Abstract:
A smart battery charger is provided that includes one or more sensors to identify a particular battery, generate a usage profile for the battery over time, and develop a charging strategy that maximizes the useful life of the battery. The useful life of the battery may be maximized by minimizing the charge on the battery over the course of the battery&#39;s life. The charge may be minimized by delayed charging and undercharging.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application Ser. No. 61/240,497, filed on Sep. 8, 2009, which application is hereby incorporated by reference. 
     
    
     SUMMARY 
       [0002]    Embodiments of the invention are defined by the claims below, not this summary. A high-level overview of various aspects of embodiments of the invention are provided here for that reason, to provide an overview of the disclosure and to introduce a selection of concepts that are further described below in the detailed-description section. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in isolation to determine the scope of the claimed subject matter. 
         [0003]    Embodiments of the present invention relate generally to a system, method, and/or apparatus for managing the charge on a battery over the battery&#39;s life in order to maximize the useful life of the battery. The useful life of many types of batteries may be extended by minimizing the total charge on the battery over the life of the battery. The total charge may be minimized by delaying the initiation of the charge cycle so that it is completed immediately before the battery is used. The total charge in the battery over its life may also be reduced by charging the battery to less than its maximum capacity during a charge cycle. Embodiments of the present invention may use both of these mechanisms and others to minimize the charge on the battery over the battery&#39;s life. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0004]    Illustrative embodiments of the present invention are described in detail below with reference to the included drawing figures, wherein: 
           [0005]      FIG. 1  is a diagram showing a smart battery charger suitable for managing charge cycles on a plurality of batteries in order to prolong the operational life of the batteries, in accordance with an embodiment of the present invention; 
           [0006]      FIG. 2  is a line graph illustrating a usage history for a battery over the course of a five-day workweek, in accordance with an embodiment of the present invention; 
           [0007]      FIG. 3  is a diagram of an exemplary battery for use in embodiments of the present invention; 
           [0008]      FIG. 4  is a flow chart showing a method of charging a battery, in accordance with an embodiment of the present invention; and 
           [0009]      FIG. 5  is a flow chart showing a method of scheduling charge cycles for a battery in order to minimize an average charge on the battery over the life of the battery, in accordance with an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    Embodiments of the present invention relate generally to a system, method, and/or apparatus for managing battery charge cycles in order to maximize the useful life of one or more batteries. The useful life of many types of batteries may be extended by minimizing the total charge on the battery over the life of the battery. The total charge may be minimized by delaying the initiation of the charge cycle so that it is completed immediately before the battery is used. The total charge in the battery over its life may also be reduced by charging the battery to less than its maximum capacity during a charge cycle. Embodiments of the present invention may use both of these mechanisms and others to minimize the charge on the battery over the battery&#39;s life. 
         [0011]    In one embodiment, the battery&#39;s charge cycles are managed by a smart battery charger. The smart battery charger identifies a particular battery and associates the particular battery with a usage history. The usage history may be stored on the battery charger or in memory that is part of the battery. In another embodiment, the charge cycles are managed by a device utilizing the battery, such as a laptop computer, a cell phone, a PDA, a power tool, a hand-held scanner, or other device. 
         [0012]    Embodiments of the present invention may utilize one or more computer-storage media with computer-executable instructions or computer-readable data embodied thereon. Computer-storage media include both volatile and nonvolatile media, removable and nonremovable media, and contemplate media readable by a database, a switch, and various other network devices. The computer-storage media is nontransitory. By way of example, and not limitation, computer-storage media comprise media implemented in any method or technology for storing information. Examples of stored information include computer-useable instructions, data structures, program modules, and other data presentations. Media examples include, but are not limited to, information-delivery media, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile discs (“DVD”), holographic media or other optical disc storage, magnetic cassettes, magnetic tape, magnetic disk storage, and other magnetic storage devices. These technologies can store data momentarily, temporarily, or permanently. 
         [0013]    Turning now to  FIG. 1 , a smart battery charger  100  suitable for managing charge cycles on a plurality of batteries in order to prolong the operation life of the batteries is shown, in accordance with an embodiment of the present invention. The smart battery charger  100  includes a body  105  that houses the components of the battery charger  100 . The housing may be plastic, metal, aluminum, or other suitable material. The battery charger  100  includes charging port  110  and charging port  130 . The charging port  110  is shown with battery  112 , battery  114 , battery  116 , battery  118 , battery  120 , and battery  122 . The charging port  130  is shown with battery  132 , battery  134 , battery  136 , battery  138 , battery  140 , and battery  141 . As can be seen, each charging port holds six batteries. Embodiments of the present invention are not limited to charging ports that hold six batteries. For example, an exemplary battery charger may include just a single charging port. The charging port  110  and the charging port  130  are sized and shaped to receive one or more batteries. Though not shown in  FIG. 1 , each battery port includes a charging plug that couples with a charging port on the battery. The charging plug and the charging port couple to enable an electrical current to pass between the battery charger  100  and an individual battery placed in the charger. 
         [0014]    In one embodiment, charging port  110  and charging port  130  are sized to fit the battery plus the box in which a battery is packaged. Each of the batteries in  FIG. 1  is shown outside of a box or casing in which a battery may typically be shipped. In the embodiment where the battery is charged while in a shipping package, the shipping package may have openings that allow access to the charging ports on the battery. The shipping package may also have an opening allowing a communications plug on the battery charger to couple with a communications port on the battery. The communications port allows a computer-storage media in the battery to be accessed by the battery charger when the battery and charger are coupled together. 
         [0015]    Charging a battery in a packaging box may be useful to charge the battery immediately prior to shipment to a use point. Thus, in this embodiment, the smart battery charger  100  would be used to charge batteries prior to their first use. The batteries could be left on a shelf within the shipping package uncharged until they are ready to be shipped, at which time they could be placed in the battery charger  100  and charged. The first charge cycle could then be recorded on memory within the battery and then the battery could be shipped to the customer. A battery charger at the point of use could utilize the initial usage and charging information to estimate the future life of the battery more accurately. The battery charger at the point of use may be a different battery charger than the one used prior to shipment. 
         [0016]    Charging the battery for the first time as the battery is shipped and on an as-needed basis may benefit warranty programs offered to battery customers. For example, leaving a charged, or partially charged, battery on a shelf prior to shipment to a customer decreases the useful life of the battery. A vendor with inconsistent shelf time may be forced to offer a shorter warranty to avoid warranty claims. However, by starting the “life” of the battery at the time of shipment the predictability of the useful life the battery is increased and a longer warranty may be offered. A warranty could also be based on the total energy delivered by the battery, which is roughly the sum of the amount of energy put into the battery at each charge cycle. Offering a warranty based on total energy delivery may not be possible unless the charge-cycle details are recorded. The total energy used may be recorded in the battery as each charge and use cycle is recorded. 
         [0017]    In addition to charging the battery while in a shipping box or outside of the device in which the battery is used, the battery charger may also couple with the device in which the battery is used. Thus, the battery charger could include a cradle for receiving a device and coupling with the battery in the device for the purpose of charging the battery and exchanging information with the battery. In this case, the ports in the battery couple with plugs in the battery charger via the device in which the battery is located. Thus, the plugs in the battery and the ports in the battery charger may not be in direct contact with each other. As used throughout the present application, communicatively coupling occurs when a communication is passed from the charger to the battery or from the battery to the charger. Multiple conduits and devices may carry the communication between the battery and the charger. The charger and battery do not need to be in direct contact even when a plug on the battery is described as coupling with a port on the battery charger or vice versa. Similarly, a conductive couple occurs when an electrical current is able to pass between the battery and the charger. Multiple conduits and devices may carry the current. The charger and battery do not need to be in direct contact for a conductive coupling to occur even when a plug on the battery is described as coupling with a socket on the battery charger or vice versa. In another embodiment, the battery charger connects to the device and the battery in the device through one or more cables. 
         [0018]    Continuing now with  FIG. 1 , the body  105  of the battery charger  100  defines an opening  190  into which battery packaging may be stored. As can be seen, battery packaging  194  may be collapsed and placed into the opening. A door  192  may cover the opening  190  and secure the battery packaging within the body  105 . Storing a battery packaging  194  within the battery charger facilitates recycling the battery at the end of the battery&#39;s useful life by making a return package readily accessible to the user of the battery. 
         [0019]    The battery charger  100  includes a display  180 . The display  180  may display information related to one or more batteries within the battery charger  100 . For example, the display  180  may display the percent charged  182  for a particular battery, an identifier  184  for the particular battery, the current charge cycle  186  for the particular battery, and the remaining estimated life  188  of the particular battery. The remaining life may be determined by calculating how long it will take for the remaining usage cycles to be used if the present usage pattern for the battery continues into the future. The remaining usage cycles may be calculated by subtracting the total cycles on the battery to date from the expected lifetime charge cycles. The information for an individual battery may be accessed by pushing a button adjacent to a battery. For example, the information related to battery  112  may be accessed by pushing the button  142 . Similarly, buttons  144 ,  146 ,  148 ,  150 ,  152 ,  162 ,  164 ,  166 ,  168 ,  170 , and  172  may be pushed to access information related to the batteries adjacent to the respective buttons. The display  180  may be an LCD display, touch-screen display, or other suitable display type. Other buttons (not shown) may allow the user to navigate menu options presented on the display  180 . 
         [0020]    Turning now to  FIG. 2 , a line graph illustrating a usage history for a battery over the course of a five-day workweek is shown according to an embodiment of the present invention. The Y axis  210  shows the charge percent on the battery. The X axis  220  shows the time and day. The solid line indicates smart charging on an as-needed basis in accordance with an embodiment of the present invention. The dash line indicates traditional charging which begins soon after the battery is placed in the battery charger. Under the smart charging regime, on Friday, from approximately 2:00 A.M. to 5:00 AM, the battery is charged  230  from 40 to 100% of capacity. At approximately 6:00 AM to about 2:00 PM on Friday, the battery is discharged  232  during use. As can be seen, the discharge cycle will be similar for both the traditional and smart charge cycles. As the battery ages, the discharge cycle may differ significantly for batteries charged under the traditional and smart charge cycles. Under the traditional regime, charging  234  begins immediately upon the battery being placed in the battery charger at roughly 2:00 PM on Friday. In contrast, under the smart charging, the charging  238  does not begin until about 2:00 AM on Monday. This allows the battery to remain at about 40% charge capacity for an additional two days. The initiation of charging  238  begins with enough time to complete the charge cycle prior to the anticipated next usage at about 6:00 AM on Monday. The anticipated next usage may be determined based on previous usage cycles recorded for the battery. Viewing the entire line graph  200 , it can be seen, for example, that the usage cycle typically begins at about 6:00 AM on weekdays and concludes at 2:00 PM after an eight hour shift. Embodiments of the present invention are not limited for use with batteries having a particular use/charge cycle. Thus, the initiation of charging under a smart regime may begin with enough time to be completed before 6:00 AM. In  FIG. 2 , the smart charge cycles are completed at 5:00 AM, which is one hour before the battery&#39;s anticipated usage. 
         [0021]    Continuing with  FIG. 2 , once again at about 6:00 AM, the battery begins to discharge  240  until it reaches 40% capacity around noon on Monday. Again, under the traditional regime, the battery would initially begin charging  242  to full capacity at about 2:00 PM on Monday. In contrast, by waiting until just before the battery would actually be used, charging  246  may begin at about 2:00 AM on Tuesday. This cycle essentially repeats each day on the remaining graph. 
         [0022]    From roughly 6:00 AM until 2:00 PM on Tuesday, the battery discharges  248  as it is used. Under the traditional regime, the battery is charged  250  at roughly 2:00 PM. In contrast, under the smart regime the battery is charged  254  at roughly 2:00 AM on Wednesday. On Wednesday, the battery discharges  256  during use. Under the traditional regime, the battery is charged  258  at 2:00 PM on Wednesday. Under the smart regime the battery is charged  262  at 2:00 AM the following day on Thursday. The final use cycle occurs on Thursday when the battery is discharged  264 . One final charge  266  under the traditional regime is shown. For the one-week period of time shown in  FIG. 2 , the battery charged under the traditional regime averages 91% charged. In contrast, the battery charged under the smart regime averages 53% charged. This difference may significantly extend the useful life of the battery. 
         [0023]    Turning now to  FIG. 3 , an exemplary battery  300  for use in embodiments of the present invention is shown. The battery  300  includes a first charging port  302  and a second charging port  304 . The first and second charging ports  302  and  304  are sized and shaped to receive a charging plug from a battery charger. In one embodiment, the first and second charging ports  302  and  304  are simply exposed conductive contacts for contacting charging plugs on the battery charger. The first charging port  302  and the second charging port  304  are coupled to a wire or conduit that carries an electrical charge from the battery charger to the portion of the battery that holds the charge. In one embodiment, the battery  300  is a lithium ion battery. However, embodiments of the present invention are not limited to use with a particular type of battery. 
         [0024]    The battery  300  includes an identification  306 . In one embodiment, the identification  306  is a bar code. The bar code may be read by a scanner on the battery charger or other device to identify an individual battery and distinguish batteries from each other. In another embodiment, the identification  306  is an RFID tag that could similarly communicate a unique identification number to an appropriately equipped device or battery charger. Identifying a particular battery is important for embodiments of the present invention to associate the batteries with a specific usage history, especially if the usage history is not stored on the battery. 
         [0025]    In one embodiment, the usage history for the battery  300  is stored on a computer-readable media  310  within the battery. The media  310  may be accessed by communications port  308 . Communications port  308  is conductively coupled to the media  310  by a conduit  312 . The communications port  308  may interface with a plug on a battery charger or other device. In one embodiment, the media  310  also includes a unique identifier that is used by a battery charger or other device to identify a specific battery. 
         [0026]    Turning now to  FIG. 4 , a method  400  of charging a battery is shown, in accordance with an embodiment of the present invention. As described previously, the method may be used on any battery that benefits from having a lower charge on the battery over the life of the battery. The primary benefit is extending the useful life of the battery. Extension of the useful life of the battery may be evidenced by enabling the battery to be charged for additional cycles. A charge cycle consists of discharging the charge on the battery and recharging the battery to either full or less than full capacity. Extension of the useful life of the battery may also be evidenced by the battery holding a full charge for additional charge cycles or any other measure by which the battery remains valuable to the user for a longer period of time. 
         [0027]    At step  410 , a battery is received. In one embodiment, the battery is received by placing the battery into a charging port on a battery charger. In another embodiment, the battery may be received by a device that uses the battery. 
         [0028]    At step  420 , a usage history for the battery is retrieved. In one embodiment, the usage history is retrieved from computer-readable memory or storage located in the battery. In another embodiment, the usage history for the battery is stored on the battery charger or device utilizing the battery. When the usage history is stored in a location other than in the battery, the individual battery may be identified by a unique identifier, such as a bar code or RFID tag or other mechanism. The usage history includes the charge on the battery over time. Thus, the characteristics of a discharge cycle or a charge cycle may be determined from the usage history on the battery. The characteristics of interest include the beginning and end time for the discharge cycle and the energy used during a charge cycle. In one embodiment, the usage history may indicate that the battery has never been charged before. 
         [0029]    At step  430 , an optimal time to initiate a charge cycle on the battery is determined from the usage history. The optimal time is a time when the battery is likely to be next used minus a period of time required to complete the charge cycle. As illustrated previously in  FIG. 2 , if the next use cycle is to begin at about 5 o&#39;clock and the charge cycle takes an hour to complete, then the optimal time to initiate a charge cycle on the battery would be roughly 4 o&#39;clock. In one embodiment, a time buffer may be used to ensure that the charge cycle is completed in time for the next use cycle to begin. The buffer is illustrated by about a two-hour time period in  FIG. 2 . Embodiments of the present invention are not limited to including a buffer. In one embodiment, the usage history is evaluated by a machine-learning algorithm that determines the optimal time. 
         [0030]    At step  440 , the optimal charge on the battery is determined from the usage history for the battery. The optimal charge is a minimum charge plus an amount of energy historically used during a single use cycle. For example, if 50% of the battery&#39;s capacity is typically used during a single-use cycle and the minimum charge is 20%, then the optimal charge on the battery would be 70%. Charging the battery to the optimal charge reduces the total charge on the battery over the life of the battery. In one embodiment, an additional buffer is added to the minimum charge and the amount of energy historically used during a single cycle to calculate the optimal charge. At step  450 , a charge cycle is initiated at the optimal time, and the battery is charged during the charge cycle to the optimal charge. 
         [0031]    At step  460 , an updated usage history is generated based on the recent charging of the battery. At step  470 , the updated usage history is uploaded to a computer-readable media on the battery. In this case, the previously retrieved usage history would have been retrieved from the same computer-readable media on the battery. As stated previously, embodiments of the present invention are not limited to storing the battery usage data on the battery. The updated usage history may be stored on the battery charger or use device with the other usage history. 
         [0032]    At step  480 , a request to display information related to the battery is received. In one embodiment, the request is received by pushing a button adjacent to the battery in a battery charger. In another embodiment, the request is received when a user makes the request through a user interface on the device in which the battery is used. At step  490 , the information associated with the battery is displayed. The information includes the usage history, charge cycles on the battery to date, anticipated charge cycles left over the life of the battery, and anticipated energy delivery remaining in the battery. The anticipated energy delivery remaining in the battery is the rated-energy-delivery capacity of the battery minus the total energy delivered by the battery. The total energy delivered by the battery may be calculated by totaling the energy delivered in each charge cycle. The energy delivered during each charge cycle may be recorded on the battery memory or in memory in the battery charger. The rated-energy-delivery capacity may also be stored on the battery memory by a manufacture, vendor, or the battery charger. 
         [0033]    In one embodiment, if the usage history indicates that the battery has never been charged, a first charge amount is retrieved from memory in the device using the battery or a battery charger charging a battery for the first time. A usage history is then created and stored where appropriate based on the setup. 
         [0034]    Turning now to  FIG. 5 , a method  500  of scheduling charge cycles for a battery in order to minimize an average charge on the battery over the life of the battery is shown, in accordance with an embodiment of the present invention. Method  500  may be used to manage one or a plurality of batteries. At step  510 , an indication that a battery is coupled to the battery charger is received. This indication may be generated when a sensor in the battery charger detects the insertion of a battery. In one embodiment, the coupling of a charging port or a communications port in the battery with a charging plug or communications plug in the battery charger may serve as the indication that a battery has been coupled to the battery charger. Though described as a plug in a port, the plugs and ports may simply be contacts suitable for communicating a current between the battery and the battery charger. The port does not need to have a socket into which the plug fits. In another embodiment, a plug is on the battery and a port is in the battery charger. Further, the communications between the battery memory and the battery charger may be wireless. In addition, the charge to the battery could be delivered inductively without use of either a plug or socket in either the battery or the battery charger. 
         [0035]    At step  520 , a usage history for the battery is retrieved. As described previously, the usage history may be retrieved from memory in the battery charger or from memory located in the battery. At step  530 , the usage history is used to determine an optimal time to initiate a charge cycle in the battery. The optimal time is a time when the battery is likely to be next used minus a period of time required to complete the charge cycle for the battery. At step  540 , the charge cycle for the battery is initiated at the optimal time. As described previously, the charge cycle may include charging the battery to an optimal charge, which is determined based on the typical battery discharge during a use cycle. 
         [0036]    In one embodiment, the battery is just one of a plurality of batteries managed by the battery charger. The plurality of batteries managed by the battery charger may be interchangeable batteries. Interchangeable batteries may be used interchangeably between similar devices compatible with the batteries. In one embodiment, when multiple batteries are managed by the battery charger, one of the plurality of interchangeable batteries is kept as a hot battery. The hot battery is fully charged and available for use outside of the typical or expected usage. In other words the hot battery is not charged based on an optimal time or charge but is fully charged as soon as it is placed in the battery charger. In another embodiment, at least one battery is kept fully charged, but an individual battery is not designated as a hot battery. 
         [0037]    In one embodiment, when a plurality of batteries are managed, the charge cycles between the batteries are managed to equalize the life of each battery within the plurality of batteries. The service life of a population of batteries is maximized by equalizing the wear on each battery over time. This may be done by indicating to users of the batteries which batteries should be used first or next. Batteries with less overall usage should be recommended for next use. 
         [0038]    Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the spirit and scope of embodiments of the present invention. Embodiments of the present invention have been described with the intent to be illustrative rather than restrictive. Certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated to be within the scope of the claims.