Background Art Battery backup devices for computers and other electronic equipment are used to provide electrical power in case of loss of continuity or quality of power-such battery backup units are often called uninterruptible power supplies (UPSs). Such battery backup devices are frequently used for equipment that contains computers, since volatile memory in a computer is subject to complete loss during power outages and power sags. Such computerized devices include traditional personal computers (PCs), server computers, telecommunications routers and hubs, and industrial and medical equipment. Recently, these devices are being used for"Internet appliances", including home servers, set-top boxes, at the like. Although traditional uninterruptible power supplies are located outside of the equipment that they protect, recently, certain uninterruptible power supplies have been devised which operate from within the protected equipment. An example of such an internal uninterruptible power supply (iUPS) is that of Faberman and Mills in U. S Patent 5,978,236.

The design of an iUPS, however, admits to a number of practical impediments in the physical organization of the device. Most particularly, the batteries that provide the backup power for the iUPS should ideally be removable from the electronic equipment in which the iUPS is mounted. This allows the user to both replace batteries which have lost their ability to function adequately, as well as to remove the batteries when the electronic equipment becomes out-of-service, since many batteries such as Nickel-Cadmium (NiCd) batteries are otherwise environmentally damaging without proper disposal. Removal of the batteries from the case causes a number of attendant physical design problems, including the need for the batteries to fit into constrained spaces, the need for separable, secure and safe, high-current electrical connections to be made between the batteries and the il) PS electronics, and the need for user-feedback information to be passed from the

iUPS electronics to the outside of the protected equipment through the case or compartment holding the batteries.

The present invention provides a practical solution to these vexing problems.

Summary of the Invention In order to allow the maximum iUP S battery size within the fixed openings within a computer, the present invention uses a battery holder in which the batteries are not completely enclosed. Thus, the diameter ofthe surface ofthe batteries is made to be the thickness dimension of the filled battery holder, yet the battery terminals are shielded by the holder. This allows the battery holder to fit into the tightest vertical dimension.

It is a further property of the present invention that the battery holder for the iUPS be accessible and removable through the external case of the computer, in order to allow the batteries to be replaced upon failure or removed for computer disposal without the need to open the computer. Such a capability is also absolutely necessary for the safe implementation of a hot-swappable battery. Thus, the iUPS of the present invention comprises a modular design in which the battery holder is located adjacent to or flush with the wall of the computer and can be removed through the outside wall of the computer, and various electronics, such as the electronic and communications interface of the computer is fixed internally within the computer. When the battery holder is removed, one or more connectors between the battery holder and the other iUPS electronics are separated.

The electrical connection between the battery holder and the fixed internal components must be both electronically and physically secure, and typically will comprise connectors with tight grips. In order to aid the user in removing the battery holder, and simultaneously avoid pulling the battery holder with excessive force, the present invention uses mechanical advantage to remove the battery holder in a controlled fashion to the point at which the electrical connection is broken, and to then allow the user to gently remove the battery holder without the need for such mechanical advantage. The front panel of the battery holder acts as a lever against the fixed portion of the iUPS or the computer itself, as the front panel folded up or down from the normal engaged position flush or nearly flush with the wall of the computer.

Computer components such as the iUPS generally have diagnostic lights (e. g.

LEDs) that are visible outside the computer to warn or indicate aspects of component function or maintenance. These LEDs are generally located on the main board of the peripheral. However, because the battery holder is placed flush or adjacent to the external wall ofthe computer, and the main iUPS electronics are more internally located, it become more difficult to place these LEDs such that they are visible on the exterior of the computer. This is particularly the case where the front panel of the battery holder is a movable piece to allow mechanical advantage as described in the previous paragraph, so that the panel may be physically moved with respect to the battery holder. The present invention circumvents this problem by placing the LEDs on the main electronics board of the iUPS, and then using a first light pipe made of plastic or other suitable material that is located on the battery holder, transmitting the light from the interior iUPS electronics board to the front panel. Furthermore, the front panel itself has a second light pipe, communicating with the first light pipe, to transmit the light across the thickness of the front panel.

For safety reasons, the iUPS requires a fuse to prevent untoward electrical situations that could be cause fires, damage electrical components of the computer, or pose health threats to computer users. It is of further benefit that this fuse be removable with the battery holder, so as to be replaceable by replacing the entire battery holder or simply by removing the battery holder and replacing the fuse that is attached to the battery holder. It is of further importance that the connections that connect the battery holder and the internal electronics be arranged so that a linear conductor not be able to bridge the connections, causing a short. It is a further characteristic of the present invention to use the fuse, attached to the battery holder, and located between the positive and negative power connections, and being of such a dimension and orientation, so as to prevent the shorting of the connections by a linear conductor.

Brief Description of the Drawings Fig. 1 is a perspective view of the battery holder according to the present invention.

Fig. 2 is a vertical cross-section through the battery holder of Fig. 1.

Fig. 3 is a perspective view of the battery holder of Fig. 1 with an attached front plate with the rails of the iUPS case.

Figs. 4 a-d are cross-sections of the front part of the iUPS through the rail as the battery holder is disconnected from the iUPS electronics.

Fig. 5 is a front view ofthe front panel wherein the two parts ofthe front panel are separated.

Fig. 6 is a perspective view of the light generation and light transmission pathway for light indication.

Fig. 7 is a top view of the light generation and light transmitting components of Fig. 6.

Best Mode for Carrying-Out the Invention The design of the present invention is described in this specification in reference to a battery backup iUPS used to protect a conventional desktop computer. It should be understood that the present invention has application to many other computerized devices, such as Internet appliances, servers, and medical or industrial equipment. It should also be noted that there are only a limited number of points of access to which an iUPS would be accessible from the outside of the computer without opening the computer case. The most likely points of access include the 3.5 and 5.25 inch drive bays usually found on the front of the computer case, as well as the expansion slots usually found on the back of the computer. Furthermore, other equipment (such as telecommunications routers, point-of- sale devices, and embedded computers for industrial applications) may have other orifices to the inside of the equipment that is of limited dimensions. The limited dimensions of these standard orifices restrict the size of the objects that may be placed into or removed from them.

Furthermore, it should be noted that the batteries of most common use, and therefore of least expensive supply, are available in a limited number of physical formats.

For example, a particularly advantageous battery for many applications is the Sub-C sized nickel-cadmium (NiCd) battery, such as the P-120SCPM from Matsushita Electric Corporation of America (Secaucus, NJ), which comes as a cylinder of diameter 0.91

inches. Because the opening ofthe 3.5-inch drive bay is only 1.00 inches high, this leaves only a limited amount of clearance for the battery to fit in the 3.5 inch drive bay.

The following specification uses as a representative example a modular iUPS that incorporates Sub-C sized batteries in a 3.5 inch drive bay of a desktop computer. It should be understood that the present invention has beneficial application to other sized batteries in other orifices or compartments of equipment other than desktop computers.

Battery Location Relative to Electronics and Case In a modular iUPS, it is convenient for the batteries to be proximal to the outside of the case, with the iUPS power electronics more internal. The reason for this is that while the power electronics are rarely if ever to be removed from the computer, the batteries are more likely to be removed for replacement with newer batteries as the batteries lose their ability to function. Furthermore, the power electronics ofthe iUPS will need to be connected to the proper energy-using components on the inside of the computer. Thus, if the power electronics were proximal to the outside of the case, connection with the rest of the computer through these electronics would be hindered.

Thus, the optimal arrangement of components for an iUPS (though not required) is for the battery to be proximal to the case exterior, with the power electronics distal to the exterior and more accessible for connection to the computer internal components.

Furthermore, it is convenient for the battery holder to be flush with the exterior of the computer case. If the battery holder is further internal to the computer case, it consumes valuable internal space within the computer, and it further requires a means for the user to grab onto the holder for battery removal. If the batter holder protrudes from the case, it may snag external objects, or may interfere with the insertion or removal of other devices from the computer. For instance, the 3.5 inch and 5.25 inch drive bays are generally closely stacked within a computer, and a device protruding from one bay is likely to interfere with access to devices in another bay.

Battery Holder Structure As discussed above, the orifice of a 3.5-inch drive bay has little clearance for the batteries that must be placed through it. As mentioned above, standard NiCd battery size

(SC) has a diameter of 0.91 inches, while the bezel around the standard 3. 5-inch drive bay slot has a vertical dimension of only 1.00 inches, leaving clearance of 0.09 inches. It should be appreciated that within the drive bay, the batteries and electronics must be enclosed for safety reasons. Thus, the problem arises that the 0.09 inch clearance must accommodate the safety shell enclosing the iUPS (both top and bottom), the holder around the battery holder (both top and bottom), as well as free space to allow the battery holder to slip within the shell (both top and bottom). Given the dimensions of the shell and battery holder, conventional materials suitable for high-volume production provide insufficient strength to serve the required functions within the available space.

The present invention teaches the use of a novel battery holder to solve this problem. Fig. 1 is a perspective view of a battery holder 42 according to the present invention. Eight cylindrical batteries 30 are arranged in 4 parallel pairs with each pair aligned along their longitudinal axis. The battery holder 42 is comprised of a top shell 32 and a bottom shell 34, which snap together along a seam 40 which is contiguous along the front and sides of the battery holder 42.

Importantly, both the top shell 32 and the bottom shell 34 have a series of three crossbeams 38 parallel to the batteries 30, between which beams 38 are open grooves in which the batteries 3 0 are open to the exterior of the holder 42. This arrangement is more easily seen in Fig. 2, which is a vertical cross-section through the battery holder 42, whose cross-sectional position is indicated in Fig. 1. The batteries 30 can be seen to rest on internal surfaces of the beams 3 8 which are curved so as to fit the batteries 30 with a small amount of slack, so that the batteries 30 fit snugly into the battery holder 42.

From this cross-section, it can be appreciated that the diameter ofthe batteries 30 is similar to the vertical dimension of the battery holder 42, and may in fact be larger than the vertical dimension of the battery holder 42, depending on the geometry and spacing of the beams 38. This is very important since, as stated above, the case into which this battery holder 42 inserts may have only minute clearance for the holder 42. The arrangement of the battery holder 42 described in Figs. 1 and 2 has no material above and below the batteries 30, which allows the battery holder 42 more clearance. This allows the diameter of the batteries 30 to be nearly the same dimension as the inside dimension

of the case, which may be tightly constrained by the bezel size or rack size for devices inserted into computers.

It should be appreciated that the diameter of the battery may be considered either with or without insulation. The battery 30 shown in Figs. 1 and 2 is generally covered with either a plastic or cardboard insulator, or with both. The battery 30 is considered to be comprised of both the electrical energy storage compartment as well as the associated insulation.

Battery Holder Insertion and Removal The batteries 30 within the battery holder 42 are electrically connected to the rest ofthe iUPS through a set of releasable connectors at the back of the holder 42. The user, in inserting the holder 42 into the iUPS, has no direct view or physical access to the connectors as they are being electrically mated. Furthermore, power is supplied through the connectors at a low voltage (i. e. that of the batteries), and therefore to support computer operations, must be supplied at high current. It is not unusual for this current to reach 20 amperes, requiring substantial high-current connectors so that resistive heating does not damage the iUPS. Such high-current connectors, in order to meet these strict electrical resistance criteria, must be somewhat large and the male and female connectors must grip tightly.

These connectors thus present a problem for battery holder 42 removal from the computer. Because the connectors must grip so tightly, the user must pull with considerable force. However, as soon as the connectors are free, there is little friction to retard movement of the holder 42, and so it will generally be caused to be pulled out too quickly, and may cause damage if not pulled out straight, or if it hits an object outside the computer. It should also be appreciated that the batteries 30 are generally of low internal impedance, and so their inadvertent discharge can potentially be dangerous or harmful.

Thus, any potential for damage to the battery holder 42 is to be strictly avoided.

In order to prevent unsafe removal of the battery holder 42, the present invention teaches a means of extracting the battery in a controlled manner using mechanical advantage, so that the user does not need to exert significant force, nor does the user

require the use of tools. Once the battery holder 42 is electrically disconnected from the rest of the iUPS, it can then be slid out slowly and carefully.

Fig. 3 is a perspective view of the battery holder 42 with an attached front plate 46 with rails 48. At the rear of the enclosing rails is an iUPS backplate 50, which is placed most distal from the wall of the computer from which the battery holder 42 may be removed. Between the backplate 50 and a rear wall 44 of the battery holder 42 is a space in which the iUPS electronics are located. Thus, a number of electrical connections are mounted on the rear wall 44 of the battery holder 42, including a pair of positive terminal male connector blades 52 and negative terminal male connector blades 53, connected respectively to the positive and negative terminals ofthe batteries 30, as well as a fuse 54 around which a fuse guard 56 is positioned. These connections between the battery holder 42 and the iUPS electronics provide for the supply of power for charging the batteries 30 and also provide for the batteries 30 to supply power to the iUPS electronics and the computer. Additional male connector blades may also be present in order to provide communications and safety features as needed between the battery holder 42 and the iUPS electronics.

In order to physically release the battery holder 42 from the iUPS electronics, the battery holder 42 must be slid forward a distance that is roughly equal to the distance that the male connector blades 52 and 53 insert into their female counterparts in the iUPS electronics (not shown). This capability is provided by a moveable front panel 46 attached to the front of the battery holder 42. The front panel 46 exerts force, as will be shown, on the rails 48 lining the iUPS, leveraging the holder 42 forward relative to the rails 48, and also therefore to the iUPS electronics which are fixed relative to the rails 48.

Figs. 4 a-d are cross-sections of the front part of the iUPS through the rail 48 as the battery holder 42 is disconnected fromthe iUPS case and electronics. Rail 48 has two mounting holes 76 used for attaching top and bottom iUPS covers (not shown). At the anterior aspect of the rail 48 is a rail hook 66. The rail 48, being the major structural beam of the iUPS, is preferably made of a metal such as aluminum or steel, or a stiff and resilient plastic such as anti-ballistic styrene (ABS). The battery holder 42 top shell 32 and bottom shell 34 are shown as dotted lines, and are located to one side of the rail 48 cross-section. An extension 72 extends from the front of the bottom shell 34, and

contains a hole through which a stiff peg 74 (typically metal or plastic) is inserted. This peg additionally passes through a matching hole in the front panel 46, so that the front panel 46 rotates around the peg 74. Furthermore, the front panel 46 extends across the entire front of the battery holder, even so as to interface directly with the rail hook 66.

The sequence of Figs. 4a-d indicates the steps of disconnection of the battery holder 42 from the iUPS electronics. Fig. 4a shows the iUPS as the battery holder 42 is securely attached in normal operation. To remove the battery holder 42, the user places his fingernail into a groove 70 on the front panel 46 and depresses the top frame 60 of the panel 46. The top frame 60 is attached to a bottom frame 62 along a guide 78 that allows movement of the frames 60 and 62 relative to each other. A spring action within the front panel 46 maintains a distance between the top and bottom frames 60 and 62, which may be easily overcome by finger force. Notice that the top frame 60 has a panel hook 68 which is so arranged that it makes intimate contact with the rail hook 66, thus eliminating movement of the front panel 46 forward. Since the front panel 46 is attached to the battery holder 42 through the peg 74, this means that the battery holder is securely held within the iUPS rails 48.

Fig. 4b shows the case when the top frame 60 is compressed close to the bottom frame 62, across a separator stem 78, the rail hook 66 and the panel hook 68 disengage from one another, leaving clearance for the front panel 46 to either translate away from the rails 48, or to rotate around the peg 74. This front panel 46 rotation is shown in Fig.

4c. Note that after a short rotation of approximately 30 degrees, further rotation of the front panel 46 is impeded by the bottom corner of the rail 48. At this point, the user will generally remove the pressure from their fingernails on the top frame 60, allowing the expansion of the top frame 60 from the bottom frame 62, and move their fingers so that additional pressure can be easily exerted on the top of the front panel 46, causing it to rotate around the peg 74. As shown in Fig. 4d, as the front panel 46 rotates, the bottom frame 62 has leverage against the corner of the rail 48, forcing the bottom frame 62 forward relative to the rail 48. When the front panel 46 is nearly horizontal, as shown in Fig. 4d, the front panel 46 has moved approximately 4 mm, which is enough to cause disconnection of the battery holder 42 from the iUPS electronics by the male connector blades 52 and 53.

There are a number of salient features about this manner of connection. Firstly, the mechanical leverage of the bottom frame 62 of the front panel 46 against the rails 48 allows the controlled removal of the battery holder 42 against the tight grip of the male connector blades 52 and 53. The mechanical advantage is large enough so that the user does not need tools. Secondly, even with the tight grip of the battery holder 42 to the iUPS electronics, the battery holder 42 may be removed without tools. Thirdly, because the entire front panel 46 constitutes the source of mechanical advantage, it must be entirely moveable, rather than using sub-components such as screws to effect mechanical engagement and disengagement. Fourthly, if the front panel 46 is flush with the front of the computer, it is hard to allow the user to grasp the battery holder 42 for removal.

However, once the front panel 46 rotates forwards even a modest amount (20-30 degrees), it can be easily grasped and manipulated by the user's fingers.

From a safety perspective, the manner of battery holder 42 insertion and connection has a very significant safety advantage. When the battery holder 42 is within the rails (and enclosed within the iUPS top and bottom covers, which are not shown), the user cannot get access to the live connections at the rear of the battery holder 42 (such as the male connector blades 52 and 53). Once the battery holder 42 is physically disconnected from the iUPS electronics, it is simultaneously electrically disconnected as well, since the physical connection and the electrical connection are one and the same thing, being instantiated in the same connectors.

It should be appreciated that leverage of the front panel 46 in a cam action is not the only means of securing the battery holder 42 to the iUPS. Other conventional means include friction fit between the battery holder 42 and the enclosing rails 48, or screws accessible from the front panel. Additionally, many means of removing the battery holder 42 may be employed, including a screw that can be used to lever out the holder 42, or a ring or handle that extracts from or swings out from the front panel 46 and through which the user can insert his fingers or hand for pulling.

Fig. 5 is a front view of the front panel 42 components separated. The bottom component is comprised of the physically integrated bottom frame 62 and the guide 78.

The guide 78 performs the functions of physically guiding the relative movements of the top frame 60 and the bottom frame 62, preventing their separation, and providing spring

action to mediate the extent of their separation under user control. The elements of the guide 78 that perform these functions are mostly arranged in pairs roughly symmetrically around the midpoint of the long dimension of the guide 78. These elements in the guide interface with hollow sections of the top frame 60 indicated in Fig. 5 with dotted lines.

These hollow sections are deep enough to accommodate the elements of the guide 78, which are less deep than the depth of the bottom frame 62.

A pair of end guides 100 fit into corresponding end guide hollows 110 in the top frame, and provide the most lateral guides in the relative movement of the top frame 60 and the bottom frame 62. These end guides 100 are supplemented with a single main body guide 108 which interfaces with the main hollow 114 in the top frame 60. The end guides 100 and main body guide 108 provide for smooth vertical movement of the top frame 60 relative to that of the bottom frame 62.

A pair of stop-posts 102 are present on each end of the guide 78, and interface with corresponding stop-post channels 112. When inserted into the stop-post channels 112, the"L"s on the top of the stop-posts 102 prevent removal of the top frame 60 from the bottom frame 62, limiting the extent of vertical movement. In order to place the top frame 60 on the bottom frame 62, the two juxtaposed stop-posts 102 are pressed together so that they fit into the stop-post channels 112. When the"L"s on the stop-posts 102 have cleared the widening of the stop-post channels 112, they spring out and lock the top frame 60 and the bottom frame 62 together.

In order to provide spring action to keep the top frame 60 and the bottom frame 62 at full extension, as in Fig. 4a and Fig. 4d, wire springs and plastic tensioners are accommodated. Sets of angled plastic fingers 104 are placed so that they are bent along the top of the main hollow 114. As the top frame 60 and the bottom frame 62 are brought together, as in Fig. 4b, the plastic fingers 104 are bent, which presses back against the top frame 60. The strength of the action can be controlled by the thickness of the fingers 104, their angle with respect to the top of the main hollow 114, and the number ouf lingers 104.

In conjunction with or instead of these fingers 104, normal wire springs may be included. A pair of spring posts 106 are provided, onto which wire springs (not shown) may be fitted. The tops of the wire springs press against the top of the main hollow 114.

In order to make sure that the springs do not buckle, the spring posts 106 may be made

longer, or additional spring posts may be placed downward pointing within the main hollow 114. iUPS Communication with Case Exterior The placement of the iUPS battery close to the external wall of the computer case impedes the placement of the usual types of visual signaling that are common to similarly- placed computer devices such as floppy drives and CD-ROM drives. Such devices normally have LED indicators denoting that the devices are electrically powered or that the devices are functioning either normally or abnormally. For a iUPS device such as the present invention, useful signals to the user might include that the iUPS is in electrical connection with the computer power supply, that the iUPS is supplying power to the computer in the case of a power outage, that the iUPS battery is being charged, or that the iUPS battery needs replacement.

The electronics that would control the LED indicators in the present invention would be located distally from the front panel 46 of the iUPS on the exterior of the computer, being separated from the iUPS electronics by the battery holder 42. Thus, if an LED were to be placed on the front panel 46, electrical connections would need to be made either directly with the front panel, or to the wall of the battery holder 42 proximal to the front panel 46. This requires the placement of electrical wires along the length of the battery holder 42, which may be difficult due to the small clearance above and below the batteries. Furthermore, the LED would need to be mounted on the battery holder 42 box, which would require a separate manufacturing step given the lack of other similar components in a similar place. In addition, there would need to be a means of powering the LED from the main iUP S electronics, which would involve the placement of additional male connector blades and their corresponding female counterparts in the iUPS electronics.

The present invention teaches the use of light pipes that transmit light generated in the iUPS electronics to the front panel 46. Fig. 6 is a perspective view of the battery holder 42 with the attached front panel 46, in which a light emitting diode (LED) 86 is placed on an iUPS electronics board 88 behind the battery holder 42. The LED 86 is oriented so that its light output is directed forwards (i. e. towards the front panel 46). A

light pipe 84 is placed directly in front of the LED 86 along the axis of light generation so as to capture a maximal amount of the light output from the LED 86. The light pipe 86 is located within a light pipe channel 82, which can be more conveniently seen in Figs. 1 and 3. The light pipe channel 82 runs along a top lateral edge of the battery holder 42, and is designed so that the light pipe 84 rests securely within the channel 82. In order to retain the light pipe 84 within the channel 82, small amounts of adhesive may be used, or constrictions within the channel 82 may be placed at intervals in order to provide a friction-clamping grip. The light pipe 84 is conveniently made of plastic rod, with a highly polished end facing the LED 86 in order to allow maximal light acceptance into the light pipe 84. Alternatively, the light pipe may be comprised of glass. The light pipe 84 may be uncoated, with internal reflections occurring by means of refractive index mismatching between the plastic and surrounding air, or alternatively, the light pipe may be coated with a reflective material, such as aluminum metal on fiber optic material. The light pipe 86 may be as narrow as 0.030" or less, but is conveniently as large as 0.0625" or larger, in order to capture significant amounts of the LED 86 generated light.

Light from the LED 86 is captured by the light pipe 84 and is transmitted through internal reflections along its length. At the other end of the battery holder 42, the light pipe terminates at a lightly or highly polished surface. In order to transfer the light to the exterior surface of the front panel 46, a short front panel light pipe 80 is placed across the depth of the front panel 46 (conveniently approximately 0.12-0.15"). This front panel light pipe 80 is oriented so that it captures a significant amount ofthe light energy radiated from the end of the light pipe 84, and then transmits it to the wall of the front panel 46 along the exterior of the computer. The outer surface of the front panel light pipe 80 may be lightly sanded so that it properly and aesthetically disperses light.

Fig. 7 is a top view of the light generation and light transmitting components of the present invention. The LED 86 is placed with a short gap 90 in front of the light pipe 84, which in turn is placed with a second gap 92 between the light pipe 84 and the front panel light pipe 80. Because the light from the LED 86 is not well collimated, there is a spread angle of light from the LED 86, so that light capture by the light pipe is more efficient if the gap 90 is relatively small (on the order of a couple of millimeters or less).

Likewise, the spread of light from the end of the light pipe 84 proximal to the front panel

light pipe 80 may be large, in part due to roughness on that end that disperses the light.

Therefore, it is also efficient for the second gap 92 to be as small as possible in order that it may capture a large fraction of the light emitted from the light pipe 84. A front surface 94 of the front panel light pipe 80 is, as discussed before, made rough to aesthetically disperse light and make the light visible from a wide range of user positions and angles relative to the computer exterior. In addition, to optimize its visibility, the front surface 94 should be either flush with the exterior surface of the front panel 46, or may even protrude a small distance (a millimeter or two) from the exterior surface. The dimensions of the light pipe 84 can be large, and given the need to accommodate the entire battery holder 42, may be 3 or 4 inches in length.

If two light indicators are desired, it is within the spirit of the present invention for two LEDs 86, two light pipes 84 and two front panel light pipes 80 to be implemented within the battery holder 42. Conveniently, there are two lateral top edges of the battery holder 42 into which channels 82 may be placed, thus placing LED indicators on both the left and right sides of the front panel 42. These LED indicators can be used to communicate with the user a number of different operational states of the iUPS.

Additional channels 82 could also run along the bottom lateral edges of the battery holder 42 to provide additional means of light indication.

Safety Issues The batteries 30 contained within the battery holder 42 are of generally low impedance, so that they can deliver the high power levels necessary to maintain a desktop computerin operation. Thus, inadvertent shorting across positive terminal male connector blades 52 and negative terminal male connector blades 53 that are connected to the positive and negative terminals of the batteries 30 with a conductive object could result in either health threatening or equipment damaging events where the batteries 30 discharge improperly. For instance, a thin wire object such as a paper clip would nearly instantly achieve temperatures that would vaporize the metal, and if a person were holding the paper clip, they would suffer deep burns. Equipment that caused a short could suffer physical and/or electrical damage. It should be appreciated that after the battery holder 42 is removed from the iUPS, the male connector blades 52 and 53 on its rear wall 44 are

exposed to the outside environment, where they may freely come in contact with conductive objects.

Thus, it is desirable and in many cases mandated by safety regulatory bodies such as Underwriters'Laboratory (UL) that the positive terminal male connector blades 52 and the negative terminal male connector blades 53 be so arranged so that a linear conductor would not short the batteries 30. Because of the small amount of space available within the iUPS, and the minimal surface area on the rear wall 44 within which to place barriers, it is a teaching of the present invention to make use of the fuse 54 and fuse guard 56 as physical barriers to prevent the aforementioned shorting. Fig. 3 shows the location of the fuse 54 and fuse guard 56 in a position intermediate between that of the blades 52 and the blades 53. Furthermore, the height of the fuse 54 from the surface of the wall 44 is such that it greatly exceeds that of the blades 52 and 53. Thus, a linear conductor would be unable to simultaneously contact both sets of connector blades 52 and 53.

This placement of the fuse 54 on the wall 44 of the battery holder 42 has the additional benefit that it makes the fuse 54 accessible in case it is shorted, and the battery holder 42 removed from the computer, thus facilitating the replacement of the fuse 54 by the user.

It should be apparent to one skilled in the art that the above-mentioned embodiments are merely illustrations of a few of the many possible specific embodiments of the present invention. Numerous and varied other arrangements can be readily devised by those skilled in the art without departing from the spirit and scope of the invention.