Abstract:
A portable power station including a current, light, and voltage sources as well as a control panel to permit a user to selectively operate the current and light sources. A housing contains the sources and is suitable to contain a main power source that has positionally fixed and polarized power terminals. The housing includes positionally fixed attachment posts to which the polarized conductors of the sources are electrically connected, and which are suitable for electrical connection of the polarized power terminals of the main power source.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/883,615, filed Sep. 27, 2013, hereby incorporated by reference in its entirety. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
       [0003]    Not applicable. 
       INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC 
       [0004]    Not applicable. 
       COPYRIGHT NOTICE AND PERMISSION 
       [0005]    This document contains some material which is subject to copyright protection. The copyright owner has no objection to the reproduction with proper attribution of authorship and ownership and without alteration by anyone of this material as it appears in the files or records of the Patent and Trademark Office, but otherwise reserves all rights whatsoever. 
       BACKGROUND OF THE INVENTION 
       [0006]    1. Technical Field 
         [0007]    The present invention relates generally to methods and apparatus for controlled or regulated charging, discharging, or combined charging and discharging of power sources, such as batteries, and more particularly to where an internal such power source charges or operates an external second power source. 
         [0008]    2. Background Art 
         [0009]    In some manner, we have had electrical power stations nearly as long as we have had electrical power sources. Of present interest are electrical power stations that followed the addition of electrical starting and other electrical accessories in motor vehicles. Such power stations typically have had to meet the electrical requirements of their end application as well as be nominally portable to often be transported to such applications. For instance, a common application is to start an automobile where the owner has left the headlights on depleted the vehicle&#39;s battery. A power station suitable for this application must provide 12 volt direct current at sufficient amperes to operate the starter of the vehicle (typically while the vehicle&#39;s battery is still connected and presents an additional load as it recharges). Such a power station also usually must be portable to wherever a vehicle&#39;s owner parked when they left the headlights, typically a parking lot at their place of employment or at a store or restaurant. 
         [0010]    The simplest power station for such an application is another vehicle that has a powerful enough battery, and a set of jumper cables. This simple solution, however, is not one that automotive and other service professionals are comfortable with. For example, a small service vehicle used to service large trucks in the field may not inherently come with or even be fit able with a large enough battery. Moreover, even when this can be done it is inefficient, in the small service vehicle when it is used for other tasks, and it is risky. Batteries become “weak” over time and use, and an aged or heavily used battery that starts a small service vehicle may embarrassingly not still be strong enough in a service application. 
         [0011]    Most service professionals tend to prefer stand alone power stations. Historically, continuing mostly with automotive service scenarios but obviously extendable to aviation, nautical, and many other applications as well, a service profession would build or buy a power station with a large battery in an at least semi-portable housing, the a set of heavy cables terminated with suitable clams. In auto service stations one will frequently see such a power station today. It usually has two wheels, to permit easy limited movement, and it can be lifted into a service vehicle for field service calls. 
         [0012]    Our society has increasingly come to rely on electrical power, and especially direct current power. Let us consider a few examples. Automobiles are now ubiquitous in some places, but so are cellular telephones and laptop computers. In fact many of us routinely use chargers for these devices that attach to a 12 volt DC power source in our automobiles. Many emergency and other specialty radios today can additionally be or are exclusively are powered with 12 VDC. Some televisions, small air compressors, lighting systems, and heating systems similarly can use 12 VDC. Ironically, an increasingly common electronic device today is power inverters, to convert 12 VDC to 120 or 240 volts, 60 cycle alternating current (AC) power. 
         [0013]    Increasingly, people who are not service professionals, as well as ones who are but who want an appliance for personal use, are interested in power stations. These prospective new users want more than an expensive and awkward to handle box. They are willing to compromise on power to get economy, portability, and safety. Unlike service professionals, users here typically need a solution that can be stored between infrequent uses, that can be reliable when needed, and that is safe and easy. Thus, unlike professional service scenarios where lead technology batteries with their attendant their flammable hydrogen fumes, corrosive sulfuric acid, and expensive and environmentally threatening disadvantages may be manageable, a potential user here prefers a non lead-based power source or at least a very reliably sealed and storage-life optimized lead-based power source. 
         [0014]    Moreover, these users typically have specific applications in mind and they want a power station that as flexibly as possible fulfills those applications as well as others that they may later encounter. These prospective new users often want sophistication in a power station. Many would like an air compressor and/or a power inverter integrated into a power station, but commercial offerings of such are not common. 
         [0015]    Often unappreciated until needed, many such users (as well as many service professionals) would like a power station that provides lighting. There are only two basic ways hook two power sources, such as an automobile battery and a power station. When one cannot see what they are doing they will get it wrong 50% of the time, with great risk to safety and equipment. Service professionals appreciate this an strive to get it right, by also have a separate light source and using it (e.g., having an assistant hold a flash light, even if they have to wait for or go ask an assistant to do this). Lay users are not always so prepared in advance, or so patient, or will have read a power station&#39;s safety and usage instructions. 
         [0016]    Accordingly, there is a growing market for economical power stations, but this market is not currently well served. Those who have tried to serve this market have tended to not study to scope of the market, and thus have tried to serve this market with offerings that retailers and end users find lacking. 
         [0017]    Having mentioned retailers for the first time, let us consider their concerns. When a retailer has an adult in a suite or any adolescent buy a set of jumper cables the retailer cringes. In exchange for a relatively small profit, the retailer is taking a serious risk of litigation. Does an adult man or woman in a suit know how to work with lead-acid technology? For that matter does an adult in overalls know this? Has an adolescent enough life experience that a personal injury jury would find it reasonable to sell them jumper cables? Is such a retailer now willing to also stock and sell economical power stations? Clearly, such power stations must be as inherently safe and intuitively usable as possible. 
         [0018]    Current economical-grade power stations offerings are jumper cables, already discussed at length; trickle chargers; and secondary battery-in-a-boxes. A trickle charger, in this context, is an AC powered battery charger. Its portability is limited to the length of extension cords that one can use to connect it to an AC power source. In general, trickle chargers put out such a small current (a “trickle) that connecting them incorrectly is relatively safe and at most damages the application or the trickle charger itself. 
         [0019]    In contrast, a secondary battery-in-a-box is kludge, usually a minimalist make do solution. A battery-in-a-box is distinguishable from a professional-grade stand alone power station, and from the about to be disclosed invention, in that these other solutions are optimized for suitability for their anticipated users and their particular end applications. As the label “battery-in-a-box” implies, this usually consists of a box, often an ice chest or a container that markedly resembles one; a battery, very often a standard automotive lead-acid battery; and a set of cable clamps. 
         [0020]    The ice-chest rebalance of battery-in-a-box devices can perhaps be attributed to a desire to evoke similar convenience in the minds of potential buyers. This is unfortunate, since a potential buyers should instead be considering if the device has drainage, if sulfuric acid exits the power source, or ventilation if hydrogen gas exits the power source. Potential purchasers of a battery-in-a-box are frequently enticed by claims of high power output and fast recharge ability, with these claims achieved by not “going cheap” on the standard automotive lead-acid battery and the charger used. This exacerbates sulfuric acid and hydrogen gas risks. Bigger battery-in-a-box devices often have wheels in the same manner as larger ice chests. Where manufactures of battery-in-a-box devices do sometimes do go cheap is on cable clamps. Copper is relatively expensive, hence savings can be had by using less of it. This can be done by using smaller gage wire in cables, providing shorter cables, and using little copper and more plastic in clamps. 
         [0021]    Typically, battery-in-a-box devices are only a high current or ampere-hours solution, but the present inventor has recently observed one exception. Recently a Chinese-manufactured battery-in-a-box device has appeared in some U.S. automotive accessory stores that includes a 120/240 VAC power inverter. 
       BRIEF SUMMARY OF THE INVENTION 
       [0022]    Accordingly, it is an object of the present invention to provide a improved power station. 
         [0023]    Briefly, a preferred embodiment of the present invention is an a power station suitable for portable use by a human user. Included is a current source, a light source, and a voltage source each having positive and negative polarity conductors. Further included is a control panel including controls to permit the user to selectively operate the current and light sources. A housing contains the sources and control panel, and is suitable to contain a main power source that has positionally fixed positive and negative power terminals. The housing has positionally fixed attachment posts to which the polarized conductors of the sources are electrically connected, and which is also suitable for electrical connection of the positive and negative power terminals of the main power source. 
         [0024]    These and other objects and advantages of the present invention will become clear to those skilled in the art in view of the description of the best presently known mode of carrying out the invention and the industrial applicability of the preferred embodiment as described herein and as illustrated in the figures of the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         [0025]    The purposes and advantages of the present invention will be apparent from the following detailed description in conjunction with the appended figures of drawings in which: 
           [0026]      FIG. 1  is a schematic block diagram depicting how the functions of the portable modular power station are integrated together. 
           [0027]      FIG. 2  is a perspective view of an exemplary power station in accord with the present invention. 
           [0028]      FIG. 3  shows the control panel of the power station in  FIG. 2 . 
           [0029]      FIG. 4  shows the lighting panel of the power station in  FIG. 2 . 
           [0030]      FIG. 5  shows the back of the power station with the main power source being installed. 
           [0031]      FIG. 6  also shows the back of the power station with some of the components of the control panel and the lighting panel being installed. 
           [0032]      FIG. 7  shows the front of the power station with the rest of the control panel being installed. 
           [0033]      FIG. 8  is an exploded view of the entire power station. 
           [0034]      FIG. 9  is a cross-section view along section A-A in  FIG. 2 . 
           [0035]      FIGS. 10   a - b  are schematic views showing how the same attachment posts can receive two alternated sizes of the main power source of the power station. 
           [0036]      FIGS. 11   a - b  are front and rear views, respectively, of an option module for use with the power station, here an air compressor module. 
           [0037]      FIG. 12  shows how option modules are connected to the power station, in essence, being “piggy-backed” onto the back shell piece of the housing. 
           [0038]      FIG. 13  is a stylized and basic schematic diagram of an electrical diagram for circuitry suitable for use in the inventive power station. 
       
    
    
       [0039]    In the various figures of the drawings, like references are used to denote like or similar elements or steps. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0040]    A preferred embodiment of the present invention is a portable modular power station. As illustrated in the various drawings herein, and particularly in the views of  FIGS. 1-2 , wherein an embodiment of the invention is depicted by the general reference character  10 . 
         [0041]    The present invention is termed a “portable modular power station” because it is portable (i.e., it can be easily moved about by a human adult) modularly assembled, yet provides a set of functions (functions  12  collectively and functions  12   a - d  individually) that traditionally are found only in a stationary setting. For instance, the power station  10  may provide a heavy current sourcing function  12   a , a light sourcing function  12   b , an external device voltage sourcing function  12   c , and an optional module source function  12   d.    
         [0042]    The current sourcing function  12   a  of the power station  10  may particularly be used for jump starting vehicles and charging batteries, as well as for many other tasks that require high amperage direct current or high ampere-hours power. For instance, the power station  10  might be used to power heating cables wrapped around water pipes in a home during a cold spell or to power radio communications equipment in an emergency situation. 
         [0043]    The light sourcing function  12   b  of the power station  10  may be used for illumination and signaling. For instance, a very common problem when jump starting a vehicle is lack of illumination to correctly and safely connect jumper cables to the vehicle battery. Light as a signal can take many forms. Thus, for example, a user could set the power station  10  where it can be seen, say, to warn passing motorists to be cautious when driving by. Or a user could waive the power station  10  from side to side to both draw attention and to imply a safe direction for passing motorists to taken when driving by. Due to the already discussed high ampere-hours capability, the power station  10  can provide light for at least some hours. 
         [0044]    The voltage sourcing function  12   c  of the power station  10  include sourcing 12 VDC at a conventional automotive type accessory female plug (sometimes called a cigarette lighter plug) and sourcing 5 VDC at a conventional USB type-A female plug. The range of external devices that can be powered by or recharged from these two types of plugs and voltages is huge, including medium power devices like marine-band radios and low power devices like cellular telephones. 
         [0045]    Finally, the module source function  12   d  of the power station  10  can include any option that can use 12 VDC and for which there is a need. One embodiment described below includes an air compressor function. This permits inflating vehicle tires to their correct pressure, the repair of flats, inflating of inflatable boats, toys, etc. This can also be used as a source of compressed air for typical “shop uses,” such as blowing away dust, flushing sludge out of narrow hoses, etc. Another optional module for the power station  10  that the inventor is presently working on is a power inverter function, to convert 12 VDC to 120/240 VAC. 
         [0046]      FIG. 1  is a schematic block diagram depicting how the functions  12  of the power station  10  are integrated together. The current sourcing function  12   a , light sourcing function  12   b , and voltage sourcing function  12   c  are literally integrated within a housing  14 , whereas the optional module source function  12   d , when present, is physically attached to the exterior of the housing  14 . 
         [0047]      FIG. 2  is a perspective view of an exemplary power station  10  in accord with the present invention. This power station  10  does not include an optional module source function, although one might be added. The major physical feature of the power station  10  is the housing  14 , that, in turn, has a front shell piece  16 , a back shell piece  18 , a handle unit  20 , and two base units  22 . The power station  10  here also has two large cable clamps  24  (a positive clamp  24   a  and a negative clamp  24   b ) which are used in straightforward manner for the heavy current or power sourcing function. 
         [0048]    As can also be seen in  FIG. 2 , the front shell piece  16  of the housing  14  here includes a control panel  26 , a lighting panel  28 , and a face panel  32 . The control panel  26  permits a user of the power station  10  to controllably employ its features and to receive feedback about those features. The lighting panel  28  provides the lighting functionality of the power station  10 , and is controlled by the control panel  26 . The face panel  32  is a location where information about the power station  10  is typically put. 
         [0049]      FIG. 3  shows the control panel  26  of the power station  10  in  FIG. 2 . A rubber-like flip-up door  34  is provided to protect both an underlying automotive accessory plug  36  (a female plug able to source 12 VDC) and an underlying USB type-A plug  38  (a female plug able to source 5 VDC). A charge gauge  40  is provided to indicate the state of charge of the main power source inside the power station  10 . In the embodiment here the charge gauge  40  includes multiple light emitting diodes (LEDs) that are red, yellow, and two shades of green. Pressing a charge check button  42  completes a circuit with the charge gauge  40  and the main power source, permitting the LEDs to graphically and colorfully indicate the state of charge. A charging port  44  is provided to permit connection of an external charging unit (not shown) that can charge some versions of the main power source in straightforward manner. A lighting button  46  is provided to control the lighting panel  28 , discussed presently. And a main power switch  48  is provided to control connection of the terminals of the main power source to the cable clamps  24 . 
         [0050]      FIG. 4  shows the lighting panel  28  of the power station  10  in  FIG. 2 . Included here is a clear lens  52  that covers white-light LEDs  54  (three LEDs is preferred, but that quantity is not a limitation). Simple embodiments of the power station  10  can have the lighting button  46  permit toggling the white-light LEDs  54  on and off. More sophisticated embodiments can have the lighting button  46  permit cycling through the white-light LEDs  54  in various other useful manners. 
         [0051]      FIG. 5  shows the back of the power station  10  with a main power source  56  being installed. As can be seen, the main power source  56  is contained fully in a compartment  58  in the back shell piece  18  of the housing  14 , behind a compartment door  60 . A subtle but very beneficial aspect of the power station  10  that can be appreciated here is that the main power source  56  is installed nearly last, after all of the other functional elements have been installed. Thus, all of the controls will have been installed into or inside of the housing  14  and the front shell piece  16  and the back shell piece  18  will have been assembled together before the main power source  56  is installed. This permits easy, modular, flexible, and robust assembly to be particular benefits of the power station  10 . A more detailed discussion of these benefits and the main power source  56  are provided, below. 
         [0052]      FIG. 6  shows the back of the power station  10  with the handle unit  20  being installed. The handle unit  20  has end blocks  62  that engage with corresponding end openings  64  in the top of the front shell piece  16 . In a later assembly stage than shown in  FIG. 6  (see e.g.,  FIG. 8 ), the back shell piece  18  which has similar end openings is added, thus capturing the end blocks  62 . When screws are inserted to attach the back shell piece  18  to the front shell piece  16  two such screws pass through the back shell piece  18 , into the end openings there, through the end blocks  62  of the handle unit  20 , into the end openings  64  of the front shell piece  16 , and part way into the front shell piece  16 . This particularly clamps the handle unit  20  securely in the finally assembled power station  10 . 
         [0053]      FIG. 6  also shows the back of the power station  10  with some of the components of the control panel  26  and the lighting panel  28  being installed. The automotive accessory plug  36  and the USB type-A plug  38  are part of a device plug block  66  that is installed as a unit. Similarly, the main power switch  48  is installed as a unit. In alternate embodiments, the entire control panel  26  can be installed as a single pre-assembled a module. Two attachment posts  68  (a positive post  68   a  and a negative post  68   b ) are also shown being installed here, and are discussed in more detail presently. Finally, the lighting panel  28  is installed here as a module. 
         [0054]      FIG. 7  shows the front of the power station  10  with the rest of the control panel  26  being installed. Specifically, a cover plate block  72  is installed that will cover the device plug block  66  and the main power switch  48 . This cover plate block  72  also includes the flip-up door  34 , charge gauge  40 , charge check button  42 , charging port  44 , and lighting button  46 . 
         [0055]      FIG. 8  is an exploded view of the entire power station  10 . In addition to providing a summary of aspects already discussed, the view here particularly helps to see some overall features of the power station  10 . For example, here it can be seen how the base units  22  engage over both the front shell piece  16  and the back shell piece  18 , to clamp and hold these together and thus make the overall housing  14  of the power station  10  much more robust. Returning briefly also to  FIG. 7 , it can be seen that the front shell piece  16  has two wing pieces  74  (top wings  74   a ) and that the base units  22  each also have two wing pieces  74  (bottom wings  74   b ). When the power station  10  is not in use the cable clamps  24  each can have the cable portion wrapped around the wing pieces  74  and the clamp portion clamped onto a respective wing piece  74 , as shown (see also,  FIGS. 2 ,  5 ). 
         [0056]    Continuing with  FIG. 8 , the use of screws in the final assembly of the power station  10  should be noted. Proceeding left to right, a first final screw set  76  comprises screws that attach the cover plate block  72 . A block screw set  78  comprises screws that assemble the cover plate block  72 , but at final assembly these are already installed as part of the cover plate block  72 . A third final screw set  80  comprises screws that attach the base units  22  to the front shell piece  16  and the back shell piece  18  of the housing  14 . Next to the right is a components screw set  82  that comprises screws that assemble components to the front shell piece  16  (for instance, the main power switch  48 ). At final assembly these are also already installed. A terminal screw set  84  comprises two screws, discussed in detail presently. A second final screw set  86  comprises screws to attach the back shell piece  18  to the front shell piece  16 . And a fourth final screw set  88  comprises screws to attach the compartment door  60  to the back shell piece  18 . 
         [0057]    The block screw set  78  and the components screw set  82  will already be installed prior to final assembly. The first final screw set  76  will therefore typically be the first set of screws installed during final assembly. Then the back shell piece  18  and the front shell piece  16  are mated together and the second final screw set  86  is installed. The base units  22  are installed with the third final screw set  80 . Now, or at some later time, the main power source  56  is installed, with the terminal screw set  84 . And the compartment door  60  is mated with the back shell piece  18  and the fourth final screw set  88  is installed. 
         [0058]    Next consider the orientation of the screws during assembly. The first final screw set  76  ultimately is at a downward angle relative to the power station  10  when finished, but during assembly the front shell piece  16  can simply be rotated as desired to facilitate installing the first final screw set  76 . Installing the block screw set  78  is even easier, since the cover plate block  72  can be rotated to face down and direct vertical and downward installation of the block screw set  78  can be used. The same manner of rotation to face down and direct vertical and downward installation of the components screw set  82 , terminal screw set  84 , second final screw set  86 , and fourth final screw set  88  can be employed. The installation of the third final screw set  80  (for the base units  22 ) then requires horizontal installation or another rotation. 
         [0059]      FIG. 9  is a cross-section view along section A-A in  FIG. 2 . Here a major safety feature of the power station  10  can be observed (see also,  FIG. 5 ). The main power source  56  cannot be incorrectly installed (e.g., with the electrical polarity reversed). The main power source  56  has two power terminals  92  (a positive terminal  92   a  and a negative terminal  92   b ) that are fixed in position. In particular, the terminals  92   a - b  are much closer to the “front” of the main power source  56 . Inside the front shell piece  16  the attachment posts  68  are fixedly mounted in positions able to connect to the terminals  92   a - b  only when they are close. Thus, for instance, putting the main power source  56  in “backwards” will result in the terminals  92   a - b  being displaced away from and not being connectable with the attachment posts  68 . This is a substantial safety improvement over other systems that employ high-power automotive type batteries that can be incorrectly installed or incorrectly connected, e.g., due to the use of movable cables for connection. 
         [0060]      FIGS. 10   a - b  are schematic views showing how the same attachment posts  68  can receive two alternated sizes of the main power source  56  (shown in ghost outline).  FIGS. 10   a - b  show the same attachment posts  68 , and how they are mounted inside the front shell piece  16  ( FIG. 6 ) with mounting screws  94  holding them in place. The attachment posts  68  here are L-shaped brackets. Other shaped brackets may alternately be used, of course. For example, brackets that are L-shaped or angular in one plane but have a z-offset in another plane. The point in labeling these “posts” is to invoke a point like image of electrical connection points, one where positive electrical connection occurs and one where negative connection occurs. The attachment posts  68  each have wiring screws  96  that receive respective wires  98 , positive polarity wires  98   a  to the positive post  68   a  and negative polarity wires  98   b  to the negative post  68   b . In keeping with the goal of modularity in the power station  10 , an effective minimum of wires  98  are employed (as described in more detail presently). The back shell piece  18  has openings that provide access from the compartment  58  to the attachment posts  68 , thus permitting connection of a main power source  56  to the attachment posts  68  with the terminal screw set  84 . 
         [0061]    Continuing with the attachment posts  68 , the ones shown in the figures herein are nominally “L-shaped,” that is, they have the positions for the wiring screws  96  and the connection points  102  closer together rather than at opposed ends of I-shaped attachment posts  68 . This is not a requirement, for example, the attachment posts  68  could be straight (e.g., I-shaped or have another shape), but this L-shape permits an overall more compact construction of the power station  10 , as well as more subtle benefits like minimizing the areas of the openings from the compartment  58  to the interior of the power station  10 , etc. 
         [0062]    In this manner the power station  10  can be fully assembled except for installation of the main power source  56  and closing the compartment  58  by installing the compartment door  60  with the fourth final screw set  88 . In particular, all operations related to installation, connection, disconnection, replacement, upgrade, etc. of the main power source  56  are compartmentalized. 
         [0063]    The main power source  56  will typically be a 12 volt automotive type battery, but a one-use chemical power pack and fuel cells are potential alternates. The main power source  56  thus will necessarily require periodic access, and the power station  10  especially provides for and facilitates this in a manner that is easy and safe, and that does not require extensive disassembly (e.g., separating the front shell piece  16  and the back shell piece  18 , and/or tampering with other wiring or any internal parts). 
         [0064]      FIG. 10   a  shows a typical full or maximum size main power source  56  installed. One that will permit maximum capacity of the functions provided by the power station  10 . In contrast,  FIG. 10   b  shows a smaller size main power source  56  installed, with bridge bars  100  added. One that will provide a lesser capacity of the functions provided by the power station  10 . Embodiments of the power station  10  thus can be manufactured with one size of compartment  58  and be provided to end users with a variety of function capacities. 
         [0065]    Many benefits are provided by this arrangement. The power station  10  can be manufactured and distributed without a main power source  56  installed. Then the party providing the power station  10  (e.g., a wholesaler providing to a retailer, or a retailer selling to an end user) can install a main power source  56  of a size and type as desired. One core model of the power station  10  can be stocked yet a variety of models can be provided to end users. Additionally, since the main power source  56  can be installed later, a larger single production run may be made and stocked without concern about the main power source  56  aging (i.e., discharging, degrading, corroding, etc.). A stock of the core power stations  10  can be keep for long periods, with fresh new main power sources  56  procured and installed only just before sale or use. 
         [0066]    Another set of benefits peripherally relates to upgradability. A person can purchase a power station  10  with one type or size of the main power source  56  and easily change to another type or size of main power source  56  later. For instance, such a purchaser may be enticed by a lower price for a power station  10  that has a main power source  56  of the size (small) shown in  FIG. 10   b , but then find that they use the power station  10  enough that they want the larger main power source  56  shown in  FIG. 10   a . Or such a purchaser may obtain a power station  10  that has a main power source  56  that is a one-use chemical power pack, say, intending use only in an emergency, but find that they use their power station  10  enough that they want to install (upgrade to) a rechargeable 12 volt automotive type battery. Or a purchaser may obtain a power station  10  that has no optional modules (e.g., an air compressor module, power inverter module, high intensity lighting module, etc.) and then later purchase such a module and then also replace the original main power source  56  to one with a different type or size. 
         [0067]    Another set of benefits relates to safety, both actual and perceived. As noted above in the discussion of  FIG. 9 , the main power source  56  cannot be installed incorrectly. It cannot be installed with the electrical polarity reversed, which might damage the power station  10  itself or which could damage other equipment or injure a user. Thus, wholesalers, retailers, and end users can all handle the power station  10  safely and with confidence. The wholesalers and retailers can rest assured that any end user with the basic intelligence to avoid directly shorting two power terminals together should be able to safely handle maintenance and upgrade of the power station  10  with regard to the main power source  56 . And the end users can rest assured that their investment in the power station  10  can be long term and upgradeable, and that they themselves can perform maintenance and upgrades economically and safely. 
         [0068]    Continuing with  FIGS. 10   a - b , and summarizing, a key point of novelty in the power station  10  that permits its benefits is the modular and compartmentalized reduction of power routing between the main power source  56  and the rest of the power station  10  to simply two connection points  102 . This subtle aspect distinguishes the power station  10  over devices. Rather than have a hodge-podge of serial, parallel, and series-parallel wiring, forming a “rats-nest” that most end users would not dare to stick their hands into, the power station  10  keeps complexity in modules and has only minimal necessary complexity there. The compartmentalization of the main power source  56  is safe and minimally intimidating and the modularization of the overall power station  10  permits fast diagnosis and easy repair if any part of the power station  10  ever requires such. 
         [0069]      FIGS. 11   a - b  are front and rear views, respectively, of an option module for use with the power station  10 , here an air compressor module  104 . The air compressor module  104  is able to provide adequate pressure and volumetric capacity to inflate flat tires, inflatable boats, etc., or to provide pressurized air for many other uses. The air compressor module  104  here has an on/off switch  106 , a pressure gauge  108 , an air hose  112  with a nozzle  114 , and an accessory compartment  116 . The rear view ( FIG. 11   b ) particularly shows power wires  118  from the air compressor module  104  that will be connected to the power station  10  as wires  98  at the attachment posts  68 . 
         [0070]    Of course, other optional modules may be constructed for use with the power station  10 . For example, the inventor is building a power inverter module to provide 120 and/or 240 volt alternating current (AC) that can be used to power many low to medium power AC devices, such as radios, televisions, hand power tools, etc. Another optional module might be a high intensity lighting module. Whereas the lighting panel  28  in most embodiments of the power station  10  is expected to provide 10-100 lumens of illumination, which is more than adequate for most tasks, an optional high intensity lighting module might provide 200-800 lumens and could additionally have a semi-rigid cable arm (sometimes termed a “goose neck” feature) that can be bend, wrapped, aimed, etc. as desired and to retain its position. 
         [0071]      FIG. 12  shows how option modules are connected to the power station  10 , in essence, they are “piggy-backed” onto the back shell piece  18  of the housing  14 . The drawing, like  FIGS. 5 and 8 , have so far shown the compartment door  60  in the back shell piece  18  as being plain, but the present inventor actually envisions that few instances of the power station  10  will have a plain compartment door  60 . Rather, it is expected that most instances of the power station  10  will be sold with an option module that uses the modified compartment door  60   a  in  FIG. 12 . As can be seen in  FIG. 11 , the modified compartment door  60   a  includes support and mounting holes for the air compressor module  104  and a hole  120  to permit the power wires  118  to be passed into the compartment  58  of the power station  10  and connected there to the attachment posts  68 . 
         [0072]      FIG. 13  is a stylized and basic schematic diagram of an electrical diagram for circuitry suitable for use in the inventive power station  10 . The functions  12 ,  12   a - 12   d , main power source  56 , controls and features  40 - 48 , and particularly the wires  98 ,  98   a - b  are shown. The modular nature of the power station  10  is stylistically emphasized here by how the wires  98 ,  98   a - b  connect at the two connection points  102 . As has been discussed herein, the use of only the two simple connection points  102  is more than just a coincidental matter. This promotes ease in manufacturing and repair, and particularly simplifies and increases safety in end user servicing. 
         [0073]    While various embodiments have been described above, it should be understood that they have been presented by way of example only, and that the breadth and scope of the invention should not be limited by any of the above described exemplary embodiments, but should instead be defined only in accordance with the following claims and their equivalents.