A system for connecting a battery in a circuit

Abstract

A system for connecting batteries in a circuit, placing no less than two batteries in a series-parallel switching circuit, where a group of batteries are connected in parallel and series in two separate stages using fast switching devices, where average voltage is output to a load based on duty cycle. Renewable energy power sources such as solar panels can be connected in parallel with the batteries in the first stage and the same batteries are connected in series with the load in the second stage using transistor switches, first enabling the batteries to charge and discharge simultaneously, secondly enabling the solar panels to divert voltage, which as an additional battery in series provides the required voltage for the load, and adjusting the duty cycle of charging and discharging by converting the voltage waveform.

Description

TECHNICAL FIELD

[0001] The present invention relates to an energy storage system and method to improve battery performance. BACKGROUND

[0002] Series and parallel are common connection methods in the electrical field. Parallel connection prioritizes charging the batteries from the power source because parallel can increase the current, allowing the batteries to charge faster. Series connection prioritizes discharging the batteries to the load or device because the battery voltage needs to be higher than the load or device for current to flow.

[0003] Since the batteries in a parallel configuration are connected directly together, they naturally balance. However, batteries in a series configuration can have different State of Charge (SoC) and when the voltage is further reduced, the battery with less capacity can be depleted before the battery with more capacity, resulting in low battery efficiency. Therefore, batteries in a series configuration can need battery balancing to maintain the voltage level of each battery for maximum efficiency. Changes in voltage levels can cause the batteries to become unbalanced, which can cause various problems. For example, battery unbalance can cause thermal runaway, battery degradation, incomplete battery pack energy usage, or incomplete battery pack charging. Batteries can become unbalanced due to changes in SoC, internal resistance, or temperature.

[0004] The working principle of series circuits is the same for solar photovoltaic cells. If there is a problem with the connection of one panel in a series circuit, the entire circuit will fail. In a parallel circuit, a defective panel or loose circuit will not affect the rest of the solar panels. Charge controllers are a determining factor in solar panel wiring, with solar panels wired in series tending to use Maximum Power Point Tracking (MPPT) charge controllers and solar panels wired in parallel tending to use Pulse Width Modulation (PWM) charge controllers.

[0005] Furthermore, charge controllers require a separate inverter device to power AC output devices from the DC energy produced by the renewable source. Also, because of the intermittent nature of solar and other renewable energy sources, multiple batteries can be charged directly from an AC input source without stepping down through a transformer with heat energy loss.

[0006] Typical batteries or energy storage systems can not be able to charge and discharge at the same time. Therefore, they can not be able to drive a load while charging. This can be a problem when the energy storage system is used with renewable energy sources. These systems typically require a central controller to control the charge and discharge of the system. Figure 3A typical prior art solar charge controller configuration is shown. A solar photovoltaic (PV) cell 302 is connected to a solar charge controller 304. The charge controller controls the connection between the power source (solar PV cell 302), the battery 306, and the load 308. The battery 306 can be connected to charge the battery, and the load 308 can be connected to drive the load. When the battery 306 is fully charged, the battery current (I_bat) is turned off. When the battery 306 is depleted, the battery load (I_load) is turned off, and the battery 306 is charged instead of driving the load 308. If the solar PV cell 302 absorbs low or below minimum energy, the power source current (I_pv) is turned off. The disadvantage of this battery charging system is that when using a charge controller, the battery competes with the required load, resulting in the load and battery sharing the power from the renewable power source such that I_pv = I_bat + I_load.

[0007] Electric vehicle and other equipment manufacturers typically use batteries as hardware in series or parallel configurations, which are not flexible to reconfigure by software. SUMMARY

[0008] Batteries can be connected using logic switches connected across their positive and negative terminals, such that two or more batteries can be connected to a load in "series-parallel" (i.e., parallel and series) fashion in alternating cycles to produce an average parallel voltage and series voltage to the load depending on the relative duration of the cycles.

[0009] Batteries can also be connected with an isolation circuit to a renewable energy source and a load, where the battery is connected to the renewable energy source in one cycle, and the same battery is connected to the load in another cycle, such that the load receives power in a series duty cycle, which can vary between 0% and 100%. For example, a battery that switches between a renewable energy source and a load can be referred to as a switching battery.

[0010] Thus, a battery can be coupled to a small solar PV renewable energy source to be connected to a larger load when isolated from the load. In addition, the battery SoC can be improved when the power source is larger than the load.

[0011] The control unit can be configured to execute a set of instructions, which are in the form of a program or code. The program or code can form software installed on the control unit. The control unit can control the duty cycle to the load and also change the relative switching speed between the two phases using voltage comparators through the software code to convert the square wave to a sine wave. The control unit can also use voltage comparators to balance the batteries. The voltage comparators are used as input and output comparators. Further, the control unit can use a synchronized charging method to use the AC input to be used to charge the plurality of batteries. The control unit can also add a second set of independent batteries in the load cycle of 50% duty cycle to provide a constant energy supply to the load. The control unit can further implement secondary or tertiary renewable energy sources to ensure 100% duty cycle to the load. BRIEF DESCRIPTION OF DRAWINGS

[0012] The advantages of embodiments of the present application will be described in detail with reference to the following examples and in conjunction with the associated drawings, in which like numerals denote like elements:

[0013] Figure 1A is an embodiment schematic of a series-parallel discharge method.

[0014] Figure 1B is an embodiment schematic of a series-parallel discharge method.

[0015] Figure 2A is an embodiment schematic of an energy storage system with isolated loads.

[0016] Figure 2B is an embodiment schematic of an energy storage system with isolated loads.

[0017] Figure 3 is an embodiment schematic of an energy storage system in the prior art.

[0018] Figure 4 is an embodiment schematic of battery cell balancing using a series-parallel discharge method.

[0019] Figure 5A is an embodiment schematic of battery charging waveforms (power supply current 8A).

[0020] Figure 5B is an embodiment schematic of battery charging waveforms (power supply current 10A).

[0021] Figure 5C is an embodiment schematic of battery charging waveforms (power supply current 5A).

[0022] Figure 6A is an embodiment schematic of a method to implement a switching circuit.

[0023] Figure 6Bis an embodiment schematic of a method of implementing a switching circuit.

[0024] Figure 7A is an embodiment schematic of a current signal waveform.

[0025] Figure 7B is an embodiment schematic of a voltage signal waveform.

[0026] Figure 7C is an embodiment schematic of an output voltage waveform (50% duty cycle).

[0027] Figure 7D is an embodiment schematic of an output voltage waveform (25% duty cycle).

[0028] Figure 8A is an embodiment schematic of an energy storage system implementing an exemplary isolated load charging system using 4 batteries.

[0029] Figure 8B is an embodiment schematic of an energy storage system implementing an exemplary isolated load charging system using 8 batteries.

[0030] Figure 9 is an embodiment schematic of an energy storage system implementing an exemplary isolated load charging system supplying a constant load voltage.

[0031] Figure 9A is an embodiment schematic of a battery charging waveform (power supply current 8A).

[0032] Figure 9B is an embodiment schematic of a battery charging waveform (power supply current 10A).

[0033] Figure 9C is an embodiment schematic of a battery charging waveform (power supply current 5A).

[0034] Figure 9D is an embodiment schematic of an input capacitance waveform.

[0035] Figure 9E is an embodiment schematic of a transition capacitance waveform.

[0036] Figure 9F is an embodiment schematic of an output capacitance waveform.

[0037] Figure 10A is a table schematic for calculating specified times for 0 to 7 groups of batteries connected in series.

[0038] Figure 10B is an exemplary circuit schematic for converting a square wave to a sine wave.

[0039] Figure 10Cis an exemplary circuit schematic diagram for converting a DC output to an AC output.

[0040] Figure 10D is an exemplary circuit schematic diagram for converting an AC input to a DC input.

[0041] Figure 11A is an exemplary schematic diagram of an embodiment of a multi-battery isolated load charging method using a renewable power source.

[0042] Figure 11B is an exemplary schematic diagram of an embodiment of a multi-battery isolated load charging method using AC power from the grid.

[0043] Figure 12A is an exemplary schematic diagram of an apparatus for switching multiple batteries.

[0044] Figure 12B is an exemplary schematic diagram of an apparatus for switching multiple batteries.

[0045] Figure 13 is an exemplary circuit schematic diagram of an embodiment of the present invention.

[0046] Figure 14 is an exemplary graph of an embodiment of the present invention.

[0047] Figure 15A is an exemplary graph of charge versus time in an embodiment of the present invention.

[0048] Figure 15B is an exemplary graph of charge versus time in an embodiment of the present invention.

[0049] Figure 15C is an exemplary graph of charge versus time in an embodiment of the present invention.

[0050] Figure 15D is an exemplary graph of charge versus time in an embodiment of the present invention.

[0051] Figure 16 is an exemplary graph of charge versus time in an embodiment of the present invention. DETAILED DESCRIPTION

[0052] Aspects of the present invention are disclosed in the description and drawings of specific embodiments of the present invention. Alternative embodiments of the present invention can be devised without departing from the spirit or scope of the present invention. Additionally, well-known elements of the present invention will not be described in detail or will be omitted so as not to obscure the relevant details of the present invention. Further, many of the terms used herein are discussed in the description of the description below.

[0053] As used herein, the word "exemplary" is used to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. The terms "can include," "may include," "includes," "can," "may," and "includes" are not restricted to equivalents of the listed recitations. The terms "coupled," "coupled to," and "coupled with" as used herein refer to any direct or indirect electrical, mechanical, or optical coupling. The terms "program" and "application program" as used herein refer to any type of computer instruction or computer executable code stored in memory and capable of being executed by a processor.

[0054] Batteries connected in series-parallel only

[0055] Embodiments can implement a "series-parallel" discharge method as shown in FIG. 1. A first cycle can connect the batteries in parallel with a load. A second cycle can connect the batteries in series with the same load as shown in FIG. 1. The control unit can switch between independent cycles of any desired frequency, producing a desired average output voltage and average output current according to the relative duration of each cycle. By rapidly switching between parallel and series configurations, the circuit can output the average of the series output and the parallel output. The output of the switching circuit can be adjusted by adjusting the phase frequency or the time between switches. Higher voltages can be obtained by increasing the time the circuit is in the series configuration. Figure 1A Figure 1B An advantage of the series-parallel discharge embodiment is that it can enable efficient discharge of all the electrons stored in non-rechargeable batteries. In the embodiment shown in FIG. 1, when two 4V 2Ah non-rechargeable batteries (first battery 102 and second battery 104) are used to power a 2.5V 0.5A output load 120, the batteries can be connected in parallel with the load (as shown in FIG. 1), and the 4V batteries are sufficient to power the 2.5V output load 120 with a voltage drop of 0.5V. However, when the battery voltage drops below the voltage drop of 3V, the first battery 102 and the second battery 104 will not discharge to the output load 120 since no current will flow. Therefore, a control device with a voltage comparator circuit can activate the switching to the appropriate series-parallel ratio, making the voltage the minimum voltage based on the required voltage drop (3V). The control unit can activate the first switch 106 (as a first logic switch), the second switch 108 (as a second logic switch), the third switch 110 (as a third logic switch), and the fourth switch 112 (as a fourth logic switch) to switch between the series configuration and the parallel configuration.

[0056] An advantage of the series-parallel discharge embodiment is that it can enable efficient discharge of all the electrons stored in non-rechargeable batteries. In the embodiment shown in FIG. 1, when two 4V 2Ah non-rechargeable batteries (first battery 102 and second battery 104) are used to power a 2.5V 0.5A output load 120, the batteries can be connected in parallel with the load (as shown in FIG. 1), and the 4V batteries are sufficient to power the 2.5V output load 120 with a voltage drop of 0.5V. However, when the battery voltage drops below the voltage drop of 3V, the first battery 102 and the second battery 104 will not discharge to the output load 120 since no current will flow. Therefore, a control device with a voltage comparator circuit can activate the switching to the appropriate series-parallel ratio, making the voltage the minimum voltage based on the required voltage drop (3V). The control unit can activate the first switch 106 (as a first logic switch), the second switch 108 (as a second logic switch), the third switch 110 (as a third logic switch), and the fourth switch 112 (as a fourth logic switch) to switch between the series configuration and the parallel configuration. Figure 1A 1B An advantage of the series-parallel discharge embodiment is that it can enable efficient discharge of all the electrons stored in non-rechargeable batteries. In the embodiment shown in FIG. 1, when two 4V 2Ah non-rechargeable batteries (first battery 102 and second battery 104) are used to power a 2.5V 0.5A output load 120, the batteries can be connected in parallel with the load (as shown in FIG. 1), and the 4V batteries are sufficient to power the 2.5V output load 120 with a voltage drop of 0.5V. However, when the battery voltage drops below the voltage drop of 3V, the first battery 102 and the second battery 104 will not discharge to the output load 120 since no current will flow. Therefore, a control device with a voltage comparator circuit can activate the switching to the appropriate series-parallel ratio, making the voltage the minimum voltage based on the required voltage drop (3V). The control unit can activate the first switch 106 (as a first logic switch), the second switch 108 (as a second logic switch), the third switch 110 (as a third logic switch), and the fourth switch 112 (as a fourth logic switch) to switch between the series configuration and the parallel configuration. Figure 1A Reference is made to

[0057] Figure 1A ​​​In the parallel phase, an additional switch (second switch 108) can be connected to the negative of the second battery 104. In the parallel phase, the second switch 108 can be configured to be connected to the negative of the first battery 102. Thus, the second switch 108 has a node connecting the negative of the first battery 102 and the negative of the second battery 104. In addition, the output can be connected to the third switch 110 and the fourth switch 112. In the parallel phase, the third switch 110 can be configured to connect the output load 120 to a node created by the positive of the first battery 102 and the positive of the second battery 104. At the same time, the fourth switch 112 can be configured to connect the negative of the output load 120 to a node created by the negative of the first battery 102 and the negative of the second battery 104. In this way, the positives of the above-mentioned batteries and the positive of the output load are all connected, and the negatives of the above-mentioned batteries and the negative of the output load are also connected, forming a parallel circuit.

[0058] Referring now to Figure 1B , the circuit can be shown in a series configuration. The series configuration can occur in a different phase than the parallel configuration. In the series configuration, the first switch 106, the second switch 108, the third switch 110, and the fourth switch 112 can all be switched in the opposite direction of the previous phase. The above-mentioned switches can be connected so that they can be switched simultaneously. To form the series configuration, the first switch 106 and the third switch 110 can connect the positive of the second battery 104 directly to the output load 120. The negative of the second battery 104 can be connected to the positive of the first battery 102 through the second switch 108. The first battery 102 can be connected to the output load 120 through the fourth switch 112. The above-mentioned switches can be any of a variety of types of switches or breakers. The switches can flip or commutate simultaneously. The output signal (current and voltage) depends on the commutation or switching time between the two phases.

[0059] Table 1 shows 7 possible cases:

[0060]

[0061]

[0062] Table 1

[0063] If the battery voltage of each of the batteries in scheme 4 in table 1 drops to 2.5V, the available voltage to the load can be increased to 3.5V by gradually adjusting the series-parallel ratio to 67% (67% parallel and 33% series). The increase in voltage provided to the load will decrease the remaining current stored in the batteries until there are no more electronic charges left in the batteries. The power required by the control device with comparator circuit can need to be considered when designing the circuit, which will typically be low and can be included in the voltage drop.

[0064] Batteries in parallel configuration can naturally balance as they are directly connected to each other. When two batteries are connected in series and have different SoC, the smaller capacity battery can be depleted before the larger capacity battery, resulting in a lower voltage across the smaller capacity battery. In active balancing, the excess charge from one battery is transferred to another low charge battery to balance the charge. In prior art embodiments, active balancing is achieved through charge storage elements such as capacitors and inductors.

[0065] In Figure 4 In the embodiment shown, the first 4V 2Ah rechargeable battery 402 and the second rechargeable battery 404 connected to the second load 406 are disconnected so that the first 4V 2Ah rechargeable battery 402 can be connected to the second 3.0V 1Ah depleted rechargeable battery 404. The switch configuration is set by the control device 400 with voltage comparison circuit, which controls the disconnection of the batteries from the second load 406 instead of connecting the first 4V 2Ah rechargeable battery 402 in parallel with the depleted 3.0V 1Ah second rechargeable battery 404. This allows the batteries to balance. The control device 400 is then triggered to connect the two batteries in parallel or series to discharge to the load. The energy required by the control device with comparator circuit and switch needs to be considered in such embodiments and sized accordingly.

[0066] Series-parallel isolated load battery charging

[0067] Embodiments of the isolated load battery charging method are in Figure 2AThe control device can alternate between two cycles, where in the first cycle, the 16V 8A solar photovoltaic power source 122 is in parallel with the 12V 5Ah first battery 102 and second battery 104 and charges them. In the second cycle, the control device can power the 24V 8A third load 124 by discharging the first battery 102 and the second battery 104 in series. In this embodiment, the load is isolated from the power source, and the fast switching speed of 50-60 hertz makes it possible to charge the batteries while driving the load. During the first cycle, the first battery 102 and the second battery 104 are charged with current I pv, while during the second cycle, the first battery 102 and the second battery 104 are discharged with current I load. The initial first cycle of one 12V renewable energy source (such as a photovoltaic panel) and two 12V batteries in parallel, can power a 24V load in the second cycle when the two 12V batteries are discharged in series, creating a pseudo-sine wave (square wave).

[0068] In the first cycle, the first battery 102 and the second battery 104 are in parallel on the power source, where each of the two batteries receives 4A current from the 8A solar power source 500. Since the storage capacity of each battery is 5Ah, the battery can receive 4Ah. In the second cycle, the batteries are connected in series to provide a voltage of 24V to the load, which can be used to drive an 8A load. Each 12V battery can typically be charged to around 12.9V when full, and to around 11.4V when fully discharged, and when the first battery 102 and the second battery 104 of 12V are configured in series, it results in the 24V required by the third load 124.

[0069] Figure 5A The SoC (in Coulombs) is shown, where the solar photovoltaic power source 122 is 8A, and the third load 124 is also 8A. In another embodiment, Figure 2A the solar photovoltaic power source 122 is 10A, and the third load 124 current is 8A. As shown, Figure 5B the battery SoC can increase. In a further embodiment, Figure 2A the solar photovoltaic power source 122 is 5A, and the third load 124 is 8A, as shown, Figure 5C the battery SoC can decrease.

[0070] In Figure 2AIn the illustrated embodiment, the solar photovoltaic power source 122 is 20A and the third load 124 is 5A, where the first battery 102 and the second battery 104 can each receive 5Ah, after which the control unit cuts off power. The circuit can add a fifth switch 114 (as a fifth logic switch) and a sixth switch 116 (as a sixth logic switch) to connect the solar photovoltaic power source 122 or the third load 124. In Figure 2B In another illustrated embodiment, the solar photovoltaic power source 122 is 20A and the third load 124 is 5A, where a third battery 101 of 12V 5Ah can be added to balance the circuit with an additional 5Ah instead of cutting off power, where in the second phase, when the batteries are connected to the load, the load voltage can be kept at 24V with a 50% duty cycle of series-parallel ((12V+36V) / 2). An additional seventh switch 103 (as a seventh logic switch) and an eighth switch 105 (as an eighth logic switch) can also be added when the third battery 101 is added. Voltage offsetting enables lower voltage solar panels to be coupled with the batteries. Adding batteries connected to the load in series phase can deplete the batteries faster, as shown in Table 7. As the solar panel voltage decreases, more batteries can be added and used for their voltage, which can result in faster depletion of the load. Any added batteries can be used to store excess energy generated by the power source.

[0071] Referring to Figure 6A In the illustrated flowchart in FIG. 6, an embodiment can start with a first phase of parallel charging, a second phase of series charging, and discharging the batteries to the load. The first phase starts 600, then the circuit is switched to series 610 for the Energy Storage Units (ESUs) to charge the load 615. Then, the second phase starts 620. During the second phase start 620, the circuit can be switched to parallel 630 for the Energy Storage Units (ESUs) to charge the power source 635. Figure 6B Another embodiment is shown where the batteries can be fully charged, a first phase of series discharging the batteries to the load, and a second phase of parallel charging the batteries from the power source. Thus, in Figure 6B In the illustrated flowchart in FIG. 6, an embodiment can start with a first phase of parallel charging, a second phase of series charging, and discharging the batteries to the load. The first phase starts 600, then the circuit is switched to series 610 for the Energy Storage Units (ESUs) to charge the load 615. Then, the second phase starts 620. During the second phase start 620, the circuit can be switched to parallel 630 for the Energy Storage Units (ESUs) to charge the power source 635.

[0072] Thus, when the battery is not connected to a power source, the two periods are independent, where the load can be isolated and discharged during the periods. One advantage of the isolated load battery charging method is that it allows the battery to power the entire voltage load. Thus, only the battery voltage can need to be higher than the load voltage, which can be achieved by the series connection of multiple batteries. Isolating the load also allows the battery to be charged and discharged simultaneously, for example, at a rate of 60 Hz.

[0073] In another embodiment, the power source can also have a minimum voltage, with higher capacity to power higher voltage loads, as the required battery voltage will provide additional voltage to the load. To enable higher current from the solar power implementer to charge the battery, the connecting wires can need to be scaled in thickness to enable the increased current to pass through efficiently. By rapidly switching the battery connection between the power source and the load in independent separate periods, the battery can produce the maximum load voltage when connected in series during the second period.

[0074] In another embodiment of the isolated load battery charging method, the first period can connect the battery in parallel with the power source, and the second period can connect the battery in parallel with the load. In this example case, as the first stage is isolated from the second stage, both the first stage and the second stage can be in a parallel-parallel arrangement. The first stage independently charges the battery from the power source, and the second stage connects the load to the battery. By rapidly switching the battery connection between the power source and the load in independent separate periods, the battery can produce the minimum load voltage when connected in parallel during the second period. In another embodiment, the first stage can be parallel, and the second stage can be series-parallel, to enable the load to obtain the appropriate average voltage depending on the relative duration between parallel and series.

[0075] The control unit can configure the relative duration of the first stage independently of the duration of the second stage. This can be achieved by adjusting the duty cycle of the relative position of the first and second periods in each stage. Adjusting the duty cycle of the first and second periods will result in the charging stage and the discharging stage being adjusted respectively.

[0076] In an embodiment, ti can be the time spent in the first parallel period, and t2 can be the time spent in the second series period. Further, the time T can represent the period corresponding to the fundamental frequency, so T = 1 / fundamental frequency = ti + t2. If f(t) can represent the input signal, the average value of the signal can be calculated using the following formula:

[0077]

[0078] Equation (1) can refer to the example Figure 7A switching signal shown in FIG. D. As Figure 7A shown, the signal can be a square wave signal.Figure 7A is the output of an example switching signal. The integral of the voltage (V) of the example signal can produce the following equation.

[0079]

[0080] Figure 7B is the output of an example voltage signal. The width of the second horizontal line 304 corresponds to time t1, and the width of the first horizontal line 302 corresponds to time t2.

[0081] Assuming the battery is charged in parallel during the first period when the signal is "on", the voltage integral of the example signal can produce the following equation:

[0082]

[0083] Assuming the battery is discharged in series during the second period when the signal is "off", the voltage integral of the example signal can produce the following equation:

[0084]

[0085] where V In corresponds to V signal,On is the first period charging voltage in parallel. Figure 7A The example signal voltage V signal is shown. The output voltage corresponding to V signal,Off and the second period discharging voltage in series is defined as V Out .

[0086] In the example case where t1 = t2, the average of the output current is I2 / 2, and the average output voltage is V2 / 2, which can reduce the output voltage.

[0087] When the load is in series with the battery, the output load is determined by the second period t2. A battery system with a duty cycle of 100%, where t1 = 0 and t2 = T, V out = V2, the circuit only discharges in series. At a duty cycle of 50%, where t1 = 0.5T, t2 = 0.5T, V out = 0.5V2, the circuit charges and discharges in alternating periods. Figure 7B is the voltage signal for an example 50% duty cycle.

[0088] The duty cycle of the embodiment is 25%, where t1 = 0.75T, t2 = 0.25T, V out = 0.25V2, the circuit charges 75% of the time and discharges 25% of the time. Figure 7CThe graph of the output voltage of this embodiment is shown in FIG. 6. During the parallel charging phase, the amount of charge from the energy source can exceed the amount of discharge by the load during the series phase, thus the battery gains charge over time. The amount of charge in the battery increases when the duty cycle is below 50% or the current from the power source exceeds the load current. It is contemplated that when the battery reaches a certain level, excess charge is prevented from reaching the battery to reduce the risk of overcharging. In an alternative embodiment, the energy source can be selected such that the amount of energy it charges is equal to the amount of discharge during the series phase. In this alternative embodiment, the energy storage unit can constantly hold the same amount of charge.

[0089] The duty cycle of the embodiment is 75% where ti = 0.75T and t2 = 0.25T, V out = 0.25V2, the circuit charges 25% of the time and discharges 75% of the time. Figure 7D The graph of the output voltage of this embodiment is shown in FIG. 6. During the parallel charging phase, the amount of charge from the energy source can exceed the amount of discharge by the load during the series phase, thus the battery gains charge over time. The amount of charge in the battery increases when the duty cycle is below 50% or the current from the power source exceeds the load current. It is contemplated that when the battery reaches a certain level, excess charge is prevented from reaching the battery to reduce the risk of overcharging. In an alternative embodiment, the energy source can be selected such that the amount of energy it charges is equal to the amount of discharge during the series phase. In this alternative embodiment, the energy storage unit can constantly hold the same amount of charge.

[0090] Thus, the embodiment of 50% duty cycle can be supplemented by a second set of power sources and batteries to ensure uninterrupted energy supply to the load.

[0091] The two 12V battery isolated load battery charging method can produce a square wave voltage output of 0V and 24V during the series discharge cycle, thus complementing another system during the period when no energy is supplied to the load, it can ensure that the load is supplied with a constant voltage of 24V using two sets of batteries. Thus, the output voltage is raised.

[0092] The embodiment can implement a second two-phase isolated load battery charging method as shown in Figure 8A Using a 50% duty cycle, the second set of batteries is also at a 50% duty cycle, i.e. during the phase when the first isolated load circuit is connected to the power source (solar power source 702), current is supplied to the load when there is no current supply to the load. When the first set of batteries (BATT1 and BATT2) is charging, the second set (BATT3 and BATT4) can discharge to the fourth load 704, and vice versa.

[0093] Figure 8B Another embodiment shown in FIG. 8 uses 8 batteries, 4 in group A and the other 4 in group B, each group complementing the charging and discharging. Another embodiment can implement Figure 8BThe four-phase input shown in FIG. 1, where batteries Al, Bl, Cl, and Dl can be charged from the solar power source 702, and where batteries A2, B2, C2, and D2 can discharge to the fourth load 704, for example, each battery providing a steady 100% charge to the load at a 25% series duty cycle.

[0094] As shown in FIG. 2, the second set of batteries can be different types of energy storage units, such as capacitors, and can provide different voltages or currents. Each energy storage unit, if initially not charged, must receive a charge in the first phase, and discharge in the second phase. Each battery can be of a similar type under each respective set of energy storage. Figure 9

[0095] Figure 9 The embodiment illustrated includes two isolated circuits, including a first isolated circuit 1 and a second isolated circuit 2, connected to the same solar power source 702 and fourth load 704. Each individual circuit includes a single battery of 12V 8Ah, which is connected in parallel to an input capacitor 902, causing the input capacitor 902 to receive a 12V voltage. Each input capacitor 902 in its respective circuit is connected in parallel to a transition capacitor 904, causing each transition capacitor 904 (D) to receive a 12V voltage from the respective input capacitor 902 (B). An output capacitor 906 is connected in parallel to the transition capacitor 904 (which is now disconnected from the input capacitor 902), causing the charge to flow to the individual output capacitor 906. Each output capacitor 906 (E) is also connected in series to another output capacitor 906 (F), causing the load to receive a 24V voltage. Each of the first isolated circuit 1 and the second isolated circuit 2 has two phases, causing the capacitors (which are charged, for example, in the earlier phase 2) to discharge to the fourth load 704 in the same phase 1 when the batteries are charging in phase 1. In either phase 1 or phase 2 of the respective circuit, only the input capacitor 902 or the output capacitor 906 is connected to the fourth load 704 in an alternating cycle, and not simultaneously connected to the fourth load 704. Thus, the output is isolated from the input. The input is also isolated from the output when charging from the renewable power source (solar power source 702). The fourth load 704 and the solar power source 702 are shared between the two circuits, causing the solar power source 702 to be connected to the second isolated circuit 2 when the fourth load 704 is connected to the first isolated circuit 1, and vice versa. Thus, each circuit has 3 phases:

[0096] Phase 1: Charging - charging the batteries using solar or wind power;

[0097] Phase 2: Discharging the batteries - discharging from the batteries to a pair of input capacitors;

[0098] Phase 3: Discharging to the load - discharging from the output capacitors to the load. ​

[0099] When the battery is charging, it stores the power provided by the renewable energy source (solar power 702) in the form of charge according to the following equation:

[0100]

[0101] Where:

[0102] q i (t) is the charge of the battery i at time t (i e (1,2))

[0103] q j (t) is the charge of the capacitor j at time t (j e (A,B,C,D,E,F,G,H,I,J,K,L

[0104] V k is the element voltage (k e (1,2,A,B,C,D,E,F,G,H,I,J,K,L

[0105] i k is the element current (k e (renewable energy,1,2,A,B,C,D,E,F,G,H,I,J,K,L,load

[0106] C is the capacitance value of the capacitor

[0107] When the battery is connected to the input capacitor 902 and the transition capacitor 904, each capacitor is in parallel with the battery and charges to the capacity of the voltage provided by the battery multiplied by the capacitance value:

[0108]

[0109] When the input capacitor 902 is disconnected, its charge does not change during the cycle:

[0110] q j (t) = q j (t-1)

[0111] When the input capacitor 902 is connected to the battery, its charge is equal to the voltage across it multiplied by the capacitance value:

[0112] q j (t) = V i C

[0113] When the transition capacitor 904 is connected to the output capacitor 906, the transition capacitor 904 and the output capacitor 906 form a system with an equivalent capacitance C, according to the law of conservation of charge, the charge is evenly distributed between them, and the charge absorbed by the load is absorbed equally from all capacitors:

[0114]

[0115] When the transition capacitor 904 is connected to the batteries, its charge is equal to the voltage across it multiplied by the capacitance value, as follows:

[0116] q j (t) = V i C

[0117] When the output capacitor 906 is disconnected, its charge does not change during the cycle:

[0118] q j (t) = q j (t-1)

[0119] When the output capacitor 906 is connected to the transition capacitor 904 and the fourth load 704, the transition capacitor 904 and the output capacitor 906 form a system with an equivalent capacitance C, according to the law of conservation of charge, the charge is evenly distributed between them, the charge absorbed by the load is absorbed equally from all the capacitors:

[0120]

[0121] Figure 9A The SoC is shown where the current from the renewable source (8A) is equal to the load requirement (8A), the charge on both batteries becomes constant in steady state and oscillates around the average value.

[0122] Figure 9B The SoC is shown where the current from the source (5A) is less than the load requirement (8A), the charge on both batteries decreases over time and oscillates around a decreasing average value.

[0123] Figure 9C The SoC is shown where the current from the source (10A) is higher than the load requirement (8A), the charge on both batteries increases in steady state and oscillates around an increasing average value.

[0124] The charge variation of the input, transition and output capacitors is also shown in Figure 9D , 9E and 9F, respectively, when the source and load are in steady state at 8A, showing that the capacitors reach a stable charge quickly.

[0125] The following table 2 illustrates the energy loss and gain of the batteries after 1 / 60 of a second:

[0126]

[0127]

[0128] Table 2

[0129] The control unit can select the switching time based on rotations per second or any other time measurement. There can be any number of switches or rotations per second. The control unit can configure the circuit to be in one phase much longer than the other. The length of the phases can be different. By changing the relative proportion of time spent in the phases, the output voltage can be changed. In addition, the control unit can be set to have the initial circuit remain in a particular state. For example, the control unit can be configured to start the parallel phase until the energy storage unit is fully charged, and the control unit then starts the switching cycle.

[0130] When the load is isolated, a portion of the output that is not needed by the load device can be redirected to another system or battery powered. The example isolated load battery charging method can thus provide flexibility in redirecting current by adjusting the duration of the first cycle (when the battery is being charged) relative to the second cycle (when the battery is being discharged).

[0131] Since the example isolated load battery charging method can enable discharging the load while charging the battery to steady state, the battery is not fully depleted. This allows the use of common battery types, such as lead-acid and lithium, which are often damaged when used at 100% capacity.

[0132] Without considering the power source, the energy to provide the load can be designed as needed. For example, when designing a 12V load, only the battery design depends on the combined voltage of the series connected batteries, which must match the load voltage of 12V. The current of the renewable power source needs to match the load current. With a low SoC of the battery, the duty cycle should ideally be set to 0% to fully charge the battery in parallel mode. However, when the current (or capacity) of the battery is low and the current of the renewable power source is high, it can not be possible to pass full current through the load.

[0133] Multi-battery isolated load charging method

[0134] Batteries and energy storage systems are typically limited by their physical topology. In addition to the physical topology (nodes) found in the example swap structure method, the example multi-battery isolated load charging method described herein can also use logical topology (links) to make batteries digital with flexibility by combining hardware and software.

[0135] The nodes are the positive and negative terminals of each battery, the nodes can also be the positive and negative terminals of the power supply and electronic devices, where all the positive terminals can be connected to a single host or board or printed circuit board. There can be one host (host 1) that holds all the positive boards together and another host (host 2) that holds all the negative boards together. Host 1 can include a board or printed circuit board that can be connected to host 2, which includes another board or printed circuit board. There can be multiple ways to connect the nodes of the positive boards to the nodes of the negative boards. One embodiment can have a connection on / off switch for the positive board connection (primary grid) that can be connected to the secondary grid based on a vector. Thus, using a graph theory approach, the shortest method to connect the primary door to the secondary door while traversing multiple additional nodes can be determined.

[0136] The nodes of each of host 1 and host 2 can be connected by a circuit. Each individual photovoltaic cell in a solar photovoltaic system can represent a node to be connected to host 1 and host 2. Electronic components such as resistors, capacitors, comparators, transistors, diodes, and inductors can also be nodes.

[0137] These links are circuits on a printed circuit board that are initially connected to power supplies, loads, batteries, and other electronic components. The circuits in the links are interrupted by switches that are initially closed until a connection is needed.

[0138] The software control unit can select similar types of batteries at each energy storage device or stage, connect only by appropriate rules such as the laws of thermodynamics, and allow energy to flow. For example, it can be considered to connect a large number of batteries, where each battery can receive a charge in the first stage and discharge in the second stage. The software control unit can enable all or part of the batteries in the energy storage interval to be connected in series or parallel, and further connected to any number of power supplies and any number of output devices.

[0139] The software control unit can connect a large number of batteries, where a smaller portion of the batteries can accept charging from a 120V or 240V sinusoidal wave power supply as needed by synchronizing charging. The software control unit can also connect one phase of the battery to the power supply and the other phase to the load, while using another set of batteries to mirror or supplement the first set, ensuring constant energy output to the load. The software control unit can also convert a square wave output load to a 120V or 240V RMS sinusoidal wave of the desired number of batteries, directly producing an AC output at the desired frequency, such as 50Hz or 60Hz. The software control unit can select to disconnect the batteries from the load to achieve battery equalization, or select another set of batteries to discharge to the load while another set of batteries is simultaneously performing battery equalization. The software control unit can connect multiple batteries as needed or step up or step down the power supply voltage by changing the relative duration of the charging and discharging phases.

[0140] To illustrate, an embodiment of a multi-battery isolated load battery charging circuitry using 3 batteries, battery A, battery B, and battery C is provided. It should be noted that the number of batteries indicated is not a limitation and the same principle can be applied to any number of batteries. In this example, in the first cycle, the batteries are connected in parallel to the renewable energy source, in the second cycle, the same batteries (or any number of batteries) can be arranged in series to power the required load.

[0141] This embodiment can implement two hosts, host 1 and host 2. Host 1 is the plate that connects the positive terminals of the batteries and host 2 is the plate that connects the negative terminals of each battery. In addition, each positive terminal (A+, B+, and C+) is a single logic switch and each negative terminal (A-, B-, and C-) is a single logic switch.

[0142] In this embodiment, the A+ logic switch can be connected to any other positive or negative switch, the positive or negative terminal of the renewable energy source, or to the load.

[0143] Table 3 shows the 6 possible switch connections for the positive terminal A+ in this embodiment.

[0144]

[0145] Table 3

[0146] Table 4 shows the 6 possible switch connections for the negative terminal A- in this embodiment.

[0147]

[0148]

[0149] Table 4

[0150] Table 5 illustrates 9 possible programming algorithms that can be executed by combining host 1 and host 2 of a 3 battery energy storage system / device, where each logic switch is controlled by the user or software code.

[0151]

[0152] Table 5

[0153] The software control unit executing the corresponding software code or machine instructions can determine the most efficient method of delivering the load. For example, the software control unit can determine that the most efficient method is to supplement the second or third system, etc., to enable the load to receive a steady charge dependent on the duty cycle, e.g., the software control unit uses a comparator circuit to determine any input voltage to each battery cell, determine if a battery is present in the individual compartment. Once the software control unit confirms the presence of a battery, the software control unit can determine if each battery is ready for discharge and charge mode by matching individual batteries with the same voltage and current, prepare for the discharge phase to drive the load or balance the unbalanced batteries in the battery storage. Likewise, the software control unit can determine if the battery voltage when combined is sufficient to power the entire load. If the voltage is not large enough, the software control unit can select additional batteries to change the voltage to provide a large enough voltage. Hardware and software can be combined through an exchange network to ensure there is enough power to drive the load.

[0154] In embodiments, the switches can be transistors, such as Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs), and can have an I 2 C capability, such that each switch can become a controller. The software controller can change the mode of all other controllers simultaneously. Embodiments can implement a multi-controller system that allows multiple controllers to communicate with a host through, e.g., a smartphone app, IoT device, cloud, etc.

[0155] In embodiments, multiple connected batteries can be balanced. In a series configuration, once the output voltage of the series circuit matches the load voltage, no current will flow. This embodiment provides a method and configuration for balancing batteries that maximizes the capacity and useful life of the batteries by maintaining an equivalent state of charge for each battery over as large a range as possible.

[0156] Direct-to-alternating current output

[0157] From the isolated load battery charging method that produces a square wave, a sinusoidal waveform can be produced. In embodiments that use multiple batteries, each individual battery, when connected to a load, can be connected in series or parallel to other batteries such that the load voltage forms a sinusoidal waveform at specified times. This is done by switching different numbers of batteries at the correct times to produce the sinusoidal wave. The remaining batteries, when connected to the load, contribute nothing to the alternating waveform in the second cycle, being connected in parallel or not connected.

[0158] Table 6 shows a multiple battery embodiment, including a 12V battery, where there are 10 batteries available for a series configuration in timed steps:

[0159] Step Time Number of series connected cells Voltage 0 0.000000 0 0 1 0.000319 1 12 2 0.000641 2 24 3 0.000970 3 36 4 0.001310 4 48 5 0.001667 5 60 6 0.002048 6 72 7 0.002468 7 84 8 0.002952 8 96 9 0.003564 9 108 10 0.005000 10 120

[0160] Table 6

[0161] The H-bridge with time switch can form the correct negative voltage waveform generation time, so as to generate the combined voltage in the negative range.

[0162] In the United States, the alternating current from the grid is a 60Hz sine waveform, generating 120V AC, i.e. the root mean square value (RMS) corresponds to the peak value of 168V. In the embodiment, in a multi-battery consisting of 10 24V batteries, 7 batteries are connected by a timing circuit to generate a 168V sine wave in the second cycle, as shown in Figure 10A

[0163] Figure 10B The sine waveform generated using a logic switch is shown.

[0164] Figure 10C The example circuit diagram using 7 24V batteries is shown, where the block labeled "series battery" can each contain multiple batteries, for example 20 batteries in series, each 1.2V.

[0165] AC input to charge the battery

[0166] Renewable energy sources such as solar and wind energy are only available during certain periods, resulting in intermittent power generation from renewable energy sources. During the intermittent period, it is beneficial to effectively charge the battery using the alternating current in the grid power.

[0167] Figure 10D The circuit diagram in shows a sine AC power source implemented from the grid, which can be used to charge 7 24V batteries in several steps using a 120V RMS sine waveform. Therefore, the input AC voltage follows the synchronous waveform of the sine waveform to charge a single battery or a group of batteries. Using a voltage comparator, when the input AC voltage is 24V, 1 24V battery will be charged. Similarly, when the input AC voltage is 72V, 120V and 168V respectively, 3, 5 and 7 batteries will be charged.

[0168] During the duration of a single step in the sequence, the voltage reaching the battery has a certain amount of variation due to the following AC waveform of the power supply output, for example, at the beginning of the first step or phase, the voltage is 24V, but at the end it is 48V, so the average voltage is 36V. In general, it is best to charge at a voltage slightly higher than the battery power supply. If this voltage level is too high, the switch timing can be adjusted to set the battery to a lower point in the waveform.

[0169] ​In one embodiment, 100 batteries can be configured in a system or battery box using host 1 and host 2. In this embodiment, the batteries can be 4V and 4Ah, the power source can be a 6V 60A solar panel, and the output load can be 400V 60A, providing 24,000 Watts. When charging in parallel, the batteries can be charged at 0.6Ah (60A divided by 100 batteries), thus fully charging each 4Ah battery in 6.7h (4.0Ah divided by 0.6Ah). When discharging in series, the load can be as high as 400V (4V per battery times 100 batteries). In this embodiment, each battery has 0.6Ah. Thus, the system can continuously power the load for approximately 30 seconds in the second phase.

[0170] Table 7 illustrates 12 cases for a battery box using 100 4V 4Ah batteries:

[0171]

[0172]

[0173] Table 7

[0174] In the isolated load battery charging embodiment, the increase in the number of batteries in series in case 4, case 8, and case 12 increases the discharge to the load, thus depleting the batteries faster. In case 1, case 5, and case 8, there are fewer batteries in series with the load, and the battery discharge is correspondingly lower.

[0175] The amp-hour rating of a battery depends on the intended use of the battery. When using a battery for heavy loads, a higher amp-hour rating is usually better. Battery manufacturers usually recommend charging a battery at about one-tenth of the amp-hour rating, so a 40 amp-hour battery is charged at 4A. In an embodiment, the battery can be configured according to the manufacturer's requirements, and the control unit can be programmed with software code.

[0176] Figure 11A An embodiment of a multi-battery isolated load charging method using a renewable power source is shown. A solar photovoltaic cell 1102 can provide a direct current input (DC input 1108) to a system that includes rechargeable batteries 1110 with individual logic switches and a control unit 1112 with voltage comparators that compare the voltage of the batteries and control the corresponding switches, balancing the system. The voltage comparators can be used as input and output comparators on the input and output. Figure 11B Another embodiment of a multi-battery isolated load charging method using a grid AC power supply is shown, using a grid 1104 as an alternating current input (AC input 1106). As in the previous embodiment, the system includes rechargeable batteries 1110 with individual logic switches and a control unit 1112 with voltage comparators that compare the voltage of the batteries and control the corresponding switches, balancing the system. The voltage comparators can be used as input and output comparators on the input and output. Figure 11A and 11BAs shown in the embodiments in FIG. 11, exemplary embodiments can include AC input 1106 and DC input 1108, as well as alternating current output (AC output 1116) and direct current output (DC output 1118), depending on the use case.

[0177] Solar photovoltaic

[0178] Improvements in solar panel efficiency generally depend on the variety of materials used to manufacture the solar panel. Different materials require different amounts of photon energy to produce current. Hybrid panels can cover multiple different electron volt values to maximize captured energy. One problem with this approach is manufacturing cost. Standard solar panels are made of silicon, a material that is well known and widely used. As the materials used in solar panels become more and more rare and specialized, manufacturing costs rise.

[0179] When an electron in an atom of a solar cell is excited by energy in sunlight, the solar cell produces electrical energy. The outermost electrons in an atom exist in an energy level called the valence band. When they get enough energy from sunlight, the electrons jump to an energy level called the conduction band. When the cell is heated, the difference between the valence and conduction bands decreases. Thus, while electrons are more easily released at high temperatures, they do not carry much energy when they are released.

[0180] Cells in a solar panel can be connected in series or parallel to obtain a variety of voltage and current combinations to produce a variety of rated output power. Similar to avoiding cell balancing issues when cells are connected in parallel, solar panels can avoid shading issues when connected in parallel. If a shaded cell is connected in series with other cells, the solar panel can become unbalanced. In extreme cases, power imbalance can damage the solar panel. For this reason, panels are often fitted with bypass diodes that redirect the current flow around a shaded or damaged cell.

[0181] In embodiments, a solar panel can house a master of all cells (master 1 and master 2 combined), where the cells in the solar panel can be connected to a control unit through a logic switch, such that a solar cell can be connected in series to another solar cell in one cycle and in parallel in the next cycle. In further embodiments, the control unit can be programmed to switch to parallel when one cell in the solar panel is shaded, to make the solar panel more efficient.

[0182] For example, a solar panel manufacturer can have 1000 watts of available solar energy per square meter on average. The power output of a solar panel depends on the voltage and current produced by its individual cells. A typical silicon solar cell produces 0.5-0.6V of voltage. The output current varies depending on the size of the cell. Commercially available silicon cells typically produce between 28 and 35 milliamps per square centimeter of current.

[0183] Reference Figure 3 An embodiment of the prior art is shown, a 16V 8A (128 watt) solar panel, a load of 12V 8A (96 watt), a battery of 12V 8Ah (96 watt / hour). Thus, the solar panel is designed higher than the load, with an extra power of 32 watts.

[0184] In an embodiment, the solar panel can be sized 12V 8A (96 watt), 2 batteries of 6V 4Ah connected and switched by the control unit, during the first cycle the batteries are connected in parallel to the 12V solar panel to charge each 6V battery; in the second cycle the batteries are connected in series to provide 12V voltage to the load. In a further embodiment of the solar panel, the batteries are connected in parallel configuration and connected to the control unit through a logic switch, enabling the solar panel to provide the required ambient voltage and current using software code and algorithms.

[0185] Solar panels release some energy in the form of heat, depending on the way the panel is installed and the surrounding air conditions, this heat can affect the working temperature of the panel. For example, a panel installed on a roof will not dissipate heat as much as a standalone panel. This will increase the heat of the panel and thus reduce the efficiency. On the other hand, wind helps to take the heat away from the cell. Therefore, cold and windy days are ideal for solar power generation. This will increase the power output of the panel and dissipate the heat of the panel itself.

[0186] 100 battery cell box

[0187] An embodiment can implement an arrangement of batteries connected to a switch. For example, an arrangement of 100 Lithium Ion 18650 batteries can be charged by a power source of 6V and 300A. The energy from the batteries can be consumed by a load, for example, 120V AC used in the USA, 300A 220V used in India. In an embodiment, the batteries can be connected in parallel with the energy source during half of the cycle and in series with the load during the other half of the cycle. The cycle can switch between series and parallel at any desired frequency, for example, 60Hz used in the USA, or 50Hz used in India. To implement AC output, the batteries can be connected one after another, gradually, in series to the load to implement an approximate sine wave. When the batteries are not connected to the load, they can be connected in parallel to the power source for charging. In an embodiment, an H-bridge configuration can be connected to the load and used to invert the polarity of the voltage during the negative half cycle of the operation.

[0188] Figure 13An example circuit diagram is shown, which includes three load positive switches LPS1 / LPS2 / LPS3 and three load negative switches LNS1 / LNS2 / LNS3, as well as three batteries BT1 / BT2 / BT3 and three battery switches BS1, BS2 and BS3. Figure 13 The example circuit diagram can generate a modified sine wave at the load. Each quarter of the pseudo-sine wave period can be divided into any number of sub-parts depending on the number of batteries. Each sub-part may progressively increase the voltage applied to the load. For example, in an embodiment with three batteries, each quarter of the period can be divided into three equal parts, and each battery can then be connected to the load. If the period time is 1 unit, then each sub-part (one-third of a quarter of the period) will be 1 / 4 × 1 / 3 = 1 / 12 units. Each sub-part can also be divided in half, with each half being 1 / 24 of a time unit, or 1 / 24 of the period.

[0189] Still referencing Figure 13 In the embodiment described, the load can be connected using switches S1 and S4 during the first half of the cycle. During the first 1 / 24 of the cycle, no battery is connected to the load. During the next 1 / 24 of the cycle, the load can be connected to BT1 by connecting LPS1 and LNS1 and switching BS1. BT1 remains connected to the load for the next 1 / 24 of the cycle. By switching BS2 and LNS2 and turning off LNS1, BT2 is connected in series to the load, while LPS1 remains unchanged. This state is maintained for 1 / 12 of the cycle.

[0190] Next, by switching BS3 and LNS3 and turning off LNS2, BT3 is connected in series to the load. LPS1 remains unchanged, and this state is maintained for 1 / 12 of a unit time. At this point, all three batteries are connected to the load, reaching peak voltage. Now, BT1 is disconnected from the load by switching BS1 and LPS1, LPS2 is turned on, and LNS3 remains unchanged, maintaining this state for 1 / 12 of a unit time. BT2 is disconnected from the load by switching BS2 and LPS2, LPS3 is turned on, and LNS3 remains unchanged, maintaining this state for 1 / 12 of a unit time. BT3 is disconnected from the load by switching BS3 and LPS3, and LNS3 is also turned off, maintaining this state for 1 / 24 of a unit time. Now, to reverse the load polarity, the load can be connected to switches S2 and S3. Repeating the above cycle generates a negative mirror step wave, such as... Figure 14 As shown.

[0191] The charge balance equation solves for the charge in a two-phase battery of a circuit. In embodiments, multiple identical batteries can be implemented, outputting a constant voltage through their terminals. It can be assumed that the batteries and solar panels have no efficiency, that the voltage and current supplied by the power source and consumed by the load are constant, and that the resistance of all connecting wires is negligible. In this example embodiment, the circuit can be governed by the following equations:

[0192]

[0193] where q i (t) is the charge of battery i at time t (i e (1,2,3...n))

[0194] i R is the current supplied by the renewable energy source

[0195] i L is the current consumed by the load

[0196] n is the number of batteries connected to the renewable energy source / load at any given time

[0197] When the batteries are charging, the power supplied by the renewable energy source can be stored as charge according to the above equation. The supplied charge is evenly distributed among all n batteries.

[0198] When the batteries are connected in series to the load, each battery can release an equal amount of charge to power the load, and can do so by the required current based on the following equation:

[0199]

[0200] Implementing the above equations, a simulation in MATLAB can illustrate some effects of embodiments. For example, in a simulation of 46 batteries, frequency 60 Hz, batteries initially full, the batteries run out after 1104 seconds without a connected power source, with an RMS load voltage of 120.349574 V. Figure 15A A graphical output of the change in charge of the batteries over time for this example simulation is illustrated.

[0201] In another example simulation, a US use case is simulated using 46 batteries, frequency 60 Hz, batteries initially 50% full. The batteries in this example simulation run out after 552 seconds, with an RMS load voltage of 219.349574. Figure 15B A graphical output of the change in charge of the batteries over time for this example simulation is illustrated.

[0202] In the third example simulation, simulating the Indian use case, using 84 Ah battery, frequency 50 Hz, simulation with battery initially full, the battery in this example simulation depletes after 2016 seconds with an RMS load voltage of 219.768788. Figure 15C The graphical output illustrating the variation of battery charge with time for this example simulation is shown.

[0203] In the fourth example simulation, simulating the Indian use case, using 84 Ah battery, frequency 50 Hz, simulation with battery initially 50% charge, the battery in this example simulation depletes after 1008 seconds with an RMS load voltage of 120.768788. Figure 15D The graphical output illustrating the variation of battery charge with time for this example simulation is shown.

[0204] As Figure 15A As shown in -D, the charge of the battery can vary continuously throughout the cycle, possibly decreasing when the battery is connected to the load and possibly increasing when the battery is connected to the power source. The rate of change of charge can also vary continuously depending on the number of batteries connected to the load and the power source.

[0205] In another embodiment, the battery bank is powered to a load in an example real test scenario. In this embodiment, the load can be a 70 W ceiling fan and an 18 W LED bulb. Based on these values, the battery bank can power the load at 220 V and 1512000 seconds before the battery depletes. Figure 16 The graphical output illustrating the variation of battery charge with time is shown.

[0206] The foregoing description and accompanying drawings illustrate the principles, preferred embodiments and modes of operation of the present application. However, the present application should not be construed to be limited to the particular embodiments discussed above. Additional variations of the above described embodiments will occur to those skilled in the art once advised of the principles of the present application.

[0207] Therefore, the above described embodiments should be regarded as illustrative and not restrictive in nature. It will be appreciated that those skilled in the art can modify the embodiments without departing from the scope of the present application as defined by the following claims.

Claims

1. A system for connecting batteries in a circuit, comprising: a first logic switch connecting a positive terminal of a first energy storage unit; a second logic switch connected to a negative terminal of the first energy storage unit; a third logic switch connected to a positive terminal of a second energy storage unit; a fourth logic switch connected to a negative terminal of the second energy storage unit; a fifth logic switch connected to a positive terminal of an output device; a sixth logic switch connected to a negative terminal of the output device; a printed circuit board having a control unit that regulates a cycle comprising a first phase and a second phase, wherein, in the first phase, the first logic switch, the third logic switch, the fifth logic switch are connected to form a first circuit, the second logic switch, the fourth logic switch, the sixth logic switch are connected to form a second circuit, the first circuit, the second circuit form a parallel connection between the first energy storage unit, the second energy storage unit, and the output device; in the second phase, the first logic switch, the fourth logic switch are connected to form a third circuit, the second logic switch, the sixth logic switch are connected to form a fourth circuit, the first circuit and the second circuit form a series connection between the first energy storage unit, the second energy storage unit, and the output device; the third logic switch, the fifth logic switch are connected to form a fifth circuit; wherein a frequency between the first phase and the second phase is above 0.1 hertz; wherein the control unit varies a relative duration of the first phase, the relative duration of the first phase being independent of a duration of the second phase, such that the first phase comprises 0% to 100% of the cycle, the second phase comprises a remainder of the cycle; wherein an output of the output device is determined based on the relative duration of the first phase and the duration of the second phase.

2. The system of claim 1, wherein, the control unit further comprises an input and output comparator for comparing an input and an output of each energy storage unit, operating each logic switch of the control unit, configuring the energy storage units in series or parallel based on the input and output of each energy storage unit; each energy storage unit comprises one or more batteries.

3. The system as recited in claim 1, wherein, further comprising a plurality of energy storage units connected to the printed circuit board, wherein each positive terminal and each negative terminal of the plurality of energy storage units are switchably connected to the printed circuit board.

4. The system as recited in claim 1, wherein, the control unit converts an input voltage to a lower output voltage.

5. The system as recited in claim 1, wherein, in the first phase, the first energy storage unit and the second energy storage unit are connected in parallel to the output device, and in the second phase, the first energy storage unit and the second energy storage unit are connected in series to the output device, wherein a relative duration of the first phase and the second phase determines a voltage of the output and a current required to balance batteries in the first energy storage unit and the second energy storage unit.

6. The system as recited in claim 1, wherein, the control unit is a computer programmable software code.

7. The system as recited in claim 1, wherein The first energy storage unit and the second energy storage unit are a plurality of individual cells within a non-rechargeable battery.

8. The system as recited in claim 1, wherein, The control unit is one of a programmable mechanical chip, an electronic chip, a printed circuit board chip, or an integrated circuit chip.

9. The system as recited in claim 5, wherein, In the case of matching the input AC sinusoidal waveform, the control unit converts the sinusoidal waveform AC input to a DC input to charge the plurality of cells in a synchronous charging method, to identify and match the number of the plurality of cells, to charge the plurality of cells at a time determined using the control unit.

10. The system as recited in claim 1, wherein, Further comprising a rechargeable power source connected to the output, wherein, in the second phase, the control unit further connects the positive terminal of the first energy storage unit and the positive terminal of the second energy storage unit to the positive terminal of the rechargeable power source, and connects the negative terminal of the first energy storage unit and the negative terminal of the second energy storage unit to the negative terminal of the rechargeable power source, such that the rechargeable power source is connected to the circuit and receives charge from the circuit using a parallel connection.

11. The system as recited in claim 1, wherein, Further comprising a plurality of switches connected to the positive and negative terminals of the first energy storage unit and the positive and negative terminals of the second energy storage unit, such that the switches can configure the circuit in a series configuration in the first phase, and then configure the circuit in a parallel configuration in the second phase.

12. A system for connecting cells in a circuit, comprising: a first logic switch connecting a positive terminal of a first energy storage unit; a second logic switch connected to a negative terminal of the first energy storage unit; a third logic switch connected to a positive terminal of a second energy storage unit; a fourth logic switch connected to a negative terminal of the second energy storage unit; a fifth logic switch connected to a positive terminal of an output device; a sixth logic switch connected to a negative terminal of the output device; a seventh logic switch connected to a positive terminal of a power source; an eighth logic switch connected to a negative terminal of the power source; a printed circuit board having a control unit that regulates a cycle comprising a first phase and a second phase, wherein, in the first phase, the first logic switch, the third logic switch, and the seventh logic switch are connected to form a first circuit, the second logic switch, the fourth logic switch, and the eighth logic switch are connected to form a second circuit, to form a parallel connection between the first energy storage unit, the second energy storage unit, and the power source; wherein, in the second phase, the first logic switch and the fourth logic switch are connected to form a third circuit, the second logic switch and the sixth logic switch are connected to form a fourth circuit, to form a series connection between the first energy storage unit, the second energy storage unit, and the output device, such that the output is isolated from the power source, the third logic switch and the fifth logic switch are connected to form a fifth circuit; wherein the frequency between the first phase and the second phase is above 0.1 hertz; wherein the control unit varies a relative duration of the first phase, the relative duration of the first phase being independent of a duration of the second phase, such that the first phase comprises 0% to 100% of the cycle and the second phase comprises a remainder of the cycle; wherein the output device produces a duty cycle, the duty cycle being determined based on the relative duration of the first phase relative to the second phase.

13. The system of claim 12, wherein, The control unit can: detect a voltage from the power source or a voltage required by the output, and vary the relative duration of the first phase and the second phase in accordance with the detected voltage.

14. The system of claim 12, wherein, The output comprises an associated load voltage, the load voltage being offset from the power source and being reduced via a plurality of additional storage units, the additional storage units being coupled in series with the output.

15. The system as recited in claim 12, wherein, The power source is a renewable direct current power source.

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