Abstract:
A battery pack includes a housing. A first battery is located in the housing, the first battery using a first cell technology. A second battery is located in the housing, the second battery using a second cell technology that is different from the first cell technology. The battery pack can be connected to a portable computer chassis to provide an extended life power source.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims priority to and is a divisional of co-owned, co-pending U.S. patent application Ser. No. 10/836,505, filed Apr. 30, 2004, which is incorporated herein by reference in its entirety. 

   BACKGROUND 
   The present disclosure relates generally to information handling systems, and more particularly to a battery pack for an information handling system. 
   As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems. 
   In order to increase portability, information handling systems may rely on batteries to provide their power. Battery packs are used to house batteries and provide easy connection of the batteries to the information handling system. It is desirable for the information handling system to operate on the battery power for as long as possible, which may require larger battery packs that hold more batteries. This is in conflict with the desire to reduce the size of the information handling system as much as possible to further increase portability. 
   One solution to this problem is to provide multiple battery packs for the information handling system. This allows a user to choose between a standard battery pack which provides power to the information handling system over a given period of time, and an extended life battery pack which provides power to the information handling system over a longer period of time than the standard battery pack but takes up more space than the standard battery pack. 
   Extended life battery packs may use different battery cell technologies than the standard battery packs, the result being that an extended battery pack battery will have a different chemistry, different shape, different capacity, and generally different properties than the standard battery pack battery. The extended life battery packs may be larger in size than the standard battery packs, and may not fit in the battery port in the information handling system chassis which is designed for the standard battery pack. However, it is desirable for the extended battery pack to use the same battery connection on the information handling system that the standard battery pack uses. Typically a connector is extended from the extended life battery and through the battery port to the battery connection on the information handling system. The result is that the portion of the extended life battery pack containing the battery may be situated external to the information handling system chassis when it is connected to the battery connection. 
   Situating the extended life battery pack partially external to the information handling system, then extending the battery connector through the battery port to the battery connection on the information handling system in order to connect the extended life battery, results in wasted volume in the unused portion of the battery port. 
   Accordingly, it would be desirable to provide a battery pack for an information handling system absent the disadvantages found in the prior systems and methods discussed above. 
   SUMMARY 
   According to one embodiment, a battery pack includes a housing. A first battery is located in the housing, the first battery using a first cell technology. A second battery is located in the housing, the second battery using a second cell technology that is different from the first cell technology. 
   A principal advantage of this embodiment is that two batteries with different cell technologies may be used in the same battery pack. This allows different type and sized batteries to be implemented in a battery pack to optimize the use of available volume in an information handling system. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic view illustrating an embodiment of an information handling system. 
       FIG. 2  is a schematic view illustrating an embodiment of a battery pack. 
       FIG. 3  is a schematic view illustrating an embodiment of a battery pack. 
       FIG. 4  is a perspective view illustrating an embodiment of an information handling system and a battery pack. 
       FIG. 5  is a perspective view illustrating an embodiment of an information handling system connecting to a battery pack. 
   

   DETAILED DESCRIPTION 
   For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system may be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components. 
   In an embodiment, information handling system  10 ,  FIG. 1 , includes a microprocessor  12 , which is connected to a bus  14 . Bus  14  serves as a connection between microprocessor  12  and other components of computer system  10 . An input device  16  is coupled to microprocessor  12  to provide input to microprocessor  12 . Examples of input devices include keyboards, touchscreens, and pointing devices such as mouses, trackballs and trackpads. Programs and data are stored on a mass storage device  18 , which is coupled to microprocessor  12 . Mass storage devices include such devices as hard disks, optical disks, magneto-optical drives, floppy drives and the like. Computer system  10  further includes a display  20 , which is coupled to microprocessor  12  by a video controller  22 . A system memory  24  is coupled to microprocessor  12  to provide the microprocessor with fast storage to facilitate execution of computer programs by microprocessor  12 . It should be understood that other busses and intermediate circuits can be deployed between the components described above and microprocessor  12  to facilitate interconnection between the components and the microprocessor. 
   A battery pack  100 ,  FIG. 2 , includes a housing  102 . Housing  102  houses a number of components, including a battery management unit  104 , a battery  106  coupled to the unit  104 , and a battery  108  coupled to the unit  104 . Battery management unit  104  is a local controller that may monitor and control cell temperature, charge cycle, charge level, and other operating parameters of the batteries. Battery  106  and  108  use conventional cell technologies such as prismatic, cylindrical, polymer, or nickel metal hydride, with battery  108  using a cell technology that is different from the cell technology used by battery  106 . Battery  108  may be larger than battery  106  depending on the power requirements of the system. A battery connector  110  is included on the battery pack  100 , the connector  110  being coupled to the unit  104 . The battery pack  100  may include a section  112  housing battery  106 , and a section  114  housing battery  108  which may be larger than section  112  due to the size of the battery  108  needed to satisfy the power requirements of the system. The battery connector  110  may be housed in the housing  102  or may be totally or partially external to the housing  102 , and provides a connection for connecting the battery pack  100  to an information handling system such as the information handling system  10  of  FIG. 1 . 
   Within the scope of the embodiments described herein, battery technology used in batteries  106  or  108  may be conventional commercially available prismatic batteries such as, for example, Sanyo 125280 cells; conventional commercially available cylindrical batteries such as, for example, Sony 18650 cells; conventional commercially available polymer batteries such as, for example, Sanyo 5540100 cells; or conventional commercially available nickel metal hydride batteries such as, for example, Eveready Energizer NiMH AA cells. 
   In an embodiment, a battery pack  200 ,  FIG. 3 , includes a housing  202 . Housing  202  houses a number of components, including a battery  204  coupled to a battery management unit  206 , and a battery  208  coupled to a battery management unit  210 . Battery management units  206  and  210  are local controllers that may monitor and control cell temperature, charge cycle, charge level, and other operating parameters of the batteries. Batteries  204  and  208  use conventional cell technologies such as prismatic, cylindrical, polymer, or nickel metal hydride, with battery  204  using a cell technology that is different from the cell technology used by battery  208 . Battery  208  may be larger than battery  204  depending on the power requirements of the system. A battery connector  212  is included on the battery pack  200 , the connector  212  being coupled to the battery management units  206  and  210 . The battery pack  200  may include a section  214  housing battery  204 , and a section  216  housing battery  208  which is larger than section  214  due to the size of battery  208  needed to satisfy the power requirements of the system. The battery connector  212  may be housed in the housing  202  or may be totally or partially external to the housing  202 , and provides a connection for connecting the battery pack  200  to an information handling system such as the information handling system  10  of  FIG. 1 . While one battery management unit may be used to manage multiple batteries using different cell technologies in the battery pack, such as in  FIG. 2 , dedicating a battery management unit to each battery using different cell technologies provides a simpler battery management unit design. 
   Within the scope of further embodiments described herein, battery technology used in batteries  204  or  208  may be similar to the battery technology described above with reference to batteries  106  and  108 . 
   In operation,  FIGS. 4 and 5 , an information handling system  300 , which may be the information handling system  10  of  FIG. 1 , includes a battery port  302  with a system connector  304 . A battery pack  400 , which may be the battery pack  100  of  FIG. 1  or the battery pack  200  of  FIG. 2 , includes a section  402  with a pack connector  406  on it&#39;s surface, and a section  404  adjacent to the section  402 . Connection of battery pack  400  to information handling system  300  is accomplished by placing section  402  of battery pack  400  in battery port  302 , such that pack connector  406  engages system connector  304 . With pack connector  406  engaged with system connector  304 , battery pack  400  is coupled to microprocessor  306  in information handling system  300  through a bus  308  such as a system management bus. The bus  308  controls the operation of the batteries by communicating with the battery management units, shown in  FIGS. 2 and 3 , connected to the batteries in the battery pack. With the battery pack  400  connected, section  404  of the battery pack  400  sits external to the information handling system  300 . 
   Although illustrative embodiments have been shown and described, a wide range of modification, change and substitution is contemplated in the foregoing disclosure and in some instances, some features of the embodiments may be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the embodiments disclosed herein.