, which in turn claims priority from, and the filing date benefit under 35 USC §119 of, U.S. application Ser. No. 62/033,748 filed on 6 Aug. 2014 and entitled METHOD AND APPARATUS FOR A MULTI-MODE CHARGING SYSTEM. The applications referred to in this paragraph are hereby incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This invention pertains to a method and apparatus for a multi-mode electric vehicle charging system capable of delivering power through a plurality of transmission modes, where at least one of those modes is wireless power transfer. Particular embodiments, provide methods and apparatus for retrofitting wireless electric vehicle chargers into existing electric vehicle charging systems. 
       BACKGROUND 
       [0003]    Despite the anticipated rollout of wireless charging for electric vehicles (“EVs”), there will be, for the foreseeable future, a simultaneous market for both wired and wireless charging of EVs. Providing separate charging systems for wireless and wired systems (also referred to as plug-in systems) can lead to more drawbacks as not all chargers will be compatible with all vehicles, a problem which standardization in wired vehicle electrical connections (such as the SAE J1772 cable interface) is attempting to solve. It is expected that multiple standards and systems will likely exist simultaneously, and that the technologies underlying these standards may be non-interoperable. There is a general desire to enhance the roll-out of wireless charging infrastructure in a cost-effective manner, while simultaneously maintaining existing wired charging infrastructure and minimizing the amount of costly overlap between the two systems. 
         [0004]    There is a general desire to provide charging stations capable of charging a wide variety of electric vehicles through both wireless and wired (i.e. plug-in) charging. There may also be a general desire to provide simple, inexpensive wireless charging systems that can be retrofitted to pre-existing plug-in (i.e. wired) chargers. There may be a general desire to provide charging stations for charging multiple vehicles simultaneously. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0005]    Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive. 
           [0006]      FIG. 1  is a schematic illustration of a multi-mode charging station for a single vehicle according to a particular embodiment. 
           [0007]      FIG. 2  is a schematic illustration of a multi-mode charging station for a single vehicle according to a particular embodiment. 
           [0008]      FIG. 3  is a schematic illustration of a multi-mode charging station for supplying power from wired and wireless chargers to an electric vehicle according to a particular embodiment. 
           [0009]      FIG. 4  is a schematic illustration of a multi-mode charging station for supplying power to multiple electric vehicles according to a particular embodiment. 
           [0010]      FIG. 5  is a schematic illustration of a multi-mode charging station for supplying power from multiple wired chargers to electric vehicles according to a particular embodiment. 
           [0011]      FIG. 6  is a schematic illustration of a multi-mode charging station for supplying power from multiple power sources to multiple electric vehicles at a single secondary charging station according to a particular embodiment. 
           [0012]      FIG. 7  is a schematic illustration of a multi-mode charging station for supplying power from multiple power sources to multiple electric vehicles from a plurality of wired and wireless charging systems according to a particular embodiment. 
       
    
    
     DESCRIPTION 
       [0013]    Throughout the following description specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense. 
         [0014]    One aspect of the invention provides an electric vehicle charging station. An electric vehicle supply equipment (EVSE) unit may be connected to a power source and configured to provide output power. The EVSE unit may comprise any EVSE unit as known in the art. For example, the EVSE unit may be configured to enhance safety by enabling two-way communication between the charging station and the electric vehicle. Two-way communication may ensure that current passed to the vehicle is below limits of the power source and what the vehicle can receive. The EVSE unit may comprise conductors, including ungrounded, grounded and equipment grounding conductors, electric vehicle connectors, attachments plugs, and other fittings, devices, power outlets or apparatuses installed for the purpose of delivering power from a power source (e.g. the power grid) to the electric vehicle. A plug-in (i.e. wired) charger may be electrically connected (e.g. through a wired connection) to the EVSE unit to receive output power therefrom. The plug-in charger may comprise any type of wired or plug-in charger that is known in the art. For example, the plug-in charger may comprise an output connector according to at least any of the following standards: an SAE J1772 output connector, a CHAdeMO output connector, a Tesla Motors Supercharger output connector or any other plug-in charger that is physically electrically connectable (i.e. can be unconnected and reconnected) to an electric vehicle for transferring power from the EVSE unit to the electric vehicle. A wireless charger may be physically electrically connectable (e.g. through a wired connection) to the EVSE unit to receive power therefrom. The wireless charger may comprise any type of wireless charger that is known in the art such as an induction charger or a magneto-dynamic coupling (MDC) charger that is wirelessly electrically connectable to an electric vehicle for transferring power from the EVSE unit to the electric vehicle. Examples of MDC chargers are provided in PCT application No. PCT/CA2010/000252 (published under WO/2010/096917) and PCT application No. PCT/CA2015/050327, both of which are hereby incorporated herein by reference. In some embodiments, the wireless charger is electrically connectable to the EVSE unit via the plug-in charger (e.g. an output connector of the plug-in charger is connected to an input connector of the wireless charger to thereby transfer at least a portion of the output power from the EVSE unit to the wireless charger). 
         [0015]    In some embodiments, the electric vehicle charging station comprises a secondary charger distribution panel electrically connectible to the EVSE unit to receive power therefrom. For example, the secondary charger distribution panel may be electrically connectable to the EVSE unit via the plug-in charger (e.g. an output connector of the plug-in charger is connected to an input connector of the secondary charger distribution panel to thereby transfer power from the EVSE unit to the secondary charger distribution panel). The secondary charger distribution panel may also be connected to the wireless charger to provide power from the EVSE unit thereto and to at least one secondary charger to provide power from the EVSE unit thereto. In some embodiments, the secondary chargers comprise one or more secondary plug-in chargers physically electrically connectable to an electric vehicle for transferring power from the EVSE unit to the electric vehicle. The secondary plug-in chargers may comprise any type of wired or plug-in charger that is known in the art. For example, the secondary plug-in chargers may comprise an output connector according to any of at least the following standards: an SAE J1772 output connector, a CHAdeMO output connector, a Tesla Motors Supercharger output connector or any other plug-in charger that is physically electrically connectable to an electric vehicle for transferring power from the EVSE unit to the electric vehicle. In some embodiments, the secondary chargers comprise one or more secondary wireless chargers wirelessly electrically connectable to an electric vehicle for transferring power from the EVSE unit to the electric vehicle. The secondary wireless chargers may comprise any type of wireless charger that is known in the art such as an induction charger or a magneto-dynamic coupling (MDC) charger that is wirelessly electrically connectable to an electric vehicle for transferring power from the EVSE unit to the electric vehicle. Examples of MDC chargers are provided in PCT application No. PCT/CA2010/000252 (published under WO/2010/096917) and PCT application No. PCT/CA2015/050327. In some embodiments, secondary chargers may comprise one or more secondary plug-in chargers and one or more secondary wireless chargers. The secondary plug-in chargers may each be of the same type or may each be of different types. Similarly, the secondary wireless chargers may each be of the same type or may each be of different types. 
         [0016]    In some embodiments, there is more than one power source to provide output power to the charging station. For example, in some embodiments, there are two power sources to provide power to the charging station and there is a corresponding EVSE unit for each power source (e.g. see  FIG. 6 or 7 ). The output power from both EVSE units may be directed to a secondary charger distribution panel. The secondary charger distribution panel may then distribute the output power from the first EVSE unit and the second EVSE unit combined or separately to each of the wireless charger and secondary chargers. In some embodiments, the secondary charger distribution panel may limit how much output power is drawn from a particular EVSE unit (and corresponding power source) according to limitations of the power source and/or the required power output. 
         [0017]    In some embodiments, the secondary charger distribution panel is configurable to distribute the output power (from one or more EVSE units and/or power sources) to the wireless charger and secondary chargers according to a distribution ratio. The distribution ratio may be based at least in part on the capacity of the wireless charger, the capacity of one of the secondary chargers, the state of charge of one or more of the vehicles, user input, a desirability to share output power between vehicles using a charging station and/or any other relevant factors. 
         [0018]    Another aspect of the invention provides an electric vehicle wireless power charger that is retrofittable to a pre-existing wired (i.e. plug-in) electric vehicle charger and a method for installing the wireless charger. The wireless power charger may comprise a wireless power transmitter as is known in the art such as an inductive wireless transmitter or an MDC wireless transmitter. The wireless transmitter may comprise a power input connector according to any of at least the following standards: an SAE J1772 input connector, a CHAdeMO input connector, a Tesla Motors Supercharger input connector or any other plug-in charger that is physically electrically connectable to a plug-in charger for transferring power from the plug-in charger. In this way, the wireless transmitter is physically electrically connectable to a pre-existing plug-in charger having an output connector according to any of at least the following standards: an SAE J1772 output connector, a CHAdeMO output connector, a Tesla Motors Supercharger output connector or any other plug-in charger that is physically electrically connectable to an electric vehicle for transferring power to an electric vehicle. By connecting the pre-existing plug-in charger outlet connector into the input connector of the wireless charger, power from the plug-in charger, which may come from an EVSE unit (although this is not mandatory) may be transferred to the wireless charger. 
         [0019]    Another aspect of the invention provides a method for charging an electric vehicle when the electric vehicle is located in proximity to an electric vehicle charging station. The charging station may for example be a charging station according to any of the embodiments herein. The charging station comprises a plug-in charger to which power is provided. The plug-in charger may be physically electrically connectable to an electric vehicle to provide power thereto. The plug-in charger may comprise any type of wired or plug-in charger that is known in the art. For example, the plug-in charger may comprise an output connector according to at least any of the following standards: an SAE J1772 output connector, a CHAdeMO output connector, a Tesla Motors Supercharger output connector or any other plug-in charger that is physically electrically connectable to an electric vehicle for transferring power to the electric vehicle. The charging station also comprises a wireless charger to which power is provided. The wireless charger may be wirelessly electrically connectable to an electric vehicle to provide power thereto. The wireless charger may comprise any type of wireless charger that is known in the art such as an induction charger or a magneto-dynamic coupling (MDC) charger that is wirelessly electrically connectable to an electric vehicle for transferring power to the electric vehicle. Examples of MDC chargers are provided in PCT application No. PCT/CA2010/000252 (published under WO/2010/096917) and PCT application No. PCT/CA2015/050327. A vehicle is charged by one or more of: a physical connection of the plug-in charger to the electric vehicle and a wireless electrical connection of the wireless charger to the electric vehicle. 
         [0020]    For example, in one embodiment, the wireless charger is electrically connected to a power source via the plug-in charger, such as is described above and depicted in  FIG. 2 , for example. In this way, power is provided to both the plug-in charger and the wireless charger. A car may then be charged via the wireless charger. In another example, the charging station comprises a plug-in charger that is not connected to the wireless charger. To charge the vehicle wirelessly, the charging station is switched from a first configuration in which power is only provided to the plug-in charger, to a second configuration in which power is provided to the wireless charger (e.g. by connecting the wireless charger to the power source via the plug-in charger). The electric vehicle may then be charged via the wireless charger. In a further example still, the charging station may comprise a wireless charger connected to a power source and a plug-in charger separately connected to a power source wherein power is provided to both simultaneously so that a vehicle can be charged by either or both of the wireless charger or the plug-in charger without switching configurations. 
         [0021]    In some embodiments, the wireless charging station comprises at least one secondary charger. The secondary charger may comprise a secondary wireless charger or a secondary plug-in charger. For example, the secondary plug-in charger may comprise an output connector according to at least any of the following standards: an SAE J1772 output connector, a CHAdeMO output connector, a Tesla Motors Supercharger output connector or any other plug-in charger that is physically electrically connectable to an electric vehicle for transferring power to the electric vehicle. The secondary wireless charger may be wirelessly electrically connectable to an electric vehicle to provide power thereto. The secondary wireless charger may comprise any type of wireless charger that is known in the art such as an induction charger or a magneto-dynamic coupling (MDC) charger that is wirelessly electrically connectable to an electric vehicle for transferring power to the electric vehicle. Examples of MDC chargers are provided in PCT application No. PCT/CA2010/000252 (published under WO/2010/096917) and PCT application No. PCT/CA2015/050327. The method may comprise charging a vehicle by one or more of: a physical connection of the plug-in charger to the electric vehicle and a wireless electrical connection of the wireless charger to the electric vehicle. 
         [0022]    In some embodiments, the method comprises providing power to any combination of the plug-in charger, the wireless charger and the secondary chargers. The power may be distributed according to a distribution ratio based at least in part on one or more of the capacity of the wireless charger, the capacity of one of the secondary chargers, the state of charge of one or more of the vehicles, user input and any other relevant factors. One or more of the plug-in charger, the wireless charger and the secondary chargers may be powered simultaneously to charge one or more vehicles simultaneously. In some embodiments, the method comprises combining or separating power from multiple power sources and distributing the combined or separated power from multiple power sources to one or more of the plug-in charger, the wireless charger and the secondary chargers. 
         [0023]      FIG. 1  depicts a multi-mode charging station  100  for charging one electric vehicle at a time. In charging station  100  of the  FIG. 1  embodiment, power from the grid  102  is supplied to an EVSE unit  104 . Station  100  comprises a cable  106  EVSE unit  104  capable of being directly plugged into (i.e. physically electrically connectable to) an electric vehicle (EV)  108  to charge EV  108  by providing power from EVSE unit  104  to EV  108 . Cable  106  (at its end distal from EVSE unit  104 ) may comprise: a SAE J1772 output connector; a CHAdeMO output connector; a Tesla Motors Supercharger output connector and/or a similar standardized connector for connection to EV  108 . In charging station  100  of the  FIG. 1  embodiment, station  100  comprises an additional cable  110  that provides power from EVSE unit  104  to an additional power transmission system such as a wireless power transmission (WPT) system  112  (i.e. a wireless charger). WPT unit  112  may comprise an inductively coupled wireless power transfer charging system, a magnetically coupled (i.e. MDC) wireless power transfer charging system and/or some other form of wireless charging system for charging EV  108 . EVSE unit  104  may deliver output power to EV  108  through plug-in cable  106  (i.e. a physical electrical connection), through WPT unit  112  (i.e. a wireless electrical connection) and/or through a combination of both, as may occur in the case when EV  108  is rated for Level 1 charging (corresponding to a power level of 3.3 kW) via charging cable  106  and WPT unit  112  individually, leading to the power sum capability of the EV  108  to accept a total charging power of 6.6 kW (or the equivalent Level 2 charging standard of 7 kW) when both cable  106  and WPT unit  112  are used simultaneously. In the  FIG. 1  embodiment, EVSE unit  104  may split power output, driving charging cable  106  and WPT unit  112  with a desired amounts of power (e.g. at 3.3 kW each). Optionally, EVSE unit  104  may deliver the full available power to either charging cable  106  or to WPT unit  112 , depending on the charging method selected by the user. In a different configuration of the  FIG. 1  embodiment, a plurality of charging systems may be present and connected to EVSE unit  104  to facilitate simultaneous charging of a plurality of EVs  108 . Each such charging system may comprise a plug-in cable  106  and a WPT unit  112  for delivering power from EVSE unit  104  to a corresponding EV  108  via either a physical electrical connection (plug-in cable  106 ) or a wireless connection (WPT unit  112 ). Power may be delivered via any single system or a combination of these systems depending on the output method desired by the user. The  FIG. 1  embodiment has several advantages. Firstly it allows EVs  108  with or without a wireless charging capabilities to still charge through the same EVSE unit  104  and at the same charging station  100 . Secondly, the  FIG. 1  embodiment provides diversity against any one charging technique becoming defective (e.g. damage to the charging cable). 
         [0024]      FIG. 2  depicts a multi-mode charging station  200  for charging one electric vehicle at a time. In multi-mode charging station  200  of the  FIG. 2  embodiment, output power is supplied from the grid  102  to an EVSE unit  104 . In contrast to the  FIG. 1  embodiment (which comprises two separate cables  106 ,  110  to either plug into EV (plug-in cable  106 ) or to power a WPT unit  112  (cable  110 )), station  200  of the  FIG. 2  embodiment comprises a single cable  202  which provides an interface between EVSE unit  104 , a wired (i.e. plug-in) charging system for charging EV  108  and a wireless charging system for charging EV  108 . Charging station  200  may comprise a plurality of wired connections to EVSE unit  104  (each similar to cable  202 ), but for clarity and ease of description, the illustrated  FIG. 2  charging station  200  is shown with a single cable  202 . In a first possible configuration  204  (represented by dashed lines) of cable  202 , cable  202  may be directly plugged in (i.e. physically electrically connected to) an EV  108 . Cable  202  (at its end distal from EVSE unit  104 ) may comprise a SAE J1772 output connector, a CHAdeMO output connector, a Tesla Motors Supercharger output connector and/or some other form of standardized plug-in connector. In a second possible configuration  206  (represented by dotted lines) of cable  202 , cable  202  may be plugged into a charger receptacle  208  (which may be provided at a suitable location in station  200 ) where charger receptacle  208  is further physically electrically connected (via cable  210 ) to a WPT unit  112 . WPT unit  112  may comprise an inductively coupled wireless power transfer charging system, a magnetically coupled (i.e. MDC) wireless power transfer charging system and/or some other form of wireless charging system for charging EV  108 . Charger receptacle  208  may comprise a standard input connector (similar to those provided on EVs), such as an input connector corresponding to the SAE J1772 standard, the CHAdeMO standard, the Tesla Motors Supercharger standard and/or some other form of standardized plug-in connector. A corresponding output connector of cable  202  may be plugged into charger receptacle  208  to provide electrical power to WPT unit  112 . In the  FIG. 2  embodiment, system  200  comprising a single EVSE output cable  202  cannot deliver power simultaneously to EV  108  via a physical (plug-in) electrical connection and via a wireless connection. When it is elected to charge EV  108  via wired power transfer, cable  202  is plugged directly into EV  108  (as shown in configuration  204 ), which means that (in the absence of a second cable from EVSE unit  104  to charger receptacle  208 ), WPT unit  112  is unpowered. When it is elected to charge EV  108  via wireless power transfer, cable  202  is plugged into charger receptacle  208 , thereby providing power to WPT unit  112 . The  FIG. 2  embodiment also encompasses the scenario where a WPT unit  112  is added (i.e. retrofitted) to an existing EVSE unit  104 . This allows for the possibility for existing and more commonly found single-mode wired charging systems to be retrofitted with a wireless charging system to create a multi-mode charging system. 
         [0025]      FIG. 3  depicts a multi-mode charging station  300  for supplying output power from wired (i.e. plug-in) and wireless chargers to EV  108 . In charging station  300  of the  FIG. 3  embodiment, a plurality of secondary power transmission systems may be powered from a secondary power charger distribution panel  304 . Secondary power charger distribution panel  304  may comprise a standardized input connector (similar to those of charger receptacle  208  described above in connection with the  FIG. 2  embodiment) for connection to a corresponding output connector of plug-in cable  202  from EVSE unit  104 . Secondary power charger distribution panel  304  may then distribute power as between the secondary power transmission systems, as described in more detail below. In charging station  300  of the  FIG. 3  embodiment, power is supplied from the grid  102  to EVSE unit  104 . Charging station  300 , of the illustrated embodiment, comprises cable  202  which (like system  200  of  FIG. 2 ) provides the interface between EVSE unit  104 , a wired (i.e. plug-in) connection to EV  108  and multiple secondary wireless charging systems which may be used to charge EV  108 . Charging station  300  may comprise a plurality of wired connections to EVSE unit  104  (each similar to cable  202 ), but for clarity and ease of description, the illustrated  FIG. 3  charging station  300  is shown with a single cable  202 . In a first possible configuration  204  (represented by dashed lines) of cable  202 , cable  202  may be directly plugged in (i.e. physically electrically connected to) an EV  108 . Cable  202  (at its end distal from EVSE unit  104 ) may comprise a SAE J1772 output connector, a CHAdeMO output connector, a Tesla Motors Supercharger output connector and/or some other form of standardized plug-in connector. In a second possible configuration  302  (represented by dotted lines) of cable  202 , cable  202  may be plugged into secondary charger distribution panel  304  (which may be provided at a suitable location in station  200 ) where secondary charger distribution panel  304  is further physically electrically connected (via cables  210 ,  306 ,  310 ) to WPT units  112 ,  308 ,  312 . WPT units  112 ,  308 ,  312  may comprise two or different types of WPT units, although this is not necessary. In the illustrated  FIG. 3  embodiment, secondary charger distribution panel  304  provides power to three WPT units  112 ,  308 ,  312 . In general, however, secondary charger distribution panel  304  may provide power to any suitable number of WPT units and/or wired (plug-in) charging systems (not shown). Secondary charger distribution panel  304  allows for the capability to provide charging station  300  with multiple different types of wireless or wired charging systems comprising various technologies. In the illustrated  FIG. 3  embodiment, WPT units  112 ,  308 ,  312  which receive power from secondary charger distribution panel  304  are used to power a single EV  108 , but this is not necessary. It will be appreciated that WPT units  112 ,  308 ,  312  could provide power to multiple EVs  108 . Charging station  300  of the  FIG. 3  embodiment is versatile and can be retrofitted to an existing charging station in a manner similar to that of charging system  200  described above. Charging system  300  is also capable of being upgraded at a later time with to-be-developed wireless charging systems or wired standards by plugging suitable cables into secondary charger distribution panel  304  for supplying power to the new charging technologies and, possibly, by adding appropriate power conversion hardware to secondary charger distribution panel  304 . 
         [0026]      FIG. 4  depicts a multi-mode charging station  400  for supplying output power from multiple wired (i.e. plug-in) chargers to electric vehicles  108 ,  406 . Charging station  400  of the  FIG. 4  embodiment comprises a plurality of wired (plug-in) charger cables  402 ,  404  to supply power from EVSE unit  104 , via secondary charger distribution panel  304  to EVs  108 ,  406 . In many respects, charging station  400  is similar to charging station  300  described above. Charging station  400  of the  FIG. 4  embodiment differs from charging station  300  of the  FIG. 3  embodiment in that charging station  400  comprises wired (plug-in) charger cables  402 ,  404  delivering power from secondary charger distribution panel  304  to EVs  108 ,  406  and in that charging station  400  is explicitly shown with multiple EVs  108 ,  406 . Cables  402 ,  404  may comprise (at their ends distal from secondary charger distribution panel  304 ) any of the standard output connectors described herein for connection to corresponding input connectors on EVs  108 ,  406 . These output connectors can comprise one or more different types of output connectors, although this is not necessary. In some embodiments, charging system  400  can comprise different numbers of plug-in cables (similar to cables  402 ,  404 ) for charging a suitable number of EVs. Charging system  400  may comprise interlocks (not explicitly shown) to ensure safe disconnection of one or more of the wired connections to enable wired EV charging without significant interruption to the EVs  108 ,  406 . 
         [0027]    It will be appreciated by those skilled in the art from the description of the embodiments of  FIGS. 3 and 4 , that one or more plug-in charging cables (similar to plug-in cables  402 ,  404  of charging system  400 ) could be added to the  FIG. 3  charging system  300  and that one or more WPT units (similar to WPT units  112 ,  308 ,  312 ) could be added to the  FIG. 4  charging system  400 . 
         [0028]      FIG. 5  depicts a multi-mode charging station  500  for supplying output power from multiple wired (i.e. plug-in) chargers and one or more WPT units  112  to one or more electric vehicles  108  (represented in the  FIG. 5  illustration by a single EV  108 ). Charging station  500  of the illustrated  FIG. 5  embodiment comprises a plurality of wired (plug-in) charger cables  402 ,  404  and one or more WPT units  112  to supply power from EVSE unit  104 , via secondary charger distribution panel  304 , to one or more EVs  108 . In many respects, charging station  500  is similar to charging stations  300 ,  400  described above. Charging station  500  of the  FIG. 5  embodiment differs from charging stations  300 ,  400  of the  FIG. 3  and  FIG. 4  embodiments in that charging station  500  explicitly comprises wired (plug-in) charger cables  402 ,  404  for delivering power from secondary charger distribution panel  304  to EVs  108  via physical electrical connection and one or more WPT units  112  for power from secondary charger distribution panel  304  to EVs  108  via wireless electrical connection. Although only one WPT unit  112  is shown in the  FIG. 5  illustration, it will be appreciated that system  500  could comprise a plurality of WPT units, which my be of the same WPT type or different WPT types. Plug-in charging cables  402 ,  404  may comprise (at their ends distal from secondary charger distribution panel  304 ) any of the standard output connectors described herein for connection to corresponding input connectors on EVs  108 . These output connectors can comprise one or more different types of output connectors, although this is not necessary. In some embodiments, charging system  500  can comprise different numbers of plug-in cables (similar to cables  402 ,  404 ) for charging a suitable number of EVs. Charging system  500  may comprise interlocks (not explicitly shown) to ensure safe disconnection of one or more of the wired connections to enable wired EV charging without significant interruption to EV  108 . 
         [0029]    Charging station  500  of the  FIG. 5  embodiment also differs from charging stations  300 ,  400  in that charging station  500  comprises a plurality (e.g. two) cables  502 ,  504  which are physically electrically connected to EVSE unit  104  for receiving power therefrom. Each of cables  502 ,  504  is a plug-in charging cable which comprises (at its end distal from EVSE unit  104 ) any of the standard output connectors described herein for connection to corresponding input connectors on EV  108 . As shown in the illustrated embodiment, one of cables  502 ,  504  (e.g. cable  502 ) may be directly plugged into EV  108  for physically electrically charging EV  108  and the other one of cables  502 ,  504  (e.g. cable  504 ) may be plugged into secondary charger distribution panel  304  to provide a physical electrical connection from EVSE unit  104  to secondary charger distribution panel  304 . It will be appreciated that any of the embodiments described herein which comprise a secondary charger distribution panel  304 , may be provided with multiple plug-in charging cables (similar to cables  502 ,  504 ) which receive power from EVSE unit  104  and that such plug-in charging cables may be additional to or alternative to plug-in cable  202  described in some of the embodiments herein. 
         [0030]    In the scenario of the  FIG. 5  system  500 , where one cable (e.g. cable  502 ) is physically electrically connected to a receptacle on an EV  108  for charging EV  108  and one cable (e.g. cable  504 ) is connected to a receptacle of secondary charge distribution panel  304 , power may be distributed between the wired connections (provided by cables  502 ,  504 ) at a distribution ratio dependent on one or more of: the capacity of the wired connections and their corresponding cables, the presence of wireless charging ability in the EVs which may be connected to receive power, the battery state of EVs connected to receive power and/or the like. For example, if the battery state of one EV  108  is less charged than the battery state of a second EV  108  and there is not sufficient power output by EVSE unit  104  to charge both EVs  108  at a maximum power, additional power may be directed to the EV  108  with the lower charge battery state. In this embodiment, a load balancing controller (not explicitly shown) may be employed in EVSE unit  104  or as an add-on connected between EVSE unit  104  and cables  502 ,  504  to determine the optimum power through each of the wired (i.e. plug-in) connections  502 ,  504  to ensure suitable and/or maximum power reaches EVs  108 . Such a load-balancing controller may additionally monitor and log power consumed by and delivered to each EV  108  such as for billing purposes. 
         [0031]      FIG. 6  depicts a multi-mode charging station  600  for supplying output power to multiple electric vehicles  108 ,  604  from a single secondary charger distribution panel  304 . In charging station  600  of the  FIG. 6  embodiment, secondary charger distribution panel  304  is connected to receive power from EVSE unit  104  in a manner similar to that of the embodiments shown in  FIGS. 3 and 4  described above. In charging station  600  of the  FIG. 6  embodiment, secondary charger distribution panel  304  is also optionally connected to a second EVSE unit  602  for receiving power therefrom. In the illustrated embodiment, second EVSE unit  602  is connected to secondary charge distribution panel  304  via a cable  202  that is similar to cable  202  described elsewhere herein. However, it will be appreciated that, in other embodiments, secondary charge distribution panel  304  may be connected to EVSE units  104 ,  602  in a manner similar to that in charging system  500  of  FIG. 5 . In the illustrated  FIG. 6  embodiment, secondary charger distribution panel  304  is connected to a plurality of WPT units  112  for wireless connection to charge EVs  108 ,  604  and to a plurality of wire plug-in charging cables  606  for physical connection to charge EVs  108 ,  604 . It will be appreciated that WPT units  112  and plug-in cables  606  may comprise any of the features of WPT units and plug-in cables described elsewhere herein and that the number of WPT units  112  and plug-in cables  606  may vary. 
         [0032]      FIG. 7  depicts a multi-mode charging station  700  for supplying output power to multiple electric vehicles  108 ,  604 ,  706  from a single secondary charger distribution panel  304 . In charging station  700  of the  FIG. 7  embodiment, secondary charger distribution panel  304  is connected to receive power from EVSE unit  104  in a manner similar to that of the embodiments shown in  FIGS. 3 and 4  described above. In charging station  700  of the  FIG. 7  embodiment, secondary charger distribution panel  304  is also optionally connected to a second EVSE unit  602  for receiving power therefrom. In the illustrated embodiment, second EVSE unit  602  is connected to secondary charge distribution panel  304  via a cable  702 . Cable  702  of the illustrated embodiment is a dedicated cable from EVSE unit  602  to secondary charger distribution panel  304 , but this is not necessary. In some embodiments, cable  702  may additionally or alternatively comprise a cable similar to cable  202  described elsewhere herein. It will be appreciated that, in other embodiments, secondary charge distribution panel  304  may be connected to EVSE units  104 ,  602  in a manner similar to that in charging system  500  of  FIG. 5 . In the illustrated FIG.  7  embodiment, secondary charger distribution panel  304  is connected to a plurality of WPT units  112  for wireless connection to charge EVs  108 ,  604 ,  706  and to one or more plug-in charging cables  704  for physical connection to charge EVs  108 ,  604 ,  706 . It will be appreciated that WPT units  112  and plug-in cables  704  may comprise any of the features of WPT units and plug-in cables described elsewhere herein and that the number of WPT units  112  and plug-in cables  704  may vary. 
         [0033]    In an additional aspect of the various embodiments described herein, a notification system (not shown) may be present to identify to the end user or operator if a specific charge delivery technique is currently not configured to deliver power, such as in the case, for example, where a previous user did not correctly reconnect the power cable to the standard receptacle (i.e. output connector), where the system may be damaged leaving the secondary charging system unable to draw power from the EVSE unit and/or the like. This notification system may include, but not be limited to, visual, audible, or electronic notifications delivered to a portable electronic device or to the dashboard of the EV. 
         [0034]    In a further aspect of the embodiments described herein, a secondary charging system may be provided which does not include wireless power transmission but takes, at its input, power from a standard output receptacle and delivers it to a vehicle via a different technique or in a different format, such as the case where a charging system takes a standard high-power DC connection as its input and, through an internal inverter, delivers AC power to an EV through a wired connection or where a system takes high-power AC through a standard input or plurality of inputs and rectifies it to DC power which is delivered to an EV. This includes the scenario where a plurality of low-power AC units may be connected via standard connections to a secondary module which rectifies and combines the power into a high-power DC connection. 
         [0035]    In another aspect of the embodiments described herein, a secondary charging system which draws power from vehicles (i.e. discharges the vehicles) connected to the charging system in a vehicle-to-vehicle network, where some power is drawn (i.e. discharged) from an existing vehicle over a wireless power connection to charge another EV. This embodiment is a variation of vehicle to grid (V2G) applications where instead of having EVs providing excess electrical power to the grid (such as for credit), EVs can provide direct electrical power to other EVs via wireless power transfer. 
         [0036]    It will be apparent to those skilled in the technology of wireless power charging systems that numerous changes and modifications can be made in the preferred embodiments of the invention described above without departing from the scope of the invention. Accordingly, the foregoing description is to be construed in an illustrative and not in a limitative sense.