Power conversion equipment monitor/controller method and apparatus

• US 5,939,855 A
• Filed: 06/27/1997
• Issued: 08/17/1999
• Est. Priority Date: 09/06/1994
• Status: Expired due to Term

• Current Assignee: Schneider Electric Solar Inverters Usa, Inc. (Schneider Electric SE)
• Original Assignee: Cruising Equipment, Inc.
• Inventors: Kahle, Steven H., Stokes, Warren D., Proctor, Richard L., Young, Richard H. Jr.
• Primary Examiner(s): Tso, Edward H.
• Application Number:
  US08/898,881
• Time in Patent Office: 781 Days
• Field of Search: 320/104, 320/118, 320/123, 320/125, 320/128, 320/132, 320/134, 320/136, 320/163, 320/DIG. 18, 320/DIG. 21, 320/FOR 104, 320/FOR 105, 320/FOR 138 , 320/FOR 147, 324/426, 324/427, 324/428, 324/432, 324/433, 307/9.1, 307/10.1, 340/636, 322/14, 322/28, 322/78, 429/90
• US Class Current: 320/104
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: H02J 7/1423 with multiple batteries
• CPC Class Codes: H02J 7/1438 in combination with power supplies for loads other than batteries

Abstract

Power inverter equipment monitor/controller method and apparatus are described. The invented apparatus provides for the semi-automatic state steering and monitoring of an inverter/charger and alternator system. A flat panel user interface includes an array of switches, displays and indicators for establishing modes of operation of the system, for initializing operating parameters of the system and a connected battery, for establishing rates for the system'"'"'s operation, permit the user to monitor the system'"'"'s operating mode and charging data (including charging efficiency factor or CEF) while it is operating to charge the battery and to supply AC power to connected appliances. By the one of the preferred methods of the invention, ramping-up the alternator'"'"'s output of current, sustaining the output until the voltage of the battery is acceptable, adjusting the output while maintaining the battery voltage at an acceptable level, reducing output until float level voltage is obtained and further adjusting output to maintain float level voltage to preserve the battery charge. By the other of the preferred methods, certain charge data related to the charging of the battery--including a present CEF, maximum amp-hour charge level capacity of the battery (AH CL capacity), and the present status of amp-hour charge level--are given and stored in memory, the battery is discharged, the lowest-recorded (LR) AH CL is recorded with recharge begins, completing the recharge and storing amount of amp-hours used to recharge, determining an intermediate CEF by dividing AH used-to-recharge battery by difference between the AH CL capacity and LR AH CL, averaging the present CEF with the intermediate CEF to produce a result which is stored in memory as the present CEF, and resetting present status to the AH CL capacity.

Claims

1. For use with a system including an alternator that supplies a variable alternator-current-output to a connected battery with a multi-cycle battery charger connected thereto, wherein the battery has a battery voltage and receives a charging current, and wherein the alternator is controlled by a regulator, an alternator regulation method comprising:

ramping-up the alternator-current-output until the alternator-current-output reaches an alternator-current-limit;

sustaining the alternator-current-output substantially at the alternator-current-limit until the battery voltage is substantially at an acceptance voltage;

adjusting the alternator-current-output for maintaining the battery voltage substantially at the acceptance voltage, until the battery'"'"'s charging current is substantially at a fully-charged-indication current;

reducing the alternator-current-output, which lowers the battery voltage, until the battery voltage is substantially at a float voltage; and

further adjusting the alternator-current-output for maintaining the battery voltage substantially at the float voltage to preserve a fully charged condition of the battery.

2. The method of claim 1, wherein the system includes a sensor for measuring and a processor comparing, and wherein the regulator is connected to the sensor and the processor, the method further comprising:

a battery-current measuring of the charging current flowing through the battery;

an alternator-current measuring of the alternator-current-output;

a voltage measuring of the battery voltage across the battery;

an alternator-current comparing of the alternator-current-output to the alternator-current-limit;

a battery-current comparing of the charging current to the fully-charged-indication current;

an acceptance-voltage comparing of the battery voltage to the acceptance voltage; and

a float-voltage comparing of the battery voltage to the float voltage.

3. The method of claim 2, wherein

the ramping-up step includes an alternator-current measuring of the alternator-current-output and an alternator-current comparing of the alternator-current-limit thereto;

the sustaining step includes a battery-current measuring of the charging current, a voltage measuring of the battery voltage and an acceptance-voltage comparing of the acceptance voltage thereto;

the adjusting step includes a battery-current measuring of the charging current and a battery-current comparing of the fully-charged-indication current thereto;

the reducing step includes a battery-current measuring of the charging current, a voltage measuring of the battery voltage and a float-voltage comparing of the float voltage thereto; and

the further adjusting step includes a battery-current measuring of the charging current, a voltage measuring of the battery voltage and a float-voltage comparing of the float voltage thereto.

4. The method of claim 2, wherein the system includes a first battery and a second battery with each having a voltage and receiving a charging current, and wherein the battery-current measuring steps and voltage measuring steps are preceded by:

a measuring of the first battery'"'"'s voltage and the second battery'"'"'s voltage;

a comparing of the first battery'"'"'s voltage to the second battery'"'"'s voltage; and

a using of the first battery for measuring of the battery voltage and of the charging current if the first battery'"'"'s voltage is greater than the second battery'"'"'s voltage, otherwise

a using of the second battery for measuring of the battery voltage and of the charging current.

5. The method of claim 1, which further comprises before the ramping-up step,

a defining of settings for the alternator-current-limit, the acceptance voltage, the fully-charged-indication current and the float voltage, and

a storing of the settings in a memory connected to the regulator.

6. The method of claim 5, wherein the setting defining the fully-charged-indication current is a percentage of battery capacity.

7. The method of claim 1, which further comprises before the ramping-up

a starting of the alternator by the regulator, and

a providing of a delay before the ramping-up.

8. The method of claim 1, which further comprises after adjusting, a step of periodically adjusting the alternator-current-output to maintain the battery voltage for a hold-time.

9. The method of claim 8, wherein the periodically adjusting step includes a repeating of the ramping-up, sustaining and adjusting steps if the battery voltage falls below the acceptance voltage.

10. The method of claim 1, wherein the ramping-up step includes a raising of the alternator-current-output to the alternator-current-limit within a defined ramp-up time period.

11. The method of claim 1, wherein the system further includes the regulator connected to the battery charger and after the further adjusting step,

a directing of the battery charger into a battery electrolyte equalization mode, and

a varying of the alternator-current-output to maintain the charging current substantially at the fully-charged-indication current, and

a continuing of the varying of the alternator-current-output, which raises the battery voltage, until the battery voltage is substantially at an equalization voltage.

12. For use with a system including a battery charger, a battery, and a controller including a processor for storing into a memory connected thereto, the charge efficiency factor determination method comprising:

a providing of a present charge efficiency factor, a maximum amp-hour charge level capacity of the battery, and a present status of amp-hour charge level;

a storing of the present charge efficiency factor, the maximum amp-hour charge level capacity of the battery, and the present status of amp-hour charge level in the memory;

a discharging of the battery and while discharging, decrementing the present status of amp-hour charge level;

a recharging of the battery and a storing of the present status of amp-hour immediately before recharging in the memory as the lowest-recorded amp-hour charge level;

a measuring of amp-hours used to recharge battery and a storing in memory the amp-hours used as amp-hours used-to-recharge the battery;

a completing of the recharging of the battery;

a determining of an intermediate charge efficiency factor by dividing amp-hours used-to-recharge battery by difference between the maximum amp-hour charge level capacity and the lowest-recorded amp-hour charge level;

an averaging of the present charging efficiency factor with the intermediate charge efficiency factor to produce a result; and

a storing of the result in memory as the present charging efficiency factor.

13. The method of claim 12, which further comprises, following the storing of the result, a step of setting the present status of amp-hour charge level to the maximum amp-hour charge level capacity.

14. The method of claim 12, for use with a display connected to the controller, which further comprises a displaying of the present charge efficiency factor and the present status of amp-hour charge level.

15. A battery charge monitoring apparatus for use with a battery charging system which includes a battery charger for storing AC-to-DC converted electric power in a battery connected thereto, wherein the battery has an amp-hour charge level, the apparatus comprising:

an ammeter connected to the battery, the ammeter for measuring current flow through the battery;

a processor for calculating a charge efficiency factor, wherein during a charging of the battery, the processor calculates a present status of the amp-hour charge level based on the charge efficiency factor and the processor is connected to the ammeter and connected to the battery charger; and

a display that indicates the charge efficiency factor and the present status of the amp-hour charge level of the battery, wherein the display is connected to the processor.

16. The apparatus of claim 15, further comprising:

a memory connected to the processor, wherein the memory is for storing a present charge efficiency factor, a lowest-recorded amp-hour charge level and a maximum amp-hour charge level capacity of the battery, and

wherein after the battery charger fully charges the battery, the processor calculates an intermediate charge efficiency factor by dividing amp-hours used to charge battery by an difference between the maximum amp-hour charge level capacity and the lowest-recorded amp-hour charge level and averaging the present charging efficiency factor with the intermediate charge efficiency factor to produce a result, and

the processor stores the result into the memory as the present charging efficiency factor.

17. The apparatus of claim 15, which further comprises:

a voltmeter connected to the battery, the voltmeter for measuring voltage across the battery, and

wherein the display further indicates a voltage across the battery and the current flow through the battery, wherein the voltage is measured by the voltmeter and the current flow is measured by the ammeter.

18. The apparatus of claim 17, further comprising a console including:

a processor-scanned keypad with keys, wherein the keypad is connected to and scanned by the processor, and

the display, wherein the display further indicates a present status of charging data when a user selects a key on the keypad, wherein each key is associated one or more of the charging data and wherein the charging data include the voltage across the battery, the current flow through the battery, the present charge efficiency factor, and the present status of the amp-hour charge level of the battery.

19. The apparatus of claim 15, further comprising a regulator for regulating an alternator'"'"'s current output, wherein the regulator is connected to the processor and to an alternator, and wherein the regulator includes an enablement indicator for indicating the enablement of the regulator and a drive indicator for indicating an intensity of a drive current that the regulator sends to the alternator for controlling operation of the alternator.

20. The apparatus of claim 15, further comprising a remote controller connected to the battery charging system, wherein the system includes an inverter/charger that includes the battery charger and an inverter, the controller including:

a processor-scanned keypad for receiving a user-input, wherein the keypad is connected to the processor, and

the processor, wherein the processor is for scanning the keypad, storing setup parameters in a memory connected thereto, and controlling the inverter/charger based on the user-input and the setup parameters of the inverter/charger.

21. A microcontroller-based monitor and control unit for interconnection with an electrical power system of the type that includes an inverter for supplying an AC signal for powering alternating current electrical loads, a battery charger having input terminals for receiving an AC input signal from an AC power source, and one or more batteries, at least one of the one or more batteries connected for supplying current to one or more direct current loads that include the inverter, the at least one of the one or more batteries being connected for receiving a charging current that includes current supplied by the battery charger, the battery charger being of the type that provides a multi-state battery charging sequence in which the relationship between charging current produced by the battery charger and the terminal voltage produced by the battery charger across the terminals of the at least one battery is established during each particular state of the multi-state charging sequence by a control parameter, said microcontroller-based monitor and control unit comprising:

a programmable microprocessor operable in response to stored program instructions for selectively monitoring the terminal voltage of the at least one of the one or more batteries and for selectively monitoring the battery charging current supplied to the at least one of the one or more batteries and the current supplied by the at least one of the one or more batteries to the one or more direct current loads that include the inverter, said programmable microprocessor being further operable in response to stored program instructions for establishing the control parameter for at least one state of the multi-state charging sequence and for determining one or more power system status indications that include a state-of-charge indication for the at least one of the one or more batteries;

a display unit operably interconnected with said programmable microprocessor for selective display of said one or more power system status indications;

manually operable input means connected for supplying signals to said programmable microprocessor for establishing the control parameter for said at least one state of the multi-state charging sequence and for controlling said selective display of said one or more power system status indications by said display unit; and

memory means for storing said program instructions for said programmable microprocessor and for storing the control parameter for said at least one state of the multi-state charging sequence.

22. The microcontroller-based monitor and control unit of claim 21 wherein said state-of-charge indication is representative of the present value of the number of ampere-hours that the at least one battery is capable of providing and said microprocessor means is operable in response to said stored program instructions for decrementing said state-of-charge indication in response to the current supplied by the at least one battery to the one or more direct current loads and is operable in response to said stored program instructions for incrementing said state-of-charge indication in response to the charging current received by the at least one battery.

23. The microcontroller-based monitor and control unit of claim 22 wherein said memory means stores a charge efficiency factor and said microprocessor means is operable in response to said stored program instructions for incrementing said state-of-charge indication by using said charge efficiency factor as a multiplicative factor in combination with the charging current supplied to the at least one battery.

24. The microcontroller-based monitor and control unit of claim 21 wherein the inverter and battery charger are an integrated unit.

25. The microcontroller-based monitor and control unit of claim 21 wherein the electrical power system includes at least two batteries connected for receiving the charging current and for supplying current to the one or more loads and wherein said microprocessor is responsive to said stored programmed instructions for monitoring the terminal voltage of each battery to determine the battery having the highest terminal voltage and is further responsive to said stored program instructions for monitoring the charging current supplied to the battery having the highest terminal voltage and the current supplied by that battery to the one or more direct current loads that include the inverter for use in determining said state-of-charge indication.

26. The microcontroller-based monitor and control unit of claim 25 wherein said memory means stores a charge efficiency factor and said microprocessor means is operable in response to said stored program instructions for incrementing said state-of-charge indication by using said charge efficiency factor as a multiplicative factor in combination with the charging current supplied to the battery having the highest terminal voltage.

27. The microcontroller-based monitor and control unit of claim 25 wherein the inverter is operable in a low power idle mode and a demand mode in which the inverter supplies demanded AC current, with the inverter switching from the low power idle to the demand mode when the AC current demanded of the inverter is greater than an idle mode control parameter and wherein said manually operable input means is operable for supplying signals to said programmable microprocessor for establishing the idle mode control parameter at a selected value;

said programmable microprocessor being responsive to said signal supplied by said manually operable input means for storing said selected value of said idle mode control parameter in said memory.

28. The microcontroller-based monitor and control unit of claim 27 wherein the inverter and battery charger are an integrated unit.

29. The microcontroller-based monitor and control unit of claim 21 wherein the multi-state battery charging sequence includes:

(a) a bulk charge cycle during which the battery charger supplies a substantially constant current that is determined by a bulk charge control parameter to increase the battery terminal voltage to an acceptance voltage value that is established by an acceptance voltage control parameter;

(b) an acceptance charge cycle during which the battery charger supplies a charging current sufficient to maintain the battery terminal voltage substantially equal to the acceptance voltage that is established by said acceptance voltage control parameter; and

(c) a float charge cycle during which the battery charger decreases the battery terminal voltage from the acceptance voltage established by said acceptance voltage control parameter to a float voltage value that is established by a float voltage control parameter, and current is supplied by the battery charger at a value sufficient to maintain the battery terminal voltage substantially equal to the float voltage value;

and wherein a default value is stored in said memory means for said bulk charge control parameter, said acceptance voltage control parameter, and said float voltage control parameter;

said manually operable input means being operable for supplying signals to said programmable microprocessor for establishing one or more of said bulk charge control parameter, acceptance voltage control parameter, and float voltage control parameter at a selected value;

said programmable microprocessor being further operable in response to said stored program instructions for substituting each selected bulk charge control parameter, selected acceptance voltage control parameter, and selected acceptance voltage control parameter for said default bulk charge control parameter, said default acceptance voltage parameter, and said default acceptance float voltage parameter.

30. The microcontroller-based monitor and control unit of claim 29 wherein said state-of-charge indication is representative of the present value of the number of ampere-hours that the at least one battery is capable of providing and said microprocessor means is operable in response to said stored program instructions for decrementing said state-of-charge indication in response to the current supplied by the at least one battery to the one or more direct current loads and is operable in response to said stored program instructions for incrementing said state-of-charge indication in response to the charging current received by the at least one battery.

31. The microcontroller-based monitor and control unit of claim 29 wherein said memory means stores a charge efficiency factor and said microprocessor means is operable in response to said stored program instructions for incrementing said state-of-charge indication by using said charge efficiency factor as a multiplicative factor in combination with the charging current supplied to the at least one battery.

32. The microcontroller-based monitor and control unit of claim 29 wherein the multi-state battery charging sequence further includes an equalization charge cycle during which the battery charger maintains the battery terminal voltage at a predetermined equalization voltage, said memory means stores said equalization voltage value and said manually operable input means is operable for supplying a signal for initiation of the battery charger equalization cycle.

33. The microcontroller-based monitor and control unit of claim 29 wherein the multi-state battery charging sequence includes an acceptance hold cycle that is initiated to terminate the acceptance charge cycle when the current supplied to the battery reaches a fill charge value with the battery charger maintaining the battery terminal voltage at least equal to the acceptance voltage for a predetermined period of time and said memory means stores said full charge value.

34. The microcontroller-based monitor and control unit of claim 33 wherein said microprocessor is responsive to said stored program instructions for maintaining the battery charger in the acceptance hold cycle for a first predetermined period of time when the current supplied to the battery is continuously at or below the full charge value throughout said first predetermined period of time and said microprocessor is further responsive to said stored program instructions for maintaining the battery charger in the acceptance hold cycle for a second predetermined period of time that is greater than said first predetermined period of time when the current supplied to the battery is not continuously above the full charge value during said first predetermined period of time.

35. The microcontroller-based monitor and control unit of claim 29 wherein the inverter is operable in a low power idle mode and a demand mode in which the inverter supplies demanded AC current, with the inverter switching from the low power idle to the demand mode when the AC current demanded of the inverter is greater than an idle mode control parameter and wherein said manually operable input means is operable for supplying signals to said programmable microprocessor for establishing the idle mode control parameter at a selected value;

said programmable microprocessor being responsive to said signal supplied by said manually operable input means for storing said selected value of said idle mode control parameter in said memory.

36. The microcontroller-based monitor and control unit of claim 35 wherein the inverter and battery charger are an integrated unit.

37. The microcontroller-based monitor and control unit of claim 29 wherein the electrical power system includes an alternator and a regulator connected for controlling the output current supplied by the alternator, the alternator being operable for supplying charging current to the at least one of the one or more batteries and wherein said microprocessor is responsive to said programmed instructions for controlling the output current of the alternator to implement a multi-state charging sequence having a bulk charge cycle during which the alternator supplies a substantially constant current, an acceptance charge cycle during which the alternator supplies a charging current sufficient to maintain the battery terminally voltage substantially equal to the acceptance voltage, and a float charge cycle during which the alternator decreases the battery terminal voltage from the acceptance voltage to the float voltage value.

38. The microcontroller-based monitor and control unit of claim 37 wherein said microprocessor is further responsive to said stored program instructions for initiating each bulk charge cycle with a current ramp that increases to a maximum battery charging current.

39. The microcontroller-based monitor and control unit of claim 37 wherein said state-of-charge indication is representative of the present value of the number of ampere-hours that the at least one battery is capable of providing and said microprocessor means is operable in response to said stored program instructions for decrementing said state-of-charge indication in response to the current supplied by the at least one battery to the one or more direct current loads and is operable in response to said stored program instructions for incrementing said state-of-charge indication in response to the charging current received by the at least one battery.

40. The microcontroller-based monitor and control unit of claim 39 wherein said memory means stores a charge efficiency factor and said microprocessor means is operable in response to said stored program instructions for incrementing said state-of-charge indication by using said charge efficiency factor as a multiplicative factor in combination with the charging current supplied to the at least one battery.

41. The microcontroller-based monitor and control unit of claim 40 wherein the multi-state battery charging sequence further includes an equalization charge cycle during which the battery charger maintains the battery terminal voltage at a predetermined equalization voltage, said memory means stores said equalization voltage value and said manually operable input means is operable for supplying a signal for initiation of the battery charger equalization cycle.

42. The microcontroller-based monitor and control unit of claim 41 wherein the multi-state battery charging sequence includes an acceptance hold cycle that is initiated to terminate the acceptance charge cycle when the current supplied to the battery reaches a full charge value with the battery charger maintaining the battery terminal voltage at least equal to the acceptance voltage for a predetermined period of time and said memory means stores said fall charge value.

43. The microcontroller-based monitor and control unit of claim 37 wherein the electrical power system includes at least two batteries connected for receiving the charging current and for supplying current to the one or more loads and wherein said microprocessor is responsive to said stored programmed instructions for monitoring the terminal voltage of each battery to determine the battery having the highest terminal voltage and is further responsive to said stored program instructions for monitoring the charging current supplied to the battery having the highest terminal voltage and the current supplied by that battery to the one or more direct current loads that include the inverter for use in determining said state-of-charge indication.

44. The microcontroller-based monitor and control unit of claim 42 wherein the electrical power system includes at least two batteries connected for receiving the charging current and for supplying current to the one or more loads and wherein said microprocessor is responsive to said stored programmed instructions for monitoring the terminal voltage of each battery to determine the battery having the highest terminal voltage and is further responsive to said stored program instructions for monitoring the charging current supplied to the battery having the highest terminal voltage and the current supplied by that battery to the one or more direct current loads that include the inverter for use in determining said state-of-charge indication.

45. A monitor and control unit for interconnection and use with an electrical power system of the type having an inverter for supplying AC power, the inverter being connected to a battery that provides DC current that includes at least a drive current for the inverter and the battery being connected for periodically receiving charging current that includes at least current that is supplied by a multi-state battery charger that is connectable to an AC power source, the multi-state battery charger being operable to provide a bulk charge cycle during which the multi-state battery charger supplies a substantially constant bulk charge current to increase the battery terminal voltage to an acceptance voltage value, the multi-state battery charger further being operable to provide an acceptance charge cycle during which the multi-state battery charger supplies a charging current sufficient to maintain the battery terminal voltage substantially equal to the acceptance voltage value, the multi-state battery charger being additionally operable to provide a float cycle during which the multi-state battery charger decreases the battery terminal voltage from the selected acceptance voltage value to a float voltage value, and supplies charging current sufficient to maintain the battery terminal voltage substantially equal to the float voltage value, said monitor and control unit connectable to the electrical power system for receiving signals representative of the battery terminal voltage and for receiving signals representative of the charging current supplied to the battery and the DC current supplied by the battery, said monitoring and control unit comprising:

input means operable for selecting one or more operational parameters of the electrical power system from a group of operational parameters that includes a desired value for the substantially constant bulk charge current supplied by the multi-state battery charger during the bulk charge cycle, a desired value for the acceptance voltage value, and a desired value for the float voltage value;

a display unit for displaying current and voltage values during operation of said input means to select one or more of said operational parameters of the electrical power system, said display unit also for displaying a battery state-of-charge value indicative of the charge condition of the battery;

a microprocessor connected for receiving the signals representative of the battery terminal voltage and the signals representative of the charging current supplied to the battery and the DC current supplied by the battery, said microprocessor being responsive to stored program instructions for operative interaction with said input means and said display unit for establishing one or more the operational parameters of the electrical power system at a desired value and being responsive to stored program instructions for determining and displaying said battery state-of-charge value based upon said signals representative of the charging current supplied to the battery and the DC current supplied by the battery; and

memory means interconnected with and operationally interactive with said microprocessor, said memory means for storing said program instructions and said operational parameters of the electrical power system, including any desired value established by operation of said input means for the substantially constant bulk charge current supplied by the multi-state battery charger during operation of the multi-state battery charger in the bulk charge cycle, any desired value established for the acceptance voltage value and any desired value established for the float voltage value, said memory means further including means for storing at least the present value of said battery state-of-charge value.

46. The monitor and control unit of claim 45 wherein said state-of-charge value is representative of the present value of the number of ampere-hours that the battery is capable of providing and said microprocessor is operable in response to said stored program instructions for decrementing said state-of-charge indication in response to the DC current that includes at least the drive current for the inverter and is operable in response to said stored program instructions for incrementing said state-of-charge indication in response to the charging current received by the battery.

47. The monitor and control unit of claim 46 wherein said memory means stores a charge efficiency factor and said microprocessor is operable in response to said stored program instructions for incrementing said state-of-charge indication by using said charge efficiency factor as a multiplicative factor in combination with the charging current supplied to the at least one battery.

48. The monitor and control unit of claim 47 wherein the battery is characterized by a maximum state-of-charge value and said microprocessor is responsive to said stored program instructions for updating said charge efficiency factor during selected periods of time in which charging current is supplied to the battery by determining an intermediate charge efficiency factor that is equal to the amount of charge supplied to the battery during the selected period of time divided by a quantity equal to the maximum state-of-charge value of the battery minus the state-of-charge value existing at the beginning of the selected period of time, and by determining the average value of the value of said charge efficiency factor existing during the selected period in which charging current is supplied to the battery and said intermediate charge efficiency factor and by replacing the value of charge efficiency factor stored in said memory means with said average value.

49. The monitor and control unit of claim 45 wherein the electrical power system includes first and second batteries that provide DC current and receive charging current and wherein said microprocessor is responsive to said stored program instructions for monitoring the terminal voltages of the first and second batteries to determine the battery having the highest terminal voltage and is further responsive to said stored program instructions for monitoring the charging current supplied to the battery having the highest terminal voltage and the DC current provided by that battery for use in determining said battery state-of-charge value.

50. The monitor and control unit of claim 49 wherein the inverter and battery charger are an integrated unit.

51. The monitor and control unit of claim 50 wherein said state-of-charge value is representative of the present value of the number of ampere-hours that the battery is capable of providing and said microprocessor is operable in response to said stored program instructions for decrementing said state-of-charge indication in response to the DC current that includes at least the drive current for the inverter and is operable in response to said stored program instructions for incrementing said state-of-charge indication in response to the charging current received by the battery.

52. The monitor and control unit of claim 51 wherein said memory means stores a charge efficiency factor and said microprocessor is operable in response to said stored program instructions for incrementing said state-of-charge indication by using said charge efficiency factor as a multiplicative factor in combination with the charging current supplied to the at least one battery.

53. The monitor and control unit of claim 52 wherein the battery is characterized by a maximum state-of-charge value and said microprocessor is responsive to said stored program instructions for updating said charge efficiency factor during selected periods of time in which charging current is supplied to the battery by determining an intermediate charge efficiency factor that is equal to the amount of charge supplied to the battery during the selected period of time divided by a quantity equal to the maximum state-of-charge value of the battery minus the state-of-charge value existing at the beginning of the selected period of time, and by determining the average value of the value of said charge efficiency factor existing during the selected period in which charging current is supplied to the battery and said intermediate charge efficiency factor and by replacing the value of charge efficiency factor stored in said memory means with said average value.

54. A microprocessor implemented method for controlling and monitoring a remotely located power conversion system that includes a battery for supplying DC current to one or more DC loads that include an inverter for supplying AC current to one or more AC loads, the battery being connected to a multi-state battery charger that provides a sequence of battery charging cycles in which the current supplied by the battery charger during each cycle of the battery charging sequence is determined by a control parameter that is associated with that particular cycle of the battery charging sequence, said method for monitoring and controlling comprising the steps of:

storing at least a portion of the control parameters for the cycles of the multi-state charging sequence in a memory of a microprocessor that is operably coupled to the multi-state battery charger for controlling the charging current during at least a portion of the multi-state battery charging sequence;

storing in the memory of the microprocessor a battery state-of-charge value that is representative of the then present charge state of the battery;

monitoring with the microprocessor the current supplied to the remotely located battery during operation of the battery charger during each cycle of the multi-state battery charging sequence to determine when the current supplied to the battery by the battery charger is less than a predetermined current that indicates that the battery is fully charged;

incrementing the battery state-of-charge value that is stored in memory when the multi-state battery charger is operating in each cycle of the multi-state battery charging sequence to maintain said battery state-of-charge indication substantially equal to the amount of charge stored by the battery;

monitoring with the microprocessor the current supplied to the inverter by the battery when the inverter is supplying AC current to the one or more AC loads; and

decrementing the stored value of the battery state-of-charge indication when the inverter supplies AC current to one or more AC loads to maintain the stored value of said battery state-of-charge indication substantially equal to the charge condition of the battery.

55. The method of claim 54 further comprising the steps of:

monitoring with the microprocessor the battery voltage to determine when the battery voltage is less than a predetermined charge initiation value; and

supplying a signal from the microprocessor to initiate the multi-state battery charging sequence when the battery voltage is less than said predetermined value.

56. The method of claim 55 further comprising the step of initially storing said predetermined charge initiation value in the memory of the microprocessor.

57. The method for controlling and monitoring a remotely located power conversion system of claim 54 wherein at least a portion of the control parameters stored in the memory of the microprocessor are default values for the remotely located power conversion system and said method further comprises the steps of selectively substituting desired control parameter values for one or more of said stored default values to thereby control the operation of the multi-state battery charging sequence.

58. The method for controlling and monitoring a remotely located power conversion system of claim 55 further comprising the step of selectively displaying the battery terminal voltage, the current supplied to the battery during operation of the battery charger, the current supplied to the inverter by the battery, and at least a portion of the control parameters for the cycles of the multi-state charging sequence.

59. The method for controlling and monitoring a remotely located power conversion system of claim 54 further comprising the steps of:

storing in the microprocessor memory an initial charge efficiency factor representative of the ratio between the amount of charge stored in the battery in response to the current supplied to the battery during each cycle of the battery charging sequence and the amount of charge supplied to the battery during the charging sequence; and

using the charge efficiency factor as a multiplicative element in incrementing said battery state-of-charge value that is stored in the microprocessor memory when the multi-state battery charger is operating in each cycle of the multi-state battery charging sequence.

60. The method for controlling and monitoring a remotely located power conversion system of claim 57 further comprising the steps of:

determining an initial charge efficiency factor for the battery;

storing the initial charge efficiency factor in the microprocessor memory as the existing charge efficiency factor;

determining the value of the battery state-of-charge value at initiation of a battery charging sequence;

storing said value of the battery state-of-charge value in the microprocessor memory as a lowest recorded charge condition;

determining an immediate charge efficiency factor equal to the amount of charge supplied to the battery during the battery charging sequence divided by a quantity that is equal to the initial state-of-charge of the battery minus said lowest recorded charge level;

determining the average between the existing charge efficiency factor and the intermediate efficiency factor; and

replacing the existing charge efficiency factor in the microprocessor memory by said average.