Patent Publication Number: US-2023142408-A1

Title: Electric apparatus

Description:
FIELD 
     The present disclosure relates to an electrical apparatus. 
     BACKGROUND 
     Known electrical apparatuses are powered by batteries. WO 2019/017249 describes an illuminator powered by batteries for power tools. 
     BRIEF SUMMARY 
     Technical Problem 
     Electrical apparatuses powered by batteries are often used at work sites. Electrical apparatuses are to be miniaturized for placement that does not obstruct operations or for easy portability. 
     One or more aspects of the present disclosure are directed to an electrical apparatus that is powered by batteries and miniaturized. 
     Solution to Problem 
     A first aspect of the present disclosure provides an electrical apparatus to which a first battery or a second battery is detachably attachable, the apparatus including:
         a body including an output portion;   a battery holder having a first surface and a second surface;   a first battery mount on the first surface, the first battery mount including a first guide to allow the first battery to slide on the first battery mount while being guided along the first guide for attachment to and detachment from the first battery mount; and   a second battery mount on the second surface, the second battery mount including a second guide to allow the second battery to slide on the second battery mount while being guided along the second guide for attachment to and detachment from the second battery mount.       

     A second aspect of the present disclosure provides an electrical apparatus to which a first battery or a second battery is detachably attachable, the apparatus including:
         a body including an output portion;   a cover configured to define, with the body, a battery compartment;   a first battery mount to which the first battery is attachable, the first battery mount being located on a first surface of the body facing the battery compartment; and   a second battery mount to which the second battery is attachable, the second battery mount being located on at least one second surface of the cover facing the battery compartment.       

     Advantageous Effects 
     The electrical apparatus according to the above aspects of the present disclosure is powered by batteries and miniaturized. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a perspective view of an electrical apparatus according to a first embodiment as viewed from the left front. 
         FIG.  2    is a perspective view of the electrical apparatus according to the first embodiment as viewed from the right rear. 
         FIG.  3    is a perspective view of the electrical apparatus according to the first embodiment as viewed from the right rear. 
         FIG.  4    is a perspective view of the electrical apparatus according to the first embodiment as viewed from the left rear. 
         FIG.  5    is a perspective view of the electrical apparatus according to the first embodiment as viewed from the left rear. 
         FIG.  6    is a cross-sectional side view of the electrical apparatus according to the first embodiment. 
         FIG.  7    is a cross-sectional side view of the electrical apparatus according to the first embodiment. 
         FIG.  8 A  is a perspective view of a first battery in the first embodiment, and  FIG.  8 B  is a perspective view of a second battery in the first embodiment. 
         FIG.  9    is a rear view of the first battery attached to a first battery mount in the first embodiment. 
         FIG.  10    is a rear view of the first battery mount in the first embodiment. 
         FIG.  11    is a top view of the second battery attached to a second battery mount in the first embodiment. 
         FIG.  12    is a top view of the second battery mount in the first embodiment. 
         FIG.  13    is a view of the second battery in the first embodiment being attached. 
         FIG.  14    is a left view of the electrical apparatus according to the first embodiment partially being cut away. 
         FIG.  15    is a diagram of a switch in the first embodiment. 
         FIG.  16    is a diagram of a switch in a first modification of the first embodiment. 
         FIG.  17    is a diagram of a switch in a second modification of the first embodiment. 
         FIG.  18    is a schematic diagram of an electrical apparatus according to a second embodiment. 
         FIG.  19    is a schematic diagram of the electrical apparatus according to the second embodiment. 
         FIG.  20    is a schematic diagram of an electrical apparatus according to a third embodiment. 
         FIG.  21    is a schematic diagram of an electrical apparatus according to a fourth embodiment. 
         FIG.  22    is a schematic diagram of an electrical apparatus according to a fifth embodiment. 
         FIG.  23    is a schematic diagram of an electrical apparatus according to a sixth embodiment. 
         FIG.  24    is a perspective view of an electrical apparatus according to a seventh embodiment as viewed from the left front. 
         FIG.  25    is a perspective view of the electrical apparatus according to the seventh embodiment as viewed from the right rear. 
         FIG.  26    is a perspective view of the electrical apparatus according to the seventh embodiment as viewed from the right rear with its cover being open. 
         FIG.  27    is a rear view of the electrical apparatus according to the seventh embodiment with its cover removed. 
         FIG.  28    is a perspective view of the electrical apparatus according to the seventh embodiment as viewed from the left rear with its cover removed. 
         FIG.  29    is a perspective view of the electrical apparatus according to the seventh embodiment as viewed from the right rear with its cover removed. 
         FIG.  30    is a rear view of the electrical apparatus according to the seventh embodiment with its cover removed. 
         FIG.  31    is a rear view of the electrical apparatus according to the seventh embodiment with its cover removed. 
         FIG.  32    is a rear view of the electrical apparatus according to the seventh embodiment with its cover removed. 
         FIG.  33    is a rear view of the electrical apparatus according to the seventh embodiment with its cover removed. 
         FIG.  34    is a perspective view of the electrical apparatus with a shade according to the seventh embodiment as viewed from the left front. 
         FIG.  35    is an exploded perspective view of the electrical apparatus with the shade according to the seventh embodiment as viewed from the left front. 
         FIG.  36    is a perspective view of an electrical apparatus with a shade according to a modification of the seventh embodiment as viewed from the left front. 
         FIG.  37    is an exploded perspective view of the electrical apparatus with the shade according to the modification of the seventh embodiment as viewed from the left front. 
         FIG.  38    is a view of the shade in the modification of the seventh embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Although one or more embodiments of the present disclosure will now be described with reference to the drawings, the present disclosure is not limited to the embodiments. The components in the embodiments described below may be combined as appropriate. One or more components may be eliminated. 
     In the embodiments, the positional relationships between the components will be described using the directional terms such as front and rear (or frontward and rearward), right and left (or lateral), and up and down (or vertical). The terms indicate relative positions or directions with respect to the center of an electrical apparatus. 
     First Embodiment 
     Overview of Electrical Apparatus 
       FIG.  1    is a perspective view of an electrical apparatus  1  according to an embodiment as viewed from the left front.  FIG.  2    is a perspective view of the electrical apparatus  1  as viewed from the right rear. 
     The electrical apparatus  1  according to the embodiment is an illuminator. 
     As shown in  FIGS.  1  and  2   , the electrical apparatus  1  includes a body  2 , a cover  3 , a leg  4 , and a handle  5 . The cover  3  is joined to the body  2 . The leg  4  is joined to the body  2 . The handle  5  is joined to the body  2 . 
     The body  2  includes a housing  6  and a light emitter  7 . 
     The housing  6  includes a front housing  8  and a rear housing  9 . The front housing  8  is located frontward from the rear housing  9 . 
     The front housing  8  is a rectangular frame. The front housing  8  surrounds the light emitter  7 . The front housing  8  accommodates at least a part of the light emitter  7 . The front housing  8  has vents  10  in its upper, lower, left, and right portions. The vents  10  connect the inside and the outside of the housing  6 . 
     The rear housing  9  is connected to the rear end of the front housing  8 . The rear housing  9  includes an upper plate  9 A, a lower plate  9 B, a left plate  9 C, a right plate  9 D, and a rear plate  9 E. Each of the lower plate  9 B, the left plate  9 C, and the right plate  9 D has vents  11 . The vents  11  connect the inside and the outside of the housing  6 . 
     The light emitter  7  emits light frontward. The light emitter  7  is an output portion of the electrical apparatus  1  for outputting light. The light emitter  7  is located on a front portion of the body  2 . As shown in  FIGS.  6  and  7   , the light emitter  7  includes multiple light sources  7 S and a lens  7 L. The lens  7 L is located in front of the light sources  7 S. The light sources  7 S include, for example, light-emitting diodes (LEDs). The lens  7 L is a light-transmissive plate. 
     The cover  3  defines, with the body  2 , a battery compartment  20 . The cover  3  is connected to a rear portion of the body  2 . The body  2  in the embodiment has its rear portion being a rear portion of the rear housing  9 . 
     The rear housing  9  has rear surfaces  71 . The cover  3  has a rear surface  72 . The rear surfaces  71  are located on the left and right of the rear surface  72 . 
     Each rear surface  71  of the rear housing  9  includes an upper area  71 A, an intermediate area  71 B, and a lower area  71 C. Each intermediate area  71 B is between the corresponding upper area  71 A and the corresponding lower area  71 C. The upper areas  71 A slope upward and frontward. The lower areas  71 C slope downward and frontward. One of the rear surfaces  71  includes, on its intermediate area  71 B, an alternating current (AC) terminal  73  connectable to a utility power supply. The AC terminal  73  is covered with a cover  74 . 
     The rear surface  72  of the cover  3  includes an upper area  72 A, an intermediate area  72 B, and a lower area  72 C. The intermediate area  72 B is between the upper area  72 A and the lower area  72 C. The upper area  72 A slopes upward and frontward. The lower area  72 C slopes downward and frontward. 
     The leg  4  is joined to the rear housing  9  with joining units  14 . The leg  4  includes a left leg  4 A and a right leg  4 B. The left leg  4 A is joined to the left plate  9 C of the rear housing  9 . The right leg  4 B is joined to the right plate  9 D of the rear housing  9 . The leg  4  is pivotable about a rotation axis BX of the joining units  14 . The rotation axis BX extends in the lateral direction. The left leg  4 A and the right leg  4 B are joined together with two rods  4 C and one plate  4 D. The left leg  4 A and the right leg  4 B are pivotable together. 
     The leg  4  has lower surfaces  4 E located below the lower surface of the body  2 . The body  2  has its lower surface including the lower surface of the rear housing  9 . When the electrical apparatus  1  is placed on a placement surface FL, the leg  4  has the lower surfaces  4 E in contact with the placement surface FL. 
     The handle  5  is grippable by a user of the electrical apparatus  1 . The handle  5  includes a pair of arms  5 A and a handle portion  5 B. The handle portion  5 B connects the pair of arms  5 A. The handle  5  is joined to the rear housing  9  with hinges  15 . The handle  5  is pivotable about a hinge axis CX of the hinges  15 . The hinge axis CX extends in the lateral direction. 
     The upper plate  9 A includes a protrusion  9 F and a peripheral portion  9 G. The protrusion  9 F protrudes upward. The peripheral portion  9 G surrounds the protrusion  9 F. The peripheral portion  9 G has the upper surface located below the upper surface of the protrusion  9 F. The upper plate  9 A includes a step between the upper surface of the protrusion  9 F and the peripheral portion  9 G. The handle  5  is joined to side surfaces of the protrusion  9 F with the hinges  15 . 
     One of the arms  5 A is joined to the left side surface of the protrusion  9 F with one of the hinges  15 . The other arm  5 A is joined to the right side surface of the protrusion  9 F with another hinge  15 . The handle  5  is joined to the body  2  with the hinges  15  to have its handle portion  5 B pivotable about the hinge axis CX. 
     The handle  5  is pivotable to a retracted position and to an in-use position. At the retracted position, the arms  5 A and the handle portion  5 B face the upper surface of the peripheral portion  9 G. The handle  5  at the retracted position is at least partially located above the cover  3 . At the in-use position, the arms  5 A and the handle portion  5 B are apart from the upper surface of the peripheral portion  9 G, and the handle portion  5 B is located above the hinges  15 . The user of the electrical apparatus  1  can move the handle  5  to the in-use position and carry the electrical apparatus  1  while gripping the handle portion  5 B. 
     The electrical apparatus  1  includes a power button  17 . The power button  17  is located on a front portion of the upper plate  9 A of the rear housing  9 . The power button  17  is operable to activate the electrical apparatus  1 . 
     Battery Holder and Battery Compartment 
       FIG.  3    is a perspective view of the electrical apparatus  1  as viewed from the right rear.  FIG.  4    is a perspective view of the electrical apparatus  1  as viewed from the left rear.  FIG.  5    is a perspective view of the electrical apparatus  1  as viewed from the left rear.  FIG.  6    is a cross-sectional side view of the electrical apparatus  1 .  FIG.  7    is a cross-sectional side view of the electrical apparatus  1 . 
     The electrical apparatus  1  includes a battery holder  19 . The battery holder  19  has a support surface  31  (first surface) and a support surface  41  (second surface). The support surface  31  (first surface) receives a battery. The support surface  41  (second surface) receives a battery. The support surface  31  (first surface) and the support surface  41  (second surface) face in different directions. In the embodiment, the support surface  31  is located on the body  2 . The support surface  41  is located on the cover  3 . 
     The cover  3  defines, with the body  2 , the battery compartment  20 . The cover  3  is pivotably joined to the body  2 .  FIGS.  1  and  2    each show the cover  3  pivoted to close the battery compartment  20 .  FIGS.  3  to  7    each show the cover  3  pivoted to open the battery compartment  20 . 
     The battery compartment  20  is closed with the cover  3  pivoted to connect to the rear portion of the body  2 . The battery compartment  20  is open with the cover  3  pivoted to be apart from the rear portion of the body  2 . 
     The electrical apparatus  1  includes a hinge  12  joining the cover  3  to the body  2 . The hinge  12  joins the cover  3  to a lower rear portion of the rear housing  9 . The hinge  12  is located at the bottom of the cover  3  when the cover  3  is pivoted to close the battery compartment  20 . The cover  3  is pivotably joined to the lower rear portion of the rear housing  9  with the hinge  12 . The hinge  12  has its hinge axis AX extending in the lateral direction. The cover  3  is joined to the body  2  with the hinge  12  to have its upper end pivotable about the hinge axis AX. 
     The cover  3  pivoted to close the battery compartment  20  is herein referred to as the cover  3  being closed for convenience. The cover  3  pivoted to open the battery compartment  20  is herein referred to as the cover  3  being open for convenience. The battery compartment  20  is closed with the cover  3  being closed. The battery compartment  20  is open with the cover  3  being open. 
     In the embodiment, the cover  3  being closed may be the cover  3  having its upper portion connected to an upper rear portion of the body  2 . The cover  3  being closed has the rear surface  72  including the lower area  72 C sloping downward and frontward. The cover  3  being open may be the cover  3  having its upper portion apart from the upper rear portion of the body  2 . 
     As shown in  FIGS.  3  to  5   , the body  2  has a recess  30  in the rear portion. As described above, the rear portion of the body  2  is the rear portion of the rear housing  9 . The recess  30  is recessed frontward. The recess  30  is open at its upper end and forms an opening  35 . The cover  3  being closed is at least partially located inside the recess  30 . 
     The cover  3  includes an upper plate  3 A, a lower plate  3 B, a left plate  3 C, a right plate  3 D, and a rear plate  3 E. The left plate  3 C and the right plate  3 D are arranged in the lateral direction. The left plate  3 C and the right plate  3 D face each other. When the cover  3  is closed, the lower plate  3 B is connected to the left plate  3 C and the right plate  3 D at their lower ends. When the cover  3  is closed, the rear plate  3 E is connected to the left plate  3 C and the right plate  3 D at their rear ends. When the cover  3  is closed, the left plate  3 C and the right plate  3 D are located inside the recess  30 . The cover  3  has an opening  45 . When the cover  3  is closed, the opening  45  is defined by the upper plate  3 A, the lower plate  3 B, the left plate  3 C, and the right plate  3 D at their front ends. When the cover  3  is closed, the opening  45  is located at the front end of the cover  3 . 
     The cover  3  includes a support plate  3 F between the left plate  3 C and the right plate  3 D. The support plate  3 F has the upper end fastened to the rear plate  3 E. The support plate  3 F has the lower end fastened to the lower plate  3 B. The support plate  3 F has the left end fastened to the left plate  3 C. The support plate  3 F has the right end fastened to the right plate  3 D. 
     The recess  30  in the body  2  has an inner surface including the support surface  31 , a left inner surface  32 , and a right inner surface  33 . The left inner surface  32  is connected to the left end of the support surface  31 . The right inner surface  33  is connected to the right end of the support surface  31 . The support surface  31  is located frontward from the rear surfaces  71  of the rear housing  9 . The support surface  31  faces rearward. The left inner surface  32  faces rightward. The right inner surface  33  faces leftward. 
     The cover  3  has the inner surface including the support surface  41 , a left inner surface  42 , and a right inner surface  43 . The left inner surface  42  is connected to the left end of the support surface  41 . The right inner surface  43  is connected to the right end of the support surface  41 . The support surface  41  is located rearward from the support surface  31 . The support surface  41  is located on the support plate  3 F. When the cover  3  is closed, the support surface  41  faces upward and frontward. The left inner surface  42  is located on the left plate  3 C. The left inner surface  42  faces rightward. The right inner surface  43  is located on the right plate  3 D. The right inner surface  43  faces leftward. 
     When the cover  3  is closed, the battery compartment  20  is defined by the support surface  31 , the support surface  41 , the left inner surface  42 , and the right inner surface  43 . The support surface  31  faces the battery compartment  20 . The support surface  41  faces the battery compartment  20 . The left inner surface  42  faces the battery compartment  20 . The right inner surface  43  faces the battery compartment  20 . 
     When the cover  3  is open, the battery compartment  20  is partially defined by the support surface  31 , the left inner surface  32 , and the right inner surface  33 . The support surface  31  faces the battery compartment  20 . The left inner surface  32  faces the battery compartment  20 . The right inner surface  33  faces the battery compartment  20 . 
     When the cover  3  is open, the battery compartment  20  is partially defined by the support surface  41 , the left inner surface  42 , and the right inner surface  43 . The support surface  41  faces the battery compartment  20 . The left inner surface  42  faces the battery compartment  20 . The right inner surface  43  faces the battery compartment  20 . 
     The cover  3  includes a latch  13 . When the cover  3  is closed, the latch  13  is located at the top of the cover  3 . The latch  13  fastens the cover  3  connected to the body  2  to the rear housing  9 . In this state, the battery compartment  20  is closed. 
     The electrical apparatus  1  includes linkages  50  joining the cover  3  to the body  2 . The linkages  50  are located on the left and right portions of the cover  3 . Each linkage  50  includes a link  51 , a first joint  52 , and a second joint  54 . The first joint  52  joins an end of the link  51  to the body  2 . The link  51  has the end pivotably joined to the body  2 . The link  51  has a guide slot  53  receiving the second joint  54 . The second joint  54  is slidable along the guide slot  53 . The second joint  54  is received in the guide slot  53  in the link  51  and joined to the cover  3 . 
     In the linkage  50  on the left portion of the cover  3 , the first joint  52  joins the end of the link  51  to the left inner surface  32  of the recess  30 . The second joint  54  is received in the guide slot  53  and joined to the left surface of the left plate  3 C. 
     In the linkage  50  on the right portion of the cover  3 , the first joint  52  joins the end of the link  51  to the right inner surface  33  of the recess  30 . The second joint  54  is received in the guide slot  53  and joined to the right surface of the right plate  3 D. 
     The pivot range of the cover  3  is defined by the linkages  50 . The cover  3  is pivotable within the pivot range defined by the linkages  50 . The pivot range of the cover  3  is defined based on the length of each guide slot  53 . As shown in  FIGS.  1  and  2   , the cover  3  placed at a first end (closing end) of the pivot range is closed. The cover  3  placed at the first end of the pivot range closes the battery compartment  20 . As shown in  FIGS.  3  to  5   , the cover  3  is placed at a second end (opening end) of the pivot range and is thus open with each second joint  54  being placed at an end of the corresponding guide slot  53 . In this state, the battery compartment  20  is open. 
     Each linkage  50  includes a brake  55  between the link  51  and the second joint  54 . The brake  55  is, for example, a rubber ring located between the link  51  and the cover  3 . The brake  55  reduces the speed of the cover  3  changing from being closed to being open. The brake  55  allows the cover  3  to avoid opening suddenly. The brake  55  may be between the link  51  and the second joint  54 . 
     Each linkage  50  may include a damper that dampens the kinetic energy of the cover  3  changing from being closed to being open. The damper joins, for example, the cover  3  to the body  2 . To dampen the kinetic energy of the cover  3 , the damper may include an elastic body such as a spring or a rubber piece, or may be a viscous substance such as oil. The damper also allows the cover  3  to avoid opening suddenly. 
     As shown in  FIGS.  6  and  7   , the cover  3  placed at the second end of the pivot range is above the lower surface  4 E of the leg  4 . In other words, the cover  3  is out of contact with the placement surface FL when the lower surface  4 E of the leg  4  is in contact with the placement surface FL. 
     Battery and Battery Mount 
       FIG.  8 A  is a perspective view of a first battery  61  in the embodiment, and  FIG.  8 B  is a perspective view of a second battery  62  in the embodiment.  FIG.  9    is a rear view of the first battery  61  attached to a first battery mount  21 .  FIG.  10    is a rear view of the first battery mount  21 .  FIG.  11    is a top view of the second battery  62  attached to a second battery mount  22 .  FIG.  12    is a top view of the second battery mount  22 . 
     In  FIGS.  9  and  10   , the cover  3  and the handle  5  are not shown. In  FIGS.  11  and  12   , the handle  5  is not shown. 
     The electrical apparatus  1  includes the first battery mount  21  and the second battery mount  22 . The first battery mount  21  receives the first battery  61 . The second battery mount  22  receives the second battery  62 . 
     The first battery mount  21  is located on the support surface  31  (first surface) of the battery holder  19 . The second battery mount  22  is located on the support surface  41  (second surface) of the battery holder  19 . 
     The first battery mount  21  is located in the battery compartment  20 . The second battery mount  22  is located in the battery compartment  20 . The battery compartment  20  is defined by at least a part of the inner surface of the recess  30  in the body  2  and at least a part of the inner surface of the cover  3 . 
     The first battery mount  21  is located on the support surface  31  of the body  2  facing the battery compartment  20 . The second battery mount  22  is located on the support surface  41  of the cover  3  facing the battery compartment  20 . 
     The hinge  12  has its hinge axis AX extending in the lateral direction. The support surface  31  is parallel to the hinge axis AX of the hinge  12 . The support surface  41  is parallel to the hinge axis AX of the hinge  12 . 
     The first battery  61  and the second battery  62  are slidable. Each of the first battery  61  and the second battery  62  is a battery for power tools. 
     The first battery  61  and the second battery  62  supply power to the electrical apparatus  1 . The first battery  61  and the second battery  62  thus function as power supplies for the electrical apparatus  1 . The first battery  61  and the second battery  62  may be secondary batteries. The first battery  61  and the second battery  62  in the embodiment may be rechargeable lithium-ion batteries. 
     The first battery  61  is attached to the first battery mount  21  to supply power to the electrical apparatus  1 . The second battery  62  is attached to the second battery mount  22  to supply power to the electrical apparatus  1 . 
     As shown in  FIG.  8 A , the first battery  61  includes a housing  61 B with an attachment surface  61 A, a pair of slides  61 C, and a pair of power terminals  61 F. The housing  61 B has an internal space to accommodate a battery cell. The battery cell is a rechargeable lithium-ion battery. The slides  61 C extend in a predetermined sliding direction. The power terminals  61 F are between the pair of slides  61 C. One of the power terminals  61 F is a positive power terminal. The other power terminal  61 F is a negative power terminal. 
     As shown in  FIG.  8 B , the second battery  62  includes a housing  62 B with an attachment surface  62 A, a pair of slides  62 C, a protruding portion  62 D, a release button  62 E, and a pair of power terminals  62 F. The protruding portion  62 D is supported movably on the housing  62 B. The release button  62 E is operable to operate the protruding portion  62 D. The housing  62 B has an internal space to accommodate a battery cell. The battery cell is a rechargeable lithium-ion battery. The slides  62 C extend in a predetermined sliding direction. The protruding portion  62 D is supported movably by a spring. The protruding portion  62 D protrudes from the attachment surface  62 A under an elastic force from the spring. The power terminals  62 F are between the pair of slides  62 C. One of the power terminals  62 F is a positive power terminal. The other power terminal  62 F is a negative power terminal. 
     The first battery  61  and the second battery  62  are of different types. The electrical apparatus  1  may use, as its power supply, the first battery  61  and the second battery  62  of different types. 
     The first battery  61  and the second battery  62  differ in rated voltage (V). The first battery  61  has a higher rated voltage than the second battery  62 . The first battery  61  has a rated voltage of, for example, 36 V. The second battery  62  has a rated voltage of, for example, 10.8 V. The first battery  61  may have a rated voltage of 40 V. The second battery  62  may have a rated voltage of 18 V. 
     The first battery  61  and the second battery  62  differ in capacity (Ah). The first battery  61  has a higher capacity than the second battery  62 . 
     The first battery  61  and the second battery  62  differ in weight (g). The first battery  61  is heavier than the second battery  62 . 
     The first battery  61  and the second battery  62  differ in outer dimensions (mm). The first battery  61  has greater outer dimensions than the second battery  62 . 
     As shown in  FIG.  10   , the first battery mount  21  has a mount surface  21 A, first guides  21 B for guiding the first battery  61 , and power terminals  21 D. 
     The mount surface  21 A faces the attachment surface  61 A of the first battery  61 . 
     The first guides  21 B guide the first battery  61  in a predetermined guiding direction. The slides  61 C on the first battery  61  are guided along the first guides  21 B. Multiple first guides  21 B are arranged in the lateral direction parallel to the hinge axis AX. In the embodiment, two first guides  21 B are arranged in the lateral direction. The guiding direction of the first guides  21 B is orthogonal to the hinge axis AX of the hinge  12 . 
     The power terminals  21 D are connected to the power terminals  61 F on the first battery  61  to supply power from the first battery  61  to the electrical apparatus  1 . 
     The second battery mount  22  has a mount surface  22 A, second guides  22 B for guiding the second battery  62 , a locking slot  22 C, and power terminals  22 D. 
     The mount surface  22 A faces the attachment surface  62 A of the second battery  62 . 
     The second guides  22 B guide the second battery  62  in a predetermined guiding direction. The slides  62 C on the second battery  62  are guided along the second guides  22 B. Multiple second guides  22 B are arranged in the lateral direction parallel to the hinge axis AX. In the embodiment, two second guides  22 B are arranged in the lateral direction. The guiding direction of the second guides  22 B is orthogonal to the hinge axis AX of the hinge  12 . 
     The locking slot  22 C is located in the mount surface  22 A. The locking slot  22 C receives the protruding portion  62 D on the second battery  62 . This fastens the second battery  62  to the second battery mount  22 . In response to an operation on the release button  62 E, the second battery  62  is unlocked and released from the second battery mount  22 . 
     The power terminals  22 D are connected to the power terminals  62 F on the second battery  62  to supply power from the second battery  62  to the electrical apparatus  1 . 
     Attaching and Detaching Batteries 
     The first battery  61  is slidable on the first battery mount  21  while being guided along the first guides  21 B for attachment to and detachment from the first battery mount  21 . With the cover  3  being open, the first battery  61  is attachable to and detachable from the first battery mount  21 . 
     In the embodiment, the guiding direction of the first guides  21 B is the vertical direction. The first battery  61  is slidable in the vertical direction for attachment to and detachment from the first battery mount  21 . 
     Each first guide  21 B has a first end  23  and a second end  24 . The second ends  24  are nearer the hinge  12  than the first ends  23 . The first ends  23  are located upward from the second ends  24 . 
     To attach the first battery  61  to the first battery mount  21 , the user of the electrical apparatus  1  slides the first battery  61  downward along the first battery mount  21  after placing the slides  61 C in contact with the first ends  23  of the first guides  21 B. The first battery  61  slides from the first ends  23  toward the second ends  24 . The first battery  61  moves downward while being guided along the first guides  21 B. The first battery  61  is thus attached to the first battery mount  21 . 
     In this manner, the first battery  61  is slidable on the first battery mount  21  while being guided along the first guides  21 B toward the second ends  24  for attachment to the first battery mount  21 . 
     To detach the first battery  61  from the first battery mount  21 , the first battery  61  is slid upward. 
       FIG.  13    is a view of the second battery  62  being attached.  FIG.  13    is a left view of the electrical apparatus  1  partially being cut away. The second battery  62  is slidable on the second battery mount  22  while being guided along the second guides  22 B for attachment to and detachment from the second battery mount  22 . With the cover  3  being open, the second battery  62  is attachable to and detachable from the second battery mount  22 . 
     In the embodiment, the second battery  62  is attachable to and detachable from the second battery mount  22  when the cover  3  is at the second end of the pivot range. The guiding direction of the second guides  22 B is diagonal to the placement surface FL on which the leg  4  is placed. The second battery  62  is slidable in the diagonal direction for attachment to and detachment from the second battery mount  22 . 
     Each second guide  22 B has a third end  25  and a fourth end  26 . The fourth ends  26  are nearer the hinge  12  than the third ends  25 . The third ends  25  are located rearward from the fourth ends  26  when the cover  3  is at the second end of the pivot range. The third ends  25  are at a lower position than the fourth ends  26 . In other words, the third ends  25  are located below the fourth ends  26 . 
     To attach the second battery  62  to the second battery mount  22 , the user of the electrical apparatus  1  slides the second battery downward and rearward along the second battery mount  22  after placing the slides  62 C in contact with the fourth ends  26  of the second guides  22 B. The second battery  62  slides from the fourth ends  26  toward the third ends  25 . The second battery  62  moves downward and rearward while being guided along the second guides  22 B. With the protruding portion  62 D received in the locking slot  22 C in the second battery mount  22 , the second battery  62  is fastened to the second battery mount  22 . The second battery  62  is thus attached to the second battery mount  22 . 
     In this manner, the second battery  62  is slidable on the second battery mount  22  while being guided along the second guides  22 B toward the third ends  25  for attachment to the second battery mount  22 . 
     To detach the second battery  62  from the second battery mount  22 , the user of the electrical apparatus  1  operates the release button  62 E. The protruding portion  62 D is thus removed from the locking slot  22 C. This unlocks the second battery  62  to be released from the second battery mount  22 . The second battery  62  is then slid upward and frontward and detached from the second battery mount  22 . 
       FIG.  14    is a left view of the electrical apparatus  1  partially being cut away. In  FIG.  14   , the cover  3  is open. The first battery  61  is attached to the first battery mount  21 , and the second battery  62  is attached to the second battery mount  22 . In this state, the first battery mount  21  and the second battery mount  22  are positioned relative to each other in accordance with the profiles and dimensions of the first battery  61  and the second battery  62  to cause the cover  3  to avoid being placed at the first end of the pivot range. 
     In other words, in a two-battery attached state in which the first battery  61  is attached to the first battery mount  21  and the second battery  62  is attached to the second battery mount  22 , the user of the electrical apparatus  1  cannot close the cover  3  with the first battery  61  and the second battery  62  blocking each other. 
     Switch 
       FIG.  15    is a diagram of a switch  80  in the embodiment. The electrical apparatus  1  according to the embodiment includes the switch  80  that is operated when the cover  3  is closed. The switch  80  is located, for example, on a portion of the support surface  31  adjacent to the first battery mount  21 . The switch  80  may be, for example, a pushbutton switch. The switch  80  remains unoperated when the cover  3  is open. The switch  80  is pressed by at least a partof the cover  3  when the cover  3  is closed. The switch  80  may not be a pushbutton switch. The switch  80  may be any switch that remains unoperated when the cover  3  is open and that is operated when the cover  3  is closed. 
     The switch  80  is operable to cause the light emitter  7  to be disabled in response to the cover  3  being open and to cause the light emitter  7  to be enabled in response to the cover  3  being closed. With the light emitter  7  being disabled, the electrical apparatus  1  cannot be activated. With the light emitter  7  being enabled, the electrical apparatus  1  can be activated. In the embodiment, when the cover  3  is open and the switch  80  remains unoperated, an operation on the power button  17  does not activate the electrical apparatus  1  and does not cause the light emitter  7  to operate. When the cover  3  is closed and the switch  80  is operated, an operation on the power button  17  activates the electrical apparatus  1  and causes the light emitter  7  to operate. 
     As described above with reference to  FIG.  14   , for example, the user of the electrical apparatus  1  cannot close the cover  3  in the two-battery attached state. Thus, in the two-battery attached state, an operation on the power button  17  does not activate the electrical apparatus  1 . 
     In contrast, the user of the electrical apparatus  1  can close the cover  3  in a single-battery attached state in which the first battery  61  is attached to the first battery mount  21  and the second battery  62  is unattached to the second battery mount  22  or in which the second battery  62  is attached to the second battery mount  22  and the first battery  61  is unattached to the first battery mount  21 . With the cover  3  being closed in the single-battery attached state, an operation on the power button  17  activates the electrical apparatus  1 . 
     Activating the electrical apparatus  1  in the two-battery attached state may cause a current to flow from the first battery  61  to the second battery  62  or from the second battery  62  to the first battery  61 . In the embodiment, the cover  3  cannot be closed in the two-battery attached state, and thus an operation on the power button  17  does not activate the electrical apparatus  1 . This reduces the likelihood of the flow of current described above. 
     As shown in  FIG.  15   , the electrical apparatus  1  includes the AC terminal  73 , the first battery mount  21 , and the second battery mount  22 . The electrical apparatus  1  also includes an AC-DC converter  81  connected to the AC terminal  73 , a diode  82 , and a diode  83 . The diode  82  is connected to the first battery mount  21 . The diode  83  is connected to the second battery mount  22 . The AC-DC converter  81  is connected in parallel to each of the first battery mount  21  and the second battery mount  22 . The AC terminal  73  is connected to each of the first battery mount  21  and the second battery mount  22  at a connection point  84 . 
     The electrical apparatus  1  also includes the switch  80 , a first switching element  85 , a second switching element  86 , a third switching element  87 , a power switch  88 , a regulator  89 , a controller  90 , and a constant current circuit  91 . 
     In  FIG.  15   , various current-limiting resistors are not shown. 
     The switch  80  is an on-off switch. As described above, the switch  80  remains unoperated when the cover  3  is open and is operated when the cover  3  is closed. The switch  80  is off when the cover  3  is open, and is on when the cover  3  is closed. 
     Each of the first switching element  85 , the second switching element  86 , and the third switching element  87  is a transistor. 
     The first switching element  85  is between the connection point  84  and the light emitter  7 . A direct current voltage is applied to the connection point  84  from one of the AC-DC converter  81 , the first battery mount  21 , or the second battery mount  22 . In response to the first switching element  85  being on, the voltage at the connection point  84  is applied to the controller  90  and the light emitter  7 . In response to the first switching element  85  being off, the voltage at the connection point  84  is not applied to the controller  90  or the light emitter  7 . 
     The second switching element  86  is connected to the first switching element  85 . The second switching element  86  switches the first switching element  85  to be on or off. In response to the second switching element  86  being on, the first switching element  85  is on. 
     The power switch  88  is an on-off switch. The power switch  88  is between the switch  80  and the second switching element  86 . The power switch  88  is off when the power button  17  is unoperated, and is on when the power button  17  is operated. 
     In response to the switch  80  being on and the power switch  88  being on, the voltage at the connection point  84  is applied to the base of the second switching element  86 . This causes the second switching element  86  to be on and causes the first switching element  85  to be on. This causes the voltage at the connection point  84  to be applied to the regulator  89 , which then outputs a predetermined voltage (e.g., 5 V). This causes a voltage to be applied to the controller  90  including a microcomputer. In response to the voltage applied, the controller  90  is activated. In the embodiment, the electrical apparatus  1  being activated refers to the controller  90  being activated. 
     In response to the second switching element  86  being on and the first switching element  85  being on, the light emitter  7  receives a current through the constant current circuit  91 . This causes the light emitter  7  to operate and emit light. The controller  90  can adjust the current to be supplied to the light emitter  7  as appropriate by transmitting an analog signal to the constant current circuit  91 . This allows the light emitter  7  to have brightness adjusted as appropriate. 
     The second switching element  86  has a base electrode that is set to either a high level or a low level based on a control signal output from the controller  90 . The second switching element  86  remains on when its base electrode is at the high level. 
     In response to the voltage at the connection point  84  being applied to the controller  90 , the controller  90  is activated and outputs the control signal to the base electrode of the second switching element  86 . This causes the second switching element  86  to have its base electrode set to the high level and thus to remain on. In response to the switch  80  being on and the power switch  88  being on, the controller  90  continues outputting the control signal to the base electrode of the second switching element  86 . This causes the first switching element  85  to remain on and causes the light emitter  7  to continue emitting light. The second switching element  86  with its base electrode set to the high level remains on after the power button  17  is released and the power switch  88  is turned off. 
     In response to the switch  80  being off, the second switching element  86  has its base electrode set to the low level and is thus off. The second switching element  86  remains off after the power button  17  is operated and the power switch  88  is turned on. In this state, the first switching element  85  is also off. The voltage at the connection point  84  is not applied to the controller  90  or the light emitter  7 . 
     First Modification of Switch 
       FIG.  16    is a diagram of a switch  80  in a first modification of the embodiment. As shown in  FIG.  16   , the electrical apparatus  1  may include an open-cover detection circuit for detecting the cover  3  changed from being closed to being open. For example, the open-cover detection circuit stops the operation of the light emitter  7  upon detecting the cover  3  changed from being closed to being open while the light emitter  7  is in operation. 
     The electrical apparatus  1  includes a switch  80 B. The switch  80 B is off when the cover  3  is open, and is on when the cover  3  is closed. The switch  80 B and the above switch  80  may be a common switch, or may be separate switches. The switch  80 B is connected to a pulse generation circuit  92  with a connection point  94  in between. In response to the switch  80 B being on, the connection point  94  is connected to the ground. The connection point  94  has its potential increased in response to the cover  3  changing from being closed to being open and the switch  80 B changing from being on to being off. This causes the pulse generation circuit  92  to generate a pulse, which then causes a signal generation circuit  93  to generate a control signal. The control signal has a duration longer than the pulse width. The signal generation circuit  93  outputs the control signal to the base electrode of the third switching element  87  described with reference to  FIG.  15   . 
     The third switching element  87  has its base electrode that is set to either a high level or a low level based on the control signal output from the signal generation circuit  93 . The third switching element  87  remains on when its base electrode is at the high level. 
     For example, the third switching element  87  may be turned on in response to the cover  3  changing from being closed to being open while light is emitted from the light emitter  7 . This causes the second switching element  86  to have its base electrode connected to the ground and thus switch to the low level. This causes the second switching element  86  to be off and causes the first switching element  85  to be off. This stops the application of the voltage at the connection point  84  to the controller  90  and the light emitter  7 . 
     The open-cover detection circuit thus stops the operation of the light emitter  7  forcibly in response to the user of the electrical apparatus  1  accidentally opening the cover  3  while the light emitter  7  is in operation. 
     Second Modification of Switch 
       FIG.  17    is a diagram of a switch  80  in a second modification of the embodiment. As shown in  FIG.  17   , the electrical apparatus  1  may include a closed-cover detection circuit for detecting the cover  3  changed from being open to being closed. Upon detecting the cover  3  changed from being open to being closed, the closed-cover detection circuit causes the light emitter  7  to operate when the power button  17  remains unoperated. 
     As shown in  FIG.  17   , a switch  80 B is connected to a pulse generation circuit  92  with a connection point  94  in between. In response to the switch  80 B being off, the connection point  94  is connected to the ground. The connection point  94  has its potential increased in response to the cover  3  changing from being open to being closed and the switch  80 B changing from being off to being on. This causes the pulse generation circuit  92  to generate a pulse, which then causes a signal generation circuit  93  to generate a control signal. The control signal has a duration longer than the pulse width. The signal generation circuit  93  outputs the control signal to the base electrode of the second switching element  86  described with reference to  FIG.  15   . 
     The control signal output from the signal generation circuit  93  causes the second switching element  86  to have its base electrode set to the high level. This causes the second switching element  86  to be on and causes the first switching element  85  to be on. This starts the application of the voltage at the connection point  84  to the controller  90  and the light emitter  7 . The light emitter  7  thus starts operating. 
     The closed-cover detection circuit can thus start the operation of the light emitter  7  automatically in response to the user of the electrical apparatus  1  simply closing the cover  3 . 
     As described above, the electrical apparatus  1  according to the embodiment includes the battery holder  19  having the support surface  31  (first surface) and the support surface  41  (second surface). The support surface  31  is located on the body  2 . The support surface  41  is located on the cover  3 . The first battery mount  21  is located on the support surface  31  of the body  2 . The second battery mount  22  is located on the support surface  41  of the cover  3 . The electrical apparatus  1  with this structure can be miniaturized. The electrical apparatus  1  with this structure can be miniaturized as compared with, for example, an electrical apparatus including two battery mounts arranged in parallel on a single surface. The electrical apparatus  1  powered by a battery (the first battery  61  or the second battery  62 ) is often used at work sites such as construction sites. The electrical apparatus  1  with the smaller outer dimensions can be placed in a manner that does not obstruct operations or can be portable easily. 
     The first battery mount  21  includes the first guides  21 B. The second battery mount  22  includes the second guides  22 B. The first battery  61  is slidable on the first battery mount  21  while being guided along the first guides  21 B for attachment to and detachment from the first battery mount  21 . The second battery  62  is slidable on the second battery mount  22  while being guided along the second guides  22 B for attachment to and detachment from the second battery mount  22 . Being slidable, the first battery  61  can be easily attached to and detached from the first battery mount  21  by the user of the electrical apparatus  1 . Being slidable, the second battery  62  can be easily attached to and detached from the second battery mount  22  by the user of the electrical apparatus  1 . 
     The cover  3  is joined to the body  2  with the hinge  12 . The guiding direction of the first guides  21 B and the guiding direction of the second guides  22 B are each orthogonal to the hinge axis AX of the hinge  12 . The user of the electrical apparatus  1  can thus smoothly attach and detach the first battery  61  to and from the first battery mount  21  and smoothly attach and detach the second battery  62  to and from the second battery mount  22  with the cover  3  pivoted to open the battery compartment  20 . 
     The multiple first guides  21 B are arranged in a direction parallel to the hinge axis AX of the hinge  12 . In the embodiment, the hinge  12  has the hinge axis AX extending in the lateral direction. The two first guides  21 B are arranged in the lateral direction. The user of the electrical apparatus  1  can thus smoothly attach and detach the first battery  61  to and from the first battery mount  21  with the cover  3  pivoted to open the battery compartment  20 . 
     The multiple second guides  22 B are arranged in a direction parallel to the hinge axis AX of the hinge  12 . In the embodiment, the hinge  12  has the hinge axis AX extending in the lateral direction. The two second guides  22 B are arranged in the lateral direction. The user of the electrical apparatus  1  can thus smoothly attach and detach the second battery  62  to and from the second battery mount  22  with the cover  3  pivoted to open the battery compartment  20 . 
     The support surface  41  on which the second battery mount  22  is located in parallel to the hinge axis AX. The user of the electrical apparatus  1  can thus smoothly attach and detach the second battery  62  to and from the second battery mount  22  with the cover  3  pivoted to open the battery compartment  20 . 
     Each first guide  21 B has the first end  23  and the second end  24  nearer the hinge  12  than the first end  23 . The user of the electrical apparatus  1  can thus smoothly attach the first battery  61  to the first battery mount  21  by sliding the first battery  61  from the first ends  23  toward the second ends  24 . 
     In the first guides  21 B, the first ends  23  are at a higher position than the second ends  24 . The user of the electrical apparatus  1  can thus smoothly attach the first battery  61  to the first battery mount  21  by sliding the first battery  61  downward along the first battery mount  21 . 
     The second guides  22 B have the third ends  25  and the fourth ends  26  nearer the hinge  12  than the third ends  25 . The user of the electrical apparatus  1  can thus smoothly attach the second battery  62  to the second battery mount  22  by sliding the second battery  62  from the fourth ends  26  toward the third ends  25 . 
     The cover  3  is pivotable within a predetermined pivot range. The cover  3  placed at the first end of the pivot range is closed. In this state, the battery compartment  20  is closed. The third ends  25  are at a lower position than the fourth ends  26  when the cover  3  is at the second end of the pivot range. The user of the electrical apparatus  1  can thus smoothly attach the second battery  62  to the second battery mount  22  by sliding the second battery  62  diagonally downward along the second battery mount  22 . 
     The cover  3  placed at the second end of the pivot range is above the lower surface  4 E of the leg  4 . The cover  3  is thus out of contact with the placement surface FL when placed at the second end of the pivot range. 
     In the two-battery attached state in which the first battery  61  is attached to the first battery mount  21  and the second battery  62  is attached to the second battery mount  22 , the first battery mount  21  and the second battery mount  22  are positioned relative to each other in accordance with the profiles and dimensions of the first battery  61  and the second battery  62  to cause the cover  3  to avoid being placed at the first end of the pivot range. Activating the electrical apparatus  1  in the two-battery attached state may cause a current to flow from the first battery  61  to the second battery  62  or from the second battery  62  to the first battery  61 . In the embodiment, the cover  3  cannot be closed in the two-battery attached state, and thus an operation on the power button  17  does not activate the electrical apparatus  1 . This reduces the likelihood of the flow of current described above. 
     The first battery  61  attachable to the first battery mount  21  on the body  2  is heavier than the second battery  62  attachable to the second battery mount  22  on the cover  3 . The electrical apparatus  1  thus has a balanced weight. 
     The pivot range of the cover  3  can be properly defined by the linkages  50  joining the cover  3  to the body  2 . 
     Each linkage  50  includes the link  51 , the first joint  52  joining an end of the link  51  to the body  2 , and the second joint  54  received in the guide slot  53  in the link  51  and joined to the cover  3 . The pivot range of the cover  3  can thus be defined properly based on the length of each guide slot  53 . 
     Each linkage  50  includes the brake  55  between the link  51  and the cover  3 . This allows the cover  3  to avoid opening suddenly. 
     The cover  3  being closed has the rear surface  72  including the lower area  72 C sloping downward and frontward. The electrical apparatus  1  with this structure can be miniaturized. In the embodiment, the rear housing  9  has the rear surfaces  71  including the lower areas  71 C also sloping downward and frontward. The electrical apparatus  1  with this structure can be miniaturized. 
     The switch  80  is operable to cause the light emitter  7  to be disabled in response to the cover  3  being open and to cause the light emitter  7  to be enabled in response to the cover  3  being closed. The electrical apparatus  1  is not activated with the cover  3  being open. The electrical apparatus  1  can be activated properly with the cover  3  being closed. 
     In the above embodiment, a third battery mount (not shown) may be located on the inner surface of the cover  3  facing the battery compartment  20  or on the inner surface of the body  2  facing the battery compartment  20 . 
     In the above embodiment, the first surface (the support surface  31 ) and the second surface (the support surface  41 ) of the battery holder  19  may be both located on the body  2 . For the first surface (the support surface  31 ) and the second surface (the support surface  41 ) of the battery holder  19  being both located on the body  2 , the cover  3  may be eliminated. 
     Second Embodiment 
     The same or corresponding components as those in the first embodiment are given the same reference numerals herein, and will be described briefly or will not be described. 
     In the first embodiment, the first battery mount  21  is located on the body  2 , and the second battery mount  22  is located on the cover  3 . More specifically, the support surface  31  including the first battery mount  21  is located on the body  2 , and the support surface  41  including the second battery mount  22  is located on the cover  3 . The first battery mount  21  and the second battery mount  22  may be both located on the body  2 . In other words, the first surface (the support surface  31 ) and the second surface (the support surface  41 ) of the battery holder ( 19 ) may be both located on the body  2 . 
       FIGS.  18  and  19    are schematic diagrams of an electrical apparatus  1 B according to a second embodiment. As shown in  FIG.  18   , the electrical apparatus  1 B includes a body  2  and a cover  3 . As in the first embodiment, the cover  3  is joined to the body  2  with a hinge  12 . The hinge  12  has its hinge axis AX extending in the lateral direction. 
     The body  2  and the cover  3  define a battery compartment  20 . As in the first embodiment, the body  2  has a recess  30 . The recess  30  has an inner surface including a support surface  31 , a left inner surface  32 , a right inner surface  33 , and a bottom surface  34 . The support surface  31 , the left inner surface  32 , the right inner surface  33 , and the bottom surface  34  face in different directions. As in the first embodiment, the support surface  31  faces rearward. The left inner surface  32  faces rightward. The right inner surface  33  faces leftward. The bottom surface  34  faces upward. The support surface  31 , the left inner surface  32 , the right inner surface  33 , and the bottom surface  34  face the battery compartment  20 . 
       FIG.  19    is a top view of the body  2  in  FIG.  18   . In the present embodiment, the first battery mount  21  and the second battery mount  22  are both located on the body  2 . The first battery mount  21  is located on the support surface  31  of the body  2 . The second battery mount  22  is located on the right inner surface  33  of the body  2 . 
     As in the first embodiment, the first battery mount  21  receives a first battery  61  that is slidable. The second battery mount  22  receives a second battery  62  that is slidable. In the present embodiment, the guiding direction of the first battery mount  21  is the vertical direction. The guiding direction of the second battery mount  22  is the vertical direction. The first battery mount  21  includes first guides  21 B with its guiding direction orthogonal to the hinge axis AX of the hinge  12 . The second battery mount  22  includes second guides  22 B with its guiding direction orthogonal to the hinge axis AX of the hinge  12 . 
     The first battery  61  is slidable on the first battery mount  21  in the vertical direction while being guided along the first guides  21 B for attachment to and detachment from the first battery mount  21 . The second battery  62  is slidable on the second battery mount  22  in the vertical direction while being guided along the second guides  22 B for attachment to and detachment from the second battery mount  22 . 
     As shown in  FIG.  19   , the first battery mount  21  and the second battery mount  22  are positioned relative to each other in accordance with the profiles and dimensions of the first battery  61  and the second battery  62  to cause the second battery  62  to be unattachable to the second battery mount  22  when the first battery  61  is attached to the first battery mount  21  and to cause the first battery  61  to be unattachable to the first battery mount  21  when the second battery  62  is attached to the second battery mount  22 . 
     In other words, when the first battery  61  is attached to the first battery mount  21 , the second battery  62  is blocked by the first battery  61  and is unattachable to the second battery mount  22 . When the second battery  62  is attached to the second battery mount  22 , the first battery  61  is blocked by the second battery  62  and is unattachable to the first battery mount  21 . 
     One of the first battery mount  21  or the second battery  62  may be located on the left inner surface  32  of the recess  30 . One of the first battery mount  21  or the second battery  62  may be located on the bottom surface  34  of the recess  30 . The first battery mount  21  may be located on one of the support surface  31 , the left inner surface  32 , the right inner surface  33 , or the bottom surface  34 , and the second battery mount  22  may be located on another of these surfaces. 
     A third battery mount (not shown) may be located on the inner surface of the cover  3  facing the battery compartment  20  or on the inner surface of the body  2  facing the battery compartment  20 . 
     The cover  3  may be eliminated. 
     As described above, the body  2  in the present embodiment has a first surface and a second surface facing in different directions. The first battery mount  21  is located on the first surface. The second battery mount  22  is located on the second surface. The electrical apparatus  1 B with this structure can be miniaturized as compared with, for example, an electrical apparatus including two battery mounts arranged in parallel on a single surface. 
     In the embodiment, the first battery mount  21  and the second battery mount  22  are positioned relative to each other in accordance with the profiles and dimensions of the first battery  61  and the second battery  62  to cause the second battery  62  to be unattachable to the second battery mount  22  when the first battery  61  is attached to the first battery mount  21  and to cause the first battery  61  to be unattachable to the first battery mount  21  when the second battery  62  is attached to the second battery mount  22 . Activating the electrical apparatus  1  in the two-battery attached state may cause a current to flow from the first battery  61  to the second battery  62  or from the second battery  62  to the first battery  61 . In the present embodiment, the first battery mount  21  and the second battery mount  22  are positioned relative to each other in accordance with the profiles and dimensions of the first battery  61  and the second battery  62  to avoid the two-battery attached state. This reduces the likelihood of the flow of current described above. 
     Third Embodiment 
       FIG.  20    is a schematic diagram of an electrical apparatus  1 C according to an embodiment. As shown in  FIG.  20   , the electrical apparatus  1 C includes a body  2  and a cover  3 . As in the above embodiments, the cover  3  is joined to the body  2  with a hinge  12 . The hinge  12  has its hinge axis AX extending in the lateral direction. 
     The body  2  and the cover  3  define a battery compartment  20 . The body  2  has a recess  30 C. The recess  30 C is recessed downward from the upper surface of the body  2 . The recess  30 C is open at its upper end and forms an opening  350 C. The recess  30 C has an inner surface including a first surface  31 C, a second surface  32 C, a third surface  33 C, a fourth surface  34 C, and a fifth surface  35 C. The first surface  31 C, the second surface  32 C, the third surface  33 C, the fourth surface  34 C, and the fifth surface  35 C face in different directions. The first surface  31 C faces rearward. The second surface  32 C faces frontward. The third surface  33 C faces rightward. The fourth surface  34 C faces leftward. The fifth surface  35 C faces upward. The first surface  31 C, the second surface  32 C, the third surface  33 C, the fourth surface  34 C, and the fifth surface  35 C face the battery compartment  20 . 
     A first battery mount  21  is located on one of the first to fifth surfaces  31 C to  35 C, and a second battery mount  22  is located on another of these surfaces. In other words, a battery holder  19  has a first surface and a second surface that are both located on the body  2 . In the example of  FIG.  20   , the first battery mount  21  is located on the third surface  33 C, and the second battery mount  22  is located on the fourth surface  34 C. 
     As in the above embodiments, the first battery mount  21  receives a first battery  61  that is slidable. The second battery mount  22  receives a second battery  62  that is slidable. In the example of  FIG.  20   , the guiding direction of the first battery mount  21  is the vertical direction. The guiding direction of the second battery mount  22  is the vertical direction. 
     The first battery mount  21  and the second battery mount  22  are positioned relative to each other in accordance with the profiles and dimensions of the first battery  61  and the second battery  62  to cause the second battery  62  to be unattachable to the second battery mount  22  when the first battery  61  is attached to the first battery mount  21  and to cause the first battery  61  to be unattachable to the first battery mount  21  when the second battery  62  is attached to the second battery mount  22 . 
     A third battery mount (not shown) may be located on the inner surface of the cover  3  facing the battery compartment  20  or on the inner surface of the body  2  facing the battery compartment  20 . 
     The cover  3  may be eliminated. 
     Fourth Embodiment 
       FIG.  21    is a schematic diagram of an electrical apparatus  1 D according to an embodiment. As shown in  FIG.  21   , the electrical apparatus  1 D includes a body  2  and a cover  3 . As in the above embodiments, the cover  3  is joined to the body  2  with a hinge  12 . The hinge  12  has its hinge axis AX extending in the lateral direction. 
     The body  2  and the cover  3  define a battery compartment  20 . The body  2  has a first surface  31 D and a second surface  32 D. The first surface  31 D and the second surface  32 D face in different directions. The first surface  31 D faces rearward. The second surface  32 D faces upward. The first surface  31 D and the second surface  32 D face the battery compartment  20 . 
     A first battery mount  21  is located on the first surface  31 D, and a second battery mount  22  is located on the second surface  32 D. In other words, a holder ( 19 ) has a first surface and a second surface that are both located on the body  2 . 
     As in the above embodiments, the first battery mount  21  receives a first battery  61  that is slidable. The second battery mount  22  receives a second battery  62  that is slidable. In the example of  FIG.  21   , the guiding direction of the first battery mount  21  may be the vertical direction or the lateral direction. The guiding direction of the second battery mount  22  may be the front-rear direction or the lateral direction. 
     The first battery mount  21  and the second battery mount  22  are positioned relative to each other in accordance with the profiles and dimensions of the first battery  61  and the second battery  62  to cause the second battery  62  to be unattachable to the second battery mount  22  when the first battery  61  is attached to the first battery mount  21  and to cause the first battery  61  to be unattachable to the first battery mount  21  when the second battery  62  is attached to the second battery mount  22 . 
     A third battery mount (not shown) may be located on the inner surface of the cover  3  facing the battery compartment  20  or on the inner surface of the body  2  facing the battery compartment  20 . 
     The cover  3  may be eliminated. 
     Fifth Embodiment 
       FIG.  22    is a schematic diagram of an electrical apparatus  1 E according to a fifth embodiment. As shown in  FIG.  22   , the electrical apparatus  1 E includes a body  2  and a cover  3 . As in the above embodiments, the cover  3  is joined to the body  2  with a hinge  12 . The hinge  12  has its hinge axis AX extending in the lateral direction. 
     The body  2  and the cover  3  define a battery compartment  20 . The body  2  has a first surface  31 E, a second surface  32 E, and a third surface  33 E. The first surface  31 E, the second surface  32 E, and the third surface  33 E face in different directions. The first surface  31 E faces rearward. The second surface  32 E faces upward. The third surface  33 E faces leftward. The first surface  31 E, the second surface  32 E, and the third surface  33 E face the battery compartment  20 . 
     A first battery mount  21  is located on one of the first surface  31 E, the second surface  32 E, or the third surface  33 E, and a second battery mount  22  is located on another of these surfaces. In other words, a holder ( 19 ) has a first surface and a second surface that are both located on the body  2 . In the example of  FIG.  22   , the first battery mount  21  is located on the first surface  31 E, and the second battery mount  22  is located on the second surface  32 E. 
     As in the above embodiments, the first battery mount  21  receives a first battery  61  that is slidable. The second battery mount  22  receives a second battery  62  that is slidable. 
     A third battery mount (not shown) may be located on the inner surface of the cover  3  facing the battery compartment  20  or on the inner surface of the body  2  facing the battery compartment  20 . 
     The cover  3  may be eliminated. 
     Sixth Embodiment 
       FIG.  23    is a schematic diagram of an electrical apparatus  1 F according to an embodiment. As shown in  FIG.  23   , the electrical apparatus  1 F includes a body  2  and a cover  3 . As in the above embodiments, the cover  3  is joined to the body  2  with a hinge  12 . The hinge  12  has its hinge axis AX extending in the lateral direction. 
     The body  2  and the cover  3  define a battery compartment  20 . The body  2  has a first surface  31 F. The first surface  31 F faces rearward. The first surface  31 F faces the battery compartment  20 . 
     A first battery mount  21  is located on the first surface  31 F. A second battery mount  22  is located on the inner surface of the cover  3  facing the battery compartment  20 . 
     A third battery mount (not shown) may be located on the inner surface of the cover  3  facing the battery compartment  20  or on the inner surface of the body  2  facing the battery compartment  20 . 
     Seventh Embodiment 
     Overview of Electrical Apparatus 
       FIG.  24    is a perspective view of an electrical apparatus  1 G according to an embodiment as viewed from the left front.  FIG.  25    is a perspective view of the electrical apparatus  1 G according to the embodiment as viewed from the right rear. 
     As in the above embodiments, the electrical apparatus  1 G is an illuminator. 
     As shown in  FIGS.  24  and  25   , the electrical apparatus  1 G includes a body  102 , a cover  103 , a leg  104 , and a handle  105 . The cover  103  is joined to the body  102 . The leg  104  is joined to the body  102 . The handle  105  is joined to the body  102 . 
     The body  102  includes a housing  106  and a light emitter  107 . 
     The housing  106  includes a front housing  108  and a rear housing  109 . The front housing  108  is located frontward from the rear housing  109 . 
     The front housing  108  is a rectangular frame. The front housing  108  surrounds the light emitter  107 . The front housing  108  accommodates at least a part of the light emitter  107 . The front housing  108  has vents  1010  in its upper, lower, left, and right portions. The vents  1010  connect the inside and the outside of the housing  106 . 
     The rear housing  109  is connected to the rear end of the front housing  108 . The rear housing  109  includes an upper plate  109 A, a lower plate  109 B, a left plate  109 C, a right plate  109 D, and a rear plate  109 E. 
     The light emitter  107  emits light frontward. The light emitter  107  is an output portion of the electrical apparatus  1 G for outputting light. The light emitter  107  is located on a front portion of the body  102 . 
     The cover  103  defines, with the body  102 , a battery compartment  1020 . The cover  103  is connected to a rear portion of the body  102 . The body  102  in the embodiment has its rear portion being a rear portion of the rear housing  109 . The rear housing  109  includes, on its lower portion on the rear surface, an AC terminal  1073  connectable to a utility power supply. The AC terminal  1073  is covered with a cover  1074 . 
     The leg  104  is joined to the rear housing  109  with joining units  1014 . The leg  104  includes a left leg  104 A and a right leg  104 B. The left leg  104 A is joined to the left plate  109 C of the rear housing  109 . The right leg  104 B is joined to the right plate  109 D of the rear housing  109 . The leg  104  is pivotable about a rotation axis BX of the joining units  1014 . The rotation axis BX extends in the lateral direction. The left leg  104 A and the right leg  104 B are joined together with two rods  104 C and one plate  104 D (refer to  FIGS.  27  to  29   ). The left leg  104 A and the right leg  104 B are pivotable together. 
     The leg  104  has lower surfaces  104 E located below the lower surface of the body  102 . The body  102  has its lower surface including the lower surface of the rear housing  109 . When the electrical apparatus  1 G is placed on a placement surface FL, the leg  104  has the lower surfaces  104 E in contact with the placement surface FL. 
     The handle  105  is grippable by a user of the electrical apparatus  1 G. The handle  105  includes a pair of arms  105 A and a handle portion  105 B. The handle portion  105 B connects the pair of arms  105 A. The handle  105  is joined to the rear housing  109  with hinges  1015 . The handle  105  is pivotable about a hinge axis CX of the hinges  1015 . The hinge axis CX extends in the lateral direction. 
     The upper plate  109 A includes a protrusion  109 F and supports  109 G. The protrusion  109 F protrudes upward. The supports  109 G are located on the left and right of the protrusion  109 F. Each support  109 G has the upper surface located below the upper surface of the protrusion  109 F. The upper plate  109 A includes steps each between the upper surface of the protrusion  109 F and the corresponding support  109 G. The handle  105  is joined to side surfaces of the protrusion  109 F with the hinges  1015 . 
     One of the arms  105 A is joined to the left side surface of the protrusion  109 F with one of the hinges  1015 . The other arm  105 A is joined to the right side surface of the protrusion  109 F with another hinge  1015 . The handle  105  is joined to the body  102  with the hinges  1015  to have its handle portion  105 B pivotable about the hinge axis CX. 
     The handle  105  is pivotable to a retracted position and to an in-use position. At the retracted position, the arms  105 A and the handle portion  105 B face the upper surfaces of the supports  109 G. The handle  105  at the retracted position is at least partially located above the cover  103 . At the in-use position, the arms  105 A and the handle portion  105 B are apart from the upper surfaces of the supports  109 G, and the handle portion  105 B is located above the hinges  1015 . The user of the electrical apparatus  1 G moves the handle  105  to the in-use position and carries the electrical apparatus  1 G while gripping the handle portion  105 B. 
     The electrical apparatus  1 G includes a power button  1017 . The power button  1017  is located on a front portion of the upper plate  109 A of the rear housing  109 . The power button  1017  is operated to activate the electrical apparatus  1 G. 
     Battery Holder and Battery Compartment 
       FIG.  26    is a perspective view of the electrical apparatus  1 G according to the embodiment as viewed from the right rear with its cover  103  being open.  FIG.  27    is a rear view of the electrical apparatus  1 G according to the embodiment with its cover  103  removed.  FIG.  28    is a perspective view of the electrical apparatus  1 G according to the embodiment as viewed from the left rear with its cover  103  removed.  FIG.  29    is a perspective view of the electrical apparatus  1 G according to the embodiment as viewed from the right rear with its cover  103  removed. 
     The electrical apparatus  1 G includes a battery holder  19 G. The battery holder  19 G has a rear inner surface  1031  (first surface), a left inner surface  1032  (second surface), and a right inner surface  1033  (second surface). The rear inner surface  1031  (first surface) receives a battery. The left inner surface  1032  (second surface) and the right inner surface  1033  (second surface) receive batteries. The rear inner surface  1031  (first surface), the left inner surface  1032  (second surface), and the right inner surface  1033  (second surface) face in different directions. In the embodiment, the rear inner surface  1031 , the left inner surface  1032 , and the right inner surface  1033  are all located on the body  102 . 
     The cover  103  defines, with the body  102 , a battery compartment  1020 . The cover  103  is pivotably joined to the body  102 . The battery compartment  1020  is closed with the cover  103  pivoted to connect to the rear portion of the body  102 . The battery compartment  1020  is open with the cover  103  pivoted to be apart from the rear portion of the body  102 . 
     The electrical apparatus  1 G includes a hinge  1012  joining the cover  103  to the body  102 . The hinge  1012  joins the cover  103  to a lower rear portion of the rear housing  109 . The hinge  1012  is located at the bottom of the cover  103  when the cover  103  is pivoted to close the battery compartment  1020 . The cover  103  is pivotably joined to the lower rear portion of the rear housing  109  with the hinge  1012 . The hinge  1012  has its hinge axis AX extending in the lateral direction. The cover  103  is joined to the body  102  with the hinge  1012  to have its upper end pivotable about the hinge axis AX. 
     The body  102  has a recess  1030  in the rear portion. The body  102  has its rear portion being a rear portion of the rear housing  109 . The recess  1030  is recessed frontward. The recess  1030  is open at its upper end and forms an opening  1035 . 
     The cover  103  includes an upper plate  103 A and a rear plate  103 E. When the cover  103  is closed, the upper plate  103 A is located at the opening  1035 . 
     The cover  103  and the rear housing  109  are fastened with a latch  1013 . In this state, the battery compartment  1020  is closed. 
     The recess  1030  in the body  102  has an inner surface including the rear inner surface  1031  (first surface), the left inner surface  1032  (second surface), and the right inner surface  1033  (second surface). The left inner surface  1032  is located leftward from the rear inner surface  1031 . The right inner surface  1033  is located rightward from the rear inner surface  1031 . The left inner surface  1032  is connected to the left end of the rear inner surface  1031 . The right inner surface  1033  is connected to the right end of the rear inner surface  1031 . The rear inner surface  1031  is located frontward from the rear surface of the rear housing  109 . The rear inner surface  1031  faces rearward. The left inner surface  1032  faces rightward. The right inner surface  1033  faces leftward. The left inner surface  1032  and the right inner surface  1033  face each other. The rear inner surface  1031  and the left inner surface  1032  are substantially orthogonal to each other. The rear inner surface  1031  and the right inner surface  1033  are substantially orthogonal to each other. 
     The rear inner surface  1031  faces the battery compartment  1020 . The left inner surface  1032  faces the battery compartment  1020 . The right inner surface  1033  faces the battery compartment  1020 . 
     Battery Mounts 
     The electrical apparatus  1 G includes first battery mounts  21  and second battery mounts  22 . Each first battery mount  21  receives a first battery  61 . Each second battery mount  22  receives a second battery  62 . The first battery mounts  21  are located in the battery compartment  1020 . The second battery mounts  22  are located in the battery compartment  1020 . The battery compartment  1020  is defined by at least a part of the inner surface of the recess  1030  in the body  102  and at least a part of the inner surface of the cover  103 . 
     Two first battery mounts  21  are located on the rear inner surface  1031  of the battery holder  19 G. The two first battery mounts  21  are arranged in the lateral direction on the rear inner surface  1031 . 
     The electrical apparatus  1 G includes two second battery mounts  22 . One of the second battery mounts  22  is located on the left inner surface  1032  of the battery holder  19 G. The other second battery mount  22  is located on the right inner surface  1033  of the battery holder  19 G. 
     The first battery mounts  21  each have a mount surface  21 A, first guides  21 B, and power terminals  21 D. The first guides  21 B guide the first battery  61 . 
     The mount surface  21 A faces an attachment surface  61 A of the first battery  61  (refer to  FIG.  8 A ). 
     The first guides  21 B guide the first battery  61  in a predetermined guiding direction. The first battery  61  includes slides  61 C (refer to  FIG.  8 A ) that are guided along the first guides  21 B. The two first guides  21 B are arranged in the lateral direction. The guiding direction of the first guides  21 B is the vertical direction. 
     The power terminals  21 D are connected to power terminals  61 F on the first battery  61  (refer to  FIG.  8 A ) to supply power from the first battery  61  to the electrical apparatus  1 G. 
     The second battery mounts  22  each have a mount surface  22 A, second guides  22 B, a locking slot  22 C, and power terminals  22 D. The second guides  22 B guide the second battery  62 . 
     The mount surface  22 A faces an attachment surface  62 A of the second battery  62  (refer to  FIG.  8 B ). 
     The second guides  22 B guide the second battery  62  in a predetermined guiding direction. The second battery  62  includes slides  62 C (refer to  FIG.  8 B ) that are guided along the second guides  22 B. The two second guides  22 B are arranged in the front-rear direction. The guiding direction of the second guides  22 B is the vertical direction. 
     The locking slot  22 C is located in the mount surface  22 A. The locking slot  22 C receives a protruding portion  62 D on the second battery  62  (refer to  FIG.  8 B ). This fastens the second battery  62  to the second battery mount  22 . In response to an operation on a release button  62 E (refer to  FIG.  8 B ), the second battery  62  is unlocked and released from the second battery mount  22 . 
     The power terminals  22 D are connected to power terminals  62 F on the second battery  62  (refer to  FIG.  8 B ) to supply power from the second battery  62  to the electrical apparatus  1 G. 
     The first battery mount  21  and the second battery mount  22  have different interface structures. The mount surface  21 A, the first guides  21 B, and the power terminals  21 D are at relative positions different from the relative positions of the mount surface  22 A, the second guides  22 B, and the power terminals  22 D. For example, the pair of first guides  21 B have a distance between them different from the distance between the pair of second guides  22 B. The pair of power terminals  21 D have a distance between them different from the distance between the pair of power terminals  22 D. The mount surface  21 A has dimensions different from the dimensions of the mount surface  22 A. The mount surface  21 A has a profile different from the profile of the mount surface  22 A. 
     As in the above embodiments, the first battery  61  and the second battery  62  are slidable. Each of the first battery  61  and the second battery  62  is a battery for power tools. 
     The first battery  61  and the second battery  62  supply power to the electrical apparatus  1 G. The first battery  61  and the second battery  62  thus function as power supplies for the electrical apparatus  1 G. The first battery  61  and the second battery  62  may be secondary batteries. The first battery  61  and the second battery  62  in the embodiment may be rechargeable lithium-ion batteries. 
     The first battery  61  is attached to the first battery mount  21  to supply power to the electrical apparatus  1 G. The second battery  62  is attached to the second battery mount  22  to supply power to the electrical apparatus  1 G. 
     As described with reference to  FIG.  8 A , the first battery  61  includes a housing  61 B with the attachment surface  61 A, the pair of slides  61 C, and the pair of power terminals  61 F. The housing  61 B has an internal space to accommodate a battery cell. The battery cell is a rechargeable lithium-ion battery. The slides  61 C extend in a predetermined sliding direction. The power terminals  61 F are between the pair of slides  61 C. One of the power terminals  61 F is a positive power terminal. The other power terminal  61 F is a negative power terminal. 
     As described with reference to  FIG.  8 B , the second battery  62  includes a housing  62 B with the attachment surface  62 A, the pair of slides  62 C, the protruding portion  62 D, the release button  62 E, and the pair of power terminals  62 F. The protruding portion  62 D is supported movably on the housing  62 B. The release button  62 E is operable to operate the protruding portion  62 D. The housing  62 B has an internal space to accommodate a battery cell. The battery cell is a rechargeable lithium-ion battery. The slides  62 C extend in a predetermined sliding direction. The protruding portion  62 D is supported movably by a spring. The protruding portion  62 D protrudes from the attachment surface  62 A under an elastic force from the spring. The power terminals  62 F are between the pair of slides  62 C. One of the power terminals  62 F is a positive power terminal. The other power terminal  62 F is a negative power terminal. 
     The first battery  61  and the second battery  62  are of different types. The electrical apparatus  1 G may use, as its power supply, the first battery  61  and the second battery  62  of different types. 
     The first battery  61  and the second battery  62  differ in rated voltage (V). The first battery  61  has a higher rated voltage than the second battery  62 . The first battery  61  has a rated voltage of, for example, 36 V. The second battery  62  has a rated voltage of, for example, 10.8 V. The first battery  61  may have a rated voltage of 40 V. The second battery  62  may have a rated voltage of 18 V. 
     The first battery  61  and the second battery  62  differ in capacity (Ah). The first battery  61  has a higher capacity than the second battery  62 . 
     The first battery  61  and the second battery  62  differ in weight (g). The first battery  61  is heavier than the second battery  62 . 
     The first battery  61  and the second battery  62  differ in outer dimensions (mm). The first battery  61  has greater outer dimensions than the second battery  62 . 
     The first battery  61  is slidable on the first battery mount  21  while being guided along the first guides  21 B for attachment to and detachment from the first battery mount  21 . With the cover  103  being open, the first battery  61  is attachable to and detachable from the first battery mount  21 . 
     In the embodiment, the guiding direction of the first guides  21 B is the vertical direction. The first battery  61  is slidable in the vertical direction for attachment to and detachment from the first battery mount  21 . 
     To attach the first battery  61  to the first battery mount  21 , the user of the electrical apparatus  1 G places the first battery  61  into the recess  1030  through the opening  1035 . The user of the electrical apparatus  1 G slides the first battery  61  downward along the first battery mount  21  after placing the slides  61 C in contact with the upper ends of the first guides  21 B. The first battery  61  moves downward while being guided along the first guides  21 B. The first battery  61  is thus attached to the first battery mount  21 . 
     In this manner, the first battery  61  is slidable on the first battery mount  21  toward the lower ends of the first guides  21 B while being guided along the first guides  21 B for attachment to the first battery mount  21 . 
     To detach the first battery  61  from the first battery mount  21 , the first battery  61  is slid upward. 
     The second battery  62  is slidable on the second battery mount  22  while being guided along the second guides  22 B for attachment to and detachment from the second battery mount  22 . With the cover  103  being open, the second battery  62  is attachable to and detachable from the second battery mount  22 . 
     In the embodiment, the guiding direction of the second guides  22 B is the vertical direction. The second battery  62  is slidable in the vertical direction for attachment to and detachment from the second battery mount  22 . 
     To attach the second battery  62  to the second battery mount  22 , the user of the electrical apparatus  1 G places the second battery  62  into the recess  1030  through the opening  1035 . The user of the electrical apparatus  1 G slides the second battery  62  downward along the second battery mount  22  after placing the slides  62 C in contact with the upper ends of the second guides  22 B. The second battery  62  moves downward while being guided along the second guides  22 B. The second battery  62  is thus attached to the second battery mount  22 . 
     In this manner, the second battery  62  is slidable on the second battery mount  22  while being guided along the second guides  22 B toward the lower ends of the second guides  22 B for attachment to the second battery mount  22 . 
     To detach the second battery  62  from the second battery mount  22 , the second battery  62  is slid upward. 
     Battery Attachment Patterns 
       FIGS.  30  to  33    are rear views of the electrical apparatus  1 G according to the embodiment with its cover  103  removed. 
     The first battery mount  21  located on the left on the rear inner surface  1031  is hereafter referred to as a left first battery mount  21 L, and the first battery mount  21  located on the right is referred to as a right first battery mount  21 R for convenience. The second battery mount  22  located on the left inner surface  1032  is referred to as a left second battery mount  22 L for convenience. The second battery mount  22  located on the right inner surface  1033  is referred to as a right second battery mount  22 R for convenience. 
       FIG.  30    shows first batteries  61  attached to the two first battery mounts  21  when the second battery  62  is unattached to any of the two second battery mounts  22 . In this state, the second battery  62  is unattachable to any of the two second battery mounts  22 . 
     When the first battery  61  is attached to the left first battery mount  21 L, the second battery  62  is blocked by the first battery  61  and is thus unattachable to the left second battery mount  22 L. 
     When the first battery  61  is attached to the right first battery mount  21 R, the second battery  62  is blocked by the first battery  61  and is thus unattachable to the right second battery mount  22 R. 
     The first battery mounts  21  and the second battery mounts  22  are positioned relative to each other in accordance with the profiles and dimensions of the first battery  61  and the second battery  62  to cause the second battery  62  to be unattachable to the left second battery mount  22 L when the first battery  61  is attached to the left first battery mount  21 L and to cause the second battery  62  to be unattachable to the right second battery mount  22 R when the first battery  61  is attached to the right first battery mount  21 R. 
       FIG.  31    shows the first battery  61  attached to the left first battery mount  21 L and the second battery  62  attached to the right second battery mount  22 R when another first battery  61  is unattached to the right first battery mount  21 R and another second battery  62  is unattached to the left second battery mount  22 L. In this state, the other first battery  61  is unattachable to the right first battery mount  21 R, and the other second battery  62  is unattachable to the left second battery mount  22 L. 
     When the first battery  61  is attached to the left first battery mount  21 L, the second battery  62  is blocked by the first battery  61  and is unattachable to the left second battery mount  22 L. 
     When the second battery  62  is attached to the right second battery mount  22 R, the first battery  61  is blocked by the second battery  62  and is unattachable to the right first battery mount  21 R. 
     The first battery mounts  21  and the second battery mounts  22  are positioned relative to each other in accordance with the profiles and dimensions of the first battery  61  and the second battery  62  to cause the second battery  62  to be unattachable to the left second battery mount  22 L when the first battery  61  is attached to the left first battery mount  21 L and to cause the first battery  61  to be unattachable to the right first battery mount  21 R when the second battery  62  is attached to the right second battery mount  22 R. 
       FIG.  32    shows the first battery  61  attached to the right first battery mount  21 R and the second battery  62  attached to the left second battery mount  22 L when another first battery  61  is unattached to the left first battery mount  21 L and another second battery  62  is unattached to the right second battery mount  22 R. In this state, the other first battery  61  is unattachable to the left first battery mount  21 L, and the other second battery  62  is unattachable to the right second battery mount  22 R. 
     When the first battery  61  is attached to the right second battery mount  22 R, the second battery  62  is blocked by the first battery  61  and is unattachable to the right first battery mount  21 R. 
     When the second battery  62  is attached to the left second battery mount  22 L, the first battery  61  is blocked by the second battery  62  and is unattachable to the left first battery mount  21 L. 
     The first battery mounts  21  and the second battery mounts  22  are positioned relative to each other in accordance with the profiles and dimensions of the first battery  61  and the second battery  62  to cause the second battery  62  to be unattachable to the right second battery mount  22 R when the first battery  61  is attached to the right first battery mount  21 R and to cause the first battery  61  to be unattachable to the left first battery mount  21 L when the second battery  62  is attached to the left second battery mount  22 L. 
       FIG.  33    shows the second batteries  62  attached to the two second battery mounts  22  when the first battery  61  is unattached to any of the two first battery mounts  21 . In this state, the first battery  61  is unattachable to any of the two first battery mounts  21 . 
     When the second battery  62  is attached to the left second battery mount  22 L, the first battery  61  is blocked by the second battery  62  and is unattachable to the left first battery mount  21 L. 
     When the second battery  62  is attached to the right second battery mount  22 R, the first battery  61  is blocked by the second battery  62  and is unattachable to the right first battery mount  21 R. 
     The first battery mounts  21  and the second battery mounts  22  are positioned relative to each other in accordance with the profiles and dimensions of the first battery  61  and the second battery  62  to cause the first battery  61  to be unattachable to the left first battery mount  21 L when the second battery  62  is attached to the left second battery mount  22 L and to cause the first battery  61  to be unattachable to the right first battery mount  21 R when the second battery  62  is attached to the right second battery mount  22 R. 
     As shown in  FIGS.  30  to  33   , two batteries ( 61 ,  62 ) attached to the electrical apparatus  1 G at the same time are electrically connected in parallel. The light emitter  107  can emit light using power supplied from the two batteries. The two batteries are electrically connected in parallel. The light emitter  107  can also emit light using power supplied from a single battery ( 61 ,  62 ) attached to the electrical apparatus  1 G. The two batteries with the same rated voltage may be attached to the electrical apparatus  1 G at the same time and electrically connected in series. 
     Shade 
       FIG.  34    is a perspective view of the electrical apparatus  1 G with a shade  200  according to the embodiment as viewed from the left front.  FIG.  35    is an exploded perspective view of the electrical apparatus  1 G with the shade  200  according to the embodiment as viewed from the left front. As shown in  FIGS.  34  and  35   , the shade  200  is attached to the electrical apparatus  1 G. The shade  200  faces the front surface of the light emitter  107 . Similarly to the light emitter  7  in the first embodiment above, the light emitter  107  includes multiple light sources  7 S and a lens  7 L in front of the light sources  7 S. The light sources  7 S are LEDs. The lens  7 L is a light-transmissive plate. The light emitter  107  has its front surface being the front surface of the lens  7 L. The light emitter  107  has its front surface being a light-emitting surface for emitting light. 
     The shade  200  protects the light emitter  107 . The shade  200  disperses light emitted from the light emitter  107 . The shade  200  transmits at least part of light emitted from the light emitter  107 . 
     The shade  200  is attachable to and detachable from the front housing  108 . The shade  200  includes a left projection  201  on its left portion. The shade  200  includes a right projection  202  on its right portion. The left projection  201  is received in a left recess  211  located in a left portion of the light emitter  107  in the front housing  108 . The right projection  202  is received in a right recess  212  located in a right portion of the light emitter  107  in the front housing  108 . 
     The shade  200  is bendable. The shade  200  is elastically deformable to cause its left projection  201  and its right projection  202  to move toward each other. To attach the shade  200  to the front housing  108 , the user of the electrical apparatus  1 G places the left projection  201  into the left recess  211  and then bends the shade  200  to cause the left projection  201  and the right projection  202  to move toward each other. The user of the electrical apparatus  1 G can thus place the right projection  202  into the right recess  212  with the left projection  201  being received in the left recess  211 . The elastically deformed shade  200  is then released and attached to the front housing  108 . The user of the electrical apparatus  1 G may place the left projection  201  into the left recess  211  after placing the right projection  202  into the right recess  212 . The user of the electrical apparatus  1 G may place the left projection  201  into the left recess  211  and place the right projection  202  into the right recess  212  at the same time by bending the shade  200 . 
     The multiple light sources  7 S included in the light emitter  107  may produce multiple images (shadows) of the light sources  7 S. Such multiple images of the light sources  7 S may cause difficulty in the work when the user of the electrical apparatus  1 G works on an object illuminated with light from the light emitter  107 . 
     The shade  200  disperses light emitted from each of the multiple light sources  7 S. The shade  200  thus reduces the likelihood that multiple images of the light sources  7 S are produced. The user of the electrical apparatus  1 G can thus smoothly work on an object illuminated with light from the light emitter  107 . 
     The shade  200  disperses light emitted from the front surface of the light emitter  107 . The shade  200  has an emission surface  203  for outputting the dispersed light. The emission surface  203  protrudes frontward. The emission surface  203  includes a front surface  203 A, an upper surface  203 B, a lower surface  203 C, a left surface  203 D, and a right surface  203 E. The front surface  203 A faces frontward. The front surface  203 A is substantially parallel to the front surface of the light emitter  107 . The upper surface  203 B is connected to the upper end of the front surface  203 A. The upper surface  203 B faces frontward and upward. The lower surface  203 C is connected to the lower end of the front surface  203 A. The lower surface  203 C faces frontward and downward. The left surface  203 D is connected to the left end of the front surface  203 A. The left surface  203 D faces frontward and leftward. The right surface  203 E is connected to the right end of the front surface  203 A. The right surface  203 E faces frontward and rightward. 
     The shade  200  transmits light emitted from the front surface of the light emitter  107  and outputs the light through its emission surface  203 . The light is output from each of the front surface  203 A, the upper surface  203 B, the lower surface  203 C, the left surface  203 D, and the right surface  203 E. This structure allows light emitted from the light emitter  107  to illuminate a larger area. 
     The light emitted from the front surface of the light emitter  107  is dispersed by the shade  200  and thus becomes softer. The user of the electrical apparatus  1 G can thus avoid being dazzled by the light. 
     The electrical apparatus  1 G according to the embodiment includes the battery holder  19  having the rear inner surface  1031  (first surface), the left inner surface  1032  (second surface), and the right inner surface  1033  (second surface). The rear inner surface  1031 , the left inner surface  1032 , and the right inner surface  1033  are all located on a body  102 . The body  102  has the rear inner surface  1031 , the left inner surface  1032 , and the right inner surface  1033  facing in different directions. Two first battery mounts  21  are located on the rear inner surface  1031 , and one second battery mount  22  is located on each of the left inner surface  1032  and the right inner surface  1033 . The electrical apparatus  1 G with this structure can be miniaturized as compared with, for example, an electrical apparatus including four battery mounts arranged in parallel on a single surface. 
     In the embodiment, the left first battery mount  21 L and the left second battery mount  22 L are positioned relative to each other in accordance with the profiles and dimensions of the first battery  61  and the second battery  62  to cause the second battery  62  to be unattachable to the left second battery mount  22 L when the first battery  61  is attached to the left first battery mount  21 L. 
     The left second battery mount  22 L and the left first battery mount  21 L are positioned relative to each other in accordance with the profiles and dimensions of the first battery  61  and the second battery  62  to cause the first battery  61  to be unattachable to the left first battery mount  21 L when the second battery  62  is attached to the left second battery mount  22 L. 
     The right first battery mount  21 R and the right second battery mount  22 R are positioned relative to each other in accordance with the profiles and dimensions of the first battery  61  and the second battery  62  to cause the second battery  62  to be unattachable to the right second battery mount  22 R when the first battery  61  is attached to the right first battery mount  21 R. 
     The right second battery mount  22 R and the right first battery mount  21 R are positioned relative to each other in accordance with the profiles and dimensions of the first battery  61  and the second battery  62  to cause the first battery  61  to be unattachable to the right first battery mount  21 R when the second battery  62  is attached to the right second battery mount  22 R. 
     This structure reduces a current flowing from the first battery  61  to the second battery  62  or from the second battery  62  to the first battery  61  as described above. 
     Modifications 
     In the above embodiments, two first battery mounts  21  are located on the rear inner surface  1031 , and one second battery mount  22  is located on each of the left inner surface  1032  and the right inner surface  1033 . The second battery mount  22  may be located on the left inner surface  1032  without any second battery mount  22  located on the right inner surface  1033 . The second battery mount  22  may be located on the right inner surface  1033  without any second battery mount  22  located on the left inner surface  1032 . 
     In the above embodiments, the apparatus includes two first battery mounts  21  and two second battery mounts  22 . A single first battery mount  21  alone may be located on the rear inner surface  1031 . A second battery mount  22  may be located on either the left inner surface  1032  or the right inner surface  1033  alone. 
     In the above embodiments, the first surface (the rear inner surface  1031 ) and the second surfaces (the left inner surface  1032  and the right inner surface  1033 ) of the battery holder  19 G may be all located on the body  102 . In this case, the cover  103  may be eliminated. 
       FIG.  36    is a perspective view of an electrical apparatus  1 H with a shade  300  according to a modification as viewed from the left front.  FIG.  37    is an exploded perspective view of the electrical apparatus  1 H with the shade  300  according to the modification as viewed from the left front.  FIG.  38    is a view of the shade  300  in the modification. 
     A front housing  108  includes an elastomer portion  400 . The elastomer portion  400  is a frame. The elastomer portion  400  surrounds a light emitter  107 . 
     The shade  300  is attachable to and detachable from the elastomer portion  400  on the front housing  108 . As shown in  FIG.  38   , the shade  300  includes two lower tabs  301  on its lower portion. The shade  300  includes one upper tab  302  on its upper portion. The lower tabs  301  are fitted on a lower portion of the elastomer portion  400 . The upper tab  302  is fitted on an upper portion of the elastomer portion  400 . 
     As shown in  FIG.  38   , the shade  300  includes multiple stoppers  303  on its inner surface. The stoppers  303  protrude from the inner surface of the shade  300 . The stoppers  303  on the inner surface of the shade  300  include two stoppers  303  located on a lower portion frontward from the lower tabs  301 , two stoppers  303  located on an upper portion frontward from the upper tab  302 , one stopper  303  located on a left portion, and one stopper  303  located on a right portion. 
     The lower tabs  301  and the upper tab  302  are fitted on a rear portion of the elastomer portion  400 . The stoppers  303  are in contact with the front surface of the elastomer portion  400  with the lower tabs  301  and the upper tab  302  being fitted on the rear portion of the elastomer portion  400 . The elastomer portion  400  has its lower portion sandwiched between the lower tabs  301  and the stoppers  303  in the front-rear direction. The elastomer portion  400  has its upper portion sandwiched between the upper tab  302  and the stoppers  303  in the front-rear direction. The stoppers  303  may be slightly spaced apart from the front surface of the elastomer portion  400  with the lower tabs  301  and the upper tab  302  being fitted on the rear portion of the elastomer portion  400 . 
     The shade  300  is bendable. The shade  300  is elastically deformable to cause the lower tabs  301  and the upper tab  302  to move away from each other. To attach the shade  300  to the elastomer portion  400 , the user of the electrical apparatus  1 H fits the lower tabs  301  onto the lower portion of the elastomer portion  400  and then pivots the shade  300  to cause its upper portion to move toward the upper portion of the elastomer portion  400 . The shade  300  has its upper portion placed in contact with the upper portion of the elastomer portion  400  and is then pressed against the elastomer portion  400 . The shade  300  thus bends to cause the lower tabs  301  and the upper tab  302  to move away from each other. This causes the upper tab  302  to be fitted on the upper portion of the elastomer portion  400 . The elastically deformed shade  300  is then released and attached to the elastomer portion  400 . The user of the electrical apparatus  1 H may fit the lower tabs  301  onto the lower portion of the elastomer portion  400  after fitting the upper tab  302  onto the upper portion of the elastomer portion  400 . The user of the electrical apparatus  1 H may fit the lower tabs  301  onto the lower portion of the elastomer portion  400  and fit the upper tab  302  onto the upper portion of the elastomer portion  400  at the same time by bending the shade  300  to cause the lower tabs  301  and the upper tab  302  to move away from each other. 
     Other Embodiments 
     In the above embodiments, the cover may be eliminated. The first battery mount may be located on the first surface of the battery holder defined on the body of the electrical apparatus. The second battery mount may be located on the second surface of the battery holder defined on the body of the electrical apparatus. The first surface and the second surface may be different surfaces. The first surface and the second surface may face in different directions, may be at different positions, or may have different sizes or curvatures. 
     In the above embodiments, the electrical apparatus  1  is an illuminator. The output portion of the electrical apparatus  1  is a light emitter for emitting light. The electrical apparatus  1  may be, for example, a television or an audio output device. The output portion of the television may include a display screen for outputting display data. The output portion of the audio output device may include a speaker for outputting sound. The audio output device may be, for example, an audio amplifier for amplifying and outputting the sound input from a microphone, or a radio for outputting the sound of a radio broadcast. 
     REFERENCE SIGNS LIST 
     
         
           1  electrical apparatus 
           1 B electrical apparatus 
           1 C electrical apparatus 
           1 D electrical apparatus 
           1 E electrical apparatus 
           1 F electrical apparatus 
           1 G electrical apparatus 
           1 H electrical apparatus 
           2  body 
           3  cover 
           3 A upper plate 
           3 B lower plate 
           3 C left plate 
           3 D right plate 
           3 E rear plate 
           3 F support plate 
           4  leg 
           4 A left leg 
           4 B right leg 
           4 C rod 
           4 D plate 
           4 E lower surface 
           5  handle 
           5 A arm 
           5 B handle portion 
           6  housing 
           7  light emitter (output portion) 
           7 L lens 
           7 S light source 
           8  front housing 
           9  rear housing 
           9 A upper plate 
           9 B lower plate 
           9 C left plate 
           9 D right plate 
           9 E rear plate 
           9 F protrusion 
           9 G peripheral portion 
           10  vent 
           11  vent 
           12  hinge 
           13  latch 
           14  joining unit 
           15  hinge 
           17  power button 
           19  battery holder 
           19 G battery holder 
           20  battery compartment 
           21  first battery mount 
           21 A mount surface 
           21 B first guide 
           21 D power terminal 
           21 L left first battery mount 
           21 R right first battery mount 
           22  second battery mount 
           22 A mount surface 
           22 B second guide 
           22 C locking slot 
           22 D power terminal 
           22 L left second battery mount 
           22 R right second battery mount 
           23  first end 
           24  second end 
           25  third end 
           26  fourth end 
           30  recess 
           30 C recess 
           31  support surface (first surface) 
           31 C first surface 
           31 D first surface 
           31 E first surface 
           31 F first surface 
           32  left inner surface 
           32 C second surface 
           32 D second surface 
           32 E second surface 
           33  right inner surface 
           33 C third surface 
           33 E third surface 
           34  bottom surface 
           34 C fourth surface 
           35  opening 
           35 C fifth surface 
           41  support surface (first surface) 
           42  left inner surface 
           43  right inner surface 
           45  opening 
           50  linkage 
           51  link 
           52  first joint 
           53  guide slot 
           54  second joint 
           55  brake 
           61  first battery 
           61 A attachment surface 
           61 B housing 
           61 C slide 
           61 F power terminal 
           62  second battery 
           62 A attachment surface 
           62 B housing 
           62 C slide 
           62 D protruding portion 
           62 E release button 
           62 F power terminal 
           71  rear surface 
           71 A upper area 
           71 B intermediate area 
           71 C lower area 
           72  rear surface 
           72 A upper area 
           72 B intermediate area 
           72 C lower area 
           73  AC terminal 
           74  cover 
           80  switch 
           80 B switch 
           81  AC-DC converter 
           82  diode 
           83  diode 
           84  connection point 
           85  first switching element 
           86  second switching element 
           87  third switching element 
           88  power switch 
           89  regulator 
           90  controller 
           91  constant current circuit 
           92  pulse generation circuit 
           93  signal generation circuit 
           94  connection point 
           102  body 
           103  cover 
           103 A upper plate 
           103 E rear plate 
           104  leg 
           104 A left leg 
           104 B right leg 
           104 C rod 
           104 D plate 
           104 E lower surface 
           105  handle 
           105 A arm 
           105 B handle portion 
           106  housing 
           107  light emitter (output portion) 
           108  front housing 
           109  rear housing 
           109 A upper plate 
           109 B lower plate 
           109 C left plate 
           109 D right plate 
           109 E rear plate 
           109 F protrusion 
           109 G support 
           200  shade 
           201  left projection 
           202  right projection 
           203  emission surface 
           203 A front surface 
           203 B upper surface 
           203 C lower surface 
           203 D left surface 
           203 E right surface 
           211  left recess 
           212  right recess 
           300  shade 
           301  lower tab 
           302  upper tab 
           303  stopper 
           350 C opening 
           400  elastomer portion 
           1010  vent 
           1012  hinge 
           1013  latch 
           1014  joining unit 
           1015  hinge 
           1017  power button 
           1020  battery compartment 
           1030  recess 
           1031  rear inner surface (first surface) 
           1032  left inner surface (second surface) 
           1033  right inner surface (second surface) 
           1035  opening 
           1073  AC terminal 
           1074  cover 
         AX hinge axis 
         BX rotation axis 
         CX hinge axis 
         FL placement surface