Patent Publication Number: US-8125324-B2

Title: Charge state indicator for an electric vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 11/779,840, filed 18 Jul. 2007, the disclosure of which is incorporated herein by reference for any and all purposes. 
    
    
     BACKGROUND OF THE INVENTION 
     Electric vehicles having batteries require periodic charging of the batteries. As such, some electric car applications provide users with chargers to charge vehicles. People who are provided with such chargers desire to know how to use them. Additionally, they desire to know how well the chargers are working. For instance, users desire to know when a charger has transmitted a sufficient charge to a battery such that it is appropriate to drive the electric vehicle. 
     SUMMARY OF THE INVENTION 
     The present invention provides a battery charging monitoring and status indication system, the system comprising a charging coupler port configured to conduct charging energy to the battery of an electric vehicle; a charging coupler port door that at least partially covers the charging port; a charging coupler port door switch configured to output a first door status signal when the charging coupler port door is open and to output a second door status signal when the charging coupler port door is closed; a battery charge state circuit that outputs various charge state signals depending upon whether a charging coupler is attached to the charging coupler port, whether energy is being transmitted through the charging coupler port, and the battery SOC; a fault detection circuit configured to output a fault signal when an electrical fault, such as a malfunctioning battery, is detected; and a lighting circuit configured to activate various colored status signals depending upon the output of the charging coupler port door switch, the output of the battery charge state circuit and the output of the fault detection system. 
     A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a high level diagram of an electric vehicle with a battery and a charging indicator, according to one embodiment of the present subject matter; 
         FIG. 2  shows a vehicle system, according to one embodiment of the present subject matter; 
         FIG. 3  illustrates a partial perspective view of a system including an electric vehicle, a charger, a charging coupler port, and other components, according to one embodiment; 
         FIG. 4  illustrates a cross section along line  4 - 4  in  FIG. 3 ; 
         FIG. 5  illustrates a perspective view of a charging coupler port, according to one embodiment; and 
         FIG. 6  illustrates a process for indicating charge, according to one embodiment. 
     
    
    
     DESCRIPTION OF THE SPECIFIC EMBODIMENTS 
     In the following description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments which may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the scope of the present invention. The following description of example embodiments is, therefore, not to be taken in a limited sense, and the scope of the present invention is defined by the appended claims. 
       FIG. 1  is a high level diagram of an electric vehicle with a battery and a charging indicator, according to one embodiment of the present subject matter. An electric vehicle  102  is illustrated. Electric vehicles include, but are not limit to, ground based vehicles, aquatic vehicles, and aircraft. For the purposes of explanation, the present subject matter focuses on ground based vehicles. Plug-in hybrids and range extending vehicles are contemplated. Some embodiments of the present subject matter include a battery  104  mounted to the vehicle  102 . Various batteries are contemplated. The present subject matter includes embodiments in which the battery  104  is a secondary battery that is rechargeable using electricity rather than chemicals or other materials. Various secondary battery chemistries are contemplated, including lithium ion battery chemistries, but the present subject matter should not be construed to be limited to lithium ion or any other battery chemistry. 
     Various embodiments include a charge state circuit  106  located in the electric vehicle  102  and coupled to the battery  104 . In various embodiments, the charge state circuit  106  is configured to provide a charge state signal indicative of the charge state of the battery  104 . A charge state circuit  106 , in some embodiments, is a voltage meter. Other charge state circuits  106  are used in additional embodiments, including, but not limited to, current meters, coulomb counter, thermal meters, and other meters capable of monitoring how much energy is stored in a battery  104 . 
     Various embodiments include a charging coupler port  108  located proximate to a user accessible exterior of the electrical vehicle  102  and coupled to the battery  104 . In various embodiments, the charging coupler port  108  communicates charging energy to the battery  104 . In some examples, this includes hardware to at least partially form a conductive path from the battery  102  to a conductive terminal of the charging coupler port  108 . Some embodiments include one or more female terminals configured to receive a mating male terminal. Embodiments in which the charging coupler port  108  includes male terminals are contemplated. In some embodiments, the charging coupler port  108  is itself conductive and is in conductive communication with the battery  102 . Inductive embodiments are contemplated, in which a field is used to communicate energy. 
     In some embodiments, a male terminal is part of a charging coupler  110 . In various embodiments, a charging coupler  110  is a handheld connector mateable to the charging coupler port  108 . Some embodiments include a charging coupler  110  which is conductive and which mates to one or more terminals of the charging coupler port  108 . Various embodiments, however, include additional structure so that a user can handle the charging coupler  110  without being exposed to harmful shock. 
     In various embodiments, the charging coupler port  108  provides a charger connection signal indicative of a connection to an external power source  112 . The external power source is a charging station which is connected to a municipal power grid in some embodiments, but the present subject matter is not so limited. Batteries, generators, and other power sources comprise the external power source  112  in various embodiments. 
     Various embodiments, include a lighting circuit  114  coupled to the charging coupler port  108  and the charge state circuit  106  to control the brightness and color of an illuminated indicator  116  responsive to the charge state signal and the charger connection signal. The illuminated indicator  116  is a computer monitor in some embodiments. In additional embodiments, the illuminated indicator  116  includes at least one multi-color lamp. In some embodiments, the illuminated indicator includes at least one multi-color LED. Various embodiments include a plurality of lamps. Some embodiments include a plurality of single color LEDs. Some embodiments include a mixture of multi-color LEDs and single-color LEDs. In various embodiments, the illuminated indicator  116  includes a white LED and the at least one lighting circuit is configured to illuminate the illuminated indicator to a white color by illuminating the white LED. 
       FIG. 2  shows a vehicle system  200 , according to one embodiment of the present subject matter. In various embodiments, the vehicle  202  is an electric vehicle and includes a vehicle propulsion battery  204  and at least one propulsion motor  206  for converting battery energy into mechanical motion, such as rotary motion. The present subject matter includes examples in which the vehicle propulsion battery  204  is a subcomponent of an energy storage system (“ESS”). An ESS includes various components associated with transmitting energy to and from the vehicle propulsion battery  204  in various examples, including safety components, cooling components, heating components, rectifiers, etc. The inventors have contemplated several examples of ESSs and the present subject matter should not be construed to be limited to the configurations disclosed herein, as other configurations of a vehicle propulsion battery  204  and ancillary components are possible. 
     The battery includes one or more lithium ion cells in various examples. In some examples, the battery  204  includes a plurality of lithium ion cells coupled in parallel and/or series. Some examples include cylindrical lithium ion cells. In some examples, the battery  204  includes one or more cells compatible with the 18650 battery standard, but the present subject matter is not so limited. Some examples include a first plurality of cells connected in parallel to define a first brick of cells, with a second plurality of cells connected in parallel to define a second brick of cells, with the first brick and the second brick connected in series. Some embodiment connect 69 cells in parallel to define a brick. Battery voltage, and as such, brick voltage, often ranges from around 3.6 volts to about 4.2 volts in use. In part because the voltage of batteries ranges from cell to cell, some embodiments include voltage management systems to maintain a steady voltage. Some embodiments connect 9 bricks in series to define a sheet. Such a sheet has around 35 volts. Some embodiment connect 11 sheets in series to define the battery of the ESS. The ESS will demonstrate around 385 volts in various embodiments. As such, some examples include approximately 6,831 cells which are interconnected. 
     Additionally illustrated is a energy converter  208 . The energy converter  208  is part of a system which converts energy from the vehicle propulsion battery  204  into energy useable by the at least one propulsion motor  206 . In some instances, the energy flow is from the at least one propulsion motor  206  to the vehicle propulsion battery  204 . As such, in some examples, the vehicle propulsion battery  204  transmits energy to the energy converter  208 , which converts the energy into energy usable by the at least one propulsion motor  206  to propel the electric vehicle. In additional examples, the at least one propulsion motor  206  generates energy that is transmitted to the energy converter  208 . In these examples, the energy converter  208  converts the energy into energy which can be stored in the vehicle propulsion battery  204 . In some examples, the energy converter  208  includes transistors. Some examples include one or more field effect transistors. Some examples include metal oxide semiconductor field effect transistors. Some examples include one more insulated gate bipolar transistors. As such, in various examples, the energy converter  208  includes a switch bank which is configured to receive a direct current (“DC”) power signal from the vehicle propulsion battery  204  and to output a three-phase alternating current (“AC”) signal to power the vehicle propulsion motor  206 . In some examples, the energy converter  208  is configured to convert a three phase signal from the vehicle propulsion motor  206  to DC power to be stored in the vehicle propulsion battery  204 . Some examples of the energy converter  208  convert energy from the vehicle propulsion battery  204  into energy usable by electrical loads other than the vehicle propulsion motor  206 . Some of these examples switch energy from approximately 390 Volts to 14 Volts. 
     The propulsion motor  206  is a three phase alternating current (“AC”) propulsion motor, in various examples. Some examples include a plurality of such motors. The present subject matter can optionally include a transmission or gearbox  210  in some examples. While some examples include a 2-speed transmission, other examples are contemplated. Manually clutched transmissions are contemplated, as are those with hydraulic, electric, or electrohydraulic clutch actuation. Some examples employ a dual-clutch system that, during shifting, phases from one clutch coupled to a first gear to another coupled to a second gear. Rotary motion is transmitted from the transmission  210  to wheels  212  via one or more axles  214 , in various examples. 
     A vehicle management system  216  is optionally provided which provides control for one or more of the vehicle propulsion battery  204  and the energy converter  208 . In some examples, the vehicle management system  216  is coupled to vehicle system which monitors a safety system (such as a crash sensor). In some examples the vehicle management system  216  is coupled to one or more driver inputs (e.g., an accelerator). The vehicle management system  216  is configured to control power to one or more of the vehicle propulsion battery  204  and the energy converter  208 , in various embodiments. 
     External power  218  is provided to communicate energy with the vehicle propulsion battery  204 , in various examples. In various embodiments, external power  218  includes a charging station that is coupled to a municipal power grid. In some examples, the charging station converts power from a 110V AC power source into power storable by the vehicle propulsion battery  204 . In additional examples, the charging station converts power from a 220V AC power source into power storable by the vehicle propulsion battery  204 . Voltages in the range of from about 208 volts to about 240 volts are contemplated. Some embodiments include converting energy from the battery  204  into power usable by a municipal grid. The present subject matter is not limited to examples in which a converter for converting energy from an external source to energy usable by the vehicle  200  is located outside the vehicle  200 , and other examples are contemplated. 
     In various embodiments, the external power  218  is coupled to a charging coupler  220 . This charging coupler  220  is matable to a charging coupler port  222 , in various embodiments. In various embodiments, the charging coupler port  222  includes an illuminated indicator  224 . The illuminated indicator includes a lamp disposed proximate to a body panel of the electrical vehicle  202  in some embodiments. The lamp includes an LED in some embodiment. In additional embodiments, other lamps are used. In some embodiments, the illuminated indicator lights the exterior of the vehicle  202  and the charging coupler port  222 . In some embodiments, the illuminated indicator lights only the charging coupler port  222 . 
     Some examples include a vehicle display system  226 . The vehicle display system  226  include a visual indicator of system  200  information in some embodiments. The vehicle display system  226  includes the illuminated indicator in some embodiments. In some embodiments, the vehicle display system  226  includes a monitor that includes information related to system  200 . Some embodiments include one or more lights. Some embodiments include one or more lights, and the vehicle display system  226  in these embodiments includes the illumination and brightness of these lights. The vehicle management system, in some embodiments, coordinates the function of a charge state circuit  106 , and the charging coupler port  108 , as pictured in  FIG. 1 . In certain instances, the charge state circuit  106 , and the charging coupler port  108  are part of the vehicle management system  216 . In some of these instances, the lighting circuit  114  is part of the vehicle display system  226 . In some embodiments, the illuminated indicator  116  of  FIG. 1  is part of the vehicle display system  226 . 
       FIG. 3  illustrates a partial perspective view of a system including an electric vehicle, a charger, a charging coupler port, and other components, according to one embodiment.  FIG. 4  illustrates a cross section along line  4 - 4  in  FIG. 3 . An electric vehicle  302  is pictured. The electric vehicle  302  includes a charging coupler port recess  304 . The charging coupler port recess  304  includes a charging coupler port  306  which is in electrical communication with a battery of the electrical vehicle  302 . A charging station  308  includes a charging coupler  310  which includes a charging coupler terminal  312 . Although blade terminals are shown for the charging coupler port  304  and the charging coupler  310 , other terminals are contemplated, such as rod type, pin and socket type, pads, and other types. In some embodiments, the charging station  308  is coupled to a municipal power grid  314 . 
     In various embodiments, a lens  318  is disposed between the body panel  320  and the charging coupler port  306 . In various embodiments, the lens  318  and the charging coupler port  306  at least partially define the recess  304  in the electric vehicle  302 . In various embodiments, an illuminated indicator is shielded from the recess  304  by the lens  318 .  FIG. 4  illustrates an embodiment in which a lens  318  shields a first illuminated indicator  402  and a second illuminated indicator  404  from the recess  304 . The illuminated indicators in  FIG. 4  can be mounted on printed circuit boards, or can couple to the electric vehicle  302  in other ways. Although two illuminated indicators are shown, embodiments in which a single illuminated indicator is used are possible, as are ones with more than two illuminated indicators. The lens  318  is shown tapering down from the body panel  320  to the charging coupler port  306 , but the present subject matter is not so limited. 
     In some embodiments, the lens  318  is a diffuser. In some embodiments, the lens  318  is part of a lamp. The lens  318  can comprise a neon lamp, an LED lamp, an incandescent, or any other arc or non-arc light emitter, according to various embodiments. In some embodiments, the lens  318  includes an illuminated indicator light pipe. In some embodiments, the lens  318  casts light on the charging coupler port  306 . In additional embodiments, the lens  318  casts light on the exterior body panel  320 . Some embodiments include a lens  318  that casts light on both the charging coupler port  306  and the exterior body panel  320 . 
     In an alternative embodiment, lamps that are used primarily for other purposes on the vehicle are used in place of, or in addition to, lens  318 . In various embodiments, this includes, but is not limited to, directional lamps, headlamps, stop lamps, running lamps, interior lamps, and other lamps. 
     Embodiments are included in which the lens  318  is at least partially arcuate and encircles the charging coupler port along the exterior of the vehicle, as pictured in  FIGS. 3-4 . Additional configurations are contemplated, includes those in that the lens  318  is substantially rectangular and borders the charging coupler port. Other shapes are possible, and it is not necessary that the lens  318  encircle or otherwise circumscribe the charging coupler port  306 . In some embodiments, a charging coupler port door  316  at least partially covers a charging coupler recess  304  which contains the charging coupler port  306 . In some embodiments, the charging coupler port door  316  is coupled to the vehicle using a hinge  324 . In some embodiments, a lighting circuit (e.g., the lighting circuit  114  illustrated in  FIG. 1 ) is configured to operate the illuminated indicator and to deliver a white color if a charging coupler is not coupled to the charging coupler port  306  and the charging coupler port door is in an open state, as illustrated. In some instances, a switch is coupled to the charging coupler port door  316  and the lighting circuit to define a conductive path to the lighting circuit when the charging coupler port door  316  is open. In some instances, this lighting circuit monitors the conductive path and operates an illuminated indicator when the charging coupler port door  316  is in an open state. In various embodiments, this illuminates lens  318  so it casts visible light on at least the charge port coupler  306 . 
       FIG. 5  illustrates a perspective view of a charging coupler port, according to one embodiment. The illustration is highly detailed, and other configurations that differ from that shown are possible depending on which embodiment is studied. The illustration shows a conductive path. The conductive path at least partially includes the wiring bundle (also known as a harness or loom)  502 . The wiring bundle is part of the charging coupler port  504 . A lens assembly  506  is illustrated that includes a light pipe  508  including a diffractive surface  509  and a plurality of LEDs disposed between a printed circuit board and the light pipe  508 . A hinge  510  is shown. 
     A charging coupler port door  512  is shown. This is coupled to the hinge  510 . This door is to cover a recess in that the charging coupler port  504  is disposed. A fixture  514  is shown that is used to assist in coupling the charging coupler port  502 , the lens assembly  506 , and the hinge  510  to an electric vehicle. A lock  516  is shown that can be used to lock a first lock portion  518  to a mating lock portion  520  such that the hinge  510  is restricted from motion. A spring  521  is shown that allows the first lock portion  518  to snap into a mating relationship with mating lock portion  520 . The power of the spring can be overcome to open the charging coupler port door  512 , in various embodiments. This can be useful for safety and security, as it is desirable to prevent others from tampering with the charging coupler port  504 . A plurality of fasteners are collectively labeled  522  and are included for clarity, but can be reconfigured as needed in different embodiments. 
       FIG. 6  illustrates a method  600  for indicating charge, according to one embodiment. At  602 , the method includes connecting a charging coupler to a charging coupler port of an electric vehicle. Various embodiments include opening a charging coupler port door which is hinged to the electric vehicle and which at least partially covers the charging coupler port prior to connecting the charging coupler to the charging coupler port of the electric vehicle. At  604 , the method includes communicating a charger connection signal indicative of the state of connection of the charging coupler and the charging coupler port to a lighting controller. At  606 , the method includes determining a charge state signal indicative of the charge state of a battery coupled to the electric vehicle. At  608 , the method includes communicating the charge state signal to the illuminated indicator controller. 
     At  610 , the method includes providing an external indication of the charger connection signal and the charge state signal by controlling the brightness and the color of illuminated indicator coupled to the charging coupler port. In optional embodiments, the method includes illuminating the charging coupler port with the at least one illuminated indicator while a charging coupler port door coupled to the vehicle and covering a recess in which the charging coupler port is located is open. In some embodiments, the method includes controlling the illuminated indicator to a blue color if the charging coupler is coupled to the charging coupler port and the charging coupler port is not transmitting charging energy. Some example embodiments include a method that includes determining a target charge state, comparing the charge state to the target charge state and controlling the illuminated indicator to a green color if the charge state exceeds the target charge state. 
     Certain embodiments include detecting a first electrical vehicle fault with a fault detection circuit and controlling the illuminated indicator to a red color if the first electrical vehicle fault is detected. Certain additional embodiments include flashing the illuminated indicator to a red color if the first electrical vehicle fault is detected. In some embodiments, a method includes detecting a second electrical vehicle fault with the fault detection circuit. Some of these embodiments include varying the illumination of the illuminated indicator over time responsive to the second fault signal. Various faults are contemplated. For example, if one of a plurality of batteries malfunctions, a fault can be indicated. In one embodiment, a vehicle performs a system check and if a fault is detected, and the illuminated indicator lights red when the charging coupler port door is opened. In some of these embodiments, the light is solid. 
     Various embodiments include a method that includes controlling the illuminated indicator to a yellow color if the charging coupler is coupled to the charging coupler port and the charging coupler port is transmitting charging energy. In some of these embodiments, the method includes pulsing the illuminated indicator when the charging coupler port is transmitting charging energy. In some of these embodiments, the method includes pulsing illuminated indicator at a first frequency when the charge state of the battery is at a first charge, and at a second frequency, which is less than the first frequency, when the charge state of the battery is at a second charge which is higher than the first charge. Optional embodiments include pulsing the illuminated indicator at a first frequency when the charge state of the vehicle propulsion battery is at a first charge, and at a second frequency, which is less than the first frequency, when the charge state of the vehicle propulsion battery is at a second charge which is higher than the first charge. 
     The Abstract is provided to comply with 37 C.F.R. §1.72(b) to allow the reader to quickly ascertain the nature and gist of the technical disclosure. The Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.