BACKGROUND

Battery technology has become widely used in a variety of applications, from small electronic appliances to electric cars and trucks. Because of the improved technology of batteries, both economically and environmentally, many industries have started to switch their equipment and machines to battery operated electric. Recently, the demand for larger and higher capacity batteries has significantly increased. Battery manufacturers have started designing modular batteries that can be connected either in series, or parallel, to achieve the customer’s desired voltage and capacity.

However, connecting modular batteries in series, or in parallel, is challenging. The voltage of the individual battery modules needs to be equalized before connecting them in parallel or the individual disconnect switches will trigger due to inrush current. Moreover, the battery state of charge (SOC) must be equalized for the series modules because any imbalance of the modules’ SOC results in a reduction of the over all capacity. It would thus be desirable to improve voltage balancing in modular batteries and/or battery systems.

Having an isolated equalizer for, or within, each battery module may help to overcome these voltage equalizing challenges as it can equalize the battery module’s voltage to prevent inrush current, as well as balance a series or array of battery modules to reduce the SOC difference between the battery modules. Such an equalizer circuit may be able to control the current in both directions (charge and discharge) and provide galvanic isolation. Moreover, the modular design reduces the time and service costs as the operators can remove the defective battery module and simply replace it with a good battery module.

BRIEF SUMMARY OF THE INVENTION

The present disclosure includes disclosure of a modular battery system, comprising: a plurality of connected battery modules, a first battery module of the plurality of connected battery modules, comprising: a battery pack; a main input/ouput terminal operatively coupled to a switch to connect and disconnect the first battery module to and from a second battery module; a battery management system (BMS) and control circuit to communicate and control the first battery module’s status and to communicate with the second battery module; an equalizer circuit operatively coupled to an equalizer terminal, the equalizer circuit having transistor arrays and a DC-

1 DC converter; and wherein the equalizer circuit balances voltage and/or charge levels of the first battery module.

The present disclosure also includes disclosure of the modular battery system, wherein the equalizer circuit further balances the voltage and/or charge levels of the first battery module with the voltage and/or charge levels of the second battery module by transferring power between the first battery module and the second battery module in order to balance them.

The present disclosure also includes disclosure of the modular battery system, wherein the equalizer circuit further balances the voltage of the first battery module before connecting the first battery module to the second battery module to prevent activating a safety switch due to inrush current.

The present disclosure also includes disclosure of the modular battery system, wherein the plurality of connected battery modules are connected in series.

The present disclosure also includes disclosure of the modular battery system, wherein the plurality of connected battery modules are connected in parallel.

The present disclosure also includes disclosure of the modular battery system, wherein the DC-DC converter further comprises an unregulated bidirectional DC-DC converter.

The present disclosure also includes disclosure of the modular battery system, wherein the DC-DC converter has an inverter side to convert DC power to AC power, a fixed ratio transformer to provide galvanic isolation, and a rectifier side to convert AC power to DC power.

The present disclosure also includes disclosure of the modular battery system, wherein the equalization circuit balances voltage and/or charge levels among the plurality of battery modules by supplying power from the modules with higher voltage and/or charge levels to the modules with lower voltage and/or charge levels.

The present disclosure also includes disclosure of the modular battery system, wherein the equalizer circuits of the plurality of battery modules in the system are connected in parallel.

The present disclosure also includes disclosure of the modular battery system, wherein the BMS and control circuit comprises a CAN bus.

The present disclosure also includes disclosure of the modular battery system, wherein the equalization circuit balances the voltage and state of charge (SOC) level of the plurality of battery modules in the system to avoid a reduction of overall capacity.

2 The present disclosure also includes disclosure of the modular battery system, wherein equalization current is limited, controlled, and programmable using the equalization circuit, as the DC-DC converter provides galvanic isolation.

The present disclosure also includes disclosure of the modular battery system, used within battery powered vehicles, EV, AGV, GSE, Forklifts, electric golf cars, diagnostic imaging devices, medical carts, CTs, X-Rays, endoscopes, ultrasound devices, telecom, and data centers.

The present disclosure also includes disclosure of the modular battery system, configured to achieve a required voltage and capacity level.

The present disclosure also includes disclosure of an equalizer circuit for equalizing voltage of the first battery module of them modular battery system, the equalizer circuit comprising: the equalizer terminal operatively coupled to the equalizer circuit; and the transistor arrays to control and regulate power; the bi-directional DC-DC converter to provide galvanic isolation; the BMS and control circuit to communicate and control battery module status and to communicate with a second battery module; wherein power flows through the transistor array and through the DC-DC converter for voltage and/or charge equalization of the battery module.

The present disclosure also includes disclosure of the equalizer circuit the equalizer circuit balances voltage level of the battery module before connecting to the second battery module and wherein the equalizer circuit balances power between the battery module and the second battery module.

The present disclosure includes disclosure of a method for achieving voltage balancing of a modular battery system, comprising: providing power to the first battery module of claim 1, comprising: equalizing the voltage of the first battery module using the equalizer circuit before connecting the first battery module to the second battery module; connecting the first battery module to the second battery module; transferring power between the first battery module and the second battery module to achieve voltage and/or charge level balancing of the modular battery system.

The present disclosure also includes disclosure of the method, wherein transferring power between the battery module and the second battery module to achieve voltage and/or charge level balancing further comprises transferring power from the modules with higher voltage and/or charge level to the modules with lower voltage and/or charge level.

3 The present disclosure also includes disclosure of the method, further comprising: connecting the equalizer circuits of the first battery module and the second battery module in parallel.

The present disclosure also includes disclosure of the method, wherein connecting the first battery module to the second battery module further comprises connecting in parallel and in series.

The present disclosure includes disclosure of a battery module, comprising: a battery pack; a main input/ouput terminal operatively coupled to a switch to connect and disconnect the battery module to and from other battery modules; a battery management system (BMS) and control circuit to communicate and control the battery module’s status and to communicate with other battery modules; an equalizer circuit operatively coupled to an equalizer terminal, the equalizer circuit having transistor arrays and a DC-DC converter; and wherein the equalizer circuit balances voltage and/or charge levels of first battery module.

The present disclosure also includes disclosure of the battery module, wherein the battery module is configured to physically and/or electrically couple to another battery module to form a modular battery system.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed embodiments and other features, advantages, and disclosures contained herein, and the matter of attaining them, will become apparent and the present disclosure will be better understood by reference to the following description of the present disclosure taken in conjunction with the accompanying drawings, wherein:

FIG. 1 illustrates an exemplary battery module;

FIG. 2 illustrates a plurality of exemplary battery modules connected in series and parallel; and

FIG. 3 illustrates a block diagram of an exemplary unregulated DC-DC converter.

As such, an overview of the features, functions and/or configurations of the components depicted in the figures will now be presented. It should be appreciated that not all of the features of the components of the figures are necessarily described and some of these non-discussed features (as well as discussed features) are inherent from the figures themselves. Other non-discussed features may be inherent in component geometry and/or configuration. Furthermore, wherever

4 feasible and convenient, like reference numerals are used in the figures and the description to refer to the same or like parts or steps. The figures are in a simplified form and not to precise scale.

DETAILED DESCRIPTION

For the purposes of promoting an understanding the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of this disclosure is thereby intended.

The present disclosure includes battery module devices, methods for operating the battery modules, and modular battery systems/arrays having a plurality of battery modules connected in series and/or parallel to achieve the voltage and capacity level needed for a specific application.

FIG. 1 illustrates an exemplary embodiment of a battery module 100. In some embodiments, a plurality of battery modules 100 may be connected in series, or in parallel, to form a modular battery array or system 300. Each battery module 100 will include an equalizer circuit 200 therein. The equalizer circuit(s) 200 of each battery module 100 will be connected in parallel and used to control the inrush current, and provide voltage and State of Charge (SoC) balancing across a plurality of connected battery modules 100 (i.e., a modular battery array 300).

As shown in FIG. 1, one exemplary embodiment of a battery module 100 may include a battery pack 101, an equalizer circuit 200, and a main switch 104 to connect or disconnect the battery module 100 to/from a modular battery array 300. The battery module 100 will also have two input/output terminals, such as a main input/output terminal 102, and an equalizer terminal 103. The battery module 100 will also have a battery management system (BMS) and control circuit 203, to connect and/or communicate with other BMS circuits within other battery modules 100 and/or modular battery arrays 300. For example, the BMS and control circuit 203 may communicate with other battery modules 100 and/or modular battery arrays 300 by CAN bus, for example, to identify the status (voltage, SOC, SOH, capacity, etc.) of each battery module 100 and/or modular battery arrays 300. In one embodiment, if the battery modules 100 are imbalanced, the BMS may then balance them through the equalizer circuit 200.

In one embodiment, each battery module 100 will have an equalizer circuit 200 to balance the battery module 100 by supplying power from the higher voltage/SoC battery module 100 to the lower voltage/SoC battery module 100. Before connecting a plurality of battery modules 100 in

5 parallel, their voltage/charge may be equalized to avoid triggering the safety switch during operation, as the inrush current can go from the higher voltage battery module 100 to the lower voltage battery module 100. Additionally, imbalanced battery modules 100 connected in series and having different states-of charge (SOC) can cause a reduction in the overall capacity of the modular battery array 300. In this embodiment, the equalizer circuit 200 may be used to balance the SoC of the battery modules 100 connected in series.

In one embodiment, the equalizer circuit 200 may include the transistor array 202, the unregulated DC-DC converter, and a BMS and control circuit 203. The equalizer circuit 200 may ensure limited inrush current among parallel battery modules 100, and provides balancing across a series of battery modules 100 (such as an array). The equalizer circuit 200 transfers power/energy between the battery modules 100 in order to balance them. Additionally, the equalization current is limited, controlled (in both direction) and programmable using the equalizer circuit 200. Furthermore, the equalization circuit 200 provides galvanic isolation.

When power goes through the transistor array 202 of the equalizer circuit 200, the transistors control/regulate the amount of power. The power then goes through the unregulated bidirectional DC-DC converter 201 to the equalizer circuit 200 of another battery module 100. The unregulated DC-DC converter 201 provides galvanic isolation between the battery modules 100 and ensures the current flow in both the charge and discharge directions.

FIG 2 shows an exemplary embodiment of a plurality of battery modules 100 connected together to form an exemplary modular battery array 300, also referred to herein as a modular battery system(s) 300. In one exemplary modular battery array 300, the battery modules 100 may be connected in series and parallel (from the main input/output terminal 102) based upon the required voltage and capacity levels, while the equalizer circuits 200 may be connected in parallel. The equalizer circuit 200 may operate to balance the battery’s voltage and charge using the equalizer terminals 103 before connecting the battery modules 100 (from the main input/output terminals 102) in order to avoid the inrush current. After balancing activities (of the battery modules 100) are completed, the battery module 100 can safely be connected to the modular battery array 300, such as via the main switch 104. The equalizer circuit 200 may also be active during this operation to balance the voltage and/or SoC level of the battery array 300.

FIG. 3 illustrates an exemplary embodiment of an unregulated bidirectional DC-DC converter 201 of a battery module 100. The bidirectional DC-DC converter 201 may be

6 unregulated to increase efficiency. The unregulated DC-DC converter 201 may generally consist of 3 conversion stages. The first conversion stage may be converting the DC input to an AC power, shown as primary inverter 204 in FIG. 3. Next, a fixed ratio transformer 205 may be used to provide galvanic isolation. Finally, the power may then be rectified to supply DC power to the next battery module 100, shown as secondary inverter 206 in FIG. 3. In yet another embodiment, other unregulated DC-DC topologies may also be used with the modular battery arrays 300 disclosed herein to transfer power between battery modules 100.

Modular battery arrays 300 are advantageous for several reasons. Modular battery arrays 300 can reduce the complexity of the BMS because each battery module 100 contains its own BMS. Providing each battery module 100 with its own BMS also flexibility of the modular battery array 300. For example, a modular battery system 300 may be easily designed to a customer’s specific voltage and/or capacity requirements.

Modular battery arrays 300 are also much easier to maintain and service, and more cost effective, than non-modular batteries. With modular battery arrays 300, a service operator can simply replace a failed battery module 100 to restore the modular battery array 300 to a proper working state. However, non-modular batteries often need to be entirely replaced, or trashed, when a single failure occurs in any one of the battery modules 100. It is much more cost effective to replace only a single battery module 100 in a modular battery array 300, than to have to purchase an entirely new non-modular battery.

For example, a service operator can simply replace a failed battery module 100 of a modular battery array 300 in a few simple steps. The operator may first safely disconnect the low voltage equalizer terminal’s 103 output. After disconnecting the equalizer circuit 200, the main switch 102 may open automatically to disconnect and isolate the battery module 100 from the modular battery array 300. Then, the operator can replace the failed battery module 100 with the new battery module 100. Finally, the operator can reconnect the equalizer circuit 200 to balance the battery modules 100, and then the main switch 102 may close automatically after equalization.

While various embodiments of devices and systems and methods for using the same have been described in considerable detail herein, the embodiments are merely offered as non-limiting examples of the disclosure described herein. It will therefore be understood that various changes and modifications may be made, and equivalents may be substituted for elements thereof, without

7 departing from the scope of the present disclosure. The present disclosure is not intended to be exhaustive or limiting with respect to the content thereof.

Further, in describing representative embodiments, the present disclosure may have presented a method and/or a process as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth therein, the method or process should not be limited to the particular sequence of steps described, as other sequences of steps may be possible. Therefore, the particular order of the steps disclosed herein should not be construed as limitations of the present disclosure. In addition, disclosure directed to a method and/or process should not be limited to the performance of their steps in the order written. Such sequences may be varied and still remain within the scope of the present disclosure.

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