Abstract:
A portable battery jump start unit includes a portable, plastic, clamshell-type housing including a box-like open-top base and a box-like, open-bottom cover hingedly connected together for movement between open and closed conditions. A lead-acid battery is disposed in the housing, along with a state-of-charge monitoring circuit connected to the battery terminals and including a visible indicator viewable through an aperture in the housing. Cables are connected to the battery terminals and respectively extend through openings formed by cooperating notches in the mating edges of the base and cover, the cables respectively having clamp connectors at their distal ends which can be clamped onto posts projecting laterally outwardly from the sides of the base. A charger jack in the base is connected to the battery terminals for receiving a charger connector.

Description:
BACKGROUND 
     This application relates to portable battery pack units, and particularly to battery packs of the type used for jump starting automotive vehicles. 
     Various types of portable battery packs have heretofore been provided, including batteries disposed in portable carrying cases. These cases are typically specifically designed for the particular battery pack and often are provided with access panels or hatches for accessing the interior of the housing. One such battery pack is disclosed in U.S. Pat. No. 6,002,235, and includes cables projecting outwardly through openings in the housing and terminated in connector clamps which, when not in use, can be clamped onto posts projecting laterally outwardly from the case. Access to the inside of the housing requires the removal of a panel by removing a number of screws. 
     It is also known to provide clamshell-type or valise-type cases for various other types of applications, and at least one battery pack for use in starting airplane engines has been provided in a clamshell-type case. 
     SUMMARY 
     The present application is directed to a battery pack which is housed in a case which provides simple and easy access to the contents, but which is fully operable in the closed condition. 
     An aspect of the battery pack unit is that it is provided with monitoring circuitry which permits viewing of the state of charge of the battery from outside the case and/or viewing of the verification that the unit is charging. The circuitry also permits audible verification of the state of charge of the battery as well as certain overcharge conditions. 
     Another aspect is the provision of cables carried by the housing and with connector clamps mountable on the outside of the housing when not in use. 
     Another aspect is the provision of a charger port accessible when the housing is closed. 
     Still another aspect is the provision of a housing of the type set forth for use with a battery pack. 
     Certain ones of these and other aspects may be provided in a portable battery jump start unit comprising: a portable clamshell-type housing having a base and a cover hingedly connected together for movement between open and closed conditions and cooperating to define an interior space, a battery disposed in the interior space and having terminals, monitoring circuitry including a printed-circuit board disposed in the interior space and connected to the battery terminals and including a visible indicator, an aperture in the housing disposed for viewing the visible indicator therethrough, two cable openings in the housing, two cables respectively connected to the battery terminals and extending outwardly through the openings, two clamp connectors respectively connected to distal ends of the cables outside the housing, and a charger jack in the housing connected to the battery terminals and adapted for connection to an associated charger connector while the housing is in its closed condition. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For the purpose of facilitating an understanding of the subject matter sought to be protected, there are illustrated in the accompanying drawings preferred embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages should be readily understood and appreciated. 
     FIG. 1 is a perspective view of an embodiment of a portable jumpstart battery pack unit with the enclosure closed; 
     FIG. 2 is a top plan view of the unit of FIG. 1, with the enclosure open; 
     FIG. 3 is a front elevational view of the unit of FIG. 2; 
     FIG. 4 is a side elevational view of the left-hand side of the unit of FIG. 1, with the associated battery clamp removed; and 
     FIG. 5 is an electrical schematic diagram of the circuitry of the unit of FIG.  1 . 
    
    
     DETAILED DESCRIPTION 
     Referring to FIGS. 1-4, there is illustrated a battery pack unit, generally designated by the numeral  10 , including a battery  11  disposed in a portable, clamshell-type housing  20 . The battery  11  may be a lead-acid battery of the thin metal film-type, and may be of a type sold by Johnson Controls, Inc. under the trade designation “INSPIRA.” Foam spacer blocks  12 ,  13  and  14  may be provided to snugly position the battery  11  in the housing  20  without shifting, rattling or vibration. Also disposed in the housing  20  is a printed circuit board  15  (FIG.  2 ), on which is mounted a monitoring circuit  50 , to be described more fully below, which includes a coaxial charger jack  16  for coupling to an associated battery charging apparatus (not shown). 
     The housing  20  may be a modified form of a type of case sold by Chemplex Controls under the trade designation “PELICAN,” and may be molded of a suitable plastic material. The housing  20  includes an open-top base  21  and an open-bottom cover  30  hingedly interconnected for movement between a closed condition, illustrated in FIGS. 1 and 4, and an open condition, illustrated in FIGS. 2 and 3. In its closed condition, the housing  20  is generally in the shape of a rectangular parallelepiped. The base  21  defines therein a receptacle  22  (see FIG. 2) and has a generally rectangular upper edge  23  having formed therein at opposite sides thereof adjacent to the rear end thereof, two generally semi-cylindrical cable notches  24 . A handle  25  is pivotally mounted on the front wall of the base  21 . Formed through the left-hand side wall of the base  21 , as viewed in FIG. 4, is a charger opening  26  for providing access to the charger jack  16  (FIG.  2 ), as well as apertures  27  and  28 , respectively, for an audible annunciator and for viewing an LED on the PC board  15 . Formed through the same side wall are openings  29  for suitable fasteners to fixedly secure the printed circuit board  15  in place. 
     The cover  30  is hingedly connected to the base  21  by hinges  31 , and defines an open-bottom receptacle  32  (see FIG. 3) which is much shallower than the receptacle  22  in the base  21 , and cooperates therewith in the closed condition of the housing  20  to define an interior space or compartment. The cover  30  has a generally rectangular lower edge  33  in which are formed, respectively along the opposite sides thereof adjacent to the rear edge thereof, two semi-cylindrical cable notches  34 . Latches  35  are provided on the front wall of the cover  30  for engagement with associated keepers on the base  21  for latching the housing  20  in its closed position. As can be seen in FIG. 2, the spacers  12  and  13  are disposed in the base receptacle  22 , respectively along top and side edges of the battery  11 , while the spacer  14  (FIG. 3) is disposed in the cover receptacle  32 , being fixedly secured therein by suitable means, and being of a thickness so as to engage the upper surface of the battery  11  when the housing  20  is in its closed condition. 
     Respectively connected to positive and negative terminals of the battery  11  are two cables  40 , which respectively are seated in the cable notches  24  and extend outwardly of the housing  20 , respectively terminating in cable clamps  45  of known construction, for clamping respectively onto the positive and negative terminals of an associated battery of an automotive vehicle to be jump started. It will be appreciated that, when the housing  20  is in its closed condition, the cable notches  24  in the base respectively cooperate with the cable notches  34  in the cover to form cable openings for snugly accommodating the cables  40 . When not in use, the cable clamps  45  are respectively clamped onto posts  46 , which respectively project laterally outwardly from the opposite side walls of the base  21 , being fixedly secured thereon, as by suitable fasteners. 
     Referring now to FIG. 5, the monitoring circuit  50  includes a power supply and charger input circuit  51 , which includes the charger jack  16 . More specifically, the center or ungrounded terminal of the charger jack  16  is connected to the anode of an LED  52 , the cathode of which is connected through a resistor  53  to ground, i.e., the negative terminal of the battery  11 . The center terminal of the charger jack  16  is also connected to the anode of a diode  54 , the cathode of which is connected through resistors  55  and  56  to the positive terminal of the battery  11 , designated V+. A resistor  57  and a capacitor  58  are connected in a series across the terminals of the battery  11 . The junction between the resistor  57  and the capacitor  58  is connected to the cathode of a Zener diode  59 , the anode of which is grounded. A VCC supply voltage is provided at the cathode of the Zener diode  59 . 
     The monitoring circuit  50  also includes an over-voltage alarm circuit  60 , which includes a transistor  61  having its emitter connected to the positive terminal of the battery  11 , and its base connected through a resistor  62  to the wiper of a potentiometer  63 , connected to the cathode of a Zenner diode  64 , the anode of which is connected to ground. The collector of the transistor  61  is connected to ground through a resistor  65  and is connected through a resistor  66  to the base of a transistor  67 , the emitter of which is grounded and the collector of which is connected through a resistor  68  to the base of the transistor  61 . The collector of the transistor  67  is also connected through a resistor  69  to one terminal of a transducer  70 , the other terminal of which is connected to the resistor  63  and the positive terminal of the battery. The transducer  70  may be any of a number of suitable audible annunciators. 
     The monitoring circuit  50  also includes a timer circuit  71 , which includes an integrated circuit (“IC”) timer 72, which may be an LM555CNB. The VCC supply is connected to the VCC and RESET terminals of the IC72, these terminals also being connected through a capacitor  73  to ground, and through the series connection of resistors  74  and  75  and a capacitor  76  to ground. The junction between the resistor  75  and the capacitor  76  is connected to the trigger and threshold terminals of the IC72, while the junction between the resistors  74  and  75  is connected to the discharge terminal of the IC72. The control terminal of the IC72 is connected to ground through a capacitor  77 . The output terminal of the IC72 is connected through a resistor  78  to the base of a transistor  79 , the emitter of which is connected to the VCC supply, and the collector of which is connected to a low-voltage comparator circuit  80 . 
     More particularly, the circuit  80  includes a resistor  81  and a Zener diode  82  connected in series between the collector of the transistor  79  and ground. The cathode of the diode  82  is connected to the non-inverting input terminal of an operational amplifier (“OP AMP”)  83 , the output of which is connected to its inverting input terminal and to the non-inverting input terminals of OP AMPS  84  and  85 . Connected across the terminals of the battery  11  is a voltage divider including a resistor  86 , a potentiometer or variable resistor  87 , a resistor  88  and a resistor  89 . The junction between the potentiometer  87  and the resistor  88  is connected to the inverting input terminal of the OP AMP  84 , while the junction between the resistors  88  and  89  is connected to the inverting input terminal of the OP AMP  85 . The output of the OP AMP  84  is connected to ground through resistors  90  and  91 , the junction therebetween being connected to the inverting input terminal of an OP AMP  92 . The collector of the transistor  79  is connected to ground through a capacitor  93  and through a voltage divider including resistors  94  and  95 , the junction therebetween being connected to the non-inverting input terminal of the OP AMP  92 , which is also connected to ground through a capacitor  96 . The output of the OP AMP  92  is connected through a resistor  97  to the base of the transistor  79 . The output of the OP AMP  85  is connected through a resistor  98  to the base of the transistor  67 , which base is also connected to ground through a capacitor  99 . The OP AMPS  83 - 85  and  92  may all be portions of a common integrated circuit, such as a TLC274, the supply terminal of which is connected to the VCC supply. The circuits  60  and  80  cooperate to form a state-of-charge monitor. 
     The power supply and charger input circuit  51  provides a means of safely charging the battery  11 , and protects sensitive circuitry from voltage spikes. Jack  16  receives charging voltage from either a wall-mounted charger or a plug charger connected to the cigarette lighter of the associated vehicle. The rest voltage of the battery  11  may be higher than the rest voltage of the associated automotive battery so that, if left connected, the battery  11  would tend to discharge into the automotive battery through a cigarette lighter plug. The diode  54  prevents this from happening. Resistors  55  and  56  prevent high current inrushes, which could blow fuses in a vehicle used to charge the battery  11  through a cigarette lighter plug. The LED  52  lights in the presence of a charge voltage from any source, with current limiting by the resistor  53 , the LED being visible through aperture  28  (FIG.  4 ). The combination of the resistor  57 , the capacitor  58  and the Zener diode  59  form a protective network that suppresses high voltage spikes, which might otherwise damage the integrated circuits. 
     Under normal, non-charging conditions, the voltage of the battery pack battery  11  will be between 12.8 volts and 13.1 volts, well below the voltage rating of the Zener diode  64 , which is preferably 15.0 volts ±5%. In this normal, at rest condition, the total current draw of the circuit is approximately 190μA. When the battery  11  is being charged, its voltage will rise above 13.1 volts. If the charging method is applying an inappropriately high charging voltage, the battery&#39;s voltage could rise above 16.5 volts, which could lead to battery overheating and failure. As the battery voltage exceeds the threshold voltage of the Zener diode  64 , the excess voltage will develop across the potentiometer  63 . This potentiometer is adjusted such that transistor  61  will turn ON if the battery voltage exceeds 16.5 volts. When the voltage at the wiper of the potentiometer  63  exceeds the threshold value of the transistor  61 , typically about 0.7 volts, the base-emitter junction of the transistor  61  conducts through the resistor  62  as a current limiter, causing the collector-emitter junction to conduct. 
     With transistor  61  ON, current flows through the resistor  65 , bringing the collector of the transistor  61  from zero volts towards V+. When the voltage across the resistor  65  exceeds the threshold value of the transistor  67 , its base-emitter junction conducts through the resistor  66  as a current limiter, turning ON the transistor  67 . With the transistor  67  ON, current flows through the audible annunciator  70  and the current-limiting resistor  69 , causing the audible annunciator  70  to emit a warning tone through aperture  27  (FIG.  4 ). Conduction of the base-emitter junction of the transistor  67  also provides positive feedback to the base of the transistor  61  through the resistor  68 , forcing the transistor  61  into full conduction or saturation. This prevents a condition wherein the volume of the audible annunciator  70  transitions through a gradually increasing volume as the battery voltage transfers from below 16.5 volts to above 16.5 volts. 
     Once the voltage at the wiper of the potentiometer  63  falls below the threshold voltage of the transistor  61 , the feedback through the resistor  68  cannot sustain the transistor  61  ON, and the circuit  60  turns OFF. 
     The timer circuit  71  administers a power pulse of approximately 400 ms duration, repeated every 35 seconds. This is done to conserve battery power by powering the IC of the low-voltage comparator circuit  80  only briefly. The momentary power causes, in effect, the comparator circuit to “check” for low battery voltage every 35 seconds. The capacitor  76  and the resistors  74  and  75  establish the timer&#39;s astable operation, and set the ON time at 400 ms and OFF time at 35 seconds. Capacitor  73  provides noise immunity to the power supply pins VCC and ground. Capacitor  77  stabilizes the control terminal of the timer IC 72. The output pin drives the transistor  79  through the current-limiting resistor  78 . 
     The low-voltage comparator circuit  80  determines if the voltage of the battery  11  is below a safe storage level, and alerts the user if it is. The circuit includes two set points: at 12.4 V, where charging of the battery is needed, and again at 12.0 V, where immediate attention is required. 
     The admittance of current through transistor  79  powers the OP AMP integrated circuit, as well as the voltage reference diode  82 , through current limiting resistor  81 . The 1.250 V reference is buffered through OP AMP  83 , configured as a unity voltage gain current amplifier, for stability. This reference voltage is applied to the positive inputs OP AMPS  84  and  85 , configured as two comparators. The voltage divider circuit of resistors  86 - 89  causes the negative input of OP AMP  85  to exceed the reference voltage when the battery voltage is above 12.40 V, and causes the negative input of OP AMP  84  to exceed the reference voltage when the battery voltage is above 12.00 V. As a result, the output of OP AMP  85  is only HI if the battery voltage is less than 12.40 V, and the output of OP AMP  84  is only HI if the battery voltage is less than 12.00 V. 
     A HI at the output of OP AMP  85 , through current limiting resistor  98 , turns ON transistor  67  (of the over-voltage alarm circuit  60 ), causing the audible annunciator  70  to sound. A HI at the output of OP AMP  84  is halved at the voltage divider of resistors  90  and  91 , and this voltage (about 5.5 V), is applied to the negative input of OP AMP  92 , causing a LO at its output. This LO, through current limiting resistor  97 , keeps transistor  79  ON, even after the timer output goes HI. This LO is transient, however, because resistors  94  and  95  and capacitor  96  form an R-C network that begins charging when transistor  79  turns ON. After about 1.5 seconds, the voltage at the positive input to OP AMP  92  exceeds that of the negative input, and the output goes HI. 
     The result of all this is that if the battery voltage falls below 12.4 V, the circuit emits an audible tone of about 400 ms duration, each 35 seconds. If the battery voltage falls below 12.0 V, the circuit emits an audible tone of about 1500 ms duration, each 35 seconds. 
     Capacitor  99  slows the response of the transistor  67  to transient changes at the output of OP AMP  85 , reducing “click” sounds at voltages above alert levels. Capacitor  93  filters noise from the power supply line for the OP AMP IC. 
     The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While a particular embodiment has been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the broader aspects of applicants&#39; contribution. The actual scope of the protection sought is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.