Abstract:
Embodiments of the present disclosure provide methods, systems, and apparatuses related to managing a rechargeable battery in an enclosed lighting module. Other embodiments may be described and claimed.

Description:
FIELD 
       [0001]    Embodiments of the present disclosure relate to the field of lighting, and more particularly, to thermal control for an encased power supply in an LED lighting module. 
       BACKGROUND 
       [0002]    Multi-chemistry rechargeable batteries are used in a variety of applications. Often the lifetimes of these batteries could include a large number of charge/discharge cycles. However, the conditions in which these batteries are deployed and the way in which they are managed could result in a large variability of battery lifetimes. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]    Embodiments will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals designate like structural elements. Embodiments are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings. 
           [0004]      FIGS. 1   a  and  1   b  respectively illustrate exploded and assembled views of a lighting module in accordance with embodiments of this disclosure. 
           [0005]      FIG. 2  illustrates a circuit diagram of components of a lighting module in accordance with some embodiments. 
           [0006]      FIG. 3  is a flowchart describing controlling operations in accordance with some embodiments. 
       
    
    
     DETAILED DESCRIPTION 
       [0007]    In the following detailed description, reference is made to the accompanying drawings which form a part hereof wherein like numerals designate like parts throughout, and in which is shown by way of illustration embodiments in which the disclosure may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of embodiments in accordance with the present disclosure is defined by the appended claims and their equivalents. 
         [0008]    Various operations may be described as multiple discrete operations in turn, in a manner that may be helpful in understanding embodiments of the present disclosure; however, the order of description should not be construed to imply that these operations are order dependent. 
         [0009]    For the purposes of the present disclosure, the phrase “A and/or B” means (A), (B), or (A and B). For the purposes of the present disclosure, the phrase “A, B, and/or C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C). 
         [0010]    Various components may be introduced and described in terms of an operation provided by the components. These components may include hardware, software, and/or firmware elements in order to provide the described operations. While some of these components may be shown with a level of specificity, e.g., providing discrete elements in a set arrangement, other embodiments may employ various modifications of elements/arrangements in order to provide the associated operations within the constraints/objectives of a particular embodiment. 
         [0011]    The description may use the phrases “in an embodiment,” or “in embodiments,” which may each refer to one or more of the same or different embodiments. Furthermore, the terms “comprising,” “including,” “having,” and the like, as used with respect to embodiments of the present disclosure, are synonymous. 
         [0012]      FIGS. 1   a  and  1   b  illustrate a lighting module  100  in an exploded view and an assembled view, respectively, in accordance with some embodiments. The lighting module  100  may include one or more light emitting diodes (LEDs)  104  coupled to a mounting board  108  that provides power connections to the LEDs  104 . While three LEDs  104  are shown, other embodiments may have any number of LEDs. A lens reflector  112  may be placed around a perimeter of the mounting board  108  to provide a desired optical effect. 
         [0013]    The lighting module  100  may also include a circuit board  116  that may house and interconnect various electrical components of the lighting module  100  including, but not limited to, a controller  120 . The controller  120  may be coupled to a direct current (DC) power supply interface  124  that is configured to be coupled to a rechargeable battery  128  (hereinafter “battery  128 ”), which may be a multi-chemistry rechargeable battery. In some embodiments, the battery  128  may be removably coupled to the DC power supply interface  124  in order to be easily replaced at the end of its effective life. In other embodiments, the battery  128  may be permanently coupled to the DC power supply interface  124 . In these embodiments, the entire lighting module  100  may be replaced, rather than just the battery  128 , at the end of the effective life of the battery  128 . 
         [0014]    As used herein, “removably coupled elements” are elements in which the coupling design allows a user of the device to couple/decouple the elements in the ordinary course of operation; while “permanently coupled elements” are elements in which the coupling design does not allow the user of the device to couple/decouple the elements in the ordinary course of operation. 
         [0015]    The controller  120  may also be coupled to an alternating current (AC) power supply interface  132  that is configured to be coupled to an AC power supply through, e.g., a standard lighting fixture. The AC power supply interface  132  may be an Edison screw base, of any size, as is generally shown. In other embodiments, the AC power supply interface  132  may be any other type of light bulb connector or power connector, e.g., power plug. 
         [0016]    When power is present at the AC power supply interface  132 , the controller  120  may use the AC power to power the LEDs  104  and to recharge the battery  128 , as will be described in more detail below. When AC power is not present at the AC power supply interface  132 , the controller  120  may use the DC power from the battery  128  to power the LEDs  104 . Providing backup power from the battery  128  may allow the lighting module  100  to work independent of an available AC power system. This may allow the lighting module  100  to provide a portable and/or auxiliary light source (e.g., a light source to be used when a power outage occurs in a building&#39;s electrical network). 
         [0017]    When operating as an auxiliary light source, the lighting module  100  may detect AC power in an electrical network to which it is communicatively coupled. The lighting module  100  may be communicatively coupled to the electrical network by a direct electrical connection, e.g., by a lighting fixture plugged into an outlet, or wirelessly. The lighting module  100  may include an antenna  136  and a resonant circuit in an embodiment in which it is configured to wirelessly detect AC power in a proximally-disposed electrical network as is described in co-pending application titled LIGHTING MODULE WITH WIRELESS ALTERNATING CURRENT DETECTION SYSTEM filed on Mar. 31, 2009, assigned Ser. No. 12/415,888. The specification of said application is hereby incorporated in its entirety except for those sections, if any, that are inconsistent with the present specification. 
         [0018]    The lighting module  100  may also include a state switch  140  coupled to the controller  120  through the circuit board  116 . The state switch  140  may be operated to change between various operating states of the lighting module  100 . For example, in one embodiment the lighting module  100  may have two states. In a first state, the lighting module  100  may function as an auxiliary light. That is, the LEDs  104  are activated when AC power is not detected in an electrical network to which the lighting module  100  is communicatively coupled. In a second state, the LEDs  104  may be activated, regardless of the presence/absence of AC power in the electrical network. In other embodiments, additional and/or alternative states may be provided. 
         [0019]    The components of the lighting module  100 , including the battery  128  when it is coupled to the DC power supply interface  124 , may be disposed within an enclosure defined, at least in part, by a bulb-shaped, light passable body  144  (hereinafter “body  144 ”) and a base  148 , which may include the AC power supply interface  132 . The lighting module  100  may include a temperature sensing device  152  that is coupled to the controller  120  and thermally coupled to the battery  128 . The temperature sensing device  152  may be thermally coupled to the battery  128  by being proximately disposed with the battery  128  such that an output of the temperature sensing device  152  is proportional to a temperature of the battery  128 . 
         [0020]    The temperature sensing device  152  is shown as being disposed on the circuit board  116 ; however, in other embodiments it may be disposed in other locations within the enclosure. Furthermore, in other embodiments, additional temperature sensing devices may be placed throughout the enclosure. For example, one temperature sensing device may be placed near the battery  128  while another temperature sensing device may be placed near the LEDs  104 . 
         [0021]    Disposing the components of the lighting module  100  within the enclosure, as shown, facilitates use of the lighting module  100  as an interchangeable replacement for conventional light bulbs. However, the confinements of the enclosure may restrict heat dissipation and compromise the utility and/or longevity of the battery  128 . For example, if the battery  128  is exposed to excessively high temperatures, a separator, separating an anode and a cathode, may break down and damage the battery  128  and/or the lighting module  100 . Recharging the battery  128  and powering the LEDs  104 , if not properly managed, may accelerate the separator breakdown. 
         [0022]    While excessively high temperatures could compromise the performance of elements of the lighting module  100  so, too, could excessively low temperatures. In some embodiments, it may be that when the temperature of the battery  128  is below a threshold temperature the power provided by the battery  128  may be backed off a certain amount from a rated power to avoid damage to the battery  128 . The amount of the back-off may be determined by a derating curve associated with the battery  128 . 
         [0023]    In some embodiments, the lighting module  100  may include a heating element  156  that may be used to increase a temperature associated with the battery  128  when it is determined that the temperature is excessively low. This may also work to reduce humidity within the enclosure that, uncontrolled, may adversely effect the LEDs  104 . 
         [0024]    Accordingly, embodiments of the disclosure described herein present various management techniques and/or analyses that the controller  120  may employ to increase the useful life of the battery  128  and/or lighting module  100 . 
         [0025]    The controller  120  may be coupled with memory  160 , which may be volatile and/or non-volatile memory that stores data that may relate to the operation of the battery  128 . The data may include impedance, temperature, current, electric reflectivity, number of cycles, and total coulomb-metric data for the life of the battery  128 , etc. The controller  120  may acquire this data from a programming device through a programming interface  164 , from one or more sensors of the lighting module  100 , e.g., the temperature sensing device  152 , and/or from monitoring/testing the operation of the battery  128  itself. The controller  120  may use this data as a basis for managing the lighting module  100  including, e.g., controlling the recharging cycles of the battery  128  and/or controlling the powering of the LEDs  104 . 
         [0026]    The controller  120  may control an indicator LED  168  in a manner to communicate information that may correspond to the battery  128 . For example, the indicator LED  164  may indicate that a temperature associated with the battery  128  is outside of a predetermined operating range, e.g., it is either above an upper predetermined threshold temperature or below a lower predetermined threshold temperature. In other embodiments, other indication methods, which may include more than one indicator LED, may be employed. 
         [0027]      FIG. 2  is a circuit diagram  200  of elements of the lighting module  100  in accordance with some embodiments. The circuit diagram  200  includes the controller  120 , the LEDs  104 , the battery  128 , the temperature sensing device  152 , and the indicator LED  164 , previously introduced. The circuit diagram  200  may also include a resistor  204 , a converter  208 , a diode  212 , and a switch  216  coupled to one another and the early elements at least as shown. 
         [0028]    Briefly, the converter  208  may be a DC-DC converter and/or an AC-DC converter used to provide a desired charging current to the battery  128  and/or a desired powering current to the LEDs  104 . The converter  208  may be set for a constant voltage or a constant current operation. The converter  208  may be coupled to the battery  128  and LEDs  104  through the diode  212 , which may function as a forward biasing diode, and the switch  216 . 
         [0029]    The controller  120  may receive thermal feedback from the temperature sensing device  152 . The temperature sensing device  152  may be a thermistor, as is generally shown, that has a negative temperature coefficient causing the resistance to decrease in response to a corresponding increase in temperature. The controller  120  may control the switch  216 , which may include one or more switching elements distributed throughout the circuit, to control operation of the elements of the lighting module  100  based at least in part on the thermal feedback provided by the temperature sensing device  152 . 
         [0030]    The resistor  204  may be used to set the desired voltage for the indicator LED  164 . 
         [0031]      FIG. 3  is a flowchart  300  showing controlling operations of the controller  120  in accordance with some embodiments. 
         [0032]    At block  304 , the controller  120  may receive thermal feedback from the temperature sensing device  152 . The thermal feedback may be an output, e.g., a resistance measurement, that is proportional to a temperature of the battery  128 . 
         [0033]    At block  308 , the controller  120  may determine whether the temperature of the battery  128  is within, above, or below an operating range. The operating range may be defined, e.g., by an upper predetermined threshold temperature value and a lower predetermined threshold value. In various embodiments, any number of intermediary threshold values may be used to define any number of operating ranges. 
         [0034]    If the controller determines that the temperature is within the operating range, it may, at block  312 , provide full charging and powering cycles. A full charging cycle may mean that the controller  120  may recharge the battery  128  at a recharge rate that is not constrained by operating temperature considerations. It may be noted that the recharge rate during a full charging cycle may be a variety of rates, e.g., a float-charging rate that takes 300 hours to recharge a full capacity of the battery  128  or a boost-charge rate that takes 2 hours to recharge the full capacity of the battery  128 . 
         [0035]    Similar to a full charging cycle, a full powering cycle may mean that the controller  120  may power the LEDs  104  at a powering rate that is not constrained by considerations of the operating temperature of the battery  128 . 
         [0036]    In the event the controller  120  determines the temperature is below the operating range, the controller  120  may, at block  316 , control the heating element in a manner to heat the battery  128 . The controller  120  may then again receive thermal feedback at block  304 . In various embodiments, the controller  120  may power the LEDs  104  from the battery  128  according to an attenuated powering cycle that corresponds to the derating curve when the temperature is below the operating range. An attenuated powering cycle may mean that the controller  120  may power the LEDs  104  at a reduced powering rate due to considerations of the operating temperature of the battery  128 . 
         [0037]    If the controller  120  determines the temperature is above the operating range, it may, at block  320 , recharge the battery  128  with an attenuated recharging cycle and/or power the LEDs  104 , from the AC power supply or the battery  128 , with an attenuated powering cycle. Similar to an attenuated powering cycle, an attenuated charging cycle of the battery  128  may mean that the controller  120  may recharge the battery  128  at a reduced recharge rate due to considerations of the operating temperature of the battery  128 . In some embodiments, the controller  120  may recharge the battery  128  according to an attenuated recharging cycle while powering the LEDs  104  from the AC power supply with a full powering cycle. 
         [0038]    Managing the recharging, heating, and powering of the components of the lighting module  100  as described may increase in the operational life of the lighting module  100 . 
         [0039]    Although certain embodiments have been illustrated and described herein for purposes of description of the preferred embodiment, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent embodiments or implementations calculated to achieve the same purposes may be substituted for the embodiments shown and described without departing from the scope of the present disclosure. Similarly, memory devices of the present disclosure may be employed in host devices having other architectures. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that embodiments in accordance with the present disclosure be limited only by the claims and the equivalents thereof.