Abstract:
An improved battery charging method is usable by a battery charger to charge a battery. The charging method may include an optional desulfation process, a first constant current process, a constant voltage process, a second constant current process and a float charge process. The charging method preferably improves various charge and usage characteristics of the battery through a single or continued use of the battery charger utilizing the charging method.

Description:
[0001]    This application claims priority to U.S. Provisional Application No. 61/050,687, filed May 6, 2008, and International Application No. PCT/US2009/002797filed May 6, 2009, both of which are incorporated herein by reference in their entirety. 
     
    
     BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The present inventions relate to a method of charging a battery, a charging device and a charging system for a battery. The present inventions more specifically relate to an improved device and method for charging a secondary battery and extending battery life. 
         [0004]    2. Background of the Invention 
         [0005]    It is known to provide for a secondary battery that may be used for powering stationary and portable devices. It is also known to provide such secondary batteries to start and/or power vehicles such as boats, cars and the like and that use various chemistries (e.g., nickel cadmium batteries, nickel metal hydride batteries, lithium ion batteries, lithium ion polymer batteries, or lead acid batteries designated as, for example, starting, lighting and ignition (SLI) batteries, deep cycle batteries, absorbent glass mat (AGM) batteries, valve regulated (VRLA) batteries, gel batteries, etc.). In general, a secondary battery is a rechargeable battery that uses a reversible chemical reaction to provide a potential difference across two poles. Secondary batteries can be recharged by providing a current to the battery and reversing the chemical reaction used by the battery to provide energy. 
         [0006]    It is also known to provide a charger that charges a secondary battery. Battery chargers are used to reverse the chemical reaction that the battery uses to provide energy. Simple chargers may provide a constant voltage and/or a constant current to the battery and generally do not monitor the battery state or alter the provided voltage and/or current during the charging process. As such, simple chargers can easily overcharge and damage a battery. Chargers that are more complex may use a charging method to monitor one or more characteristics of the battery and/or alter the supplied voltage and/or current to charge the battery to full capacity more safely and/or efficiently (e.g., by avoiding overcharging the battery). 
       SUMMARY 
       [0007]    An exemplary method of charging a battery with a battery charger includes applying a first substantially constant current to the battery, applying a first substantially constant voltage to the battery, applying a second substantially constant current to the battery and applying a second substantially constant voltage to the battery. 
         [0008]    An exemplary method of charging a battery with a battery charger includes providing the battery with a first substantially constant current until either a voltage of the battery reaches a first desired value or a first time period has expired. The method also includes providing the battery with a first substantially constant voltage until either a current of the battery reaches a desired value or a second desired time period has expired. The method also includes providing the battery with a second substantially constant current until either the voltage of the battery reaches a second desired value or a third desired time period has expired. The method also includes providing the battery with a second substantially constant voltage. 
         [0009]    An exemplary battery charging method includes a first current applying step or process, a voltage applying step or process, a second current applying step or process and a float charge applying step or process. 
         [0010]    In various exemplary embodiments, a current applying step or process includes providing a battery with a substantially constant current until a voltage of the battery reaches a desired value or a desired time period has expired. 
         [0011]    In various exemplary embodiments, a voltage applying step or process includes providing a battery with a substantially constant voltage until a current of the battery reaches a desired value or a desired time period has expired. 
         [0012]    In various exemplary embodiments, a float charge applying step or process includes providing a battery with a substantially constant voltage. In various exemplary embodiments, the float charge process includes providing a tapering current. In various exemplary embodiments, the substantially constant voltage and/or tapering current substantially counteracts a self-discharge rate of the battery. 
         [0013]    These and other features and advantages of various exemplary embodiments of systems and methods according to this invention arc described in, or are apparent from, the following detailed descriptions of various exemplary embodiments of various devices, structures and/or methods according to this invention. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0014]    Various exemplary embodiments of the systems and methods according to this invention will be described in detail, with reference to the following figures, wherein: 
           [0015]      FIG. 1  is a flowchart representing a charging method according to an exemplary embodiment; 
           [0016]      FIG. 2  is a flowchart representing a desulfation process according to an exemplary embodiment; 
           [0017]      FIG. 3  is a flowchart representing a first current process according to an exemplary embodiment; 
           [0018]      FIG. 4  is a flowchart representing a voltage process according to an exemplary embodiment; 
           [0019]      FIG. 5  is a flowchart representing a second current process according to an exemplary embodiment; 
           [0020]      FIG. 6  is a flowchart representing a float charge process according to an exemplary embodiment; 
           [0021]      FIG. 7  is a flowchart representing a charging method according to a second exemplary embodiment; and 
           [0022]      FIG. 8  is a schematic representation of a battery charging system according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    It should be appreciated that the following description addresses, in part, charging systems. In various embodiments, a charging system includes a secondary battery and a charging device. In various embodiments, the charging system may include multiple batteries and/or charging devices. 
         [0024]    The secondary battery may be any known or later-developed rechargeable battery. In various embodiments, the battery is a lead acid battery. In various embodiments, the battery includes substantially immobilized electrolyte. In various embodiments, the battery includes absorbent-glass-mat separators (AGM). According to various exemplary embodiments, the battery is of a type commercially available under the brand Optima from Johnson Controls, Inc., Milwaukee, Wis. According to an exemplary embodiment, the battery is of a type commercially available under the brand Optima group 31 marine batteries available from Johnson Controls, Inc., Milwaukee, Wis. 
         [0025]    In various exemplary embodiments, the charging device (e.g., a battery charger), includes a microprocessor. In various exemplary embodiments, the charging device includes memory. In various exemplary embodiments, the microprocessor and/or memory include instructions according to a charging method to be executed by the microprocessor. 
         [0026]    As outlined above, a battery charger may utilize a charging method to charge a battery. A charging method is a series of steps that a battery charger uses to help optimize the charging of a battery. Charging methods help or allow a charger to determine when to and/or change supplied voltage and/or current levels to safely and/or efficiently charge the battery to a full charge. 
         [0027]    Charging methods according to exemplary embodiments may improve characteristics of the battery related to, for example, a final charge capacity of the battery, an overall time period required to charge the battery, a life span of the battery (e.g., a length of time before the battery fails and/or a number of charge/discharge cycles of the battery before the battery fails) and/or any other known or later-developed qualities of charging and/or using a battery. For example, a charging method may desirably increase or substantially maintain the charge capacity of a battery by eliminating, preventing or reducing the level of sulfation on one or more plates of the battery. Such charging methods may thus reduce the likelihood that a battery will fail, die or become unreliable do to a build up of crystallized sulfates on the electrodes, or reduction of electrolyte due to water loss. Likewise, a charging method may desirably increase or substantially maintain the charge capacity of a battery by counteracting a self-discharge rate of the battery. 
         [0028]    Additionally, charging methods according to exemplary embodiments may help effectively recharge a battery that has been partially or completely discharged, deeply discharged or over-discharged. Likewise, charging methods according to exemplary embodiments of this invention may help reliably recharge a battery to a full or nearly full capacity. 
         [0029]    It should be appreciated that, in various exemplary embodiments, as the battery is charged, the resistance between the terminals increases. As such, as the battery is charged, the voltage across the terminals will increase and/or the current across the terminals will decrease. Typically, either a substantially constant current or a substantially constant voltage may be applied to the battery such that if a substantially constant current is applied, the voltage across the terminals will increase as the battery charges; and if a substantially constant voltage is applied, the current across the terminals will decrease as the battery charges. 
         [0030]    In various exemplary embodiments, a charging method according to this invention includes applying a first current, applying a voltage and applying a float charge. Various exemplary embodiments also include applying a second current. Various exemplary embodiments also include an optional desulfation step or process. 
         [0031]      FIG. 1  is a flowchart outlining one exemplary embodiment of a charging method  100 . As shown in  FIG. 1 , the charging method  100  begins at step  102  and continues to step  110 , where a desulfation process is applied to the battery. Then, in step  120 , a first current process is applied to the battery. Next, in step  140 , a voltage process is applied to the battery. Operation then continues to step  150 . 
         [0032]    In step  150 , a second current process is applied to the battery. Then, in step  160 , a float charge process is applied to the battery. Operation then continues to step  170 , where the method ends. It should be appreciated that the float charge process applied in step  160  may be utilized to maintain the battery in a substantially fully charged state. As such, operation may continue in step  160  indefinitely and/or until the battery is removed from the battery charger. 
         [0033]    It should be appreciated that, in various embodiments, various ones of steps  110 - 160  may be omitted. For example, the desulfation process performed in step  110 , may be omitted. In this case, operation of the method continues from step  102  directly to step  120 . The second current process applied in step  150  may also be omitted. In this case, operation of the method continues from step  140  to step  160 . 
         [0034]    It should also be appreciated that, in each step  110 - 160  of the charging method  100 , a determination when to move from a present step or process to a next step or process may be based upon any number of factors, including a voltage of the battery, a current of the battery, a temperature of the battery, a manual prompt from a user and/or an amount of time elapsed since the beginning of the present step or process. 
         [0035]      FIG. 2  is a flowchart outlining one exemplary embodiment of the desulfation process performed in step  110  shown in  FIG. 1 . As shown in  FIG. 2 , the desulfation process begins at step  112  and continues to step  113 , where a timer is set to a first time period and the timer is started. Then, in step  114 , the battery is provided with a first voltage and a first current. 
         [0036]    In step  115 , a determination is made whether the first time period has expired. If the first time period has not expired, operation remains in step  115  until the first time period has expired. Once the first time period has expired, operation continues to step  116 , where the desulfation process is ended. 
         [0037]    In various exemplary embodiments, the first voltage is substantially constant and has a value between about 15.3 volts and about 18.0 volts. In various ones of these exemplary embodiments, the first voltage has a value between about 15.7 volts and about 17.5 volts. 
         [0038]    It should also be appreciated that during the desulfation process, the current of the battery may vary depending on the conditions of the battery (e.g., state of charge, level of sulfation, applied voltage, etc.). In various exemplary embodiments, the current of the battery varies or is varied within a range of about 0.5 amps and about 3.0 amps. In various ones of these exemplary embodiments, the current of the battery varies or is varied within a range of about 1.0 amps and about 2.5 amps. It should also be appreciated that the current of the battery may alternatively be substantially constant. In various exemplary embodiments, the current remains substantially constant if the first voltage is greater than about 17.4 volts. In various other exemplary embodiments, the current may decrease or be decreased if the first voltage is less than about 17.4 volts. 
         [0039]    The above-outlined desulfation process may help break up (e.g., disintegrate, disperse or dissolve) lead sulfate crystals that have accumulated on the plates of the battery. By breaking up the crystallized lead sulfates, the available surface area of the plates may be increased and the available capacity of the battery may be increased and, ideally, substantially restored to its original value. Typically, the desulfation step is optional, but if used is the first step of the charging method  100  according to various embodiments. The desulfation process may continue for a desired time length, which may be preset to a length from about 15 minutes to as much as about 48 hours. In various exemplary embodiments, the desulfation step is preset to continue for up to about 36 hours. 
         [0040]      FIG. 3  is a flowchart outlining one exemplary embodiment of the first current process shown at step  120  in  FIG. 1 . As shown in  FIG. 3 , operation of the first current process begins in step  121  and continues to step  122 . At step  122 , a timer is set to a second time period and the timer is started. Then, in step  123 , the battery is provided with a second current. Operation then continues to step  124 . 
         [0041]    It should be appreciated that, in various exemplary embodiments, the second current is substantially constant. As such, while the second current is applied to the battery, the voltage of the battery will tend to increase. Additionally, as the second current is applied to the battery, a temperature of the battery may increase. 
         [0042]    In step  124 , a determination is made whether the temperature of the battery is below a maximum value. If the temperature of the battery is not below the maximum value (e.g., the temperature of the battery has reached a predefined threshold), operation continues to step  125 . Otherwise, if the temperature is below the maximum value, operation jumps to step  129 . In step  125 , the current (e.g., the current applied at step  123 ) is removed from the battery. It should be appreciated that, by removing the current from the battery, the battery will no longer be increasing in temperature and may begin to equalize with the temperature of the environment around the battery. Next in step  126 , a determination is made whether the temperature of the battery is above a minimum value. If the temperature is above the minimum value, operation jumps to step  128 . Otherwise, if the temperature is at or below the minimum value (e.g., the battery has sufficiently cooled), operation continues to step  127 , where the current is again applied to the battery. Operation then jumps to step  129 . 
         [0043]    In step  128 , a determination is made whether the timer has expired. If the timer has expired, operation jumps to step  131 . Otherwise, if the timer has not expired, operation jumps back to step  126 . Thus, operation continues to loop through steps  126 - 128  until the battery has sufficiently cooled or the timer has expired. 
         [0044]    In step  129 , a determination is made whether the present voltage of the battery has reached a desired target value. If the voltage of the battery has not reached the desired target value (e.g., the voltage is still below a desired threshold), operation continues to step  130 . Otherwise, if the voltage of the battery has reached the desired target value (e.g., the voltage has risen up to or above a desired threshold), operation jumps to step  131 . In step  130 , a determination is made whether the second time period has expired. If the second time period has not expired, operation jumps back to step  124 ; otherwise, operation continues to step  131 , where the first current process is ended. 
         [0045]    In various exemplary embodiments, the first current process provides the second current within a range of about 5 amps to about 100 amps until the voltage of the battery increases to a desired voltage level, which is typically within the range of about 14.5 volts to about 18.0 volts. In various embodiments, the first current process provides the second current within a range of about 10 amps to about 40 amps. In various exemplary embodiments, the first current process provides the second current within a range of about 25 to about 30 amps. In various embodiments, the first current process provides the second current until the voltage increases to a desired target level within the range of about 14.8 volts to about 16.0 volts. The first current process may take from between about 15 minutes to about 18 hours and may be terminated after a specified (e.g., preselected) length of time, regardless of the then-present voltage level, to, for example, help prevent overcharging. In various embodiments, the first current process may take from about 2 hours to about 4 hours. 
         [0046]    It should be appreciated that steps  124  to  128  may be omitted. In this case, the temperature of the battery is not monitored and the operation continues from step  123  directly to step  129 . in various exemplary embodiments that include steps  124  to  128 , the first current process includes monitoring or otherwise reading the temperature of the battery and the first current process may be stopped at least temporarily if the temperature of the battery reaches a specified (e.g. preselected) limit. In various exemplary embodiments, the specified temperature limit is about 150 deg F. In various other exemplary embodiments, the specified temperature limit is about 125 deg F. 
         [0047]      FIG. 4  is a flowchart outlining one exemplary embodiment of the voltage process performed at step  140  shown in  FIG. 1 . As shown in  FIG. 4 , operation begins in step  142  and continues to step  143 . At step  143 , the timer is set to a third time period and the timer is started. Then, in step  144 , the battery is provided with a second voltage. Operation then continues to step  145 . 
         [0048]    It should be appreciated that, in various exemplary embodiments, the second voltage is substantially constant. As such, while the second voltage is applied to the battery, the current of the battery tends to decrease. In step  145 , a determination is made whether the then-present current of the battery has reached a desired target value. If the current of the battery has not reached the desired target value (e.g., the current is still above a desired target), operation continues to step  146 ; otherwise, if the current of the battery has reached the desired target value (e.g., the current has fallen to or below a desired target), operation jumps to step  147 . In step  146 , a determination is made whether the third time period has expired. If the third time period has not expired, operation jumps back or returns to step  145 ; otherwise, operation continues to step  147  and the voltage process is ended. 
         [0049]    In various exemplary embodiments, during the voltage process performed in step  140 , the second voltage is provided to the battery until the current of the battery drops to a desired value. In various exemplary embodiments, the second voltage is within the range of about 14.1 volts to about 16.0 volts. In various embodiments, the second voltage is further within the range of approximately 14.4 volts to approximately 15.6 volts. In various exemplary embodiments, the current starts at or below approximately 100 amps and tapers to a limit that is less than or about 1 amp. In various exemplary embodiments, the current ranges from approximately 60 amps to approximately 1 amp. The voltage process may take from between about 30 minutes to about 24 hours and may be ended, at least temporarily, after a certain or specified (e.g. preselected) time period, regardless of the then-present current level. In various exemplary embodiments, the voltage process is preset to be stopped after a time period between about 3 hours and about 5 hours. 
         [0050]      FIG. 5  is a flowchart outlining one exemplary embodiment of the second current process shown at step  150  in  FIG. 1 . As shown in  FIG. 5 , operation begins in step  152  and continues to step  153 . In step  153 , the timer is set to a fourth time period and the timer is started. In step  154 , the battery is provided with a third current. Operation then continues to step  155 . 
         [0051]    It should be appreciated that, in various exemplary embodiments, the third current is substantially constant. As such, while the third current is applied to the battery, the voltage of the battery tends to increase. In step  155 , a determination is made whether the present voltage of the battery has reached a desired target value. If the voltage of the battery has not reached the desired target value (e.g., the voltage is still below a desired target), operation continues to step  156 ; otherwise, if the voltage of the battery has reached the desired target value (e.g., the voltage has risen up to or above a desired target), operation jumps to step  157 . In step  156 , a determination is made whether the fourth time period has expired. If the fourth time period has not expired, operation jumps back to step  155 ; otherwise, operation continues to step  157  and the second current process is ended. 
         [0052]    In various exemplary embodiments, during the second current process performed in step  150 , the battery is provided with the third current until the voltage increases to about a specific or otherwise desired value. In various exemplary embodiments, the third current is approximately 3 amps and the desired voltage is within the range of about 14.5 volts to about 18.0 volts. In various exemplary embodiments, the third current is within the range of about 2 amps to about 4 amps and the desired voltage is within the range of about 17.5 volts to about 17.8 volts. In various embodiments, the second current process is preset to end, if it has not already done so, after approximately 2 hours, regardless of the then-present voltage. In various exemplary embodiments, the second current step may take about one hour and may be ended at least temporarily after a certain or specified (e.g. preselected) time period, regardless of the then-present voltage level. 
         [0053]      FIG. 6  is a flowchart outlining one exemplary embodiment of the float charge process shown at step  160  in  FIG. 1 . As shown in  FIG. 6 , operation begins in step  162  and continues to step  164 . In step  164 , the battery is provided with a third voltage. In step  166 , the amount of current supplied to the battery is limited to a fourth current. As shown in  FIG. 6 , operation loops through steps  164  and  166 , with the third voltage provided to the battery to a limit of the fourth current, for as long as the battery remains connected to the battery charger. It should be appreciated that, in various exemplary embodiments, step  166  may be omitted. In this case, the current provided to the battery is not limited. It should also be appreciated that, in various exemplary embodiments, the current may taper (e.g., decrease over time) while the third voltage is provided to the battery. 
         [0054]    In various exemplary embodiments, during the float charge process shown in step  160 , the battery is provided with a voltage between about 13.2 volts and about 13.8 volts at a current of up to about 1 amp. In various embodiments, the float charge process provides a voltage of between about 13.5 volts and about 13.8 volts at a current between about 0.5 amps to about 1 amp. The float charge process may not have a time limit and may be continued indefinitely until the battery is disconnected from the charger. 
         [0055]      FIG. 7  shows a flowchart of a charging method  200  according to a second exemplary embodiment. As shown in  FIG. 7 , the charging method  200  begins in step  201  and continues to step  202 , where a 3 hour timer is started. Then, in step  203 , a substantially constant current of approximately 30 amps is applied to the battery. In this exemplary embodiment, the current is applied until the voltage of the battery increases to approximately 15.6 volts or the three hour timer expires. As such, in step  204 , a determination is made whether the voltage is less than 15.6 volts. If the voltage is less than 15.6 volts, operation continues to step  205 ; otherwise, if the voltage is not less than 15.6 volts, operation jumps to step  206 . In step  205 , a determination is made whether the 3 hour timer has expired. If the 3 hour timer has expired, operation continues to step  206 ; otherwise, if the 3 hour timer has not expired, operation jumps back to step  204 . 
         [0056]    It should be appreciated that, in various other embodiments, the substantially constant current applied in step  203  may be approximately 25 amps. In various exemplary embodiments, if the temperature of the battery rises to above about 125 deg F, the applied current is, at least temporarily, removed from the battery until the temperature falls to a desired level, in a similar manner to that shown in  FIG. 3 . In various embodiments, if the 3 hour timer has not expired, the applied current may be reapplied after the temperature falls to the desired level. 
         [0057]    At step  206 , a 4 hour timer is started. Next, in step  207 , a substantially constant voltage of approximately 14.8 volts is applied to the battery. In various exemplary embodiments, the current available to the battery in step  207  may be capped at a maximum of approximately 30 amps. Then, in step  208 , a determination is made whether the current of the battery is greater than about 1 amp. If the current is greater than about 1 amp, operation continues to step  209 . Otherwise, if the current of the battery is not greater than about 1 amp, operation jumps to step  210 . In step  209 , a determination is made whether the 4 hour timer has expired. If the 4 hour timer has expired, operation continues to step  210 ; otherwise, operation jumps back to step  208 . 
         [0058]    In step  210 , a 1 hour timer is started. Then, in step  211 , the battery is provided with a substantially constant current of approximately 3 amps. Next, in step  212 , a determination is made whether the voltage of the battery is less than 17.5 volts. If the voltage is less than 17.5 volts, operation continues to step  213 ; otherwise, if the voltage of the battery is not less than 17.5 volts, operation jumps to step  214 . In step  213 , a determination is made whether the 1 hour timer has expired. If the 1 hour timer has expired, operation continues to step  214 ; otherwise, if the 1 hour timer has not expired, operation jumps back to step  212 . 
         [0059]    In step  214 , a substantially constant voltage of approximately 13.8 volts is applied to the battery at a current of up to about 1 amp. As shown in  FIG. 7 , the approximately 13.8 volts may be provided to the battery indefinitely and/or until the battery is removed from the charger. 
         [0060]      FIG. 8  is a block diagram of an exemplary embodiment of a battery charging system  3000  including a battery charger  3100  and a battery  3200 . As shown in  FIG. 8 , a positive lead  3300  and a negative lead  3400  are provided between the battery  3200  and the battery charger  3100 . Typically, the positive lead  3300  and the negative lead  3400  connect to terminals or similar structures on the exterior of the battery  3200 . The leads  3300  and  3400  may include wires, cables, clamps, alligator clips, plugs and/or any other suitable known or later-developed electrical connection. 
         [0061]    As shown in  FIG. 8 , the battery charger  3100  includes a voltage supply circuit  3110 , a current supply circuit  3120 , a controller  3130 , a timer  3140 , a voltage sensor  3150 , a current sensor  3160 , a temperature sensor  3170  and a memory  3180 . 
         [0062]    The voltage supply circuit  3110 , the current supply circuit  3120 , the controller  3130 , the timer  3140 , the voltage sensor  3150 , the current sensor  3160 , the temperature sensor  3170  and the memory  3180  are each connected to a communications bus  3190 . The communications bus  3190  allows each component of the battery charger  3100  to send and/or receive information (e.g., readings, control signals, instructions, data, etc.) to and/or receive information from another component of the battery charger  3100 . For example, the controller  3130  may send instructions to and/or control the current supply circuit  3120  regarding a desired current to be provided to the battery  3200 . It should be appreciated that, while the communications bus  3190  is shown as a single wire, the communications bus  3190  may include any number of wires suitable for any desired known or later-developed communications bus and/or protocol (e.g., 1-wire, I 2 C, PCI Express, Serial Peripheral Interface Bus, etc.). 
         [0063]    It should also be appreciated that various components of the battery charger  3100  may be combined or integrated together. For example, in various exemplary embodiments, a single circuit may replace the voltage supply circuit  3110  and the current supply circuit  3120 . In various exemplary embodiments, at least some of the components of the battery charger  3100  are elements of a microcontroller, a microprocessor and/or any other suitable known or later-developed controller. 
         [0064]    The voltage supply circuit  3110 , the current supply circuit  3120 , the voltage sensor  3150  and the current sensor  3160  are each also connected to the positive lead  3300  and the negative lead  3400 . At various desired times and/or for various desired periods, the voltage supply circuit  3130  provides a desired voltage between the positive and negative leads  3300  and  3400 , and thus between the positive and negative connections of the battery  3200 . Likewise, at various desired times and/or for various desired periods, the current supply circuit  3120  provides a desired current to the positive and negative leads  3300  and  3400 , and thus to the positive and negative connections of the battery  3200 . 
         [0065]    In various exemplary embodiments, the memory  3180  includes timer data  3182 . The timer data  3182  may include information regarding desired time periods to set for the timer  3140  during various stages of charging the battery  3200  (e.g., a starting value for a count-down timer or an ending value for a count-up timer). In various exemplary embodiments, the memory  3180  also includes voltage data  3184 . The voltage data  3184  may include desired voltages to apply to the battery  3200  during various stages of charging the battery  3200 , desired target voltages during other stages of charging the battery  3200  and/or historic values of voltages sensed by the voltage sensor  3150 . In various exemplary embodiments, the memory  3180  also includes current data  3186 . The current data  3186  may include desired current values to apply to the battery  3200  during various stages of charging the battery  3200 , desired current limits and/or targets during other stages of charging the battery  3200  and/or historic values of currents sensed by current sensor  3160 . 
         [0066]    As shown in  FIG. 8 , the temperature sensor  3170  is also connected to the battery  3200 . The temperature sensor senses, monitors, records and/or determines the temperature of the battery  3200 . It should be appreciated that the temperature sensor  3170  may be directly coupled to the battery  3200 , as shown in  FIG. 8 . In various other exemplary embodiments, the temperature sensor  3170  is at least indirectly thermally coupled to the battery  3200 . In various other exemplary embodiments, the temperature sensor  3170  is capable of determining the temperature of the battery  3200  from a distance without being directly or indirectly thermally or electrically coupled to the battery  3200  (e.g., the temperature sensor  3170  may utilize a laser and/or infrared based temperature system). In various other exemplary embodiments, the temperature sensor  3170  may be integral to the battery  3200  and may be electrically connected to the battery charger  3100 . 
         [0067]    In an exemplary method of utilizing the battery charging system  3000  shown in  FIG. 8 , the battery  3200  is coupled to the battery charger  3100  to be charged. In various exemplary embodiments, the controller  3130  controls the current supply circuit  3120 , the voltage sensor  3150  the timer  3140  and/or the temperature sensor  3170  to charge the battery  3200  using a first current process or routine that uses a first set of current, voltage, timer and temperature parameters stored in the memory  3180 . In various embodiments, during the first current process or routine, the current supply circuit  3120  provides a current between the positive lead  3300  and the negative lead  3400  with a value of approximately 30 amps and the timer  3140  is set to a time period of approximately 3 hours. 
         [0068]    In various exemplary embodiments, the current supply circuit  3120  provides the current between the positive lead  3300  and the negative lead  3400  until the voltage sensor  3150  indicates that the voltage of the battery  3200 , has reached a desired value of approximately 15.6 volts. 
         [0069]    In various exemplary embodiments, if the temperature sensor  3170  indicates that the temperature of the battery  3200  reaches a value of approximately 125 deg F, the current provided by the current supply circuit  3120  is set to 0 until the temperature sensor  3170  indicates that the temperature of the battery  3200  has fallen to a desired level. After the temperature of the battery  3200  has fallen to the desired value, the current supply circuit  3120  may then again reapply the current of the previous value. 
         [0070]    In various exemplary embodiments, after either the voltage sensor  3150  indicates that the voltage of the battery  3200  has reached the desired value (e.g., approximately 15.6 volts) or the timer  3140  expires, the controller  3130  controls the voltage supply circuit  3110 , the current sensor  3160  and the timer  3140  to charge the battery  3200  using a voltage process or routine that uses a second set of current, voltage and timer parameters stored in the memory  3180 . In various exemplary embodiments, the timer  3140  is set to a time period of approximately 4 hours. In various exemplary embodiments, during the voltage process or routine, the voltage supply circuit  3110  provides a voltage of approximately 14.8 volts between the positive lead  3300  and the negative lead  3400 . In various exemplary embodiments, the current supply circuit  3120  additionally limits the available current between the positive lead  3300  and the negative lead  3400  to approximately 30 amps. 
         [0071]    In various exemplary embodiments, the voltage process or routine continues until either the current sensor  3160  indicates that the current of the battery  3200  has fallen to a value less than approximately 1 amp or the timer  3140  expires. In various exemplary embodiments, the controller  3130  then controls the current supply circuit  3120 , the voltage sensor  3150  and the timer  3140  to charge the battery  3200  using a second current process or routine that uses a third set of current, voltage and timer parameters stored in the memory  3180 . 
         [0072]    In various exemplary embodiments, at the beginning of the second current process or routine, the timer  3140  is set to a time period of approximately 1 hour. In various exemplary embodiments, during the second current step, the current supply circuit  3120  provides a current of approximately 3 amps between the positive lead  3300  and the negative lead  3400 . In various exemplary embodiments, the current supply circuit  3120  provides the 3 amps of current until either the voltage sensor  3150  indicates that the voltage of the battery  3200  has reached approximately 17.5 volts or the timer  3140  has expired. 
         [0073]    In various exemplary embodiments, the controller  3130  then controls the voltage supply circuit  3110  and the current supply circuit  3120  using a float charge process or routine that uses a fourth set of voltage and current parameters stored in the memory  3180 . In various exemplary embodiments, during the float charge process or routine, the voltage supply circuit  3110  provides a voltage of approximately 13.8 volts between the positive lead  3300  and the negative lead  3400 . In various exemplary embodiments, the current supply circuit  3120  additionally limits the current between the positive lead  3300  and the negative lead  3400  to no more than approximately 1 amp, while allowing the current to taper lower. In various exemplary embodiments, the controller  3130  continues executing the float charge process or routine for as long as the battery  3200  remains connected to the battery charger  3100 . 
         [0074]    It should be appreciated that the above-outlined method of using the battery charging system  3000  is only exemplary. In general, the battery charger  3100  of the battery charging system  3000  may utilize any of the above-outlined or other exemplary methods of charging a battery to charge the battery  3200 . 
         [0075]    It should be appreciated that the above-outlined timers and time periods (e.g., the timer  3140 , the first time period, the second time period, the third time period and the fourth time period) may utilize any known or later-developed timing device(s) and/or mechanism(s). Any particular time period may be tracked utilizing a count-up method, in which the time period ends when a timer reaches a desired value. Likewise, any particular time period may be tracked utilizing a count-down method, in which the timer period ends when a timer reaches zero. In various embodiments, each timer/time period is a function of one or more real time clock(s). In various embodiments, the real time clock is a function of or operably connected to a processor of the battery charger. 
         [0076]    It should be appreciated, that the various steps of the various processes may be performed in any order and/or simultaneously. For example, in various processes, the battery charger may simultaneously monitor a voltage and/or a current of the battery as well as a timer to determine whether the present process should be ended. In various exemplary embodiments, if any parameter indicates that the present process should be ended, that process is ended regardless of the condition of any other parameters. 
         [0077]    As shown in  FIG. 8 , one or more of the elements  3110 - 3190  of the battery charger  3100  can be implemented using a programmed general-purpose or special-purpose microprocessor, microcontroller, digital signal processor or the like. Alternatively, one or more of the elements  3110 - 3190  of the battery charger  3100  can be implemented using an ASIC or other integrated circuit, a hardwired electronic or logic circuit such as a discrete element circuit, a programmable logic device, such as, but not limited to, a PLD, PLA, FPGA or PAL, or the like. In general, any device, capable of implementing a finite state machine that is in turn capable of implementing the flowcharts shown in  FIGS. 1-7 , can be used to implement one or more of the elements  3110 - 3190  of the battery charger  3100 . It should further be appreciated that, in place of a distinct and separately-identifiable controller  3110 , the various control functions described with respect to the controller  3110  above can be distributed and implemented in various ones of the circuits  3110  and  3120 , the timer  3140  and/or the sensors  3150 - 3170 . 
         [0078]    It should be understood that one or more of the various elements, such as the controller  3130 , the circuits  3110  and/or  3120 , the timer  3140  and/or the sensors  3150 - 3170  can be implemented as software (e.g., routines, applications, objects, procedures or managers) stored on a computer readable medium that is executable on a programmed general-purpose computer or special-purpose microprocessor, microcontroller, digital signal processor or the like. The particular form of the circuits, routines, applications, objects, procedures or managers shown in  FIG. 8  will take is a design choice and will be obvious and predictable to those skilled in the art. It should be appreciated that the circuits, routines, applications, objects, procedures or managers shown in  FIG. 8  do not need to be of the same design. 
         [0079]    It should be appreciated that a routine, application, manager, procedure, object or the like can be a self-consistent sequence of processor-implemented steps that lead to a desired result. These steps can be defined by and/or in one or more computer instructions stored in a computer readable medium. These steps can be performed by a processor executing the instructions that define the steps. Thus, the terms “routine”, “application”, “manager”, “procedure”, and “object” can refer to, for example, a sequence of instructions, a sequence of instructions organized within a programmed-procedure or programmed-function, and/or a sequence of instructions organized within programmed processes. Such routines, applications, managers, procedures, objects or the like can also be implemented directly in circuitry that performs the procedure. Further, these processor-controlled methods can be performed by a processor executing one or more appropriate programs, by special purpose hardware designed to perform the method, or any combination of such hardware, firmware and software elements. 
         [0080]    As shown in  FIG. 8 , the memory  3180  can be implemented using any appropriate combination of alterable, volatile or non-volatile memory or non-alterable, or fixed, memory. The alterable memory, whether volatile or non-volatile, can be implemented using any one or more of static or dynamic RAM, a hard drive, flash memory or the like. Similarly, the non-alterable or fixed memory can be implemented using any one or more of ROM, PROM, EPROM, EEPROM or the like. 
         [0081]    While this invention has been described in conjunction with the exemplary embodiments outlined above, various alternatives, modifications, variations, improvements and/or substantial equivalents, whether known or that are or may be presently foreseen, may become apparent to those having at least ordinary skill in the art. Accordingly, the exemplary embodiments of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit or scope of the invention. Therefore, the invention is intended to embrace all known or earlier developed alternatives, modifications, variations, improvements and/or substantial equivalents.