Patent Publication Number: US-11033164-B2

Title: Surface cleaning apparatus having an energy storage member and a method of use thereof

Description:
FIELD 
     This application relates to the field of surface cleaning apparatus operable on an energy storage member, chargers for an energy storage member and a surface cleaning apparatus having an on board charger for an energy storage member. 
     INTRODUCTION 
     The following is not an admission that anything discussed below is part of the prior art or part of the common general knowledge of a person skilled in the art. 
     Various types of surface cleaning apparatus are known, including upright surface cleaning apparatus, canister surface cleaning apparatus, stick surface cleaning apparatus, central vacuum systems, and hand carriable surface cleaning apparatus such as hand vacuums. Further, various designs for cyclonic hand vacuum cleaners, including battery operated cyclonic hand vacuum cleaners, are known in the art. 
     Battery operated vacuum cleaners are known. For Example, Best (U.S. Pat. No. 7,377,007) discloses an upright vacuum cleaner having a detachable vacuum module wherein the detachable vacuum module may have an on board battery. A charger may be provided in the surface cleaning head or the detachable vacuum module. Accordingly, when the on board battery requires recharging, the on board charger may be used to recharge the battery. Alternately, the battery charger may be provided in a docking station and the battery recharged when the upright vacuum cleaner is placed in the docking station. 
     SUMMARY 
     This summary is intended to introduce the reader to the more detailed description that follows and not to limit or define any claimed or as yet unclaimed invention. One or more inventions may reside in any combination or sub-combination of the elements or process steps disclosed in any part of this document including its claims and figures. 
     In accordance with a first aspect, which may be used by itself or with any one or more other aspects set out herein, an energy storage member charger, such as a battery charger, may have its own on board energy storage member. Accordingly, when another energy storage member that is external to the charger (e.g., an energy storage member for a surface cleaning apparatus) needs charging, the energy storage member in the charger may be used to charge the energy storage member of the surface cleaning apparatus by itself or concurrently with power drawn, e.g., from a stationary source of power such as a household electrical outlet. The energy storage member of the energy storage member charger may hold sufficient charge to charge the external energy storage member at least twice and optionally 3, 4, 5, 6 or more times. Using a charger having an on board energy storage member, a user may be able to recharge an energy storage member of a surface cleaning apparatus at a rate of 2C, 3C, 4C, 5C, 6C or more. 
     In a particular embodiment of this aspect, the energy storage member of the portable surface cleaning apparatus comprises or consists of one or more capacitors such as an ultra-capacitor. 
     An advantage of this design is that a user may be able to clean an entire household without any breaks or with fewer and/or shorter breaks. For example, current domestic upright or stick type vacuum cleaners may need 6-8 or more hours to fully recharge a battery pack. Accordingly, once a battery pack is depleted, a user may have to wait overnight to finish cleaning a household. In contrast, in accordance with this design, a surface cleaning apparatus comprises a floor cleaning module and a portable surface cleaning unit (e.g., a lift away module or a hand vac) that has an on board energy storage member. A user may use the portable surface cleaning unit to clean part of a household (e.g., furniture). Once that part is cleaned or when the on board energy storage member is depleted, the portable surface cleaning unit may be mounted on the floor cleaning unit. The floor cleaning unit may then be operated on power drawn from a household electrical outlet (e.g., the surface cleaning apparatus may have an electric cord). While the user is cleaning the floor, the energy storage member of the portable surface cleaning unit may be recharged in, e.g., 1-15 minutes, 2-12 minutes, 3-10 minutes 4-7 minutes, about 5 minutes or any desired time frame less than 15 minutes. Accordingly, by the time a user needs to again use the portable surface cleaning unit, the energy storage member of the portable surface cleaning unit may be fully charged. Accordingly, this aspect allows a user to continuously use the surface cleaning apparatus in a floor cleaning and an above floor cleaning mode. 
     In accordance with this aspect, there is provide a surface cleaning apparatus comprising:
         (a) a floor cleaning unit comprising:
           (i) a surface cleaning head having a front end having a dirty air inlet, a rear end and a center positioned midway between the front and rear ends;   (ii) an upper section moveably mounted to the surface cleaning head between an upright storage position and a rearwardly inclined floor cleaning position;   (iii) a charger having an energy storage member; and,   (iv) an air flow path extending from the dirty air inlet to a floor cleaning unit air outlet; and,   
           (b) a portable surface cleaning unit connectable to the floor cleaning unit, the portable surface cleaning unit comprising a portable surface cleaning unit air inlet connectable in air flow communication with the floor cleaning unit air outlet, a main body, an air treatment member, a suction motor, a handle and a capacitor,   wherein, when fully charged, the energy storage member stores sufficient stored power to recharge the capacitor at least twice.       

     In any embodiment, the suction motor may not be operable directly on power supplied by the energy storage member. 
     In any embodiment, the suction motor may be operable only from:
         (a) power supplied from the capacitor, or   (b) the surface cleaning apparatus may further comprise an electrical cord connectable with a stationary source of power and the suction motor is operable from power supplied from the capacitor and power supplied from a stationary power supply.       

     In any embodiment, the energy storage member may be provided in the surface cleaning head and, optionally, in a forward portion of the surface cleaning head (e.g., at a location forward of the portable surface cleaning unit such as adjacent the dirty air inlet). 
     In any embodiment, the energy storage member may have a center of gravity and the center of gravity may be positioned forward of the center of the surface cleaning head. 
     In any embodiment, the floor cleaning unit may further comprise a thermal cooling unit thermally connected to the charger. 
     In any embodiment, the charger may be operable to recharge the capacitor at a rate of at least 4C or at least 6C. 
     In any embodiment, the capacitor may comprise an ultra-capacitor. 
     In any embodiment, the surface cleaning apparatus may further comprise an electrical cord connectable with a stationary source of power. 
     In any embodiment, the portable cleaning unit may further comprise an electrical cord connectable with a stationary source of power. The electrical cord may be removably connectable with the portable cleaning unit. 
     In any embodiment, the capacitor may be removably mounted in the portable surface cleaning unit. 
     In any embodiment, the portable surface cleaning unit may comprise a hand vacuum cleaner and the upper section may comprise a rigid air flow conduit having an upper end and a lower end,
         wherein the lower end of the rigid air flow conduit is moveably mounted to the surface cleaning head between the upright storage position and the rearwardly inclined floor cleaning position, and   wherein the hand vacuum cleaner is connectable to the upper end of the rigid air flow conduit,   whereby, when the hand vacuum cleaner is connected to the upper end of the rigid air flow conduit the handle is a steering handle for the vacuum cleaner.       

     In accordance with another aspect, which may be used by itself or with any one or more other aspects set out herein, a surface cleaning apparatus comprises a floor cleaning module and a portable surface cleaning unit that has an on board energy storage member that optionally comprises or consists of one or more capacitors such as an ultra-capacitor. The surface cleaning head is provided with a charger whereby the on board energy storage member may be charged at a rate of 2C, 3C, 4C, 5C, 6C or more. As discussed previously, an advantage of this aspect is that a user may be able to continuously, or more continuously clean a household without downtime while an on board energy storage member is recharged. 
     In accordance with this aspect, there is provided a vacuum cleaner comprising:
         (a) a floor cleaning unit comprising:
           (i) a surface cleaning head having a front end having a dirty air inlet, a rear end, a center positioned midway between the front and rear ends and a charger;   (ii) an upper section moveably mounted to the surface cleaning head between an upright storage position and a rearwardly inclined floor cleaning position; and,   (iii) an air flow path extending from the dirty air inlet to a floor cleaning unit air outlet; and,   
           (b) a portable surface cleaning unit removably mounted to the upper section, the portable surface cleaning unit comprising a main body, an air treatment member, a suction motor, a handle and a capacitor,   wherein, the portable surface cleaning unit is rechargeable when mounted to the floor cleaning unit and,   wherein the capacitor is rechargeable at a rate of at least 4C.       

     In any embodiment, the suction motor may be operable only from:
         (a) power supplied from the capacitor, or   (b) the surface cleaning apparatus may further comprise an electrical cord connectable with a stationary source of power and the suction motor is operable from power supplied from the capacitor and power supplied from a stationary power supply.   In any embodiment, the energy storage member may have a center of gravity and the center of gravity is positioned forward of the center of the surface cleaning head. The center of gravity may be positioned at the front end of the surface cleaning head.       

     In any embodiment, the capacitor may comprise an ultra-capacitor. 
     In any embodiment, the portable surface cleaning unit may comprise a hand vacuum cleaner and the upper section may comprise a rigid air flow conduit having an upper end and a lower end,
         wherein the lower end of the rigid air flow conduit is moveably mounted to the surface cleaning head between the upright storage position and the rearwardly inclined floor cleaning position, and   wherein the hand vacuum cleaner is connectable to the upper end of the rigid air flow conduit,   whereby, when the hand vacuum cleaner is connected to the upper end of the rigid air flow conduit the handle is a steering handle for the vacuum cleaner.       

     In any embodiment, the portable cleaning unit may further comprise an electrical cord connectable with a stationary source of power. 
     In any embodiment, the energy storage member may store sufficient stored power to recharge the capacitor at least twice. 
     In any embodiment, the floor cleaning unit may further comprise a thermal cooling unit thermally connected to the charger. 
     In accordance with this aspect, there is also provided a vacuum cleaner comprising:
         (a) a floor cleaning unit comprising:
           (i) a surface cleaning head having a front end having a dirty air inlet, a rear end, a center positioned midway between the front and rear ends and a charger;   (ii) an upper section moveably mounted to the surface cleaning head between an upright storage position and a rearwardly inclined floor cleaning position; and,   (iii) an air flow path extending from the dirty air inlet to a floor cleaning unit air outlet; and,   
           (b) a portable surface cleaning unit removably mounted to the upper section, the portable surface cleaning unit comprising a main body, an air treatment member, a suction motor, a handle and a capacitor,   wherein, the portable surface cleaning unit is rechargeable when mounted to the floor cleaning unit, and   wherein the energy storage member has a center of gravity and the center of gravity is positioned forward of the center of the surface cleaning head.       

     In any embodiment, the suction motor may be operable only from:
         (c) power supplied from the capacitor, or   (d) the surface cleaning apparatus may further comprise an electrical cord connectable with a stationary source of power and the suction motor is operable from power supplied from the capacitor and power supplied from a stationary power supply.       

     In any embodiment, the center of gravity may be positioned at the front end of the surface cleaning head. 
     In any embodiment, the capacitor may comprise an ultra-capacitor. 
     In any embodiment, the portable surface cleaning unit may comprise a hand vacuum cleaner and the upper section may comprise a rigid air flow conduit having an upper end and a lower end,
         wherein the lower end of the rigid air flow conduit is moveably mounted to the surface cleaning head between the upright storage position and the rearwardly inclined floor cleaning position, and   wherein the hand vacuum cleaner is connectable to the upper end of the rigid air flow conduit,   whereby, when the hand vacuum cleaner is connected to the upper end of the rigid air flow conduit the handle is a steering handle for the vacuum cleaner.       

     In such a surface cleaning apparatus, the portable cleaning unit may further comprise an electrical cord connectable with a stationary source of power. The suction motor may be operable only from:
         (a) power supplied from the capacitor, or   (b) the surface cleaning apparatus may further comprise an electrical cord connectable with a stationary source of power and the suction motor is operable from power supplied from the capacitor and power supplied from a stationary power supply.       

     In any embodiment, the energy storage member may store sufficient stored power to recharge the capacitor at least twice or at least three times. 
     In any embodiment, the floor cleaning unit may further comprise a thermal cooling unit thermally connected to the charger. 
     In accordance with another aspect, which may be used by itself or with any one or more other aspects set out herein, the charger may be remote from the surface cleaning apparatus. An advantage of this design is that the surface cleaning apparatus may be lighter. This may be preferred for the elderly or those with a physical disability. In particular, such a design may be used for embodiments wherein the charger includes a thermal cooling member. 
     In accordance with this aspect, there is provided a surface cleaning apparatus kit comprising:
         (a) a surface cleaning apparatus comprising:
           (i) floor cleaning unit comprising a surface cleaning head and a rigid air flow conduit having an upper end and a lower end moveably mounted to the surface cleaning head between an upright storage position and a rearwardly inclined floor cleaning position; and,   (ii) a portable surface cleaning unit removably mounted to the rigid air flow conduit, the portable surface cleaning unit comprising a main body, an air treatment member, a suction motor, a handle and a capacitor; and,   
           (b) a charger positionable remote from the surface cleaning apparatus and electrically connectable to a stationary power supply,   wherein, when the capacitor is electrically connected to the charger, the capacitor is recharged at a rate of at least 4C.       

     In any embodiment, the capacitor may comprise an ultra-capacitor. 
     In any embodiment, the charger may be operable to recharge the capacitor at a rate of at least 6C. 
     In any embodiment, the surface cleaning apparatus kit may further comprise a thermal cooling unit thermally connected to the charger. 
     In any embodiment, the capacitor may be removably mounted to the portable surface cleaning unit. 
     In any embodiment, the portable cleaning unit may further comprise an electrical cord connectable with a stationary source of power. 
     In any embodiment, the electrical cord may be removably connectable with the portable surface cleaning unit. 
     In any embodiment, the portable cleaning unit may further comprise an electrical cord connectable with the charger. The electrical cord may be removably connectable with the portable surface cleaning unit. 
     In accordance with this aspect, there is also provided a surface cleaning apparatus kit comprising:
         (a) a surface cleaning apparatus comprising:
           (i) floor cleaning unit comprising a surface cleaning head and a rigid air flow conduit having an upper end and a lower end moveably mounted to the surface cleaning head between an upright storage position and a rearwardly inclined floor cleaning position; and,   (ii) a portable surface cleaning unit removably mounted to the rigid air flow conduit, the portable surface cleaning unit comprising a main body, an air treatment member, a suction motor, a handle and a capacitor;   
           (b) a charger positionable remote from the surface cleaning apparatus and electrically connectable to a stationary power supply; and,   (c) a thermal cooling unit thermally connected to the charger.       

     In any embodiment, the capacitor may comprise an ultra-capacitor. 
     In any embodiment, the charger may be operable to recharge the capacitor at a rate of at least 6C. 
     In any embodiment, the thermal cooling unit may comprise a liquid heat sink. 
     In any embodiment, the capacitor may be removably mounted to the portable surface cleaning unit. 
     In any embodiment, the portable cleaning unit may further comprise an electrical cord connectable with a stationary source of power. The electrical cord may be removably connectable with the portable surface cleaning unit. 
     In any embodiment, the portable cleaning unit may further comprise an electrical cord connectable with the charger. The electrical cord may be removably connectable with the portable surface cleaning unit. 
     As discussed with respect to previous aspects, a user may be able to clean continuously or more continuously using any of the aspects set out herein. Accordingly, there is provided a method of cleaning a surface using a stick vacuum cleaner, the stick vacuum cleaner comprising:
         (a) a floor cleaning unit comprising:
           (i) a surface cleaning head having a front end having a dirty air inlet and a rear end;   (ii) a rigid air flow conduit having an upper end and a lower end moveably mounted to the surface cleaning head between an upright storage position and a rearwardly inclined floor cleaning position; and,   (iii) an air flow path extending from the dirty air inlet to a rigid air flow conduit air outlet; and,   
           (b) a hand vacuum cleaner removably mounted to the upper end of the rigid air flow conduit, the hand vacuum cleaner comprising a main body, an air treatment member, a suction motor, a handle and a capacitor,   the method comprising:   (a) removing the hand vacuum cleaner from the upper end of the rigid air flow conduit and using the portable cleaning unit to clean a surface;   (b) subsequently mounting the hand vacuum cleaner on the upper end of the rigid air flow conduit and using the stick vacuum cleaner to clean a floor for up to 15 minutes while the capacitor at least substantially recharges; and,   (c) subsequently removing the hand vacuum cleaner from the upper end of the rigid air flow conduit and using the hand vacuum cleaner to clean a surface.       

     In any embodiment, step (b) may comprise using the stick vacuum cleaner to clean the floor for up to 5, 6, 7, 8, 9, 120, 11, 12, 13, 14 or 15 minutes while the capacitor substantially or fully recharges. 
     In any embodiment, the floor cleaning unit may further comprise a charger having an energy storage member, wherein, when fully charged, the energy storage member stores sufficient stored power to recharge the capacitor at least twice, and step (b) may comprise using the energy storage member to recharge the capacitor. 
     There is also provided a method of cleaning a surface using a surface cleaning apparatus, the surface cleaning apparatus comprising:
         (a) a floor cleaning unit comprising a surface cleaning head and a rigid air flow conduit having an upper end and a lower end moveably mounted to the surface cleaning head between an upright storage position and a rearwardly inclined floor cleaning position; and,   (b) a portable surface cleaning unit removably mounted to the rigid air flow conduit, the portable surface cleaning unit comprising a main body, an air treatment member, a suction motor, a handle and a capacitor,   the method comprising:   (a) removing the portable cleaning unit from the floor cleaning unit and using the portable cleaning unit to clean a surface;   (b) subsequently mounting the portable cleaning unit on the floor cleaning unit and using the surface cleaning apparatus to clean a floor for up to 15 minutes while the capacitor at least substantially recharges; and,   (c) subsequently removing the portable cleaning unit from the floor cleaning unit and using the portable cleaning unit to clean a surface.       

     In any embodiment, step (b) may comprise using the stick vacuum cleaner to clean the floor for up to 5, 6, 7, 8, 9, 120, 11, 12, 13, 14 or 15 minutes while the capacitor substantially or fully recharges. 
     In any embodiment, the floor cleaning unit may further comprise a charger having an energy storage member, wherein, when fully charged, the energy storage member stores sufficient stored power to recharge the capacitor at least twice, and step (b) may comprise using the energy storage member to recharge the capacitor. 
     The method may be conducted using a stick vacuum cleaner comprising:
         (a) a surface cleaning head;   (b) a rigid air flow conduit having an upper end and a lower end moveably mounted to the surface cleaning head between an upright storage position and a rearwardly inclined floor cleaning position; and,   (c) a hand vacuum cleaner removably mounted to the upper end of the rigid air flow conduit, the hand vacuum cleaner comprising a main body, an air treatment member, a suction motor, a handle, a capacitor and an electrical cord connectable with a stationary source of power,   wherein, when the portable surface cleaning unit is mounted to the upper end of the rigid air flow conduit, the handle is a steering handle for the vacuum cleaner.       

     In any embodiment, the electrical cord may be removably connectable with the hand vacuum cleaner. 
     In any embodiment, the capacitor may be removably mounted to the hand vacuum cleaner. 
     In any embodiment, the capacitor may be an ultra-capacitor. 
     It will be appreciated that one or more of these aspects may be used with outer household self-powered appliances such as power tools, kitchen appliances, personal appliances and the like. 
    
    
     
       DRAWINGS 
       For a better understanding of the described embodiments and to show more clearly how they may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which: 
         FIG. 1  is a perspective view of a surface cleaning apparatus in accordance with an embodiment; 
         FIG. 2  is an exploded view of the surface cleaning apparatus of  FIG. 1 ; 
         FIG. 3  is a perspective view of a portable surface cleaning unit of the surface cleaning apparatus of  FIG. 1 ; 
         FIG. 4  is a cross-sectional view taken along line  4 - 4  in  FIG. 3 ; 
         FIG. 5  is a perspective view of a surface cleaning apparatus in accordance with another embodiment; 
         FIG. 6  is an exploded view of the surface cleaning apparatus of  FIG. 5 ; 
         FIG. 7  is a side elevation view of the portable surface cleaning unit of  FIG. 3  with an energy storage member removed; 
         FIG. 8  is a perspective view of the energy storage member of  FIG. 7  and a charger; 
         FIG. 9  is a schematic illustration of a surface cleaning apparatus in accordance with an embodiment; 
         FIG. 10  is a perspective view of a portable surface cleaning unit connected by a power cable to a stationary power supply, in accordance with an embodiment; 
         FIG. 11  is a schematic illustration of a surface cleaning apparatus in accordance with an embodiment; 
         FIG. 12  is a perspective view of a portable surface cleaning unit disconnected from a power cable, in accordance with an embodiment; 
         FIG. 13  is a perspective view of a surface cleaning apparatus with a floor cleaning unit connected by a power cable to a stationary power supply, in accordance with an embodiment; 
         FIG. 14  is a schematic illustration of a surface cleaning apparatus in accordance with an embodiment; 
         FIG. 15  is a perspective view of a surface cleaning apparatus with a floor cleaning unit connected by a power cable to a charger, in accordance with an embodiment; 
         FIG. 16  is a schematic illustration of a surface cleaning apparatus in accordance with an embodiment; 
         FIG. 17  is a schematic illustration of a surface cleaning apparatus in accordance with an embodiment; 
         FIGS. 18-20  are schematic illustrations of an energy storage member, a thermal cooling unit, and a charger, in accordance with various embodiments; 
         FIG. 21  is a flowchart illustrating a method of cleaning with a surface cleaning apparatus, in accordance with an embodiment; 
         FIG. 22  is a schematic illustration of a surface cleaning apparatus in accordance with an embodiment; 
         FIG. 23  is a schematic illustration of a surface cleaning apparatus in accordance with an embodiment; and, 
         FIG. 24  is a schematic illustration of a surface cleaning apparatus in accordance with an embodiment. 
     
    
    
     DESCRIPTION OF VARIOUS EMBODIMENTS 
     Numerous embodiments are described in this application, and are presented for illustrative purposes only. The described embodiments are not intended to be limiting in any sense. The invention is widely applicable to numerous embodiments, as is readily apparent from the disclosure herein. Those skilled in the art will recognize that the present invention may be practiced with modification and alteration without departing from the teachings disclosed herein. Although particular features of the present invention may be described with reference to one or more particular embodiments or figures, it should be understood that such features are not limited to usage in the one or more particular embodiments or figures with reference to which they are described. 
     The terms “an embodiment,” “embodiment,” “embodiments,” “the embodiment,” “the embodiments,” “one or more embodiments,” “some embodiments,” and “one embodiment” mean “one or more (but not all) embodiments of the present invention(s),” unless expressly specified otherwise. 
     The terms “including,” “comprising” and variations thereof mean “including but not limited to,” unless expressly specified otherwise. A listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms “a,” “an” and “the” mean “one or more,” unless expressly specified otherwise. 
     As used herein and in the claims, two or more parts are said to be “coupled”, “connected”, “attached”, “joined”, “affixed”, or “fastened” where the parts are joined or operate together either directly or indirectly (i.e., through one or more intermediate parts), so long as a link occurs. As used herein and in the claims, two or more parts are said to be “directly coupled”, “directly connected”, “directly attached”, “directly joined”, “directly affixed”, or “directly fastened” where the parts are connected in physical contact with each other. As used herein, two or more parts are said to be “rigidly coupled”, “rigidly connected”, “rigidly attached”, “rigidly joined”, “rigidly affixed”, or “rigidly fastened” where the parts are coupled so as to move as one while maintaining a constant orientation relative to each other. None of the terms “coupled”, “connected”, “attached”, “joined”, “affixed”, and “fastened” distinguish the manner in which two or more parts are joined together. 
     Further, although method steps may be described (in the disclosure and/or in the claims) in a sequential order, such methods may be configured to work in alternate orders. In other words, any sequence or order of steps that may be described does not necessarily indicate a requirement that the steps be performed in that order. The steps of methods described herein may be performed in any order that is practical. Further, some steps may be performed simultaneously. 
     Some elements herein may be identified by a part number, which is composed of a base number followed by an alphabetical or subscript-numerical suffix (e.g.  112   a , or  1121 ). Multiple elements herein may be identified by part numbers that share a base number in common and that differ by their suffixes (e.g.  1121 ,  1122 , and  1123 ). All elements with a common base number may be referred to collectively or generically using the base number without a suffix (e.g.  112 ). 
     General Description of a Hand Vacuum Cleaner 
     Referring to  FIGS. 1-6 , exemplary embodiments of a surface cleaning apparatus are shown generally as  100 . The following is a general discussion of apparatus  100  which provides a basis for understanding several of the features which are discussed herein. As discussed subsequently, each of the features may be used individually or in any particular combination or sub-combination in this or in other embodiments disclosed herein. 
     Surface cleaning apparatus  100  may be any type of surface cleaning apparatus, including for example a stick vacuum cleaner as shown in  FIG. 1 , an upright vacuum cleaner as shown in  FIG. 5 , a canister vacuum cleaner, an extractor or a wet/dry type vacuum cleaner. Optionally, the surface cleaning apparatus  100  may use one or more cyclones and may therefore be a cyclonic surface cleaning apparatus. 
     In  FIGS. 1-6 , surface cleaning apparatus  100  is illustrated as including a floor cleaning unit  104 , and a portable surface cleaning unit  108  that is connectable to the floor cleaning unit  104 . The floor cleaning unit  104  may include a surface cleaning head  112  adapted to clean floors. Portable surface cleaning unit  108  may include an air treatment member  116 . Surface cleaning apparatus  100  may include an upright configuration (also referred to as a ‘floor cleaning configuration’, see  FIGS. 1 and 5 ) in which portable surface cleaning unit  108  is mounted to floor cleaning unit  104 , and dirty air that enters the surface cleaning head  112  flows downstream to portable surface cleaning unit  108  where the dirty air is cleaned by air treatment member  116 . Surface cleaning apparatus  100  may also include a ‘portable cleaning configuration’ (also referred to as a ‘hand carriable configuration’, or ‘above-floor cleaning configuration’, see  FIGS. 3 and 6 ), in which portable surface cleaning unit  108  is separated from floor cleaning unit  104 , such as to clean above-floor surfaces and surfaces generally inaccessible to or unsuitable for cleaning with surface cleaning head  112  for example. 
     In the embodiment of  FIGS. 1-4 , surface cleaning apparatus  100  is illustrated as a stick vacuum cleaner, which may also be referred to as a “stickvac”. As used herein and in the claims, a stick vacuum cleaner is one in which portable surface cleaning unit  108  is a hand vacuum cleaner, which may also be referred to also as a “handvac” or “hand-held vacuum cleaner”. As used herein and in the claims, a hand vacuum cleaner is a vacuum cleaner that can be operated to clean a surface generally one-handedly. That is, the entire weight of the hand vacuum cleaner may be held by the same one hand used to direct a dirty air inlet of the hand vacuum cleaner with respect to a surface to be cleaned. For example, handle  120  and dirty air inlet  124  may be rigidly coupled to each other (directly or indirectly), such as being integrally formed or separately molded and then non-removably secured together such as by an adhesive or welding, so as to move as one while maintaining a constant orientation relative to each other. This is to be contrasted with canister and upright vacuum cleaners, whose weight is typically supported by a surface (e.g. a floor) during use. 
     In the embodiment of  FIGS. 5-6 , surface cleaning apparatus  100  is illustrated as a convertible upright vacuum, in which portable surface cleaning unit  108  is a ‘lift away’ pod that, in the portable cleaning configuration, can be hand carried by handle  120 . As opposed to a hand vacuum cleaner, a lift-away pod typically uses a flexible hose to deliver air for treatment to the air inlet provided in the casing of the lift-away pod. As shown, portable surface cleaning unit  108  may include a dirty air inlet  124  upstream of a flexible hose  128 . For example, dirty air inlet  124  may be located at an upstream end of a rigid conduit  132  (e.g. a wand). The user may manipulate rigid conduit  132  to position dirty air inlet  124  on or adjacent a surface (e.g. above-floor surface) to be cleaned. Optionally, rigid conduit  132  may include a handle  136  for the user to grasp while manipulating rigid conduit  132 . 
     Referring again to  FIGS. 1-6 , floor cleaning unit  104  may include surface cleaning head  112 , an upper section  140 , a dirty air inlet  144 , an air outlet  148 , and an air flow path  152  extending from dirty air inlet  144  to air outlet  148 . As shown, surface cleaning head  112  may include a front end  156  opposed to a rear end  160 , opposed sides  164  and  168 , and a lower end  172  opposed to an upper end  176 . Dirty air inlet  144  may be located on lower end  172 . For example, dirty air inlet  144  may be provide at front end  156 . Alternatively or in addition, dirty air inlet may be provided at rear end  160 , or intermediate front and rear ends  156 ,  160 . 
     Upper section  140  may be movably mounted to surface cleaning head  112  in a manner that allows upper section  140  to move between an upright storage position (e.g.  FIG. 1 ), and an inclined floor cleaning position (e.g.  FIG. 5 ). For example, upper section  140  may have a rotating connection to surface cleaning head  112  that allows upper section  140  to rotate between the upright storage and inclined floor cleaning positions. 
     As shown in  FIGS. 1-4 , the portable surface cleaning unit  108  is a hand vacuum cleaner and in  FIGS. 5-6 , the portable surface cleaning unit  108  is a lift-away pod. Accordingly, the description of apparatus  100  and portable surface cleaning unit  108  below makes frequent reference to figures showing embodiments in which portable surface cleaning unit  108  is illustrated as a hand vacuum, similar to  FIGS. 1-4 . To be clear and concise and avoid duplication, the description may not reference a lift-way pod version which has an appearance similar to the embodiment of  FIGS. 5-6 . However, it is expressly contemplated, and will be readily understood by persons skilled in the art, that the features described with reference to hand vacuum cleaners similar to the embodiment of  FIGS. 1-4  also apply mutatis mutandis to embodiments with a lift-away pod similar to  FIGS. 5-6 , unless expressly stated otherwise. 
     Referring to  FIGS. 3-4 , portable surface cleaning unit  108  includes a main body  180  having an air treatment member  116  (which may be permanently affixed to the main body or may be removable therefrom for emptying), a dirty air inlet  124 , a clean air outlet  184 , and an air flow path  188  extending between the dirty air inlet  124  and the clean air outlet  184 . 
     Portable surface cleaning unit  108  has a front end  192 , a rear end  196 , an upper end (also referred to as the top)  204 , and a lower end (also referred to as the bottom)  208 . In the embodiment shown, dirty air inlet  124  is at an upper portion of front end  192  and clean air outlet  184  is at rear end  196 . It will be appreciated that dirty air inlet  124  and clean air outlet  184  may be positioned in different locations of portable surface cleaning unit  108 . For example,  FIG. 6  illustrates an embodiment in which clean air outlet  184  is located at front end  192 . 
     Turning to  FIG. 4 , portable surface cleaning unit  108  may include a suction motor  212  to generate vacuum suction through air flow path  188 . Suction motor  212  may be positioned within a motor housing  216 . Suction motor  212  may be a fan-motor assembly including an electric motor and impeller blade(s). In the illustrated embodiment, suction motor  212  is positioned in the air flow path  188  downstream of air treatment member  116 . In this configuration, suction motor  212  may be referred to as a “clean air motor”. Alternatively, suction motor  212  may be positioned upstream of air treatment member  116 , and referred to as a “dirty air motor”. 
     Air treatment member  116  is configured to remove particles of dirt and other debris from the air flow. In the illustrated example, air treatment member  116  includes a cyclone assembly (also referred to as a “cyclone bin assembly”) having a single cyclonic cleaning stage with a single cyclone  220  and a dirt collection chamber  224  (also referred to as a “dirt collection region”, “dirt collection bin”, “dirt bin”, or “dirt chamber”). Cyclone  220  has a cyclone chamber  228 , a cyclone air inlet  232 , and a cyclone air outlet  236 . Dirt collection chamber  224  may be external to the cyclone chamber  228  (i.e. dirt collection chamber  224  may have a discrete volume from that of cyclone chamber  228 ). Cyclone  220  and dirt collection chamber  224  may be of any configuration suitable for separating dirt from an air stream and collecting the separated dirt respectively and may be in communication by a dirt outlet of the cyclone chamber. 
     In alternate embodiments, air treatment member  116  may include a cyclone assembly having two or more cyclonic cleaning stages arranged in series with each other. Each cyclonic cleaning stage may include one or more cyclones arranged in parallel with each other and one or more dirt collection chambers, of any suitable configuration. The dirt collection chamber(s) may be external to the cyclone chambers of the cyclones. Alternatively, one or more (or all) of the dirt collection chamber(s) may be internal to one or more (or all) of the cyclone chambers. For example, the internal dirt collection chamber(s) may be configured as a dirt collection area within the cyclone chamber. 
     In other embodiments, air treatment member  116  may not include a cyclonic cleaning stage. For example, air treatment member  116  may include a bag, a porous physical filter media (such as, for example foam or felt), one or more screens, or other air treating means. 
     Referring to  FIG. 4 , portable surface cleaning unit  108  may include a pre-motor filter  240  provided in the air flow path  188  downstream of air treatment member  116  and upstream of suction motor  212 . Pre-motor filter  240  may be formed from any suitable physical, porous filter media (also referred to as “porous filter material”). For example, pre-motor filter  240  may be one or more of a foam filter, felt filter, HEPA filter, or other physical filter media. In some embodiments, pre-motor filter  240  may include an electrostatic filter, or the like. As shown, pre-motor filter  240  may be located in a pre-motor filter housing  244  that is external to the air treatment member  116 . 
     In the illustrated embodiment, dirty air inlet  124  is the inlet end  252  of an air inlet conduit  248 . Optionally, inlet end  252  of air inlet conduit  248  can be used as a nozzle to directly clean a surface. Alternatively, or in addition to functioning as a nozzle, air inlet conduit  248  may be connected (e.g. directly connected) to the downstream end of any suitable accessory tool such as a rigid air flow conduit (e.g., an above floor cleaning wand), a crevice tool, a mini brush, and the like. As shown, dirty air inlet  124  may be positioned forward of air treatment member  116 , although this need not be the case. 
     In the embodiment of  FIG. 4 , the air treatment member comprises a cyclone  220 , the air treatment air inlet is a cyclone air inlet  232 , and the air treatment member air outlet is a cyclone air outlet  236 . Accordingly, when operated in the portable cleaning configuration, suction motor  212  may be activated to draw dirty air into portable surface cleaning unit  108  through dirty air inlet  124 . The dirty air is directed along air inlet conduit  248  to the cyclone air inlet  232 . As shown, cyclone air inlet  232  may direct the dirty air flow to enter cyclone chamber  228  in a tangential direction so as to promote cyclonic action. Dirt particles and other debris may be disentrained (i.e. separated) from the dirty air flow as the dirty air flow travels from cyclone air inlet  232  to cyclone air outlet  236 . The disentrained dirt particles and debris may discharge from cyclone chamber  228  through a dirt outlet into dirt collection chamber  224  external to the cyclone chamber  228 , where the dirt particles and debris may be collected and stored until dirt collection chamber  224  is emptied. 
     Air exiting cyclone chamber  228  may pass through an outlet passage  256  located upstream of cyclone air outlet  236 . Cyclone chamber outlet passage  256  may also act as a vortex finder to promote cyclonic flow within cyclone chamber  228 . In some embodiments, cyclone outlet passage  256  may include a screen  260  (also referred to as a shroud) (e.g. a fine mesh screen) in the air flow path  188  to remove large dirt particles and debris, such as hair, remaining in the exiting air flow. 
     From cyclone air outlet  236 , the air flow may be directed into pre-motor filter housing  244 . The air flow may pass through pre-motor filter  240 , and then exit pre-motor filter housing  244  into motor housing  216 . At motor housing  216 , the clean air flow may be drawn into suction motor  212  and then discharged from portable surface cleaning unit  108  through clean air outlet  184 . Prior to exiting the clean air outlet  184 , the treated air may pass through a post-motor filter, which may be one or more layers of filter media. 
     Referring to  FIGS. 1-4 , in the upright configuration ( FIG. 1 ), dirty air inlet  124  of portable surface cleaning unit  108  is fluidly connected to air outlet  148  of floor cleaning unit  104 , whereby air flow path  188  of portable surface cleaning unit  108  is located downstream of air flow path  152  of floor cleaning unit  104 . In operation, dirty air enters dirty air inlet  144  of floor cleaning unit  104 , travels along air flow path  152  to air outlet  148 , and then enters portable surface cleaning unit  108  at dirty air inlet  124 . From dirty air inlet  124 , the dirty air flow moves through portable surface cleaning unit  108  as described above in connection with the portable cleaning configuration. 
     Referring to  FIGS. 1-2 , upper section  140  of floor cleaning unit  104  may include a rigid air flow conduit  132 . Rigid air flow conduit  132  includes a conduit upper end  264  downstream of a conduit lower end  268 . Conduit lower end  268  may be movably mounted to the surface cleaning apparatus between the upright storage position and the rearwardly inclined floor cleaning position. Portable surface cleaning unit  108  may be connected to conduit upper end  264 . As shown, this allows handle  120  of handvac  108  to be used as a steering handle for stickvac  100 . 
     Fast Charging Capacitor 
     A trend in cordless vacuum cleaners is to provide longer runtime in a single charge. For example, some cordless vacuum cleaners can run continuously for 30 minutes or more before recharging. However, such vacuum cleaners require large, expensive, heavy batteries. In use, this can make these vacuum cleaners unwieldy to carry, in both size and weight. Moreover, it can take a long time to fully recharge high capacity batteries, and batteries often degrade and require replacement during the working life of a vacuum cleaner. The battery replacement cost is a significant expense for the user. 
     In some embodiments disclosed herein, a surface cleaning apparatus includes a portable surface cleaning unit equipped with an energy storage member having one or more capacitors. As compared with rechargeable batteries (e.g. lead-acid, Ni-Cad, NiMH, or lithium), a capacitor can be recharged much faster, and have a much longer lifespan (measured in charge cycles). With battery powered vacuums, traditional design philosophy is that it is important to have a long runtime to mitigate having to recharge in the middle of a cleaning session, since the recharge could take several hours (e.g., 4-8), which would be disruptive to the user who wishes to finish their cleaning session in a timely manner. In contrast, with a capacitor powered portable cleaning unit, the need to recharge mid-session may be minimally disruptive as it may only require a few seconds to a few minutes to recharge. Therefore, a capacitor powered portable surface cleaning unit may include comparatively less energy storage capacity because avoiding a recharge mid-session is not a priority. As a result, a capacitor powered portable surface cleaning unit may have a relatively smaller and lighter on board energy storage member (one or more capacitors), as compared with a high capacity battery pack. This can make a capacitor powered portable surface cleaning unit smaller and lighter overall, without compromising performance or user experience. Moreover, the long lifespan of capacitors (often 1 million charge cycles or more) means that the capacitors will not generally require replacement during the working life of the portable surface cleaning unit. 
     The features in this section may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features described herein. 
     For convenience, reference to “a capacitor” herein means “one or more capacitors”, unless expressly stated otherwise (e.g. “a single capacitor”). Similarly, reference to “a battery” herein means “one or more batteries”, unless expressly stated otherwise (e.g. “a single battery”). 
     Referring to  FIG. 4 , portable surface cleaning unit  108  is shown including an energy storage member  272 . Energy storage member  272  may include a capacitor  276 . For example, capacitor  276  may be the only significant energy storage in energy storage member  272 , or energy storage member  272  may further include a battery. Some or all of the power consuming elements of portable surface cleaning unit  108  may be powered by capacitor  276 . For example, at least suction motor  212  may be powered by capacitor  276 . In some embodiments, some or all power consuming elements of portable surface cleaning unit  108  may be exclusively powered by capacitor  276 . For example, at least suction motor  212  may be exclusively powered by capacitor  276  in some embodiments. 
     Capacitor  276  may be any capacitor suitable for supplying power required to operate at least suction motor  212 . For example, capacitor  276  may be an ultracapacitor (also referred to as a supercapacitor or Goldcap). As compared to an electrolytic capacitor, ultracapacitors have dramatically higher energy density (per unit mass and per unit volume). Types of ultracapacitors include electrostatic double-layer capacitors (EDLCs), electrochemical pseudocapacitors, and hybrid capacitors that store charge both electrostatically and electrochemically. Accordingly, it will be appreciated that a portable surface cleaning unit  108  may use only a single capacitor  276  or optionally, for example, 2, 3 or 4 capacitors  276 . 
     Capacitor  276  may be recharged by power from a power source external to portable surface cleaning unit  108 .  FIGS. 7-8  show an example in which energy storage member  272  is removable from portable surface cleaning unit  108  for electrically connecting to an external charger  280 . External charger  280  may be powered by an electrical connection to a stationary power supply  284  (e.g. mains power). An advantage of this design is that the external charger  280  also reduces the size and weight of portable surface cleaning unit  108  as compared with including charger  280  within portable surface cleaning unit  108 . Further, this design may not require portable surface cleaning unit  108  to have a power cord or power cord connector, which may also reduce the size and weight of portable surface cleaning unit  108  all else being equal. It will be appreciated that, if the capacitor is charged rapidly (e.g., 1, 2, 3, 4, or 5 minutes), then the user may be able to make a cup of coffee or make a quick call and then return to continue the cleaning operation with a fuller recharged capacitor  276 . 
     A further advantage of this design is that it can allow the user to swap a discharged energy storage member  272  for a charged energy storage member  272  that has been stored on the charger  280 . 
     Alternatively or in addition to energy storage member  272  being removable for recharging, energy storage member  272  may be rechargeable in-situ without removal from portable surface cleaning unit  108 . For example,  FIGS. 9-10  show an embodiment in which portable surface cleaning unit  108  includes a power cable  288  for transmitting power from stationary power supply  284  towards energy storage member  272 . An advantage of a non-removable energy storage member  272  is that it may not require a discrete outer shell for user handling and transportation since it is permanently held within main body  180 . Further, a non-removable energy storage member  272  may not require hardware to support easy user removal and insertion of energy storage member  272 . This may make energy storage member  272  smaller and lighter, all else being equal. 
     In accordance with the alternate exemplified embodiment of  FIGS. 9-10 , portable surface cleaning unit  108  includes charger  280  within main body  180 . An advantage of this design is that it may make connecting portable surface cleaning unit  108  to a stationary power supply  284  more convenient, in that an external charger does not need to be relocated to the selected stationary power supply  284 . 
       FIG. 11  shows an alternative embodiment in which energy storage member  272  is rechargeable in-situ without removal from portable surface cleaning unit  108 , by a corded connection to an external charger  280 . An advantage of this design is that it may reduce the size and weight of portable surface cleaning unit  108  as compared with including charger  280  within portable surface cleaning unit  108 , all else being equal. 
     In an alternate embodiment in which energy storage member  272  is rechargeable in-situ without removal from portable surface cleaning unit  108 , the portable surface cleaning unit  108  may itself be plugged into the charger  280 . 
     Energy storage member  272  may have sufficient energy capacity to power at least suction motor  212  (or all power consuming parts of portable surface cleaning unit  108 ) for at least 3 minutes (e.g. 3 minutes to 15 minutes). For example, an energy storage member  272  with a capacity of at least 5 Wh can provide 100 W of power to a suction motor  212  for at least 3 minutes. As mentioned above, all of the energy storage may be provided by capacitor  276  in some embodiments. A 3 to 5 minute runtime may be sufficient for short cleaning sessions, such as to clean crumbs off a couch, to clean dirt around a planter, or to clean cereal spilled by a child for example. 
     If a task is larger, and requires more runtime than energy storage member  272  can provide, then energy storage member  272  can be quickly recharged. For example, charger  280  (whether external or internal to portable surface cleaning unit  108 ) may be configured to recharge capacitor  276  at a rate of at least 2C, 3C or 4C (e.g. at least 6C, such as 4C to 10C, or 6C to 10C). This can allow capacitor  276  to be fully recharged in a matter of seconds or minutes, as compared with hours in the case of many batteries. 
     Returning to  FIG. 10 , in some embodiments power cable  288  may be permanently connected to portable surface cleaning unit  108 . An advantage of this design is that it may not require portable surface cleaning unit  108  to have hardware to support a removable connection, and it may make connecting portable surface cleaning unit  108  to a stationary power supply  284  more convenient to the extent that a separate power cable  288  does not need to be relocated to the selected power supply  284 .  FIG. 12  shows an alternative embodiment in which power cable  288  is removably connected to portable surface cleaning unit  108 . For example, power cable  288  may be connected to portable surface cleaning unit  108  only to recharge energy storage member  272 . An advantage of this design is that it does not require the user to carry the weight of power cable  288  when portable surface cleaning unit  108  does not require a connection to a stationary power supply  284  (e.g. when not recharging). 
     Capacitor Rechargeable in Upright Configuration 
     In some embodiments, the floor cleaning unit charges the capacitor of the portable surface cleaning unit when the portable surface cleaning unit is connected to the floor cleaning unit. For example, the capacitor of the portable surface cleaning unit may be recharged while the surface cleaning apparatus is operated in the upright configuration. Several advantages flow from this design. First, this design can mitigate the capacitor of the portable surface cleaning unit being dead when disconnected from the floor cleaning unit for use in the portable cleaning configuration. Second, this design can allow cleaning to continue in the upright configuration if the portable surface cleaning unit runs out of power in the portable surface cleaning mode. For example, if the capacitor of the portable surface cleaning unit runs out of power while cleaning an above-floor surface, the user may connect the portable surface cleaning unit to the floor cleaning unit and resume cleaning floor surfaces while the capacitor recharges. Third, this design can allow the capacitor to recharge while the portable surface cleaning unit is connected to the floor cleaning unit in the storage mode. This mitigates misplacing the floor cleaning unit, as compared to a design that requires the portable surface cleaning unit to be disconnected from the floor cleaning unit to recharge. 
     The features in this section may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features described herein. 
     Reference is now made to  FIGS. 13-14 . As shown, floor cleaning unit  104  may include a charger  280 . For example, charger  280  may be located in surface cleaning head  112  as shown, or in upper section  140 . When charger  280  is connected to a source of power, and portable surface cleaning unit  108  is connected to floor cleaning unit  104 , charger  280  may recharge energy storage member  272  (including at least capacitor  276 ). In the illustrated example, portable surface cleaning unit  108  is connected to floor cleaning unit  104  in an upright configuration. Thus, energy storage member  272  may be recharged while surface cleaning apparatus  100  is in a storage position and/or an inclined floor cleaning position. 
     Embodiments that can recharge energy storage member  272  while apparatus  100  is in the inclined floor cleaning position can allow the user to continue cleaning without interruption when portable surface cleaning unit  108  runs out of power in a portable cleaning configuration. The rapid charging rate of capacitor  276  means that capacitor  276  may be fully recharged in a short period of time, and therefore allow the user to return to the portable cleaning configuration after only a short time in the upright configuration. 
     In some embodiments, suction motor  212  may be powered only (i.e. exclusively) by (i) energy storage member  272  (e.g. when in the portable cleaning configuration), or (ii) by a stationary power supply (e.g. mains power, when in the upright cleaning configuration). As shown, when in the upright cleaning configuration, charger  280  may be electrically connected by power cable  288  to stationary power supply  284 . Power cable  288  may have a length suitable to allow surface cleaning apparatus  100  to be used for cleaning floors in the upright configuration while connected to stationary power supply  284 . For example, power cable  288  may be at least 10-15 feet long. 
     Power cable  288  may be permanently connected to floor cleaning unit  104 . For example, surface cleaning apparatus  100  may require an electrical connection to a stationary power supply  284  when in the upright configuration. This may encourage users to arrange their cleaning routine to allow energy storage member  272  to recharge between short periods of use in the portable cleaning configuration. 
     Alternatively, power cable  288  may be removably connected to floor cleaning unit  104 . This allows surface cleaning apparatus  100  to operate in a cordless manner while in the upright configuration, even if only for a short duration subject to the power capacity of energy storage member  272 . For example, this can allow surface cleaning apparatus  100  to be used in an upright configuration to clean floors (e.g. in an unfinished basement) where there is not an electrical outlet within range. 
       FIG. 15  shows an embodiment in which charger  280  is located external to floor cleaning unit  104 . This can reduce the size and weight of floor cleaning unit  104  as compared with a design having charger  280  inside floor cleaning unit  104 . 
     Floor Cleaning Unit Including an Energy Storage Member 
     In some embodiments, the floor cleaning unit may include an energy storage member. The energy storage member may have sufficient power capacity to fully recharge the capacitor of the portable surface cleaning unit several times. This allows a continuous cordless cleaning session with the surface cleaning apparatus wherein the cleaning session includes two or more iterations of (i) cleaning with the portable cleaning unit in the portable cleaning configuration, and (ii) recharging the portable cleaning unit while cleaning in the upright cleaning configuration. The floor cleaning unit may include a relatively inexpensive, rechargeable energy storage member (e.g. a lead acid, NiCad, NiMH, or lithium) with an energy storage capacity that is several times greater than the capacitor of the portable surface cleaning unit. While providing a rechargeable energy storage member in the floor cleaning unit (optionally the surface cleaning head) increases the weight of the floor cleaning unit, this added weight is supported by the floor being cleaned, and may also help stabilize the surface cleaning apparatus  100  when in the storage configuration by lowering the center of gravity. Alternately, or in addition, it can provide needed weight to help maintain the dirty air inlet of the surface cleaning head a desired distance from the floor being cleaned. 
     The features in this section may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features described herein. 
     Referring to  FIG. 16 , floor cleaning unit  104  may include an energy storage member  292 . Floor cleaning unit  104  may also include a charger  280  as shown. Charger  280  may include one or more charging circuits for one or more of:
         (i) supplying power from a stationary power supply (i.e. via power cable  288 ) to energy storage member  292 ;   (ii) supplying power from the floor cleaning unit energy storage member  292  to the portable surface cleaning unit energy storage member  272 ; and,   (iii) supplying power from a stationary power supply (i.e. via power cable  288 ) to energy storage member  272 .       

     Energy storage member  292  can be any device suitable to supply power for fully recharging energy storage member  272  one or several times. For example, energy storage member  292  may include a battery and/or a capacitor that collectively have an energy storage capacity sufficient to recharge energy storage member  272  (or at least capacitor  276 ) two or more times (e.g. three or more times, or six or more times). 
     In some embodiments, when portable surface cleaning unit  108  is connected to floor cleaning unit  104 , and floor cleaning unit  104  is disconnected from an external power supply (e.g. power cable  288  is disconnected from mains power, and/or disconnected from floor cleaning unit  104 ), energy storage member  272  is charged by charger  280  with power from energy storage member  292 . In this situation, surface cleaning apparatus  100  may be operated in the inclined floor cleaning position to clean floors while energy storage member  272  is charging. After a short period (e.g. 15 minutes or less), energy storage member  272  will have been substantially or fully recharged, and portable surface cleaning unit  108  can be removed for use again in the portable cleaning configuration. 
     While energy storage member  272  is being charged by charger  280  from power supplied by energy storage member  292 , suction motor  212  may be powered exclusively by energy storage member  272 . An advantage of this design is that it does not require portable surface cleaning unit  108  to include circuitry that can electrically reconfigure suction motor  212  to receive power directly from energy storage member  292  and/or enable suction motor  212  to receive power directly from energy storage member  292 . Further, this design does not require energy storage member  292  to be capable of discharging at a rate sufficient to supply both (i) recharging of energy storage member  272 , and (ii) powering suction motor  212 . 
     Alternatively, while energy storage member  272  is being charged by charger  280  from power supplied by energy storage member  292 , suction motor  212  may be powered exclusively by energy storage member  292 . An advantage of this design is that it may reduce or stop the discharge of energy storage member  272 , so that energy storage member  272  can sooner attain a substantially or full charge for use in the portable cleaning configuration. 
     Alternatively, while energy storage member  272  is being charged by charger  280  from power supplied by energy storage member  292 , suction motor  212  may be powered by energy storage members  272 ,  292  together. 
     In some embodiments, when portable surface cleaning unit  108  is connected to floor cleaning unit  104 , and floor cleaning unit  104  is connected to an external power supply (e.g. power cable  288  is connected to mains power and floor cleaning unit  104 ) one or more of the following may occur concurrently:
         (i) energy storage member  272  may be charged by charger  280  with power from energy storage member  292  and/or power from the external power supply;   (ii) energy storage member  292  may be charged by charger  280  with power from the external power supply; and,   (iii) suction motor  212  may be powered by energy from energy storage member  272 , and/or energy storage member  292 , and/or the external power supply.
 
An advantage of partially or completely powering suction motor  212  from the external power supply in this situation is that it can reduce or stop the discharge of energy due to energy storage members  272 ,  292  powering the suction motor  212  so that energy storage members  272 ,  292  can sooner attain be substantially or fully recharged. Once energy storage members  272 ,  292  have attained a substantial or full charge, surface cleaning apparatus  100  can again be used in a cordless configuration (e.g. power cable  288  can be disconnected from mains power and/or disconnected from floor cleaning unit  104 ).
       

     Reference is now made to  FIG. 17 . Alternatively or in addition to providing a charger  2801  in floor cleaning unit  104 , floor cleaning unit  104  may be connectable to an external charger  2802 . For example, internal charger  2801  may be configured with a charging circuit for transferring power from energy storage member  292  to energy storage member  272 , and external charger  2802  may be configured with a charging circuit for transferring power from an external power supply (e.g. mains power) to energy storage member  292 . This design may reduce the size and/or weight of floor cleaning unit  104  as compared with a design that includes both chargers  2801  and  2802  (or a single charger with the functionality of both chargers) inside floor cleaning unit  104 . 
     Referring to  FIGS. 16-17 , energy storage member  292  may be located anywhere inside floor cleaning unit  104 . For example, energy storage member  292  may be located at (e.g. inside, part of, or attached to) surface cleaning head  112  as shown, or upper section  140 . In the illustrated embodiment, surface cleaning head  112  has a center  304  located midway between front and rear ends  156 ,  160 , and energy storage member  292  has a center of gravity  296  located forward of cleaning head center  304 . An advantage of this design is that energy storage member  292  may help move the center of gravity of surface cleaning apparatus  100  forwards, and thereby help stabilize surface cleaning apparatus  100  when in the storage position. For example, a more forward center of gravity of apparatus  100  may mitigate surface cleaning apparatus tipping over rearwardly when in the storage position. 
     Thermal Cooling During Charging and/or Discharging 
     The rate at which an energy storage member can be charged, without suffering damage or substantial degradation, may be limited by heat generated during charging. When an energy storage member for an appliance is charged, the generated heat can raise the temperature of the energy storage member to dangerous or damaging levels. In some embodiments, a thermal cooling unit that, directly or indirectly, cools an appliance energy storage member during charging is provided. This can help keep the temperature of the energy storage member within safe limits when the energy storage member is charged rapidly (e.g. at a rate of 4C or faster). If the charger is in a surface cleaning unit, then the surface cleaning apparatus may include the charger and the thermal cooling unit. Alternately, if the charger is remote, then the charger may include the thermal cooling unit. Such a thermal cooling unit may be referred to as an appliance energy storage member thermal cooling unit. 
     As discussed herein, a charger which is used to charge an energy storage member may itself have an onboard energy storage member. The rate at which such an on board energy storage member can be discharged, without suffering damage or substantial degradation, may also be limited by heat generated during discharge. When an energy storage member is rapidly discharged, the generated heat can raise the temperature of the energy storage member to dangerous or damaging levels. In some embodiments, a thermal cooling unit that, directly or indirectly, cools an charger energy storage member during discharging is provided. This can help keep the temperature of the energy storage member of the charger within safe limits when the charger is rapidly charging an energy storage member (e.g. at a rate of 4C or faster). If the charger is in a surface cleaning unit, then the surface cleaning apparatus may include the charger and the thermal cooling unit. Alternately, if the charger is remote, then the charger may include the thermal cooling unit. Such a thermal cooling unit may be referred to as an charger energy storage member thermal cooling unit. 
     It will be appreciated that, in some embodiments, the appliance energy storage member thermal cooling unit and the charger energy storage member thermal cooling unit may be the same thermal cooling unit. 
     The features in this section may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features described herein. 
       FIGS. 18-20  illustrate various embodiments of a charger  280  electrically connected to an energy storage member  272  or  292 , and a thermal cooling unit  308  thermally connected to the energy storage member  272 ,  292  to remove heat generated during recharging of energy storage member  272  or  292  or the discharge of energy storage member  292 , and thereby keep the temperature of the energy storage member  272 ,  292  within safe limits when the energy storage member is charged rapidly or the energy storage member  292  is discharged rapidly. 
     It will be appreciated that the arrangements described herein including a thermal cooling unit  308  can be used in combination with energy storage member  272  and/or  292  in any embodiment of surface cleaning apparatus  100 , floor cleaning unit  104 , or portable surface cleaning unit  108  described elsewhere or illustrated in any figure. Further, a thermal cooling unit  308  may be included at a location at which the energy storage member is used (e.g., in the portable surface cleaning unit  108 ) or where the energy storage member is recharged (e.g., in the portable surface cleaning unit  108  if recharged in situ or in charger  280  if recharged exterior to appliance  100 ). For example, referring to  FIGS. 22 and 23 , the portable surface cleaning unit  108  may include a thermal cooling unit  308  as energy storage member  272  may be recharged in situ. Alternately, or in addition, as exemplified in  FIG. 23 , surface cleaning head  112  may include a thermal cooling unit  308  to cool energy storage member  292  when energy storage member  292  is charged and/or discharged. In the alternate embodiment exemplified in  FIG. 24 , energy storage member  272  is recharged external to the apparatus  100 . Accordingly, remote charger  280  is provided with a thermal cooling unit  308  that may be used to cool energy storage member  272  and/or  292  during charging and/or to cool energy storage member  292  during discharge. It will be appreciated that charger  280  may have a single thermal cooling unit  308  that is thermally connected to each of energy storage members  272 ,  292  when energy storage members  272 ,  292  are installed in the charger  280 . Alternately, a first thermal cooling unit  308  may be provided that is thermally connected to energy storage members  272  when energy storage member  272  is installed in the charger  280  and a second thermal cooling unit  308  may be provided that is thermally connected to energy storage members  292  when energy storage member  292  is installed in the charger  280 . 
     Referring to  FIG. 18 , in some embodiments, thermal cooling unit  308  may include active cooling. Any active cooling means known in the art may be used. That is, thermal cooling unit  308  may include a powered cooling element  312 . An advantage of this design is that the rate of cooling can be controlled by regulating the power supplied to cooling element  312 . This may provide better control over the temperature of energy storage member  272 ,  292 . Powered cooling element  312  may be any powered device that can be operated to remove heat from energy storage member  272 ,  292 . For example, powered cooling element  312  may be a fan as shown, a coolant circulating pump (e.g., the energy storage member or a casing in which the energy storage member is received) may include flow channels through which a cooling fluid may flow due to operation of the coolant circulating pump), or a Peltier cooler. As shown, charger  280  may be configured to control the operation of powered cooling element  312 . For example, charger  280  may include a temperature sensor that provides a signal to a controller that, in turn, controls the speed of fan  312  according to a signal from the sensor that represents the temperature of energy storage member  272 ,  292 . 
     Alternatively or in addition to a powered cooling element  312 , thermal cooling unit  308  may include a passive cooling element  316 . A passive cooling element  316  may be an unpowered device that is effective for removing heat from energy storage member  272 ,  292  during charging.  FIG. 19  shows an example in which passive cooling element  316  is a heat sink (e.g. a metal heat sink, such as an aluminum heat sink).  FIG. 20  shows an example in which passive cooling element  316  is a liquid heat sink. 
     In some embodiments, passive cooling element  316  may be configured to provide an enlarged surface area to promote natural convective cooling with the ambient air. For example, heat sink  316  in  FIG. 19  includes a plurality of fins  320  that collectively provide a large surface area for convective cooling. In use, energy storage member  272 ,  292  is positioned in thermal (e.g., abutting) contact with heat sink  316  whereby heat from energy storage member  272 ,  292  is transferred into heat sink  316  by conduction, and heat from heat sink  316  is lost by convection into the ambient air. 
     Alternatively or in addition to promoting convective heat loss, passive cooling element  316  may have a heat capacity sufficient to absorb the heat generated by one or several charges of energy storage member  272 ,  292  (e.g. at least 2 charge cycles, at least 3 charge cycles, or at least 4 charge cycles) and/or the rapid discharge of energy storage member  292 . For example, passive cooling element  316  may include a volume of material that after absorbing one or several charges of energy storage member  272 ,  292 , maintains the energy storage member  272 ,  292  below a target temperature. In the exemplary embodiment of  FIG. 19 , heat sink  316  may be composed of a sufficient volume of metal (e.g. aluminum) to achieve this effect. In  FIG. 20 , thermal cooling unit  308  is shown including a housing  324  that holds energy storage member  272 ,  292  in a volume of liquid  328  (e.g. mineral oil, or other coolant). The liquid  328  may have sufficient volume to maintain the temperature of energy storage member  272 ,  292  within safe limits after several charging cycles. 
     After passive cooling element  316  has absorbed the heat generated by a number of charge cycles, and the user has finished their cleaning session, passive cooling element  316  will passively cool back to room temperature while surface cleaning apparatus  100  rests in storage (e.g. overnight). Once at room temperature, passive cooling element  316  will again be capable of absorbing heat generated by a number of charge cycles. 
     In an alternate embodiment, it will be appreciated that passive cooling element  319  may also be provided with active cooling using any technique disclosed herein. 
     Method of Cleaning with a Capacitor-Powered Portable Surface Cleaning Unit 
     A surface cleaning apparatus operable in both upright and portable cleaning configurations, and having a portable surface cleaning unit that may be powered by a rapidly rechargeable energy storage member (e.g. a capacitor-powered portable surface cleaning unit) may be operated according to a new paradigm. Whereas conventional philosophy has been that a handvac should have a maximized runtime so that all surfaces requiring use of the handvac can be cleaned at in one continuous operation without recharging the handvac, embodiments disclosed herein promote a cleaning session that includes several iterations of: (i) cleaning in an upright configuration while the portable surface cleaning unit charges, and (ii) cleaning in a portable cleaning configuration with the portable surface cleaning unit powered by its, e.g., capacitor. This method of alternating between upright and portable cleaning configurations, lowers the required energy storage capacity of the portable surface cleaning unit. This means the portable surface cleaning unit can have a smaller, lighter, and possibly less expensive energy storage member. In order to achieve several full charges of the portable surface cleaning unit within a single uninterrupted cleaning session, the energy storage member preferably uses a capacitor which enables very fast charging. 
     It will be appreciated that, in other embodiments, a battery or battery pack that is rapidly chargeable may also be used. For example, if the handvac may have a short run time (e.g., 3, 5, 7 or 10 minutes), then the handvac may have only one or a few (e.g.,  2  or  3 ) batteries. In such a case, the amount of energy required to fully charge the batteries is reduced compared to traditional battery packs that may have 6-7 batteries. Accordingly less heat will be generated during rapid recharging and the handvac may accordingly include a thermal cooling unit  308  that does not add excessive weight to the handvac. 
     The features in this section may be used by itself in any surface cleaning apparatus or in any combination or sub-combination with any other feature or features described herein. 
     Referring to  FIGS. 2 and 21 , a method  400  of cleaning a surface using surface cleaning apparatus  100  (e.g. a stickvac) is shown. 
     At  404 , portable surface cleaning unit  108  (e.g. handvac  108 ) is removed from floor cleaning unit  104 . For example, portable cleaning unit  108  may be disconnected from rigid conduit upper end  264  to reconfigure surface cleaning apparatus  100  into a portable cleaning configuration. 
     At  408 , portable surface cleaning unit  108  is used to clean surface(s) in the portable cleaning configuration. For example, portable surface cleaning unit  108  may be used to clean surfaces unsuitable for surface cleaning head  112 , such as seat cushions, counters, drapes, and ceilings. Portable surface cleaning unit  108  may be powered by a capacitor  276  ( FIG. 4 ). 
     At  412 , portable surface cleaning unit  108  is remounted to floor cleaning unit  104 . For example, portable cleaning unit  108  may be reconnected to rigid conduit upper end  264  to reconfigure surface cleaning apparatus  100  into an upright configuration. 
     At  416 , surface cleaning apparatus  100  is used in the upright configuration to clean a floor, simultaneously while portable surface cleaning unit  108  recharges. Capacitor  276  ( FIG. 4 ) may be recharged by an internal or external charger  280  with power from an external power supply and/or another energy storage member  292 , as described above in connection with  FIGS. 9-17 . Cleaning and recharging in step  416  may continue for a period sufficient to substantially or fully recharge capacitor  276  ( FIG. 4 ). For example, step  416  may continue for up to 15 minutes or for up to 10 minutes or for up to 5 minutes or for up to 3 minutes, during which capacitor  276  ( FIG. 4 ) may be substantially recharged or fully recharged. 
     As shown, after step  416 , method  400  may return to step  404  and continue until the cleaning session is completed. Accordingly, a user may remove the portable cleaning unit  108  and use it in the portable cleaning unit configuration until portable cleaning unit  108  requires recharging or until the cleaning job is finished. 
     While the above description provides examples of the embodiments, it will be appreciated that some features and/or functions of the described embodiments are susceptible to modification without departing from the spirit and principles of operation of the described embodiments. Accordingly, what has been described above has been intended to be illustrative of the invention and non-limiting and it will be understood by persons skilled in the art that other variants and modifications may be made without departing from the scope of the invention as defined in the claims appended hereto. The scope of the claims should not be limited by the preferred embodiments and examples, but should be given the broadest interpretation consistent with the description as a whole.