Abstract:
Information handling systems are tested for proper interaction with integrated batteries by simulating a battery connection at a battery port of the information handling system. A battery connector couples to the battery port and communicates through cables with a management bus, a programmable power source and a programmable load. The management bus supports communication with a battery management unit that imitates responses for the information handling system that are expected from a battery. A battery emulator controls the programmable power source and load to provide the information handling system with an expected battery response for confirming proper operation of the information handling system power subsystem without requiring insertion of an actual battery.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates in general to the field of information handling system integrated power supplies, and more particularly to an information handling system battery emulation testing system and method. 
         [0003]    2. Description of the Related Art 
         [0004]    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. 
         [0005]    Portable information handling systems have gained wide acceptance among end users due in part to the increased flexibility that end users gain from portable systems. Portable information handling systems are built in portable housings that allow an end user to readily carry the system and use the system on the go. Increasing capabilities and decreasing sizes of components that are used to build portable information handling systems have provided portable systems comparable in processing power to desktop or other fixed systems. In order to provide portability, portable information handling systems integrate into the portable housing both I/O devices, such as a keyboard and display, and a power source, such as a rechargeable battery. An end user can thus operate the portable information handling system free from any hardwired connections for as long as the battery maintains an adequate charge. When the battery runs out of charge, the end user can continue operating the information handling system by connecting an external power source, such as an AC-to-DC adapter. The external power source also typically recharges the battery. 
         [0006]    Although more powerful processing components provide more functionally-capable information handling systems, they also tend to consume more power. Portable information handling systems have a variety of sizes, configurations and components so that different types of batteries are typically needed for different types of systems to meet different discharge rate and charge life requirements. Lithium-based rechargeable batteries tend to be expensive, particularly for portable information systems that have relatively large power consumption. Because batteries tend to lose their ability to hold a charge over time and usage, portable information handling systems typically have a battery cavity that releases the battery to allow replacement. Thus, in addition to the varied charge-life and discharge capabilities needed for different types of information handling systems, portable batteries also have varied types of housings so that the battery housing is compatible with varied types of information handling system housings. 
         [0007]    Portable information handling system batteries have evolved into smart subsystems that actively manage interactions with an information handling system. An integrated circuit included in the battery housing communicates with an information handling system through a management bus, such as SMBus. Often, the smart battery and information handling system have to exchange encrypted information before the battery provides or receives a charge in order to confirm that the battery and information handling system are compatible. The many variations in information handling system battery configurations leads to difficulties for manufacture and repair locations, which run tests on portable information handling systems to ensure that a power subsystem properly charges and discharges a battery. One difficulty is that maintaining a large inventory of different types of batteries for inserting into information handling systems during testing is expensive and often wasteful. Batteries deteriorate over time and with usage so that the inventory tends to have a substantial turnover. Disposing of batteries presents environmental difficulties since batteries tend to have potentially dangerous materials. Even shipping batteries can present a difficulty since airplanes are often limited in the number of batteries that they can carry. 
       SUMMARY OF THE INVENTION 
       [0008]    Therefore a need has arisen for a system and method which tests information handling system power subsystems without excessive reliance on batteries in the test process. 
         [0009]    In accordance with the present invention, a system and method are provided which substantially reduce the disadvantages and problems associated with previous methods and systems for testing information handling system power subsystems. A battery emulator connector couples to an information handling system battery port to imitate the battery designed for the information handling system during power subsystem testing. The use of the battery emulator minimizes or eliminates the use of actual batteries in support of power subsystem testing. 
         [0010]    More specifically, an information handling system processes information with plural processing components powered by a power subsystem and re-chargeable battery. The battery has a connector that removably couples with a battery port of the information handling system. A battery management unit integrated circuit built into the battery housing communicates with processing components of the information handling system through a management bus of the battery port to coordinate charging the battery from the information handling system and discharging the battery to the information handling system. A battery emulator imitates a battery for testing the information handling system with power transfers and management information communication passed through a battery connector to the battery port and information handling system power subsystem. A battery management unit interfaces with the battery port management bus and the battery emulator to generate management information for the power subsystem that imitates the presence of the battery, such as providing an identifier indicating the presence of the correct battery for the information handling system. The battery emulator imitates battery charge characteristics with a programmable load and imitates battery discharge characteristics with a programmable power supply. The battery emulator coordinates the use of a battery identifier, battery charge characteristics and battery discharge characteristics based upon the type of information handling system under test. 
         [0011]    The present invention provides a number of important technical advantages. One example of an important technical advantage is that the use of physical batteries in the testing of information handling system power subsystems is reduced or eliminated. A battery emulator imitates the interactions that an information handling system would normally have with a battery to allow a complete test of information handling system power subsystem functionality. Instead of maintaining an inventory of many different types of batteries, a single battery emulator provides system appropriate interactions based upon the type of information handling system under test. Ending test reliance upon an inventory of different types of batteries reduces costs and the environmental impact of testing. Further, the battery emulator provides a consistent testing system so that a failing test battery will not cause false information handling system test failure indications. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The present invention may be better understood, and its numerous objects, features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference number throughout the several figures designates a like or similar element. 
           [0013]      FIG. 1  depicts a block diagram of an information handling system and battery tester to confirm proper operations of the information handling system power subsystem; and 
           [0014]      FIG. 2  depicts a flow diagram of a process for testing interactions between an information handling system and a simulated battery. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    A battery emulator imitates the presence of a battery at an information handling system battery port to allow testing of a power subsystem of the information handling system without loading an actual battery into the battery port. 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. 
         [0016]    Referring now to  FIG. 1 , a block diagram depicts an information handling system  10  and battery tester system  12  to confirm proper operations of the information handling system power subsystem  14 . Information handling system  10  is built in a portable housing  16  that contains plural processing components that cooperate to process information, such as a CPU  18 , RAM  20 , a hard disk drive  22  and chipset  24 . An embedded controller  26  provides management functions for information handling system  10 , such as managing functions when information handling system  10  is in a powered-off or low-power state. For example, embedded controller  26  manages the operation of power subsystem  14  to permit charging of a battery  28  from an external AC-to-DC power adapter  30  during a powered down state. 
         [0017]    During normal operations, power subsystem  14  provides power to operate the processing components using either external power of AC-to-DC power adapter  30  or internal power of battery  28 . If AC-to-DC power adapter  30  is providing external power, power subsystem  14  uses any excess power not needed for running the processing components to charge battery  28 . If the processing components are powered down, power subsystem  14  uses external power to charge battery  28  to a full charge. If AC-to-DC power adapter  30  is disconnected, power subsystem  14  converts from the use of external power to instead provide power by discharging battery  28 . Once the charge of battery  28  decreases to a predetermined level, power subsystem  14  coordinates a power down of the processing components to avoid a forced shutdown by a lack of battery charge. Power subsystem  14  obtains power from battery  28  through a battery port  32  of information handling system  10  that accepts a battery connector  34 . Power pins  36  allow power transmission from battery  28  to information handling system  10  during battery discharge and from information handling system  10  to battery  28  during charge. Management pins  38  support communication of management information through a management bus between power subsystem  14  and a battery management unit  40  integrated in battery  28 . Battery management unit  40  is an integrated circuit that controls battery operations. For example, battery management unit  40  and power subsystem  14  limit interactions between battery  28  and information handling system  10  until an identifier  42  is exchanged that confirms that battery  28  is an appropriate battery for use with information handling system  10 . 
         [0018]    A conventional test of power subsystem  14  generally involves inserting a battery  28  into battery port  32  to ensure that power subsystem  14  correctly manages communication, charging and discharging with battery  28 . In order to avoid the use of a battery during a test of power subsystem  14 , battery tester system  12  imitates the presence of a battery with signals introduced by a tester battery connector  44  to battery port  32 . Battery tester accomplishes imitation of a battery by presenting an identifier of a system-compliant battery as if from a battery management unit and then responding to charges and discharges coordinated with power system  14  as a system-compliant battery would respond. Battery tester  12  imitates battery charges to a battery by receiving battery charge current generated by power subsystem  14  at port  32  and through connector  44  with a programmable active direct current load  46 . Programmable load  46  accepts current from power subsystem  14  by changing the load over time to imitate the charge characteristics of a battery associated with information handling system  10 . Battery  12  imitates battery discharges to power subsystem  14  by generating a current with a programmable direct current power supply  48 . Programmable power supply  48  generates a current for transmission through connector  44  to port  32  that imitates the discharge characteristics of a battery associated with information handling system  10 , such as by diminishing over time and expiring at an expected battery charge life. A battery management unit adapter  50  coordinates the exchange of identification information and battery events by establishing communications over a SMBus or other management bus  52  with power subsystem  14 . Battery management unit adapter  50  contains a battery management unit integrated circuit  40  like those built into batteries to provide imitations of normal battery interactions with power subsystem  14 . 
         [0019]    In operation, a battery emulator  54 , such as an information handling system having a processor and memory to execute an application, coordinates testing of power subsystem  14  by configuring battery tester system  12  to imitate a battery associated with information handling system  10 . Battery emulator  54  retrieves an identifier, charging characteristics and discharging characteristics for an information handling system type from a battery table  56 . Battery emulator  54  provides the identifier to battery management unit adapter  50  to establish communications over connector  52  and battery port  32  with power subsystem  14 . Battery emulator  54  applies battery charge characteristics to programmable load  46  to imitate a battery receiving a charge, such as parameters for the amount of time required for a charge and decreasing charge current over time. Battery emulator  54  applies battery discharge characteristics to programmable power source  48  to imitate a battery discharge for powering information handling system  10 , such as parameters for charge life of a battery and decreasing available current over a discharge time. In one embodiment, battery emulator  54  adjusts battery characteristics to imitate a battery age or useful life remaining, such as a 70% or 80% charge availability. In another embodiment, battery emulator imitates a failed battery to test the ability of power subsystem  14  to detect a failed battery. 
         [0020]    Battery emulator  54  accepts end user inputs at a user interface  58  that establish the type of battery to imitate. Alternatively, battery emulator  54  automatically establishes a battery type that is compliant with the battery type or types required by information handling system  10 . For example, battery emulator  54  inquires with information handling system  10  to obtain the type of battery and then applies the type of battery from battery table  56  to initiate battery imitation. Battery emulator  54  can inquire by reading an identifier from information handling system  10  through management bus  52  or through a separate network interface. Alternatively, battery emulator  54  directs battery management unit  40  to sequence through a list of battery identifiers until information handling system  10  responds by accepting the battery identifier as a compliant identifier. 
         [0021]    Referring now to  FIG. 2 , a flow diagram depicts a process for testing interactions between an information handling system and a simulated battery. At step  60 , battery test system  12  couples connector  44  to battery port  32  of the information handling system  10  under test. At step  62  battery management unit adapter  50  and power subsystem  14  exchange identifiers to establish the presence of an imitated battery. At step  64 , battery emulator  54  applies the battery parameters to imitate the charging characteristics and discharging characteristics of the battery. At step  66 , the power subsystem is tested by performing test charges and discharges, such as by connecting and disconnecting AC-to-DC power adapter  30 . Power characteristics of power subsystem  14  are evaluated as if an actual battery is connected to battery port  32 . In addition, power readings from programmable load  46  and programmable power supply  48  may be evaluated to determine power subsystem response. In one embodiment, certain test conditions may be created by battery emulator  54  through direction of an end user at graphical user interface  58 , such as a battery failure or a low power condition, in order to evaluate power subsystem response. At step  68 , the test is completed and connector  44  is removed from battery port  32 . Power subsystem  14  is evaluated based upon its processing of commands received over management bus  52 , control commands sent over management bus  52 , charge sent to programmable load  46  and managing application of power sent as an imitated discharge from programmable power source  48 . 
         [0022]    Although the present invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims.