Abstract:
A battery pack module having a battery and a battery charger suitable for re-charging the battery. The battery pack powers a network terminal such as an optical network terminal (ONT) upon utility-company power failure. Upon return of power from the power utility company the battery charger automatically re-charges the battery. A different battery pack having different battery charger and battery with different battery chemistry can be exchanged for the original battery pack housed within the ONT without requiring any mechanical or electrical modification to the ONT. A battery temperature sensing device in cooperation with a microprocessor, both included with the battery pack, ensures that the recharging of the battery is performed efficiently.

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional application No. 60/908,975, filed Mar. 30, 2007, the contents of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND 
     Telecommunication companies that are installing fiber to the premises (FTTP) are also installing battery backup units (BBU) which are needed to power the FTTP network during a power failure for a finite period of time. Currently, the industry uses set battery chemistries—a single kind of battery—and that can be too limiting. Thus, it is desirable to not be constrained to only one type of battery, such as a sealed lead acid battery, which may cause a customer to complain for environmental or safety reasons. 
     Moreover, when installing FTTP in homes, sometimes batteries are taken, without authorization, out of the optical network terminal (ONT) units (e.g., by customers for their own unrelated uses). In that adverse environment, it would be helpful to install non-rechargeable alkaline batteries where they have no further use after they are discharged. By contrast, where other battery chemistries are preferred, it might be more useful to use lithium ion batteries or nickel metal hydride batteries which are rechargeable and have better characteristics, generally speaking, than the alkaline batteries. 
     Currently, there is no easy manner by which these batteries can be inter-changed, because the battery chargers that are needed to charge the various rechargeable batteries are all different from each other to accommodate the chemistries of the rechargeable batteries which also are all different from each other. This can result in an inconvenient, costly and inefficient retrofitting procedure to remove the old battery charger associated with the old battery and to install a new battery charger associated with the new battery. 
     Therefore, there is a need for systems and methods by which these kinds of rechargeable batteries can be changed to other batteries responsive to need, and thereafter be recharged as may be needed during power failures, without making any other changes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts an exemplary FTTP communication system showing the locations of various system components; 
         FIG. 2  is an exemplary schematic block diagram showing signal paths and power paths between various system components including those of  FIG. 1 ; 
         FIG. 3  is a schematic diagram of an exemplary battery pack showing how a charger and a battery can be interconnected within the battery pack; and, 
         FIG. 4  shows an exemplary battery pack, including pin-out, as would be received, for example, by an ONT unit. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Exemplary embodiments include methodology and apparatus for providing a universal battery interface for a telecommunications and/or a data unit such as an ONT unit. The interface comprises a battery pack which includes a battery and a compatible charger for the battery. The battery pack also includes an electrical pin-out, the configuration of which can be standardized for ONT application. The pin-out includes a ground pin, a voltage output pin and a voltage charging pin. The ONT unit is configured to mate with the battery pack in a modular manner and further includes an electrical receptacle for receiving the ground pin, the voltage output pin and the voltage charging pin. Thereby, the battery pack can be easily unplugged from the ONT and a new battery pack (battery and charger) can be plugged in, without making any modifications to the ONT. The present invention thus allows battery/charger assemblies to be interchanged within a pre-configured “enclosure” contained within the ONT and without charging a battery that is not meant to be charged or charging a battery incorrectly; correct battery charging is guaranteed by virtue of the pre-determined battery-charger combination. 
       FIGS. 1 and 2  are identical to FIGS. 1 and 2 of U.S. patent application Ser. No. 11/460,499, filed Jul. 27, 2006 and entitled “OPTICAL NETWORK TERMINAL POWER FAILURE MANAGEMENT,” which application is incorporated by reference herein in its entirety. 
     While  FIG. 1  shows the ONT unit  102  mounted outside the customer premises, the ONT unit is now often mounted inside the customer premises. In  FIGS. 1 and 2 , ONT BBU  106  is shown as being physically separated from ONT unit  102  but, in exemplary embodiments, the BBU function can be physically and modularly located within ONT unit  102 . In other words, the functional equivalent of BBU  106  can be plugged into and plugged out from ONT unit  102 , as discussed further hereinbelow. 
       FIG. 3  is a schematic diagram of a battery pack including a battery and a battery charger. Battery pack  300  includes battery(s)  302  and battery charger  301  as a self contained assembly or cartridge or modular component. Different battery chemistries require different kinds of battery chargers. Battery charger  301  is designed or tailor-made to be compatible with the battery chemistry of battery  302 . Battery charger  301  has terminals  303 ,  304 ,  305  and  306 . Terminals  304  and  306  are ground terminals. Terminal  303  is connected to pin # 3 , shown as line  312  and is used to receive voltage to charger  301 . The voltage received is higher than the voltage to be applied to the battery and can be a constant DC voltage level or a varying DC voltage level. The voltage coming out of terminals  305  and  306  from charger  301  is the correct voltage for charging battery  302 . 
     Microprocessor and temperature sensing module  309  is contained within charger  301  and is used to sense the battery temperature. This can be done by way of temperature sensors (not shown) which are attached to the battery, the data of which is fed back into the microprocessor and temperature sensing module  309  for processing purposes. Different battery chemistries operate within prescribed temperature ranges at optimum efficiency and are charged more efficiently at particular temperatures or within particular temperature ranges. This module can be contained within each charger for its companion battery. The charging characteristics of the charging voltage which is applied to actual battery cell terminals, varies as a function of temperature. For example, in lithium ion batteries, the temperature is higher as compared with some other battery chemistries. Also, with this battery chemistry, there can be cell to cell voltage variation from one battery to the next, even if manufactured on the same line, and monitoring is necessary or desirable. Temperature sensing is a part of the algorithm used to determine the charging voltage and current. 
     Battery  302  has terminals  307  and  308 . Terminals  305  and  306  from the charger are connected to battery terminals  307  and  308 , respectively, and are used to charge the battery by way of conductive line  310 . Terminal  307  is connected to pin # 1 , shown as line  310 , and ground terminal  308  is connected to pin # 2 , shown as line  311 . The voltage output from Pin # 1  can be applied to the load (e.g., the ONT unit). 
     The battery charger is used to provide charging to the battery after it has been depleted because it has been used to supply power to the ONT during a utility company&#39;s power failure. Thus, the battery charger receives power only after utility company power has been restored. The battery charger is designed to be unique to any given battery chemistry that has unique requirements from a charging perspective. The charger itself may be conventional, but is applicable to the particular battery chemistry with which it is partnered. 
     For example, with a sealed lead acid battery, its charger can be a circuit that receives the fixed or slightly varying input DC voltage after the lost power is restored, measures temperature of the battery, adjusts the voltage being applied to the battery downward from the voltage being applied to the charger, and applies the appropriate constant voltage to the rechargeable battery. Such a battery is self-regulating from a current perspective. 
     But, with a lithium ion battery, the voltage can be temperature compensated and turned on and off depending upon the inter-cell voltages and the temperature. The charger associated with this battery chemistry typically uses a more sophisticated, microprocessor-driven charger system. All of this functionality can be contained within module  309  within charger  301  of  FIG. 3 . 
       FIG. 4  shows battery pack  300  in dashed line format as hidden lines as it might be seated or modularly inserted within the housing of ONT unit  102 . In  FIG. 1 , ONT unit  102  is shown as being positioned outside of the customer premises. In the instant invention, ONT can be positioned inside the customer premises, where space is more of a premium and where battery type may be more critical. 
     Pin # 1 , Pin # 2  and Pin # 3  are shown in dashed line format and are received by female receptacles (not shown) fixedly mounted within ONT unit  102 . Any other battery pack with its compatible charger made in accordance with exemplary embodiments would fit within the opening of the ONT unit  102 , just as the unit shown in  FIG. 4 , and its pin out configuration can also mate with the female receptacles just as those shown in  FIG. 4 . In other words, the battery pack can be invisible to the ONT and any battery pack designed for use with the ONT, and that meets this spatial configuration and pin out configuration, shall work as well as any other. 
     In the event of using a non-rechargeable battery, like an alkaline battery, there would typically not be a charger associated with it, and so only pins # 1  and # 2  might be included. They would fit into the appropriate pin # 1  and pin # 2  receptacles, respectively, and pin # 3  may not exist in such case because it may be superfluous. Alternatively, pin # 3  could exist, but not be electrically utilized because it is electrically disconnected. 
     The location of the batten pack within ONT unit  102  is particularly convenient, but it can also be housed instead within a battery backup chassis physically removed from the ONT unit. Transmission of power from the physically-removed battery pack to the ONT during power outages can then be accomplished by hard wiring between the battery pack and the ONT unit. 
     Exemplary embodiments allow for the use of any battery chemistry in an ONT battery back up situation. By having the ONT battery interface defined in terms of power needs, the actual battery charging algorithm can be integrated into the battery pack. Advantageously, this allows for usage and cost choices. 
     Since the introduction of the FTTP platform, there has been demand for alternate battery sizing and chemistries in the DC uninterrupted power supply (UPS). The reason for the choice involves costs, battery support times, and a desire for various battery chemistries. 
     Exemplary embodiments provide a universal battery interface to a DC UPS based system, and thereby allow a host device to supply constant or variable output voltage and current for application to a battery pack. 
     In exemplary embodiments, current may only flow from the host to the battery pack. The battery interface can also include a pin which accepts power from the battery. This pin allows power to flow only from the battery to the load. A third pin can exist as a ground, or common point, which can be utilized for each of the previously identified interfaces. 
     With such an interface, a battery pack can be connected to the battery interface or UPS. The battery pack can consist of any required battery chemistry as well as a battery charger which is dedicated to the chemistry of the battery. 
     Thermal sensors can be included to eliminate thermal run-a-way conditions as well as optimizing the battery charge based on battery temperature. The active components can disconnect the battery at a low voltage point based on the needs of the battery chemistry. 
     A non-rechargeable battery pack can also be utilized in which the recharge pin is not utilized. 
     While illustrative embodiments of the present invention have been shown and described, numerous variations and alternative embodiments may occur to those skilled in the art. For example, the three pins can be configured in a manner so that the combined charger/battery assembly or battery pack must be inserted in a particular orientation to engage the three pins, thereby assuring proper insertion into the receptacle space of the ONT unit. And, although the ONT unit is now typically positioned inside the customer premises, it can be re-positioned outside as well. Other variations and alternative embodiments are contemplated, and can be made without departing from the spirit and scope of the present invention as defined in the appended claims.