Patent Publication Number: US-2023163607-A1

Title: Auxiliary power case

Description:
TECHNICAL FIELD 
     Subject matter disclosed herein generally relates to auxiliary power for computing devices. 
     BACKGROUND 
     A computing device can include a processor, memory accessible by the processor, a housing and a battery. 
     SUMMARY 
     An auxiliary power case can include a frame; a panel coupled to the frame, where the panel defines at least a portion of a recess; a rechargeable battery disposed at least in part in the recess; and a power interface operatively coupled to the rechargeable battery. Various other apparatuses, assemblies, systems, methods, etc., are also disclosed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features and advantages of the described implementations can be more readily understood by reference to the following description taken in conjunction with examples of the accompanying drawings. 
         FIG.  1 A  and  FIG.  1 B  are perspective views of an example of a computing device and an example of an auxiliary power case; 
         FIG.  2    is a perspective view of an example of a computing device and an example of an auxiliary power case; 
         FIG.  3    is a perspective view of an example an auxiliary power case; 
         FIG.  4    is a perspective view of an example of an auxiliary power case; 
         FIG.  5    is a perspective view of an example of an auxiliary power case; 
         FIG.  6    is a side view of an example of a computing device and an example of an auxiliary power case; 
         FIG.  7    is a block diagram of examples of circuitry; 
         FIG.  8    is a diagram of an example of a graphical user interface; 
         FIG.  9    is a perspective view of an example of an auxiliary power case; and 
         FIG.  10    is a block diagram of an example of a system that includes one or more processors and memory. 
     
    
    
     DETAILED DESCRIPTION 
     The following description includes the best mode presently contemplated for practicing the described implementations. This description is not to be taken in a limiting sense, but rather is made merely for the purpose of describing the general principles of the implementations. The scope of the invention should be ascertained with reference to the issued claims. 
       FIG.  1 A  and  FIG.  1 B  show an example of a computing device  100  and an example of an auxiliary power case  200 . As an example, the computing device  100  can include one or more processors  112 , memory  114  (e.g., one or more memory devices), one or more network interfaces  116 , and one or more other components  118 . Such components may be, for example, housed in one or more of a first housing  120  and a second housing  140  where, the first housing  120  and the second housing  140  can be coupled via a hinge assembly  130 . 
     As indicated in  FIG.  1 A , the computing device  100  can include a battery  160 , which can be a rechargeable battery that is disposed within one of the housings  120  and  140 . As an example, the battery  160  may be a non-Customer Replaceable Unit (non-CRU) that demands some amount of disassembly of the computing device  100  (e.g., taking apart the housing  140 , etc.) or it may be a Customer Replaceable Unit (CRU) that can be uncoupled from one of the housings  120  and  140 . As to a CRU, consider one or more manual buttons or latches that can be actuated by a human, optionally in a tool-less manner, to remove the battery  160  and to replace it. In such an example, a portion of a housing may be a part of a replacement battery. As to a non-CRU, it may be recommended to replace the battery  160  at an authorized service center and/or “in the field” (e.g., a Field Replaceable Unit (FRU)) where, for example, a technician can travel to the computing device  100  to replace the battery  160 . As an example, a battery may be a sealed battery. For example, consider a non-CRU sealed battery, which may be rated in terms of a number of cycles, a number of years, etc. 
     As an example, the auxiliary power case  200  may provide for extending lifetime of a battery, whether the battery is a CRU or a non-CRU. For example, as to a non-CRU, consider utilization of the auxiliary power case  200  in a manner that can increase a rating of a 1000 cycle battery by more than 100 cycles or a three year battery by more than 3.6 months. In such examples, the auxiliary power case  200  may be utilized in an intelligent manner as determined via circuitry. For example, consider utilizing one or more triggers that can cause drawing of power from the auxiliary power case  200 . As an example, a trigger may be a temperature trigger, a pressure trigger, a current trigger, a voltage trigger, etc. A temperature trigger may aim to manage temperature of a battery, a pressure trigger may aim to manage swelling of a battery, a current trigger may aim to manage one or more chemical reactions that may lead to detrimental conditions, and a voltage trigger may aim to manage one or more chemical reactions that may lead to detrimental conditions. 
     As an example, the auxiliary power case  200  may be provided integral to the computing device  100  (e.g., integral to the housing  140 ) or as an add-on component  240  that can be coupled to the computing device  100  (e.g. coupled to the housing  140 , etc.). 
     As shown in  FIG.  1 A  and  FIG.  1 B , the housing  120  may be a keyboard housing that includes a keyboard  124  and the housing  140  may be a display housing that includes a display  144  that can be operatively coupled to one or more of the processors  112  and utilized for rendering information (e.g., images, graphics, text, etc.). For example, consider a graphical user interface (GUI)  145  that can be rendered to the display  144 . As an example, the GUI  145  may provide for rendering of information associated with the battery  160  and/or the auxiliary power case  200 . For example, consider a settings GUI, a power utilization GUI, a temperature GUI, a pressure GUI, a battery health GUI, etc. 
     As shown in  FIG.  1 A  and  FIG.  1 B , the computing device  100  can include one or more ports or connectors  150 . For example, consider one or more serial ports that can be utilized for transmission of data, power or power and data. One or more ports may be positioned on a side of a housing or sides of a housing. In the example of  FIG.  1 A  and  FIG.  1 B , the housing  120  is shown as including ports on two opposing sides, which may include, for example, one or more universal serial ports (e.g., USB ports). 
       FIG.  1 A  also shows a Cartesian coordinate system (x, y and z) that may be utilized to define one or more features of the computing device  100  and/or the auxiliary power case  200 . For example, the auxiliary power case  200  can include a surface  246  where the surface  246  can be a substantially planar surface defined via an x,y-plane in a closed orientation of the computing device  100  as shown in  FIG.  1 A . As shown in  FIG.  1 A , the surface  246  can be defined by dimensions dx and dy where the housing  140  and/or the auxiliary power case  200  can be defined by a thickness dz. 
     As an example, a rechargeable battery may be relatively thin (e.g., less than approximately 10 mm) and relatively light (e.g., less than 200 grams). As an example, a rechargeable battery may sit within a recess without extending outwardly therefrom or may extend outwardly therefrom a relatively small distance (e.g., less than approximately 8 mm, etc.). Where a rechargeable battery extends outwardly, it may be more readily contact, for example, along an edge for removal from a recess. As an example, a rechargeable battery may include a grip, which may be a fold-down grip, that can allow for removal of a rechargeable battery from a recess via a finger or fingers (e.g., consider a U-shaped foldable grip, etc.). 
     As an example, a rechargeable battery may be a flexible pouch type of lithium-ion battery. In such an example, the flexible pouch may include a protective layer, which may help to protect against punctures, leakage, etc. As an example, a rechargeable battery may have a relatively rigid shell (e.g., a protective shell) that may help to reduce risk of punctures, bending damage, leakage, etc. As an example, a rechargeable battery may include a pouch and/or a shell that can allow for some expansion, for example, as may occur under normal operation due to breathing (e.g., expansion and contraction that can occur during cycling, etc.). In such an example, breathing may be greater than 1 percent and less than approximately 15 percent of a total manufactured thickness. For example, consider a recess cover  248  as providing space for breathing, which may be via a clearance, a resilient foam, etc. In such an example, expansion of the battery  260  in the recess  245  may be accommodated without introduction of stress and/or strain to a display such as a flat panel display (e.g., to reduce risk of expansion causing a bulge, etc., in a display surface). As an example, the recess cover  248  can include a release mechanism that can be actuated responsive to force for instances where undesirable expansion of the battery  260  may occur. In such an example, the release mechanism (e.g., magnetic, interference fit, clip, etc.) may release responsive to undesirable swelling force of the battery  260  such that the undesirable swelling force does not deform the auxiliary power case  200  or one or more components of the computing device  100 . 
     As an example, the auxiliary power case  200  can include a frame  242 ; a panel  244  coupled to the frame  242 , where the panel  244  defines at least a portion of a recess  245 ; a battery  260  disposed at least in part in the recess  245 ; and a power interface  267  operatively coupled to the battery  260 . 
     In the example of  FIG.  1 A , the battery  260  can be defined by dimensions dxb, dyb and dzb where the recess  245  can be sized to accommodate the battery  260  (e.g., fully, flush, with a portion extending, etc.). As an example, the battery  260  can have a perimeter that matches a perimeter of the recess  245  where a clearance may exist between the perimeters or an interference fit may be provided by appropriate dimensions of the perimeters; noting that one or more access portions  243  may provide for access. 
     As an example, one or more magnets may be utilized for holding the battery  260  in the recess  245 . For example, consider magnetic materials that can be utilized to assure one or more of proper positioning, electrical interface coupling, securing force such that the battery  260  does not fall out of the recess  245 , etc. As an example, an electrical interface, if present, may include spring-loaded elements such as, for example, pogo pins, etc. For example, mating surfaces may be between the battery  260  and one or more surfaces of the recess  245 . 
     As to the power interface  267 , it may an electrical interface that can be a wired and/or a wireless interface that can transfer power to the computing device  100 . As shown, the battery  260  may be removable from the recess  245  where the recess  245  can include a power interface  247 , which can be operatively coupled to circuitry of the computing device  100 . As an example, the power interface  247  may be part of the computing device  100 . For example, consider one of the housings  120  and  140  as including a built in power interface. As an example, the power interface  247  may be coupled to the computing device  100  via a cable. For example, consider a power cable with a connector that can plug into one or more of the ports  150  of the computing device  100 . 
     As an example, the auxiliary power case  200  can include the recess cover  248 , which may include one or more features  249 . For example, consider a memory card holder, a display, a touch-sensitive surface, one or more solar cells, etc. As an example, the auxiliary power case  200  can include circuitry that may provide for control and/or interaction with one or more of the one or more features  249 . As an example, the auxiliary power case  200  may include communication circuitry such that it can at least receive one or more communication signals from the computing device  100 . Such communication circuitry may be operatively coupled to one or more components of the auxiliary power case  200 , which, for example, may provide for control of power from and/or to the battery  260 . 
     As an example, the recess cover  248 , if included, may be positioned to cover the recess  245  with or without the battery  260  disposed in the recess. As an example, the battery  260  and/or one or more other features of the auxiliary power case  200  may include an indicator that provides status information as to the battery  260  (e.g., amount of charge, discharge rate, remaining time, charging rate, reason for powering the computing device  100 , etc.). 
     As an example, the recess cover  248 , if included, may be coupled to the auxiliary power case  200  via an interference fit, a latch, mating features (e.g., key/keyway, etc.), magnets, etc. As an example, the recess cover  248  can include circuitry such as, for example, interface circuitry, display circuitry, etc., which may interact with circuitry of the auxiliary power case  200 , a computing device, etc. As an example, the battery  260  can include the recess cover  248 , which may be an integral feature or a removable feature of the battery  260 . As shown in the example of  FIG.  1 A , the recess  245  can include one or more access portions  243 , for example, to allow for insertion of a finger (e.g., fingertip, fingernail, etc.) to facilitate removal of the battery  260  from the recess  245 . 
     As an example, the computing device  100  and the auxiliary battery case  200  may form a system. For example, consider a system that includes the computing device  100  that includes the battery  160  as a dedicated battery and a first interface where the auxiliary power case  200  includes the frame  242  as removably attachable to one of the housings  120  and  140  of the computing device  100 , the battery  260  as a rechargeable battery, control circuitry and a second interface operatively coupled to the rechargeable battery and the control circuitry, where, responsive to a signal transmitted from the first interface to the second interface, the control circuitry energizes the second interface for transmission of power of the rechargeable battery from the second interface to the first interface. In such an example, the first and second interfaces may be wired and/or wireless. As an example, a wireless approach may utilize the Qi standard. 
     While  FIG.  1 A  and  FIG.  1 B  show the computing device  100  as including the two housings  120  and  140 , the housing  140  may be separable from the housing  120  and be utilized as a tablet (e.g., a tablet mode). As an example, the auxiliary power case  200  may be suitable for use with a tablet form factor computing device and/or a notebook form factor computing device. 
     In the example of  FIG.  1 A , the auxiliary power case  200  can include a frame  242  where the surface  246  is a surface of a panel  244  coupled to the frame  242  (e.g., as separate pieces, as integrally formed via machining, molding, etc.), where the panel  244  defines at least a portion of the recess  245 ; where the battery  260  is a rechargeable battery disposed at least in part in the recess  245 ; and the power interface  267  being operatively coupled to the battery  260  as a rechargeable battery. 
       FIG.  2    shows an example of the auxiliary power case  200  and the computing device  100 . In the example of  FIG.  2   , the auxiliary power case  200  is shown as including the frame  242  (see dashed lines) that can include a lower, inwardly facing device side panel  234  and the panel  244  as an upper, outwardly facing panel. As shown, the frame  242  may include members where spaces can be provided for circuitry, etc. As an example, the members of the frame  242  may be resilient and/or rigid. As to resilient members, consider an auxiliary power case that may be foldable, for example, to reduce storage space. As an example, the auxiliary power case  200  can include at least the panel  244 , which may be integrally formed or separately formed with respect to the frame  242  and/or the panel  234 , if present (e.g., consider the auxiliary power case  200  being integral with a display housing, etc.). As an example, an auxiliary power case  200  may be rollable such that it can be rolled into a cylindrical shape for transport, storage, etc., which may be with or without the battery  260 , depending on the configuration and/or materials of construction of the battery  260 . 
     In the example of  FIG.  2   , the auxiliary power case  200  can include one or more connectors  250 - 1  and  250 - 2  that can be plugged into one of the one or more ports  150  of the computing device  100 . As an example, the auxiliary power case  200  may be coupled to the housing  120  and/or the housing  140  of the computing device  100 . For example, the connector  250 - 2  can be utilized to couple the auxiliary power case  200  to the housing  120  where the auxiliary power case  200  may be positioned underneath the computing device  100 . In such an example, the housing  140  can be rotated to an open orientation via the hinge assembly  130  with interference from the connector  250 - 2 . As an example, the connector  250 - 1  may be positioned closer to the hinge assembly  130  and hence a rotational axis such that an arc distance is minimal where the connector  250 - 1  does not interfere with rotational opening of the housing  140  with respect to the housing  120 . 
     As explained, the computing device  100  can include the power interface  247  and the auxiliary power case  200  can include the power interface  267  such that a wired power connector is not necessarily required to transfer power and/or data. In such an example, the housing  140  may be opened or closed without interference from a cable, a connector, etc. 
       FIG.  3    shows an example of the auxiliary power case  200  as including a cable management component  270 . For example, consider a spool that can be actuated (e.g., manually, automatically, responsive to input, etc.) to reel in and/or reel out a length of cable of the connector  250 . For example, consider a button that a user may push to cause the cable management component  270  to take in a length of cable (e.g., for storage). In such an example, a push of the button may act as a release where a length of cable can be pulled out for use. 
     As explained, the auxiliary power case  200  can include the frame  242  and the panel  244 . In the example of  FIG.  3   , various components may be disposed in a frame space, for example, underneath the panel  244 . For example, the frame  242  may define a frame space for a reel that can take up or let out cable of the connector  250 . In the example of  FIG.  3   , the cable of the connector  250  may be electrically coupled to an interface that can be electrically coupled to the battery  260  via wire or wirelessly (e.g., via a coil or coils, via contacts, via spring-loaded contacts, etc.). 
       FIG.  4    shows an example of the auxiliary power case  200  where the recess  245  may be formed as a pocket. For example, consider a pocket approach where a user may insert or remove the battery  260  from the recess via an opening, which may be at an edge of the auxiliary power case  200 . In such an example, the panel  244  of the auxiliary power case  200  may be a flexible and/or resilient panel. In such an example, a user may position the battery  260  such that the interface  267 , if included, is appropriately positioned. As an example, the auxiliary power case  200  can include an elastomeric panel that can be stretched to provide a clearance sufficient for insertion of the battery  260 . For example, consider a panel (e.g., a sheet, etc.) that is made of one or more polymeric materials, which may be transparent, translucent and/or opaque, that can be stretched to generate an opening (e.g., a slit, etc.) for insertion and/or removal of the battery  260  where the panel can apply a force (e.g., a snap-back force, etc.) to help retain the battery  260  in the auxiliary power case  200 . 
       FIG.  5    shows an example of the auxiliary power case  200  where the recess  245  may be formed as a pocket. For example, consider a pocket approach where a user may insert or remove the battery  260  from the recess via an opening, which may be at an edge of the auxiliary power case  200 . In such an example, the panel  244  of the auxiliary power case  200  may be a flexible and/or resilient panel. In such an example, the battery  260  may include a cable with the connector  250  where at least the cable can be stored in the recess  245 . In such an example, the frame  242  may be a support for the panel  244  (e.g., consider the frame  242  as being a lower panel where the lower panel and the panel  244  are connected (e.g., at edges, etc.). 
       FIG.  6    shows an example of the auxiliary power case  200  with respect to the computing device  100  along with one or more components that can provide for attachment of the auxiliary power case  200  to the computing device  100 . For example, consider hooks  610  and loops  620  (e.g., VELCRO, etc.), magnetic material  630  (e.g., one or more magnets, one or more ferromagnetic materials, etc.), and/or one or more resilient couplings  650 , which may be part of or form a resilient frame (e.g., part of the frame  242 , etc.). As to a resilient frame, consider a stretchy frame that can be elastically deformed to fit over a portion of a housing and then released to snuggly attach to the housing. As an example, an auxiliary power case may be attached using an interference fit (e.g., a press-fit, etc.). In various examples, the auxiliary power case  200 , where existing as a separate assembly that is not formed as part of a housing of a computing device, can be removably attachable. 
     As an example, an auxiliary power case can be a protective case for a computing device. For example, consider an auxiliary power case that can protect a display housing and a display thereof. In such an example, the auxiliary power case can include a bumper or bumpers, which may be part of an elastomeric panel, a non-elastomeric panel, an elastomeric frame, a non-elastomeric frame, an elastomeric coupling, a non-elastomeric coupling, etc. In such an example, the auxiliary power case can provide for shock-resistance in case of a fall or other contact with an object. As an example, an auxiliary power case may include a roll-down perimeter or pull-down that can protect at least an edge of a computing device that can act as a deployable component or deployable components, which may provide for coupling the auxiliary power case to a computing device. For example, consider a roll-down or pull-down perimeter that can roll-down or pull-down past a display housing to a keyboard housing such that the keyboard housing can be protected. In such an example, once rolled down or pulled down, the computing device, as a clamshell computing device, may be maintained in a closed orientation. Where a user desires to open the computing device by transitioning from the closed orientation to an open orientation, the user may roll-up or pull-up the edge. For example, consider the one or more resilient couplings  650  of the example of  FIG.  6    as being roll-down or pull-down bumpers that can be deployed as desired to protect the computing device (e.g., the housing  140  and the housing  120 ). In such an example, the auxiliary power case can provide additional functionality, it can help protect one or more housings of a computing device (e.g., in one or more orientations, etc.) and supply auxiliary power as appropriate. As an example, such an approach may provide for two side or four side protection. For example, consider left and right side protection, front and back side protection or left, right, front and back side protection. 
       FIG.  7    shows an example of a system  700  that includes a base  720  and a device  750  where the base  720  can transmit energy to the device  750 , for example, to power the device  750 , to store power in a battery of the device  750 , etc. 
     As an example, the base  720  and/or the device  750  may operate according to one or more standards where compatibility exists such that energy can be transmitted from the base  720  to the device  750 . As an example, consider the Qi standard. Devices that operate according to the Qi standard utilize electromagnetic induction between coils, which can be planar coils. A Qi system includes two types of devices, a base (e.g., a base station), which includes or is connected to a power source and provides inductive power, and a device such as, for example, a mobile device (e.g., a mobile phone, a mobile peripheral, etc.), which can consume inductive power provided by the base. 
     As shown in  FIG.  7   , the base  720  can include a power transmitter  721  that receives power from a supply  722  where the power transmitter  721  can include one or more transmitting coils  723  that generate an oscillating magnetic field  730  in a space. In the example of  FIG.  7   , the supply  722  may be one or more types of power sources, for example, consider the battery  260  of the auxiliary power case  200  as a power source. 
     As an example, converter circuitry may be included as part of the base  720  or separately from the base  720  where such converter circuitry can convert AC power to DC power, at a level sufficient for operation of the base  720 . As an example, a cable can be provided that can electrically connect the base  720  to one or more sources of electrical power (e.g., a battery, a wall outlet, a device, etc.). 
     As shown, the device  750  can include a power receiver  751  that includes a receiving coil  753 . In the example of  FIG.  7   , the magnetic field  730  can induce an alternating current in the receiving coil  753  by Faraday&#39;s law of induction. Where there is sufficiently close spacing of the coils  723  and  753  (e.g., and sufficient shielding on their surfaces), inductive power can be transferred efficiently from the base  720  to the device  750 . 
     As to alignment of the coils  723  and  753 , one technique involves guided positioning where the device  750  is placed at a certain location of the base  720 . In such an example, the device  750  can provide an alignment aid that can be appropriate to its size, shape and function. Another technique can be referred to as free positioning, which does not demand placement of the device  750  with direct alignment as to the position of a transmitting coil (see, e.g., the one or more coils  723 , etc.). As to free positioning, a bundle of transmitting coils may be included in a base to generate a magnetic field at a location of a receiving coil or, for example, mechanical features may move one or more transmitting coils with respect to a receiving coil or, for example, a technique involving multiple cooperative flux generators may be utilized. 
     Referring again to  FIG.  7   , the system  700  includes the power transmitter  721  with a power conversion unit  724  and a communications and control unit  726 . The control and communications unit  726  can regulate transferred power to a level that a power receiver requests. While the base  720  is shown with a single transmitter, a base may include multiple transmitters (e.g., for multiple devices to be placed and inductively charged). In the system  700 , the base  720  may include features for input power provisioning, user interfacing, etc. 
     As to the power receiver  751 , it can include a power pick-up unit  754  and a communications and control unit  756 . As shown, the receiving coil  753  can interact with the magnetic field  730  such that energy is transferred to the power pick-up unit  754 . The communications and control unit  756  can regulate transferred power to a level that is appropriate for the device  750 , for example, as illustrated by the load  752 , which may be circuitry associated with one or more batteries (see, e.g., consider one or more of the batteries  160 ,  260 , etc.) electrically connected to the output of the power receiver  751 . 
     As an example from the 2017 version 1.2.2 of the Qi specification, the A2 reference Qi low-power transmitter has a coil of 20 turns (in two layers) in a flat coil, wound on a form with a 19 mm inner diameter and a 40 mm outer diameter, with a below-coil shield of soft iron at least 4 mm larger in diameter which gives an inductance of 24+/−1 microhenries. This coil is placed in a series resonant circuit with a 200 nF capacitor to yield a resonant circuit with a natural resonance at approximately 140 kHz when coupled to a receiver coil. This series resonant circuit is then driven by an H-bridge switching arrangement from a DC source; at full power, the voltage in the capacitor can reach 50 volts. Power control can be automatic; the Qi specification demands that actual voltage applied be controllable in steps at least as small as 50 millivolts. Rather than down-regulating the charging voltage in a device, a Qi specification charger meets the A2 reference using a PID (proportional-integral-derivative) controller to modulate delivered power according to a primary cell voltage. 
     Various types of Qi charge transmitters can start their connections at 140 kHz and change frequencies to find a frequency with a better match, as the mutual inductance between transmitter and receiver coils can vary according to standoff distance between transmitter and receiver coils, and thus the natural resonance frequency can vary. Various different Qi reference designs can include different coil arrangements, including oval coil and multi-coil systems as well as more complex resonance networks with multiple inductors and capacitors. Such designs may allow for frequency-agile operation at frequencies over a range, for example, from 105 to 205 kHz and with maximum resonant circuit voltages as high as, for example, 200 volts. 
     The Qi specification power receiver hardware reference design 1, from version 1.2.2 of the Qi specification, has a rectangular coil of wire 44 mm×30 mm outside size, with 14 turns of wire, and with an above-coil magnetic shield. This coil is wired into a parallel resonant circuit with a pair of capacitors (e.g., of 127 nanofarads and 1.6 nanofarads in series). The power output can be taken across the 1.6 nanofarad capacitor. To provide a digital communications channel back to the power transmitter, a resonance modulator that includes a pair of 22 nanofarad capacitors and a 10 kΩ resistor in a T configuration can be switched across the 1.6 nanofarad capacitor. Switching the T network across the 1.6 nanofarad capacitor can cause a change in the resonant frequency of the coupled system that is detected by the power transmitter as a change in the delivered power. Power output to a mobile device can be via a full-wave bridge wired across the 1.6 nanofarad capacitor; the power may be filtered, for example, with a 20 microfarad capacitor before delivery to a charge controller. 
     Various other types of Qi power receivers may use alternate resonance modulators, including switching a resistor or pair of resistors across the receiver resonator capacitor, both before and after the bridge rectifier. 
       FIG.  7    also shows an example of a data structure  740  that may be transmitted from the base  720  to the device  750  or vice versa. As shown, the data structure  740  can include a message (e.g., a payload) that can be prefaced by a header and optionally followed by a checksum. In such an example, the data structure  740  may include a preamble. 
     In the Qi standard v.1.3, the power receiver can communicate to the power transmitter using data packets. As an example, a data packet can include a preamble, a header, a message, and a checksum. In v.1.3, the preamble includes a minimum of 11 and a maximum of 25 bits, all set to 1, and encoded. The preamble enables the power transmitter to synchronize with the incoming data and accurately detect the start bit of the header. The header, message, and checksum include a sequence of three or more bytes encoded according to a byte encoding scheme. The power transmitter can consider a data packet as received correctly if: the power transmitter has detected at least 4 preamble bits that are followed by a start bit; the power transmitter has not detected a parity error in any of the bytes of the data packet (e.g., including the header byte, the message bytes, and the checksum byte); the power transmitter has detected the stop bit of the checksum byte; and the power transmitter has determined that the checksum byte is consistent. Where the power transmitter does not receive a data packet correctly, the power transmitter can discard the data packet and not use any of the information contained therein. As an example, a ping phase as well as in an identification and configuration phase, a timeout can occur, which may cause the power transmitter to remove the power signal. 
     As to the header, it can include a single byte that indicates the data packet type. The header may implicitly provide the size of the message contained in the data packet. The number of bytes in a message may be calculated from the value contained in the header of the data packet. A power receiver may turn off its communications modulator after transmitting a data packet, which may cause an additional HI state to LO state or LO state to HI state transition in a primary cell current. 
     As to a message in the Qi Standard v.1.3, the power receiver can act to ensure that the message contained in the data packet is consistent with the data packet type indicated in the header where the first byte of the message can directly follows the header. 
     The checksum can include a single byte that enables the power transmitter to check for transmission errors. If the calculated checksum and the checksum byte contained in the data packet are not equal, the power transmitter can determine that the checksum is inconsistent. 
     As explained, a computing device may utilize a wired mode and/or a wireless mode of transmission to transfer information to an auxiliary power case. As to a wireless mode, consider a mode of transmission that can utilize coils such as defined in the Qi standard. For example, a method can include transmitting a signal from a computing device to an auxiliary power case where the signal provides information that can instruct the auxiliary power case to supply power to the computing device or, for example, to stop supply of power. As an example, a code-based system may be suitable for a relatively low bandwidth mode of wireless communication. In such an example, a message may be a code where the code is utilized in combination with stored instructions. For example, consider a numeric coding system where a one, two or three digit code (e.g., or more) can be utilized. As mentioned, a signal (e.g., a trigger, etc.) may be for a temperature condition, a pressure condition, a current condition, a voltage condition, an application condition, etc. Utilization of a signal or signals (e.g., a trigger or triggers) may provide for extended battery life of a computing device and/or one or more other benefits (e.g., user experience, etc.). As explained, a computing device may include a sealed battery where utilization of a signal or signals may help to extend the life of the sealed battery. In such an example, one or more strategies may be utilized for extension of life (e.g., temperature control, minimum discharge parameters, maximum charge parameters, one or more power demand levels, etc.). As mentioned, a signal may correspond to a computing device task such as rendering (e.g., video, gaming, CAD, etc.), where a relatively large power demand may be met at least in part by a rechargeable battery of an auxiliary power case coupled to the computing device. 
       FIG.  8    shows an example of a graphical user interface (GUI)  800  that can be a GUI such as the GUI  145  of the example of  FIG.  1 B . As shown, the GUI  800  can include various fields that may provide for control of various actions. Some examples of actions are shown in  FIG.  8   , which can include triggers for delivery of power (e.g., current, charge remaining, temperature, type of application, boot, location, other, etc.), triggers for charging (e.g., plugged-in, location, other, etc.), pairing (e.g., Qi communication, BLUETOOTH communication, USB communication, other, etc.), display and/or notifications (e.g., time, power, other, etc.). As to display and/or notifications, as mentioned, an auxiliary power case may include display that can render information, which may be received via wired and/or wireless transmission from a computing device. As an example, consider an email notification, a power status notification, a meeting notification, etc. 
       FIG.  9    shows an example of the auxiliary power case  200  as including a display  280  that can render one or more GUIs  290 . As shown, the GUI  290  may render a power status, a time, a message, a meeting notification, etc. As explained, such information may be received from a computing device, optionally via a wireless interface that provides for transmission of data structures with payload (e.g., triggers, information, etc.). As mentioned, a recess cover, if present, may include one or more displays that can perform one or more of the functions of the display  280 . 
     As an example, an auxiliary power case can include a frame; a panel coupled to the frame, where the panel defines at least a portion of a recess; a rechargeable battery disposed at least in part in the recess; and a power interface operatively coupled to the rechargeable battery. In such an example, the frame can include one or more computing device housing couplings. For example, consider magnetic couplings, hook-and-loop couplings, elastomeric couplings, etc. As an example, a frame of an auxiliary power case of can include at least one resilient member. For example, consider a resilient perimeter or perimeter portions that can be stretched to fit over or clip onto a housing of a computing device. 
     As an example, an auxiliary power case can include a wireless power transmission interface and/or a wired power transmission interface. As an example, an auxiliary power case can include control circuitry operatively coupled to a power interface. For example, consider a control circuitry that, responsive to receipt of a signal, energizes the power interface for transmission of power from a rechargeable battery. In such an example, the signal can indicate a power status of a computing device. For example, consider the power status being that of the computing device where it corresponds to a power demand level and/or where the power status is that of the computing device where it corresponds to a battery health status. As an example, control circuitry can energize a power interface for transmission of a level of power from a rechargeable battery that corresponds to a battery health status. As an example, a power demand level can correspond to video rendering, which may be for viewing a movie, gaming, etc. For example, upon execution of an application that demands video rendering, a signal may be issued that indicates that power demand will increase or is increasing (e.g., to a higher level). In such an example, upon cessation of video rendering, a signal may be issued that indicates that power demand will decrease or is decreasing (e.g., to a lower level). 
     As an example, an auxiliary power case can include a display. For example, consider a display that is operatively coupled to a power interface for receipt of data. In such an example, the power interface can include a coil that receives the data wirelessly. 
     As an example, an auxiliary power case can include a cable and, for example, can include a cable recess for storage of the cable. As an example, an auxiliary power case can include a cable retractor. For example, consider a spring-loaded reel that can spin to take up or let out cable. 
     As an example, an auxiliary power case can include at least one solar cell. For example, consider a panel with one or more solar cells that can provide power to a battery and/or other circuitry. 
     As an example, an auxiliary power case can include a rechargeable battery that is removably replaceable without decoupling a frame of the auxiliary power case from a computing device housing. For example, consider a recess that can be accessed without removal, which may be a slit or pocket that can be accessed without removal, etc. 
     As an example, an auxiliary power case can include at least one permanent magnet. For example, consider a magnet that can provide for coupling to a computing device housing, a magnet that can provide for holding and/or positioning a battery or batteries, etc. As an example, an auxiliary power case can include one or more permanent magnets that can be utilized to magnetically couple the auxiliary power case to a housing of a computing device where the housing includes one or more ferromagnetic materials, which may or may not be permanent magnets. 
     As an example, a system can include a computing device that includes a dedicated battery, a housing and a first interface; and an auxiliary power case that includes a frame removably attachable to the housing, a rechargeable battery, control circuitry and a second interface operatively coupled to the rechargeable battery and the control circuitry, where, responsive to a signal transmitted from the first interface to the second interface, the control circuitry energizes the second interface for transmission of power of the rechargeable battery from the second interface to the first interface. 
     The term “circuit” or “circuitry” is used in the summary, description, and/or claims. As is well known in the art, the term “circuitry” includes all levels of available integration (e.g., from discrete logic circuits to the highest level of circuit integration such as VLSI, and includes programmable logic components programmed to perform the functions of an embodiment as well as general-purpose or special-purpose processors programmed with instructions to perform those functions) that includes at least one physical component such as at least one piece of hardware. A processor can be circuitry. Memory can be circuitry. Circuitry may be processor-based, processor accessible, operatively coupled to a processor, etc. Circuitry may optionally rely on one or more computer-readable media that includes computer-executable instructions. As described herein, a computer-readable medium may be a storage device (e.g., a memory chip, a memory card, a storage disk, etc.) and referred to as a computer-readable storage medium, which is non-transitory and not a signal or a carrier wave. 
     While various examples of circuits or circuitry have been discussed,  FIG.  10    depicts a block diagram of an illustrative computer system  1000 . The system  1000  may be a computer system, such as one of the ThinkCentre® or ThinkPad® series of personal computers sold by Lenovo (US) Inc. of Morrisville, N.C., or a workstation computer system, such as the ThinkStation®, which are sold by Lenovo (US) Inc. of Morrisville, N.C.; however, as apparent from the description herein, a system or other machine may include other features or only some of the features of the system  1000 . As an example, the computing device  100  may include at least some of the features of the system  1000 . 
     As shown in  FIG.  10   , the system  1000  includes a so-called chipset  1010 . A chipset refers to a group of integrated circuits, or chips, that are designed (e.g., configured) to work together. Chipsets are usually marketed as a single product (e.g., consider chipsets marketed under the brands INTEL, AMD, etc.). 
     In the example of  FIG.  10   , the chipset  1010  has a particular architecture, which may vary to some extent depending on brand or manufacturer. The architecture of the chipset  1010  includes a core and memory control group  1020  and an I/O controller hub  1050  that exchange information (e.g., data, signals, commands, etc.) via, for example, a direct management interface or direct media interface (DMI)  1042  or a link controller  1044 . In the example of  FIG.  10   , the DMI  1042  is a chip-to-chip interface (sometimes referred to as being a link between a “northbridge” and a “southbridge”). 
     The core and memory control group  1020  include one or more processors  1022  (e.g., single core or multi-core) and a memory controller hub  1026  that exchange information via a front side bus (FSB)  1024 . As described herein, various components of the core and memory control group  1020  may be integrated onto a single processor die, for example, to make a chip that supplants the conventional “northbridge” style architecture. 
     The memory controller hub  1026  interfaces with memory  1040 . For example, the memory controller hub  1026  may provide support for DDR SDRAM memory (e.g., DDR, DDR2, DDR3, etc.). In general, the memory  1040  is a type of random-access memory (RAM). It is often referred to as “system memory”. 
     The memory controller hub  1026  further includes a low-voltage differential signaling interface (LVDS)  1032 . The LVDS  1032  may be a so-called LVDS Display Interface (LDI) for support of a display device  1092  (e.g., a CRT, a flat panel, a projector, etc.). A block  1038  includes some examples of technologies that may be supported via the LVDS interface  1032  (e.g., serial digital video, HDMI/DVI, display port). The memory controller hub  1026  also includes one or more PCI-express interfaces (PCI-E)  1034 , for example, for support of discrete graphics  1036 . Discrete graphics using a PCI-E interface has become an alternative approach to an accelerated graphics port (AGP). For example, the memory controller hub  1026  may include a 16-lane (×16) PCI-E port for an external PCI-E-based graphics card. A system may include AGP or PCI-E for support of graphics. As described herein, a display may be a sensor display (e.g., configured for receipt of input using a stylus, a finger, etc.). As described herein, a sensor display may rely on resistive sensing, optical sensing, or other type of sensing. 
     The I/O hub controller  1050  includes a variety of interfaces. The example of  FIG.  10    includes a SATA interface  1051 , one or more PCI-E interfaces  1052  (optionally one or more legacy PCI interfaces), one or more USB interfaces  1053 , a LAN interface  1054  (more generally a network interface), a general purpose I/O interface (GPIO)  1055 , a low-pin count (LPC) interface  1070 , a power management interface  1061 , a clock generator interface  1062 , an audio interface  1063  (e.g., for speakers  1094 ), a total cost of operation (TCO) interface  1064 , a system management bus interface (e.g., a multi-master serial computer bus interface)  1065 , and a serial peripheral flash memory/controller interface (SPI Flash)  1066 , which, in the example of  FIG.  10   , includes BIOS  1068  and boot code  1090 . With respect to network connections, the I/O hub controller  1050  may include integrated gigabit Ethernet controller lines multiplexed with a PCI-E interface port. Other network features may operate independent of a PCI-E interface. 
     The interfaces of the I/O hub controller  1050  provide for communication with various devices, networks, etc. For example, the SATA interface  1051  provides for reading, writing or reading and writing information on one or more drives  1080  such as HDDs, SDDs or a combination thereof. The I/O hub controller  1050  may also include an advanced host controller interface (AHCI) to support one or more drives  1080 . The PCI-E interface  1052  allows for wireless connections  1082  to devices, networks, etc. The USB interface  1053  provides for input devices  1084  such as keyboards (KB), one or more optical sensors, mice and various other devices (e.g., microphones, cameras, phones, storage, media players, etc.). On or more other types of sensors may optionally rely on the USB interface  1053  or another interface (e.g., I 2 C, etc.). As to microphones, the system  1000  of  FIG.  10    may include hardware (e.g., audio card) appropriately configured for receipt of sound (e.g., user voice, ambient sound, etc.). 
     In the example of  FIG.  10   , the LPC interface  1070  provides for use of one or more ASICs  1071 , a trusted platform module (TPM)  1072 , a super I/O  1073 , a firmware hub  1074 , BIOS support  1075  as well as various types of memory  1076  such as ROM  1077 , Flash  1078 , and non-volatile RAM (NVRAM)  1079 . With respect to the TPM  1072 , this module may be in the form of a chip that can be used to authenticate software and hardware devices. For example, a TPM may be capable of performing platform authentication and may be used to verify that a system seeking access is the expected system. 
     The system  1000 , upon power on, may be configured to execute boot code  1090  for the BIOS  1068 , as stored within the SPI Flash  1066 , and thereafter processes data under the control of one or more operating systems and application software (e.g., stored in system memory  1040 ). An operating system may be stored in any of a variety of locations and accessed, for example, according to instructions of the BIOS  1068 . Again, as described herein, a satellite, a base, a server or other machine may include fewer or more features than shown in the system  1000  of  FIG.  10   . Further, the system  1000  of  FIG.  10    is shown as optionally include cell phone circuitry  1095 , which may include GSM, CDMA, etc., types of circuitry configured for coordinated operation with one or more of the other features of the system  1000 . Also shown in  FIG.  10    is battery circuitry  1097 , which may provide one or more battery, power, etc., associated features (e.g., optionally to instruct one or more other components of the system  1000 ). As an example, a SMBus may be operable via a LPC (see, e.g., the LPC interface  1070 ), via an I 2 C interface (see, e.g., the SM/I 2 C interface  1065 ), etc. 
     Although examples of methods, devices, systems, etc., have been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as examples of forms of implementing the claimed methods, devices, systems, etc.