System and method for efficient charging of multiple battery cassettes

1. A system for intelligently managing battery cassettes, the system comprising:

a plurality of battery cassettes coupled in series;

a control system including a controller, the controller comprising one or more processors programmed to execute instructions that cause at least one processor of the one or more processors to perform charging of the plurality of battery cassettes and balancing of the plurality of battery cassettes; and

a plurality of switches controlled by the control system to selectively couple the plurality of battery cassettes to a power grid and a secondary energy source,

wherein the charging of the plurality of battery cassettes includes:

selecting, from among the plurality of battery cassettes, at least one selected battery cassette;

calculating a forecasted energy deficit for the at least one selected battery cassette, the forecasted energy deficit being calculated based on a difference between a projected amount of energy generated by the secondary energy source and a projected amount of energy to be used;

determining a first current or a first wattage from the power grid and first charging threshold based at least in part on the forecasted energy deficit and a state of charge of the at least one selected battery cassette;

charging the at least one selected battery cassette with the first current or the first wattage and the secondary energy source while maintaining an energy level of the at least one selected battery cassette within a threshold range;

detecting an actual amount of energy generated by the secondary energy source; and

adjusting the first current or the first wattage and the first charging threshold to a second current or a second wattage and a second charging threshold based at least in part on the actual amount of energy generated by the secondary energy source;

wherein the balancing of the battery cassettes of the plurality of battery cassettes includes:

measuring a first state of charge of the at least one selected battery cassette;

determining a first actual energy deficit of the at least one selected battery cassette; and

providing a balancing current to the at least one selected battery cassette until the first state of charge reaches a target state.

2. The system of claim 1 , wherein the first charging threshold and the second charging threshold include a time duration or a state of the at least one selected battery cassette.

3. The system of claim 1 , wherein the one or more processors are programmed to execute instructions that further cause the at least one processor of the one or more processors to increase the first current when the at least one selected battery cassette is at a low state of charge and reduce the first current when the at least one selected battery cassette is at a high state of charge.

4. The system of claim 1 , wherein the secondary energy source includes at least one of a solar panel, a wind turbine, a geothermal generator, fuel cell and a combustion powered generator and wherein the second energy source is located on a same or adjacent property as an active load that draws power from the plurality of battery cassettes.

5. The system of claim 1 , wherein

the battery cassettes of the plurality of battery cassettes have energy capacities that are different from each other.

6. The system of claim 1 , wherein calculating the forecasted energy deficit for the at least one selected battery cassette includes:

receiving a weather forecast;

accessing the projected amount of energy to be used, wherein the projected amount of energy to be used is based at least in part on a historical energy use of the at least one selected battery cassette when coupled to an inverter configured to use the at least one selected battery cassette according to a modulation scheme; and

determining the projected amount of energy generated by the secondary energy source based at least in part on the weather forecast.

7. The system of claim 1 , wherein the first current or the first wattage is determined at least in part on the forecasted energy deficit and at least one of a price of grid power, a profile specifying charging currents for different voltages of a particular battery cassette, a request to charge at a specified current and a request to charge with a specified power.

8. The system of claim 1 , wherein the one or more processors are programmed to execute instructions that further cause the at least one processor of the one or more processors to allocate a respective time period for the charging of the plurality of battery cassettes and for the balancing of the plurality of battery cassettes within a predetermined time period.

9. The system of claim 1 , wherein the first state of charge is measured during a period of time that includes one zero crossing of a sinusoidal power output signal generated based on drawing energy from the at least one selected battery cassette.

10. A method of managing a plurality of battery cassettes, the method comprising:

charging of the plurality of battery cassettes that are electrically coupled in series, wherein the charging of the plurality of battery cassettes includes:

selecting, from among the plurality of battery cassettes, at least one selected battery cassette;

calculating a forecasted energy deficit for the at least one selected battery cassette, the forecasted energy deficit being calculated based on a difference between a projected amount of energy generated by a secondary energy source and a projected amount of energy to be used;

determining a first current or a first wattage from the power grid and first charging threshold based at least in part on the forecasted energy deficit and a state of charge of the at least one selected battery cassette;

charging the at least one selected battery cassette with the first current or the first wattage and the secondary energy source while maintaining an energy level of the at least one selected battery cassette within a threshold range;

detecting an actual amount of energy generated by the secondary energy source; and

adjusting the first current or the first wattage and the first charging threshold to a second current or a second wattage and a second charging threshold based at least in part on the actual amount of energy generated by the secondary energy source;

balancing of the plurality of battery cassette, wherein the balancing of the plurality of battery cassette includes:

measuring a first state of charge of the at least one selected first battery cassette;

determining a first actual energy deficit of the at least one selected first battery cassette; and

providing a balancing current to the at least one selected cassette until the first state of charge reaches a target state.

11. The method of claim 10 , wherein the first charging threshold and the second charging threshold include a time duration or a state of the at least one selected battery cassette.

12. The method of claim 10 , further comprising:

increasing the first current when the at least one selected battery cassette is at a low state of charge; and

reducing the first current when the at least one selected battery cassette is at a high state of charge.

13. The method of claim 10 , wherein the secondary energy source includes at least one of a solar panel, a wind turbine, a geothermal generator, fuel cell and a combustion powered generator and wherein the second energy source is located on a same or adjacent property as an active load that draws power from the plurality of battery cassettes.

14. The method of claim 10 , wherein calculating the forecasted energy deficit for the at least one selected battery cassette includes:

receiving a weather forecast;

accessing the projected amount of energy to be used, wherein the projected amount of energy to be used is based at least in part on a historical energy use of the at least one selected battery cassette when coupled to an inverter configured to use the at least one selected battery cassette according to a modulation scheme; and

determining the projected amount of energy generated by the secondary energy source based at least in part on the weather forecast.

15. The method of claim 10 , further comprising allocating a respective time period for the charging of the plurality of battery cassettes and for the balancing of the battery cassettes of the plurality of battery cassettes within a predetermined time period.

16. A system for intelligently managing battery cassettes, the system comprising:

a plurality of battery cassettes coupled in series;

a control system including a controller, the controller comprising one or more processors programmed to execute instructions that cause the at least one processor of the one or more processors to perform charging of the plurality of battery cassettes and balancing of the plurality of battery cassettes; and

a plurality of switches controlled by the control system to selectively couple the plurality of battery cassettes to a power grid and a secondary energy source, wherein the charging of the plurality of battery cassettes includes:

selecting, from among the plurality of battery cassettes, at least two selected battery cassettes including a first battery cassette and a second battery cassette;

calculating a forecasted energy deficit for each of the first and the second battery cassettes, the forecasted energy deficit being calculated based on a difference between a projected amount of energy generated by the secondary energy source and a projected amount of energy to be used;

setting a target threshold for the first and the second battery cassettes;

determining a first charging current for the first battery cassette, a second charging current for the second battery cassette, and a charge threshold for each of the first and second battery cassettes based at least in part on the forecasted energy deficit;

performing one cycle of charging, the one cycle of charging includes:

charging the first battery cassette with the first charging current and the secondary energy source until the charge threshold for the first battery cassette is met; and

charging the second battery cassette with the second charging current and the secondary energy source until the charge threshold for the second battery cassette is met, and

repeating the one cycle of the charging until the target threshold is satisfied.

17. The system of claim 16 , wherein the charging threshold comprises a time duration or a state of the at least one selected battery cassette.

18. The system of claim 16 , wherein the one or more processors are programmed to execute instructions that further cause the at least one processor of the one or more processors to adjust the first charging current and the second charging current based at least in part on the actual amount of energy generated by the secondary energy source.

19. The system of claim 16 , wherein calculating the forecasted energy deficit for each of the first and the second battery cassettes includes:

receiving a weather forecast;

accessing the projected amount of energy to be used, wherein the projected amount of energy to be used is based at least in part on a historical energy use of the at least one selected battery cassette when coupled to an inverter configured to use the at least one selected battery cassette according to a modulation scheme; and

determining the projected amount of energy generated by the secondary energy source based at least in part on the weather forecast.

20. The system of claim 16 , further comprising balancing of the plurality of battery cassettes and allocating a respective time period for the charging of the plurality of battery cassettes and for the balancing of the plurality of battery cassettes within a predetermined time period.