apparatus , systems and methods that implement the embodiments of the various features of the present invention will now be described with reference to the drawings . the drawings and the associated descriptions are provided to illustrate some embodiments of the present invention and not to limit the scope of the present invention . throughout the drawings , reference numbers are re - used to indicate correspondence between referenced elements . fig1 is a schematic diagram of an embodiment of the present invention . as seen in fig1 , an automobile 2 can include an engine 4 , a starter 6 , a main battery 8 , a control unit 10 , an auxiliary battery 12 , accessories 14 , a key reception unit 16 , and a warning unit 20 . as depicted in fig1 , automobile 2 is a hybrid car . although automobile 2 is a hybrid car , automobile 2 can be , for example , any suitable car for transportation such as a car with a conventional internal combustion engine , and / or a car with a hydrogen engine . engine 4 can be an internal combustion engine suitable for use in a hybrid car . engine 4 can also be an electric engine or an engine to process hydrogen , ethanol , or other types of fuel . engine 4 is connected to starter 6 , auxiliary battery 12 , and main battery 8 through a switch 22 . engine 4 can be in an active state or inactive state . in an inactive state , engine 4 is off and is not running while in an active state , engine 4 is on and is running . starter 6 is connected to engine 4 . it is also connected to main battery 8 through switch 22 which can be either engaged or disengaged . starter 6 can start engine 4 through electricity supplied by main battery 8 when switch 22 is engaged . starter 6 can include , for example , spark plugs . main battery 8 is connected to control unit 10 , engine 4 and starter 6 through switch 22 , and auxiliary battery 12 through switch 24 . main battery 8 can be , for example , a high voltage battery . main battery 8 can supply electricity to engine 4 and / or starter 6 when switch 22 is engaged . furthermore , when engine 4 is active and switch 22 is engaged , main battery 8 can provide power to aid engine 4 in moving automobile 2 . also when switch 22 is disengaged , electricity from main battery 8 does not flow to engine 4 and / or starter 6 . advantageously this can improve the safety of automobile 2 by preventing accidental discharges to engine 4 and / or starter 6 since main battery 8 can be a high voltage battery . with regards to switch 24 , when switch 24 is engaged , main battery 8 can supply electricity to auxiliary battery 12 . when switch 24 is disengaged , electricity does not flow from main battery 8 to auxiliary battery 12 . auxiliary battery 12 is connected to engine 4 , accessories 14 , control unit 10 , and switch 22 . auxiliary battery 12 is also optionally connected to main battery 8 . auxiliary battery 12 can be a battery with a smaller energy storage capacity than main battery 8 . advantageously this could reduce the weight of automobile 2 which can be particularly useful when automobile 2 is a hybrid car . in one embodiment , auxiliary battery 12 is a 12 volt battery . auxiliary battery 12 may be connected to main battery 24 through switch 24 and accessories 14 through switch 26 . switch 24 and switch 26 can be configured to be engaged or disengaged . as noted , when switch 24 is engaged , electricity can flow from main battery 8 to auxiliary battery 12 . when switch 24 is disengaged , electricity may not flow from main battery 8 to auxiliary battery 12 . advantageously this can improve the safety of automobile 2 since main battery 8 can be a high voltage battery . when switch 26 is engaged , auxiliary battery 12 can supply electricity to accessories 14 . when switch 26 is disengaged , electricity can be prevented from flowing to accessories 14 . advantageously , this can reduce the amount of electricity used by accessories 14 and prevent auxiliary battery 12 from being depleted or drained , such as when engine 4 is inactive or off . when engine 4 is active , engine 4 can recharge and replenish auxiliary battery 12 . furthermore , auxiliary battery 12 can also control switch 22 by supplying electricity to engage or disengage switch 22 . as previously noted , the engagement of switch 22 allows main battery 8 to supply power to start engine 4 using starter 6 . key reception unit 16 is connected to control unit 10 and can accept a key 18 which can engage key reception unit 16 . key 18 can engage key reception unit 16 either physically , such as when key 18 is physically placed inside key reception unit 16 , or wirelessly , such as when key 18 transmits a signal to key reception unit 16 and / or key 18 establishes communication with key reception unit 16 . key 18 can engage key reception unit 16 in two or more states such as an accessories on state or an engine on state . in the accessories on state , accessories 14 can be activated . it is also contemplated that some accessories 14 can be activated without key 18 being engaged with key reception unit 16 , or without key 18 being engaged with key reception unit 16 in the accessories on state . in such a case , the remaining accessories can be engaged when key 18 is engaged with key reception unit 16 in the accessories on state . during the accessories on state , engine 4 is inactive . the accessories on state can also be referred to as the ready off state . in the engine on state , engine 4 is activated . furthermore , during the engine on state , auxiliary battery 12 can supply electricity to accessories 14 and engine 4 can recharge auxiliary battery 12 . the engine on state can also be known as the ready on state . warning unit 20 is connected to control unit 16 and / or auxiliary battery 12 . warning unit 12 can be , for example , an audio emission device , a video display , and / or a combination of the audio emission device and the video display . thus , warning unit 12 can provide a warning to a user such as an audio warning , visual warning , or and audiovisual warning to the user . accessories 14 are connected to auxiliary battery 12 through switch 26 . accessories 14 can be radios , lights , video players , etc . accessories 14 can draw power from auxiliary battery 12 when switch 26 is engaged . if switch 26 is disengaged , accessories 14 is effectively disconnected from auxiliary battery 12 and power from auxiliary battery 12 to accessories 14 is cut off . control unit 10 is connected to main battery 8 , auxiliary battery 12 , switch 24 , switch 26 , key reception unit 16 , and warning unit 20 . control unit 10 can be an engine control unit , a microprocessor , an on - board diagnostics system , a computer chip , and / or any other device that can control or monitor the functions and / or components of automobile 2 . control unit 10 can thus monitor auxiliary battery 12 and determine the voltage , power , and / or current level of auxiliary battery 12 . furthermore , control unit 10 can also instruct auxiliary battery 12 to supply power to engage or disengage switch 22 . control unit 10 is also connected to key reception unit 16 and receives a signal from key reception unit 16 regarding the engagement of key 18 to key reception unit 16 . based on the signal , control unit 16 can also control switch 24 and switch 26 to engage or disengage appropriately . control unit 10 can also determine whether key 18 is engaged with key reception unit 16 in an engine on state or accessories on state . control unit 10 also controls warning unit 20 to display or sound an alarm at appropriate times . by selectively controlling switch 26 and warning unit 20 , control unit 10 can warn a user when accessories 14 should be turned off and also when auxiliary battery 12 will be disconnected from accessories 14 . control unit 10 can also warn a user to activate engine 4 so that auxiliary battery 4 can be replenished . by disconnecting auxiliary battery 12 from accessories 14 , the present invention can advantageously preserve a sufficient state of charge within auxiliary battery 12 to engage switch 22 when a user wishes to drive automobile 2 . otherwise , if auxiliary battery 12 is drained , then auxiliary battery 12 may not have a sufficient state of charge to engage switch 22 to allow main battery 8 to start engine 4 using starter 6 . fig2 is a flow chart of an embodiment of the present invention in operation . as seen in fig2 , the process begins in step s 200 . in step s 212 , control unit 10 determines whether engine 4 is active or not . engine 4 can be active , for example , when key 18 is engaged with key reception unit 16 in an engine on state . engine 4 is inactive when key 18 is disengaged from key reception unit 16 and / or key 18 is engaged with key reception unit 16 in an accessories on state but not in an engine on state . if engine 4 is active , then the process ends in step s 222 . otherwise , if engine 4 is inactive , the process continues in step s 214 . in step s 214 , control unit 4 determines whether auxiliary battery 12 is operating in a warning condition . for example , auxiliary battery 12 can be operating in a warning condition when the engine is inactive and when a voltage of auxiliary battery 12 falls below a first predetermined voltage threshold , a power of auxiliary battery 12 falls below a first predetermined power threshold , and / or a current of auxiliary battery 12 falls below a first predetermined current threshold . for example , if the first predetermined threshold for auxiliary battery 12 is 6 volts and the voltage of auxiliary battery 12 is 5 volts , then auxiliary battery 12 is operating in a warning condition . furthermore , auxiliary battery 12 could be operating in a warning condition when the engine is inactive when a first predetermined amount of time has expired from a triggering event , such as when accessories 14 is activated . for example , if the first predetermined amount of time is 30 minutes and more than 30 minutes has elapsed since accessories 14 was activated , then auxiliary battery 12 is operating in the warning condition when the engine is inactive . if auxiliary battery 12 is not operating in the warning condition , then the process repeats step s 212 . if , however , auxiliary battery 12 is operating in the warning condition , then in step s 216 , control unit 10 provides a warning to a user using warning unit 20 . the warning can be an audio or visual warning to indicate to the user that he should turn off or deactivate accessories 14 . the warning can also be an audio or visual warning to indicate to the user that auxiliary battery 12 has a low state of charge . the warning can also indicate to the user that the user should activate engine 4 such as by engaging key 18 with key reception unit 16 in an engine on state . by activating engine 4 , it is contemplated that engine 4 could recharge auxiliary battery 12 . in step s 218 , control unit 10 determines whether auxiliary battery 12 is operating in a shut off condition . auxiliary battery 12 is operating in the shutoff condition when the engine is inactive and when a voltage of auxiliary battery 12 falls below a second predetermined voltage threshold , a power of auxiliary battery 12 falls below a second predetermined power threshold , and / or a current of auxiliary battery 12 falls below a second predetermined current threshold . the second voltage threshold is less than the first voltage threshold , the second power threshold is less than the first power threshold , and the second current threshold is less than the first current threshold . thus , if the first voltage threshold was 6 volts , then the second voltage threshold can be , for example , 4 volts . if the voltage of auxiliary battery 12 was 5 volts , then auxiliary battery 12 would be operating in the warning condition but not in the shut off condition since 5 volts is greater than the second voltage threshold of 4 volts . however , if the voltage of auxiliary battery 12 had dropped to 3 volts , then auxiliary battery 12 would be operating in the shut off condition since 3 volts is less than the second voltage threshold of 4 volts . furthermore , auxiliary battery 12 could be operating in a shutoff condition when the engine is inactive and when a second predetermined amount of time has expired from a triggering event , such as when accessories 14 is activated . the second predetermined amount of time can be a greater amount of time than the first predetermined amount of time . for example , if the first predetermined amount of time is 30 minutes and more than 40 minutes has elapsed since accessories 14 was activated , then auxiliary battery 12 is operating in the shutoff condition when the engine is inactive . if auxiliary battery 12 is not operating in the shut off condition , then the process repeats step s 212 . if , however , auxiliary battery 12 is operating in the shut off condition , then in step s 220 , control unit 10 disengages switch 26 to disconnect auxiliary battery 12 from accessories 14 . this may be especially useful when auxiliary battery 12 has a relatively low charge capacitance when compared to the electrical demands of accessories 14 . that is , when accessories 14 may drain auxiliary battery 12 in a relatively short period of time such as in an hour or a few hours . optionally , control unit 10 can also display another warning to the user indicating that auxiliary battery 12 has been disconnected from accessories 14 . the warning can also include instructions to activate engine 4 by engaging key 18 with key reception unit 16 in an engine on state . in step 222 , the process ends . in one embodiment , switch 24 can be engaged to replenish auxiliary battery 12 at either step s 216 or step s 220 . this can be done , for example , only when control unit 10 detects that key 18 is engaged with key 16 and that there is sufficient energy within main battery 8 to replenish auxiliary battery 12 . advantageously this can replenish auxiliary battery 12 while reducing the likelihood that main battery 8 is discharged because if key 18 is engaged with key reception unit 16 , it is contemplated that the user is present . if the user is present , then the user can activate engine 4 to recharge auxiliary battery 12 . furthermore , if the user is not present , then it may be less critical that accessories 14 remain active or have the ability to remain active . also , if main battery 8 is a high voltage battery , then it may be beneficial to reduce the amount of time when main battery 8 is connected to auxiliary battery 12 such as when the user is not present in automobile 2 . in another embodiment , as soon as engine 4 is activated , the process moves to step s 222 and ends . this is because as soon as engine 4 is activated , then engine 4 is used to recharge auxiliary battery 12 . this may reduce the necessity for auxiliary battery 12 to be disconnected from accessories 14 . in yet another embodiment , key 18 can engage key reception unit 16 in a third state such as an ignition off state . during the ignition off state , switch 26 is disengaged , preventing power from flowing from auxiliary battery 12 to accessories 14 . in such an embodiment , during an accessories on state and an engine on state , switch 26 is engaged allowing power to flow from auxiliary battery 12 to accessories 14 . those of ordinary skill would appreciate that the various illustrative logical blocks , modules , and algorithm steps described in connection with the examples disclosed herein may be implemented as electronic hardware , computer software , or combinations of both . to clearly illustrate this interchangeability of hardware and software , various illustrative components , blocks , modules , circuits , and steps have been described above generally in terms of their functionality . whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system . skilled artisans may implement the described functionality in varying ways for each particular application , but such implementation decisions should not be interpreted as causing a departure from the scope of the disclosed apparatus and methods . the various illustrative logical blocks , modules , and circuits described in connection with the examples disclosed herein may be implemented or performed with a general purpose processor , a digital signal processor ( dsp ), an application specific integrated circuit ( asic ), a field programmable gate array ( fpga ) or other programmable logic device , discrete gate or transistor logic , discrete hardware components , or any combination thereof designed to perform the functions described herein . a general purpose processor may be a microprocessor , but in the alternative , the processor may be any conventional processor , controller , microcontroller , or state machine . a processor may also be implemented as a combination of computing devices , e . g ., a combination of a dsp and a microprocessor , a plurality of microprocessors , one or more microprocessors in conjunction with a dsp core , or any other such configuration . the steps of a method or algorithm described in connection with the examples disclosed herein may be embodied directly in hardware , in a software module executed by a processor , or in a combination of the two . a software module may reside in ram memory , flash memory , rom memory , eprom memory , eeprom memory , registers , hard disk , a removable disk , a cd - rom , or any other form of storage medium known in the art . an exemplary storage medium is coupled to the processor such that the processor can read information from , and write information to , the storage medium . in the alternative , the storage medium may be integral to the processor . the processor and the storage medium may reside in an application specific integrated circuit ( asic ). the asic may reside in a wireless modem . in the alternative , the processor and the storage medium may reside as discrete components in the wireless modem . the previous description of the disclosed examples is provided to enable any person of ordinary skill in the art to make or use the disclosed methods and apparatus . various modifications to these examples will be readily apparent to those skilled in the art , and the principles defined herein may be applied to other examples without departing from the spirit or scope of the disclosed method and apparatus . the described embodiments are to be considered in all respects only as illustrative and not restrictive and the scope of the invention is , therefore , indicated by the appended claims rather than by the foregoing description . all changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope .