Abstract:
A battery charger includes a housing defining a battery receptacle area configured to receive a battery therein, a piston, a moveable platform, wherein the piston and the platform are simultaneously urged in substantially orthogonal directions toward the battery receptacle area, and prongs configured to extend from the housing and electrically connect a power source to the battery when the battery is received in the battery receptacle area and engaged by the piston and moveable platform. A method for charging a battery includes connecting a pair of prongs of a battery charger to a power source and placing a battery into a battery receptacle area of the battery charger, wherein the battery is simultaneously maintained in a vertical charging position and a horizontal charging position. A method of manufacturing a battery charger assembly includes providing a housing and providing a piston and a moveable platform internal to the housing.

Description:
BACKGROUND 
     I. Field 
     The following description relates generally to recharging a variety of batteries, and more particularly to a universal battery charger. 
     II. Background 
     The evolving market for battery-powered electronic imaging devices, cellular phones, computers, peripherals, and other electronic devices has grown incredibly. As each new generation of these products is introduced, devices with more capabilities and better specifications, with lower weight and smaller size, are joining the cordless brigade. For example, audio/video capture systems such as camcorders are becoming more and more portable—even while increasing in resolution and fidelity. 
     Manufacturing electronic devices smaller and making them battery-powered, however, does not necessarily make them completely portable. Because of battery capacity, equipment run-times are normally less than desired. Battery charging typically require more time than the use of the battery. Moreover, each device typically has required its own dedicated battery and matched charger. Thus, for example, even if a consumer purchases a camcorder and a camera from the same manufacturer, each of these devices will undoubtedly require its own specific battery as well as matched charger. 
     Presently, there exists several dozen unique battery form factors for cameras. Cellular phones account for another several dozen different battery configurations- some with three or four separate power ratings. Camcorder makers have attempted to standardize on a few battery form factors, but these too come in multiple power ratings. Countless varieties of other individual types of battery cells are commonly used in photographic equipment, games, appliances and other applications. 
     One of the reasons for the proliferation of chargers is that prior art chargers are product-specific, with added constraints on size, speed, power supply and compatibility with various battery chemistries. A dedicated charger for each of these batteries, or even for each type of these batteries, becomes economically and physically prohibitive. Likewise, adaptability to different AC and DC charging power sources is frequently lacking. 
     Implementation of many charging systems requires an electromechanical connection between the battery and charger that is designed for that single type of battery. However, it is apparent that a dedicated external charger for every new type and configuration of portable battery becomes less economically attractive with the acquisition by the consumer of more devices. 
     When the size and weight penalty imposed by the need for multiple spare batteries and chargers is combined with a disparate ratio of charge-time to run-time and the constant need for multiple nearby AC outlets, it can be seen that true portability will remain more an idealistic goal than a practical reality if all the power accessories that are needed to maintain portability weigh down the consumer. 
     Consequently, it would be desirable to address one or more of the deficiencies described above. 
     SUMMARY 
     In accordance with certain aspects of the present invention, a battery charger includes a housing defining a battery receptacle area configured to receive a battery therein, a piston, a moveable platform, wherein the piston and the platform are simultaneously urged in substantially orthogonal directions toward the battery receptacle area, and prongs configured to extend from the housing and electrically connect a power source to the battery when the battery is received in the battery receptacle area and engaged by the piston and moveable platform. 
     In accordance with yet other aspects of the present invention, a method for charging a battery includes connecting a pair of prongs of a battery charger to a power source and placing a battery into a battery receptacle area of the battery charger, wherein the battery is simultaneously maintained in a vertical charging position by a platform exerting a substantially uniform vertical pressure against a lower surface of the battery and a horizontal charging position by a piston exerting a substantially uniform horizontal pressure against a side surface of the battery. 
     In accordance with another aspect of the present invention, a method of manufacturing a battery charger assembly includes providing a housing configured to define a battery receptacle for receiving a battery therein, providing a piston internal to the housing that is urged toward the battery receptacle area by a spring, and providing a moveable platform internal to the housing that is urged toward the battery receptacle area by a spring, wherein a direction in which the piston is urged is substantially orthogonal to a direction in which the platform is urged. 
     It will become readily apparent to those skilled in the art from the following detailed description, wherein it is shown and described only exemplary configurations of a universal battery charger. As will be realized, the invention includes other and different aspects of an applicator and assembly and the various details presented throughout this disclosure are capable of modification in various other respects, all without departing from the spirit and scope of the invention. Accordingly, the drawings and the detailed description are to be regarded as illustrative in nature and not as restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a right exploded perspective view of the parts of a universal battery charger configured in accordance with one aspect of the disclosure; 
         FIG. 2  is a left exploded perspective view of the parts of a universal battery charger configured in accordance with one aspect of the disclosure; 
         FIG. 3  is a first cross-sectional view illustrating a first battery inserted into the universal battery charger for charging, in accordance with certain aspects of the present invention; 
         FIG. 4  is a second cross-sectional view illustrating a second battery inserted into the universal battery charger for charging, in accordance with certain aspects of the present invention; 
         FIG. 5  is a third cross-sectional view illustrating the second battery inserted into the universal battery charger for charging, in accordance with certain aspects of the present invention; 
         FIG. 6  is a fourth cross-sectional view illustrating the first battery inserted into the universal battery charger for charging, in accordance with certain aspects of the present invention; 
         FIG. 7  is a perspective view of the first battery being inserted into the universal battery charger, in accordance with certain aspects of the present invention; 
         FIG. 8  is a front elevation view of the universal battery charger before the first battery is inserted into the universal battery charger, in accordance with certain aspects of the present invention; 
         FIG. 9  is a front elevation view of the universal battery charger after the first battery has been inserted into the universal battery charger, in accordance with certain aspects of the present invention; 
         FIG. 10  is a front elevation view of the universal battery charger after the second battery has been inserted into the universal battery charger, in accordance with certain aspects of the present invention; 
         FIG. 11  is a front perspective view of the universal battery charger, in accordance with certain aspects of the present invention; 
         FIGS. 12 and 13  are cross-sectional views of the universal battery charger, in accordance with certain aspects of the present invention; 
         FIG. 14  is a right exploded perspective view of the parts of a second universal battery charger configured in accordance with one aspect of the disclosure; ( FIG. 1 ) 
         FIG. 15  is a perspective view of exemplary batteries with which the second universal battery charger of  FIG. 14  may be used; 
         FIG. 16  is a perspective cross-sectional view of the second universal battery charge into which a customized battery interface may be inserted in accordance with certain aspects of the present invention; 
         FIG. 17  is a perspective cross-sectional view of the second universal battery charger into which the customized battery adaptor has been inserted in accordance with certain aspects of the present invention; 
         FIG. 18  is a top plan cross-sectional view of the second universal battery charger into which the customized battery adaptor has been inserted in accordance with certain aspects of the present invention; 
         FIG. 19  is a perspective cross-sectional view of the second universal battery charger into which a third battery has been inserted in accordance with certain aspects of the present invention; 
         FIG. 20  is a top plan cross-sectional view of the second universal battery charger into which the third battery has been inserted in accordance with certain aspects of the present invention; 
         FIG. 21  is a top plan cross-sectional view of the second universal battery charger into which a fourth battery has been inserted in accordance with certain aspects of the present invention; and 
         FIG. 22  is a rear perspective view of a custom battery interface of the second universal battery charger configured in accordance with certain aspects of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Various aspects of the novel systems, apparatus, and methods are described more fully hereinafter with reference to the accompanying drawings. The teachings disclosed herein may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein one skilled in the art should appreciate that that the scope of disclosure is intended to cover any aspect of the novel systems, apparatus and methods disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. 
     Various aspects of a universal battery charger may be illustrated by describing components that are coupled, attached, and/or joined together. As used herein, the terms “coupled”, “attached”, and/or “joined” are used to indicate either a direct connection between two components or, where appropriate, an indirect connection to one another through intervening or intermediate components. In contrast, when a component is referred to as being “directly coupled”, “directly attached”, and/or “directly joined” to another component, there are no intervening elements present. 
     Relative terms such as “lower” or “bottom” and “upper” or “top” may be used herein to describe one element&#39;s relationship to another element illustrated in the drawings. It will be understood that relative terms are intended to encompass different orientations of a universal battery charger in addition to the orientation depicted in the drawings. By way of example, if a universal battery charger in the drawings is turned over, elements described as being on the “bottom” side of the other elements would then be oriented on the “top” side of the other elements. The term “bottom” can therefore encompass both an orientation of “bottom” and “top” depending on the particular orientation of the apparatus. 
     Various aspects of a universal battery charger may be illustrated with reference to one or more exemplary embodiments. As used herein, the term “exemplary” means “serving as an example, instance, or illustration,” and should not necessarily be construed as preferred or advantageous over other embodiments of a universal battery charger disclosed herein. 
       FIG. 1  is a right exploded perspective view of an exemplary universal battery charger  100  configured in accordance with one aspect of the disclosure, which is adapted to be able to operate with a variety of batteries of different sizes from a particular company, such as camera and/or camcorder batteries. Typically, batteries supplied by each company have the same voltage levels, and often only differ in physical aspects such as size. In many cases, the size is directly proportional to the amount of power storage of which the battery is capable because the size is based on the number of cells in each battery. A left exploded perspective view of the universal battery charger is illustrated in  FIG. 2 . 
     The universal battery charger  100  may include an outer housing  101  (see also  FIGS. 3 and 4 ) for protection of the electrical circuitry contained therein as well as for protection of the battery during charging. The outer housing  101  may be comprised of a cover  102  secured to a base portion  160  and may be made of any suitable non-conductive, impact resistant material, such as a hard plastic material, for example. The base portion  160  may be configured with an opening  162  so that, when the cover  102  is secured to the base portion  160 , the opening  162  provides access to an internal battery receptacle area  166  for receiving and securing a battery into the housing  101 . 
     The cover  102  may be configured with a window  104  through which a display circuit board  110 , used for displaying the charge/discharge status of the battery  190 , may be seen, as further described below. The display circuit board  110  may be used to display a charge/discharge completion time (e.g., estimated charge completion time), battery charge/discharge cycle time, current charging voltage, life of battery estimation, whether the charger is charging at a trickle charge rate, and other battery-related information. In one aspect of the disclosure, the display circuit board  110  may be implemented using one or more light emitting diodes (LEDs), such as an arrangement of LEDs  112  mounted on the top surface of the display circuit board  110 . The display circuit board  110  may also be implemented using liquid crystal displays (LCDs), analog displays (e.g., an analog meter), or other suitable means of displays. 
     The display circuit board  110  may be controlled by a main circuit board  114  capable of charging batteries of multiple voltages and having circuitry that automatically or manually adapts to the power profiles of different batteries, including voltage, total power capacity, battery chemistry type and recharging rate. In accordance with one aspect of the disclosure, the main circuit board  114  may include an automatic multi-voltage switching circuit for use with power outlets worldwide without additional adapters or attachments. In accordance with other aspects, the main circuit board  114  may be adapted to operate with the power supplied by a particular region, such as the 110-120V power used in the United States or the 220-240V power used in European countries. The base portion  160  may be configured with an opening  550  into which the main circuit board  114  and the display circuit board  110  are positioned. 
     In operation of the universal battery charger  100 , a battery, such as the battery  190  with contacts  192  depicted in  FIGS. 1 and 2 , may be inserted through the opening  162  in the base portion  160  to be received into the battery receptacle area  166 . According to one aspect of the present invention, an access slot  106  may be provided on the cover  102  to provide additional clearance for a user&#39;s finger, for example, to slidably insert the battery  190  into a position of contact with a plurality of pins  800 . Thus, the contacts  192  may be electrically coupled to the main circuit board  114  using the appropriate pins from the plurality of pins  800 , as seen in the various elevational views illustrated by  FIGS. 8 ,  11 ,  12  and  13 . 
     In one aspect of the disclosure, the plurality of pins  800  may be resiliently held into place by a frame  120  and the battery  190  may be held in a secure manner both (i) vertically and (ii) horizontally through the compression forces of (i) at least one bottom spring  150  pushing a platform  150  against the bottom of the battery  190 , and (ii) one or more side springs  152  pushing a piston  140  against the side of the battery  190 , respectively. 
     The frame  120 , in one aspect of the disclosure, may include one or more slots  124  that are matched to guides  142  on the piston  140 , the guides  142  being configured to slidably engage the one or more slots  124 . One or more slots may also be provided on a bottom surface of the top cover (not shown) that are configured to slidably engage guides  142  on the piston  140 . Thus, the guides  142  may engage the slots  124  in the frame  120  and/or the slots on the bottom surface of the cover  102  to encourage movement of the piston  140  in a defined manner horizontally without skewing or twisting, which prevents the piston  140  from becoming jammed. Similarly, the platform  130  may include two pair of guides  132 ,  134 , that are matched to two respective pair of slots  126 ,  122  on the frame  120  to encourage the platform  130  to move in a defined manner vertically without skewing or twisting, which can cause jams. In other aspects of the disclosure, any or all of the slots and guides may be eliminated or additional slots and guides may be added depending on the specific implementation. Generally, a larger platform  130  or piston  140  will require more guides and associated slots in the frame  120 . 
     The platform  130  may be configured with a spring seat for mounting the bottom spring  150  in a secured position. For example, as shown in  FIGS. 3 and 4 , the spring seat  136  may comprise a cylindrical bore formed in a thicker portion of the platform  130 , the bore extending from an upper platform plate  138  and having a diameter that is slightly greater than or equal to an outer radial diameter of the bottom spring  150 . When assembled, an end portion of the bottom spring  150  may be inserted into the spring seat  136  so that the bottom spring  150  is compressed between a bottom wall  161  of the base portion  160  and the platform plate  138  of the platform  130 . In this manner, the platform  130  is continuously urged upward by the spring force toward the battery receptacle area  166 . The bottom wall  161  of the base portion  160  may be formed with additional spring securing features, such as a spring post  163  and a retaining ring  165 , for example, to further ensure a secure positioning of the bottom spring  150 . Thus, in combination with the guides  134 , the spring seat  136  and the additional spring securing features may ensure the proper positioning and vertical movement of the platform  130 . According to another aspect of the present invention, the platform  130  may be configured with a detent  139  that engages a lip  167  configured on the base portion  160  to provide an upper limit on the extent to which the platform  130  may move upward into the battery receptacle area  166 . 
     The piston  140  may be configured with spring seats  144  for mounting the side springs  152  in a secured position. For example, as shown in  FIG. 5 , the spring seats  144  may comprise bores extending into a side surface of the piston  140  that have a diameter slightly greater than or equal to an outer radial diameter of the side springs  152 . When assembled, an end of the side springs  152  may be inserted into the spring seats  144  so that the side springs  152  are compressed between a side wall  167  of the base portion  160  and an inner wall  145  of the spring seat  144 . In this manner, the piston  140  may be continuously urged inward toward the battery receptacle area  166 . 
     The frame  120 , platform  130 , and piston  144  may be coupled together by way of the various guides and slots and mounted into the base portion  160  of the universal battery charger  100  with the bottom and side springs  150  and  152  respectively positioned as described above. The cover  102  may be secured to the base portion  160  in order to secure and maintain the internal components and circuitry of the universal battery charger  100  therein. As shown in  FIGS. 7 and 8 , for example, the platform  130  and the piston  140  extend into the battery receptacle area  166  and are capable of receiving a battery of varying dimensions. The platform  130  and the piston  140  may include slanted or beveled leading surfaces, for example, to further enable the easy insertion and acceptance of the battery into the battery receptacle area  166 . 
     As shown in  FIG. 3 , a first battery  302  with contacts  392  may be inserted through the opening  162  of the base portion  160  and received into the battery receptacle area  166  so that contacts on the battery engage the pins  800 .  FIG. 12  is a cross-section view of the first battery  302  being inserted into the opening  162 . The first battery  302  may be effectively clamped vertically between a lower surface of the cover  102  and an upper surface of the platform  130  as a result of the force of the bottom spring  150  being distributed by the platform  130  to exert a substantially uniform upward pressure against a lower surface of the first battery  302 . Similarly, as shown in  FIGS. 6 and 9 , the first battery  302  may be effectively clamped horizontally between the piston  140  and the frame  120  or a sidewall of the base portion  160  as a result of the force of the side springs  152  being distributed by the piston  140  to exert a substantially uniform inward pressure against a side surface of the first battery  302 . The dually applied and distributed spring forces may simultaneously maintain the first battery  302  in a secure vertical and horizontal charging position. 
     Referring to  FIG. 4 , a second battery  402  that is of a smaller size than the first battery  302  may be inserted into the opening  162  of the bottom housing  160 . As described above, the second battery  402  may be maintained in an effective vertical charging position by being held secure against the bottom of the cover  102  due to the force of the bottom spring  150  on the platform  130  exerting a distributed upward pressure against a lower surface of the second battery  402 . Also referring to  FIGS. 5 and 10 , it is illustrated that the second battery  402  may be maintained in an effective horizontal charging position by being held secure against the frame  120  or a side wall of the base portion  160  due to the force of the springs  152  on the piston  140  exerting a distributed inward pressure against a side surface of the second battery  402 . In the case of a smaller battery, the access slot  106  may provide access for a user to effect positioning of the battery in the battery receptacle area  166 . In another aspect of the present invention, the battery may be positioned in the battery receptacle area  166  simply by direct longitudinal pushing of a distal end of the battery through the opening  162 . 
     As seen in  FIGS. 5 and 6 , the base portion  160  may include a plurality of screw holes  502  for securing the cover  102  using a plurality of screws. As further seen in  FIG. 13 , an example of a screw hole  504 , into which a screw is inserted into a matching screw hole  502  in the base portion  160  may be secured, is shown in the top cover  102 . Although shown with screw holes for securing the cover  102  to the base portion  160  with screws, any suitable securing means may be used, including adhesives, welding, heat bonding, tab and slot configurations, and press fitting, for example. 
     The universal battery charger  100  may be configured with a fold-away wall plug  170 . As shown in  FIGS. 1-4 , the wall plug  170  may be built into the base portion  160  with a pair of prongs  174  that is electrically connected to the main circuit board  114 . The fold-away wall plug  170  may include a rod  172  that is used to pivot the fold-away wall plug  170  from a first position, where the pair of prongs  174  is substantially flush with a lower surface  164  of the bottom housing  160 , to a second position, where the pair of prongs  174  may be deployed to extend substantially orthogonally from the lower surface  164  to be inserted into a power outlet. In one aspect, the prongs  174  of the fold-away wall plug  170  may be changed to other shapes for compatibility with the power outlets of any country. 
       FIG. 14  is a right exploded perspective view of a second exemplary universal battery charger  1400  configured in accordance with one aspect of the disclosure, which is adapted to be able to operate with a variety of batteries of different sizes for such devices as Digital Single-Lens Reflex (DSLR) cameras. Typically, batteries supplied by different companies have different voltage levels, and also differ in physical aspects such as in contact layout as well as size. In many cases, the size is directly proportional to the amount of power storage of which the battery is capable because the size is based on the number of cells in each battery. The second exemplary universal battery charger  1400  is able to operate with the various batteries supplied by different companies via a customized battery interface as further described herein. 
     The universal battery charger  1400  includes a cover  1402  secured to a base portion  1460  and may be made of any suitable non-conductive, impact resistant material, such as a hard plastic material, for example. The base portion  1460  may be configured with an opening  1462  so that, when the cover  1402  is secured to the base portion  1460 , the opening  1462  provides access to an internal battery receptacle area  1466  (see also  FIG. 16 ) for receiving and securing a battery such as batteries  1490   a,b  into the housing. 
     The cover  1402  may be configured with a window  1404  through which a display circuit board similar to the display circuit board  110  of the embodiment described in  FIGS. 1-13 , may be used for displaying the charge/discharge status of the batteries  1490   a,b , as further described below. The display circuit board may be controlled by a main circuit board  114 , similar to the main circuit board  114  of the previously described embodiment, which is also capable of charging batteries of multiple voltages and having circuitry that automatically or manually adapts to the power profiles of different batteries, including voltage, total power capacity, battery chemistry type and recharging rate. The main circuit board is accessed through a plurality of contacts  1800 . 
     In operation of the universal battery charger  1400 , a battery, such as the batteries  1490   a,b  with contacts  1492   a,b  depicted in  FIG. 15 , may be inserted through the opening  1462  in the base portion  1460  to be received into the battery receptacle area  1466 . According to one aspect of the present invention, an access slot  1406  may be provided on the cover  1402  to provide additional clearance for a user&#39;s finger, for example, to slidably insert batteries  1490   a,b  into a position of contact with a plurality of contacts  2200   a,b  on custom battery interfaces  1414   a,b . Thus, the contacts  1492   a,b  may be electrically coupled to the main circuit board of the charger using the appropriate contacts from the plurality of contacts  2200   a,b , as seen in the various views illustrated by  FIGS. 16-21  and as further described herein. 
     In one aspect of the disclosure, the plurality of contacts  1800  may be resiliently held into place by a frame  1420  and exposed via a plurality of openings  1802 . A custom battery interface such as the custom battery interfaces  1414   a,b  may be used to provide customized interfaces between the plurality of contacts  1800  and the contacts for the batteries  1490   a,b . For example, the custom battery interface  1414   b  may be used to electrically interface the contacts  1800  to the contacts  2200   b  so that the battery  1490   b  may be coupled to the main circuit board. The customized battery interfaces may be easily changed by a user inserting and removing the interfaces through an opening  1468  in the base portion  1460  and into an opening  1428  of the base  1420 . The custom battery interfaces may be held securely by their insertion into a slot  1408  with retaining rails  1410  in the cover  1402  that is matched to such features as slots  1412   a,b  in the custom battery interfaces  1414   a,b . After insertion, the custom battery interfaces  1414   a,b  are retained in an interface retaining portion  1668 . Thus, batteries of various electrical contact arrangements, including batteries with different number of contacts, may be charged using the same main circuit board. 
       FIG. 22  illustrates a plurality of contacts  2300   a  for the custom battery interface  2214   a  of the second universal battery charger  1400  configured in accordance with certain aspects of the present invention. As shown, the custom battery interface  2214   a  also include a slot  2212   a  to mate with retaining rails  1410  in the cover  1402 , as discussed with the slot  1412   a . As discussed above, the main circuit board is used to generate voltage and current to charge a variety of batteries that is connected to the second universal battery charger  1400 . In order to interface with all the different batteries, different custom battery interfaces may be used, as shown above. It should be noted that any number of contacts may be used for electrically interfacing the main circuit board to a battery. Thus, the number of contacts in the plurality of contacts on the custom battery interface that is used to interface the main circuit board with the battery may be customized. 
     As discussed further below, a battery such as the battery  1490   b  may be held in a secure manner both (i) vertically and (ii) horizontally through the compression forces of (i) at least one bottom spring  1450  pushing a platform  1450  against the bottom of the battery  1490   b , and (ii) one or more side springs  1452  pushing a piston such as an arm  1440  against the side of the battery  1490   b , respectively. Thus, batteries of various sizes may be held securely within the universal battery charger  1400 . 
     The frame  1420 , in one aspect of the disclosure, may include one or more slots that are used to retain guides on the platform  1430 . For example, the platform  1430  may include two pair of guides  1432 ,  1434  that are matched to two respective pair of slots  1426 ,  1422  on the frame  1420  to encourage the platform  1430  to move in a defined manner vertically without skewing or twisting, which can cause jams. In other aspects of the disclosure, any or all of the slots and guides may be eliminated or additional slots and guides may be added depending on the specific implementation. Generally, a larger platform  1430  will require more guides and associated slots in the frame  1420 . 
     The platform  1430  may be configured with a spring seat for mounting the bottom spring  1450  in a secured position. Similar to the use of the spring seat  136  of the earlier described embodiment, as shown in  FIGS. 3 and 4 , when assembled, an end portion of the bottom spring  1450  may be inserted into the so that the bottom spring  1450  is compressed between a bottom wall of the base portion  1460  and the platform  1430 . In this manner, the platform  1430  is continuously urged upward by the spring force toward the battery receptacle area  1466 . The bottom wall of the base portion  1460  may be formed with additional spring securing features, such as a spring post  163  and a retaining ring  165  of the previous embodiment, for example, to further ensure a secure positioning of the bottom spring  1450 . Thus, in combination with the guides  1434 , the spring seat and the additional spring securing features may ensure the proper positioning and vertical movement of the platform  1430 . According to another aspect of the present invention, the platform  1430  may be configured with a detent that engages a lip configured on the base portion  1460  to provide an upper limit on the extent to which the platform  1430  may move upward into the battery receptacle area  1466 . 
     The arm  1440  may be configured with spring retaining tabs  1444  for retaining the side springs  1452  in a secured position. For example, the arm  1440  may comprise openings  1446  extending into a surface of the tabs  1444  for a pin (not shown) to secure the side springs  1452 . When assembled, an end of the side springs  1452  may be inserted into the arm  1440  so that the side springs  1452  are compressed between a side wall  1467  of the base portion  1460  and an inner wall of the arm  1440 . In this manner, the arm  1440  may be continuously urged inward toward the battery receptacle area  1466 . 
     The frame  1420 , platform  1430 , and arm  1444  may be coupled together by way of the various guides and slots and mounted into the base portion  1460  of the universal battery charger  1400  with the bottom and side springs  1450  and  1452  respectively positioned as described above. The cover  1402  may be secured to the base portion  1460  in order to secure and maintain the internal components and circuitry of the universal battery charger  1400  therein. As shown in  FIGS. 17 and 18 , for example, the platform  1430  and the arm  1440  extend into the battery receptacle area  1466  and are capable of receiving a battery of varying dimensions. The platform  1430  and the arm  1440  may include slanted or beveled leading surfaces, for example, to further enable the easy insertion and acceptance of the battery into the battery receptacle area  1466 . 
     As shown in  FIG. 19 , the battery  1490   b  with the contacts  1492   b  may be inserted through the opening  1462  of the base portion  1460  and received into the battery receptacle area  1466  so that contacts  1492   b  on the battery  1490   b  engage the contacts  2200   b  on the battery interface  1414   b , and through which, the contacts  1800 . The battery  1490   b  may be effectively clamped vertically between a lower surface of the cover  1402  and an upper surface of the platform  1430  as a result of the force of the bottom spring  1450  being distributed by the platform  1430  to exert a substantially uniform upward pressure against a lower surface of the battery  1490   b . Similarly, as shown in  FIGS. 19 and 20 , the battery  1490   b  may be effectively clamped horizontally between the arm  1440  and the frame  1420  or a sidewall of the base portion  1460  as a result of the force of the side springs  1452  being distributed by the arm  1440  to exert a substantially uniform inward pressure against a side surface of the battery  1490   b . The dually applied and distributed spring forces may simultaneously maintain the battery  1490   b  in a secure vertical and horizontal charging position. 
     Referring to  FIG. 21 , the battery  1490   a  that is of a smaller size than the battery  1490   b  may be inserted into the opening  1462  of the bottom housing  1460 . As described above for the battery  1490   b , the battery  1490   a  may be maintained in an effective vertical charging position by being held secure against the bottom of the cover  1402  due to the force of the bottom spring  1450  on the platform  1430  exerting a distributed upward pressure against a lower surface of the battery  1490   a , so that the battery  1490   a  may be maintained in an effective horizontal charging position by being held secure against the frame  1420  or a side wall of the base portion  1460  due to the force of the springs  1452  on the arm  1440  exerting a distributed inward pressure against a side surface of the battery  1490   a . In the case of a smaller battery, the access slot  1406  may provide access for a user to effect positioning of the battery in the battery receptacle area  1466 . In another aspect of the present invention, the battery may be positioned in the battery receptacle area  1466  simply by direct longitudinal pushing of a distal end of the battery through the opening  1462 . 
     The universal battery charger  1400  may be configured with a fold-away wall plug similar to the fold-away wall plug  170  as shown in  FIGS. 1-4  of the previously described embodiment, the wall plug  170  may be built into the base portion  160  with a pair of prongs that is electrically connected to the main circuit board. The fold-away wall plug may pivot from a first position, where the pair of prongs is substantially flush with a lower surface of the bottom housing  1460 , to a second position, where the pair of prongs may be deployed to extend substantially orthogonally from the lower surface of the outer housing  1460  to be inserted into a power outlet. In one aspect, the prongs of the fold-away wall plug may be changed to other shapes for compatibility with the power outlets of any country. 
     The previous description is provided to enable any person skilled in the art to understand fully the full scope of the disclosure. Modifications to the various configurations disclosed herein will be readily apparent to those skilled in the art. Unless specifically stated otherwise, the terms “some” or “at least one” refer to one or more elements. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by any claims that may be directed to the various aspects. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited by any claims.